Examine individual changes

'{{Redirect|MRSA}} {{DISPLAYTITLE:Methicillin-resistant ''Staphylococcus aureus''}} {{Infraspeciesbox |name = Methicillin-resistant ''Staphylococcus aureus'' | image = Human neutrophil ingesting MRSA.jpg | image_alt = Scanning electron micrograph of a human neutrophil ingesting MRSA | image_caption = [[Scanning electron micrograph]] of a human [[Neutrophil granulocyte|neutrophil]] ingesting MRSA | genus = Staphylococcus | species = aureus | varietas = "MRSA" | authority = | synonyms = | synonyms_ref = }} '''Methicillin-resistant ''Staphylococcus aureus''''' ('''MRSA''') refers to a group of [[gram-positive bacteria]] that are genetically distinct from other strains of ''[[Staphylococcus aureus]]''. MRSA is responsible for several difficult-to-treat [[infection]]s in humans. MRSA is any strain of ''S. aureus'' that has developed, through [[horizontal gene transfer]] and [[Evolution#Natural selection|natural selection]], [[multiple drug resistance]] to [[beta-lactam antibiotics]]. β-lactam antibiotics are a [[broad-spectrum antibiotic|broad spectrum group]] which includes some [[penam]]s – [[penicillin]] derivatives such as [[methicillin]] and [[oxacillin]], and [[cephem]]s such as the [[cephalosporin]]s.<ref name = CochraneSurg2013/> Strains unable to resist these antibiotics are classified as methicillin-susceptible ''S. aureus'', or MSSA. MRSA is common in hospitals, prisons, and nursing homes, where people with open [[wound]]s, invasive devices such as [[catheter]]s, and weakened [[immune system]]s are at greater risk of [[hospital-acquired infection]]. MRSA began as a hospital-acquired infection, but has become community-acquired as well as livestock-acquired. The terms HA-MRSA (healthcare-associated or hospital-acquired MRSA), CA-MRSA (community-associated MRSA) and LA-MRSA (livestock-associated) reflect this. ==Signs and symptoms== [[File:Mrsa2.jpg|thumb|Although usually carried without symptoms, MRSA often presents as small red pustular skin infections.]] In humans, ''S. aureus'' is part of the normal [[microbiota]] present in the upper respiratory tract,<ref name=URTmicribiome2016rev>{{cite journal|last1=Schenck|first1=LP|last2=Surette|first2=MG|last3=Bowdish|first3=DM|title=Composition and immunological significance of the upper respiratory tract microbiota.|journal=[[FEBS Letters]]|date=November 2016|volume=590|issue=21|pages=3705–3720|doi=10.1002/1873-3468.12455|pmid=27730630}}</ref> and on skin and in the gut mucosa.<ref>{{cite journal|last1=Wollina|first1=U|title=Microbiome in atopic dermatitis.|journal=[[Clinical, Cosmetic and Investigational Dermatology]]|date=2017|volume=10|pages=51–56|pmid=28260936|pmc=5327846|doi=10.2147/CCID.S130013}}</ref> ''S. aureus'', along with similar species that can colonize and act symbiotically but can cause disease if they begin to take over the tissues they have colonized or invade other tissues, have been called "pathobionts".<ref name=URTmicribiome2016rev/> After 72 hours, MRSA can take hold in human tissues and eventually become resistant to treatment. The initial presentation of MRSA is small red bumps that resemble pimples, spider bites, or boils; they may be accompanied by fever and, occasionally, rashes. Within a few days, the bumps become larger and more painful; they eventually open into deep, pus-filled boils. About 75 percent of CA-MRSA infections are localized to skin and soft tissue and usually can be treated effectively.<ref name=IDSA2011/> ==Risk factors== A select few of the populations at risk: *People with indwelling implants, prostheses, drains, and catheters<ref name = CochraneSurg2013/><ref name = Sga2016/> *People who are frequently in crowded places, especially with shared equipment and skin-to-skin contact<ref name=riskfactors>{{cite web |url=https://www.cdc.gov/mrsa/community/index.html |title=General Information About MRSA in the Community |accessdate=9 October 2014 |publisher=[[Centers for Disease Control and Prevention]] |date=10 September 2013}}</ref> *People with weak immune systems ([[HIV]]/[[AIDS]], [[lupus]], or [[cancer]] sufferers; [[organ transplantation|transplant]] recipients; severe [[asthma]]tics; etc.) *[[Diabetes|Diabetics]]<ref name = CochraneSurg2013/><ref>{{cite journal |vauthors=Lipsky BA, Tabak YP, Johannes RS, Vo L, Hyde L, Weigelt JA |title=Skin and soft tissue infections in hospitalised patients with diabetes: culture isolates and risk factors associated with mortality, length of stay and cost |journal=[[Diabetologia]] |volume=53 |issue=5 |pages=914–23 |date=May 2010 |pmid=20146051 |doi=10.1007/s00125-010-1672-5}}</ref> *[[Intravenous drug]] users<ref>{{cite journal |last1=Otter |first1=J.A. |last2=French |first2=G.L. |title=Community-associated meticillin-resistant Staphylococcus aureus strains as a cause of healthcare-associated infection |journal=[[Journal of Hospital Infection]] |volume=79 |issue=3 |pages=189–193 |doi=10.1016/j.jhin.2011.04.028|pmid=21741111 |year=2011 }}</ref><ref>{{cite journal |last1=Golding |first1=George R. |last2=Quinn |first2=Brian |last3=Bergstrom |first3=Kirsten |last4=Stockdale |first4=Donna |last5=Woods |first5=Shirley |last6=Nsungu |first6=Mandiangu |last7=Brooke |first7=Barb |last8=Levett |first8=Paul N. |last9=Horsman |first9=Greg |last10=McDonald |first10=Ryan |last11=Szklarczuk |first11=Brian |last12=Silcox |first12=Steve |last13=Paton |first13=Shirley |last14=Carson |first14=Mary |last15=Mulvey |first15=Michael R. |last16=Irvine |first16=James |title=Community-based educational intervention to limit the dissemination of community-associated methicillin-resistant Staphylococcus aureus in Northern Saskatchewan, Canada |journal=[[BMC Public Health]] |volume=12 |issue=1 |pages=15 |doi=10.1186/1471-2458-12-15 |pmid=22225643 |pmc=3287965|year=2012 }}</ref> *Users of [[quinolone antibiotic]]s<ref name = Sga2016/><ref name=tacconelli2008>{{cite journal |vauthors=Tacconelli E, De Angelis G, Cataldo MA, Pozzi E, Cauda R |title=Does antibiotic exposure increase the risk of methicillin-resistant ''Staphylococcus aureus'' (MRSA) isolation? A systematic review and meta-analysis |journal=J Antimicrob Chemother |volume=61 |issue=1 |pages=26–38 |date=Jan 2008 |pmid=17986491 |doi=10.1093/jac/dkm416 |url=http://jac.oxfordjournals.org/cgi/content/full/61/1/26}}</ref> * Elderly people<ref name=Sga2016>{{cite journal|last1=Sganga|first1=G.|last2=Tascini|first2=C.|last3=Sozio|first3=E.|last4=Carlini|first4=M.|last5=Chirletti|first5=P.|last6=Cortese|first6=F.|last7=Gattuso|first7=R.|last8=Granone|first8=P.|last9=Pempinello|first9=C.|last10=Sartelli|first10=M.|last11=Colizza|first11=S.| title=Focus on the prophylaxis, epidemiology and therapy of methicillin-resistant Staphylococcus aureus surgical site infections and a position paper on associated risk factors: the perspective of an Italian group of surgeons|journal=World Journal of Emergency Surgery|volume=11|issue=1|pages=26|year=2016|issn=1749-7922|doi=10.1186/s13017-016-0086-1|pmc=4908758|pmid=27307786}}</ref><ref name=Dumyati2017/> *School children sharing sports and other equipment *College students living in dormitories<ref name=riskfactors/> *People staying or working in a health care facility for an extended period of time<ref name = Sga2016/><ref name=riskfactors/> *People who spend time in coastal waters where MRSA is present, such as some beaches in [[Florida]] and the [[west coast of the United States]]<ref name=florida>{{cite news |url=http://www.foxnews.com/story/0,2933,493604,00.html |author=Reuters |publisher=[[Fox Entertainment Group|FoxNews.com]] |title=Study: Beachgoers More Likely to Catch MRSA |date=2009-02-16}}</ref><ref name=AP1>{{cite news |url=http://www.foxnews.com/story/0,2933,549601,00.html |author=Marilynn Marchione |agency=Associated Press |title=Dangerous staph germs found at West Coast beaches |date=2009-09-12}}</ref> *People who spend time in confined spaces with other people, including occupants of homeless shelters, [[prison]] inmates, and military recruits in [[recruit training|basic training]]<ref name=soldiers>{{cite journal |vauthors=Zinderman CE, Conner B, Malakooti MA, LaMar JE, Armstrong A, Bohnker BK |title=Community-Acquired Methicillin-Resistant ''Staphylococcus aureus'' Among Military Recruits |journal=Emerging Infectious Diseases |volume=10 |issue=5 |pages=941–4 |date=May 2004 |pmid=15200838 |pmc=3323224 |doi=10.3201/eid1005.030604 |url=http://www.medscape.com/viewarticle/474843}}</ref><ref name="The University of Chicago Medical Center" /> *Veterinarians, livestock handlers, and pet owners<ref name=cmr>{{cite journal |vauthors=David MZ, Daum RS |title=Community-Associated Methicillin-Resistant ''Staphylococcus aureus'': Epidemiology and Clinical Consequences of an Emerging Epidemic |journal=Clinical Microbiology Reviews |volume=23 |issue=6 |pages=616–687 |year=2010 |pmid=20610826 |pmc=2901661 |doi=10.1128/CMR.00081-09 }}</ref> * People that ingest unpasteurized milk<ref name = Gopal2017/> *People who are immunocompromised and also colonized<ref name=Ficalora/>{{rp|249}} * People with [[Chronic obstructive pulmonary disease]]<ref name =Sga2016/> *People who had thoracic surgery<ref name = Sga2016/> As many as 22 percent of people infected with MRSA do not have any discernable risk factors.<ref name=Winn/>{{rp|637}} ===Hospitalized people=== People who are hospitalized, including the elderly, are often immunocompromised and susceptible to infection of all kinds, including MRSA; when the infection is by MRSA this is called healthcare-associated or hospital-acquired methicillin-resistant ''S. aureus'' (HA-MRSA).<ref name= CochraneSurg2013/><ref name = Sga2016/><ref name=CochraneNonSurg2013>{{cite journal|last1=Gurusamy|first1=KS|last2=Koti|first2=R|last3=Toon|first3=CD|last4=Wilson|first4=P|last5=Davidson|first5=BR|title=Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds.|journal=The Cochrane Database of Systematic Reviews|date=18 November 2013|issue=11|pages=CD010427|doi=10.1002/14651858.CD010427.pub2|pmid=24242704}}</ref><ref>{{cite journal|last1=Jacobs|first1=A|title=Hospital-acquired methicillin-resistant Staphylococcus aureus: status and trends.|journal=Radiologic Technology|date=2014|volume=85|issue=6|pages=623–48; quiz 649–52|pmid=25002642}}</ref> Generally, those infected by MRSA will stay infected for just under 10 days, if treated by a doctor, although effects may vary from person to person.<ref>{{cite web|last1=Davis|first1=Charles|title=Is MRSA Contagious?|url=http://www.medicinenet.com/is_mrsa_contagious/article.htm.|website=Medicinenet.com|accessdate=24 October 2017}}</ref> Surgical as well as nonsurgical wounds can be infected with HA-MRSA.<ref name= CochraneSurg2013>{{Cite journal|last=Gurusamy|first=Kurinchi Selvan|last2=Koti|first2=Rahul|last3=Toon|first3=Clare D.|last4=Wilson|first4=Peter|last5=Davidson|first5=Brian R.|date=2013-08-20|title=Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in surgical wounds|journal=The Cochrane Database of Systematic Reviews|issue=8|pages=CD009726|doi=10.1002/14651858.CD009726.pub2|issn=1469-493X|pmid=23963687}}</ref><ref name = Sga2016/><ref name=CochraneNonSurg2013/> Surgical site infections (SSI) occur on the skin surface but can spread to internal organs and blood to cause sepsis.<ref name=CochraneSurg2013/> Transmission occurs between healthcare providers and patients. This is because some providers may inconsistently neglect to perform hand-washing between examinations.<ref name=tacconelli2008/><ref name=muto2003/> People in [[nursing home]]s are at risk for all the reasons above, further complicated by the generally weaker immune systems of the elderly or other residents in need of such care.<ref name=Dumyati2017>{{cite journal|last1=Dumyati|first1=G|last2=Stone|first2=ND|last3=Nace|first3=DA|last4=Crnich|first4=CJ|last5=Jump|first5=RL|title=Challenges and Strategies for Prevention of Multidrug-Resistant Organism Transmission in Nursing Homes.|journal=Current Infectious Disease Reports|date=April 2017|volume=19|issue=4|pages=18|pmid=28382547|pmc=5382184|doi=10.1007/s11908-017-0576-7}}</ref><ref name=CochraneNursHomeStop2013>{{cite journal|last1=Hughes|first1=C|last2=Tunney|first2=M|last3=Bradley|first3=MC|title=Infection control strategies for preventing the transmission of meticillin-resistant Staphylococcus aureus (MRSA) in nursing homes for older people.|journal=The Cochrane Database of Systematic Reviews|date=19 November 2013|issue=11|pages=CD006354|doi=10.1002/14651858.CD006354.pub4|pmid=24254890}}</ref> ===Prison inmates, military recruits=== Prisons, and military barracks,<ref name = Gopal2017/> can be crowded and confined, and poor hygiene practices may proliferate, thus putting inhabitants at increased risk of contracting MRSA.<ref name=cmr/> Cases of MRSA in such populations were first reported in the United States, and then in Canada. The earliest reports were made by the [[Center for Disease Control]] (CDC) in US state prisons. In the news media, hundreds of reports of MRSA outbreaks in prisons appeared between 2000 and 2008. For example, in February 2008, the [[Tulsa County, Oklahoma|Tulsa County]] jail in [[Oklahoma]] started treating an average of 12 ''S. aureus'' cases per month.<ref>{{cite web|url=http://www.purebio.com/about/article/48|title=PURE Bioscience|work=purebio.com|deadurl=yes|archiveurl=https://web.archive.org/web/20090224131952/http://purebio.com/about/article/48|archivedate=2009-02-24|df=}}</ref> ===Animals=== [[Antibiotic use in livestock]] increases the risk that MRSA will develop among the livestock; strains [[MRSA ST 398]] and [[CC398]] are transmissible to humans.<ref name = Gopal2017>{{cite journal|last1=Gopal|first1=S|last2=Divya|first2=KC|title=Can methicillin-resistant ''Staphylococcus aureus'' prevalence from dairy cows in India act as potential risk for community-associated infections?: A review.|journal=Veterinary World|date=March 2017|volume=10|issue=3|pages=311–318|pmid=28435193|pmc=5387658|doi=10.14202/vetworld.2017.311-318}}</ref><ref name = Mehn2014>{{Cite journal|last=Mehndiratta, P. L.|first=& Bhalla, P.|year=2014|title=Use of Antibiotics in Animal Agriculture & Emergence of Methicillin Resistant Staphylococcus Aureus (MRSA) Clones: Need to Assess the Impact on Public Health|url=|journal=Indian J Med Res|volume=140|issue=3|pages=339–44|via=|pmid=25366200|pmc=4248379}}</ref> Generally, animals are asymptomatic.<ref name =CochraneSurg2013/> Domestic pets are susceptible to MRSA infection from their owners; MRSA infected pets can also transmit MRSA to humans.<ref>{{cite journal|title=Methicillin-resistantStaphylococcus aureus in Cat and Owner|first1=Carlo|last1=Vitale|first2=T.|last2=Gross|first3=J.|last3=Weese|publisher=|journal=Emerging Infectious Diseases|volume=12|issue=12|pages=1998–2000|doi=10.3201/eid1212.060725|pmid=17354344|pmc=3291366|year=2006}} {{CDC}}</ref> ===Athletes=== [[Changing room|Locker rooms]], [[gym]]s, and related athletic facilities offer potential sites for MRSA contamination and infection.<ref>{{cite journal |last1=Salgado |first1=Cassandra D. |last2=Farr |first2=Barry M. |last3=Calfee |first3=David P. |title=Community‐Acquired Methicillin‐Resistant Staphylococcus aureus: A Meta‐Analysis of Prevalence and Risk Factors |journal=Clinical Infectious Diseases |date=15 January 2003 |volume=36 |issue=2 |pages=131–139 |doi=10.1086/345436|pmid=12522744 }}</ref> Athletes have been identified as a high risk group.<ref name = Gopal2017/> A study linked MRSA to the abrasions caused by artificial turf.<ref>{{cite journal |vauthors=Kazakova SV, Hageman JC, Matava M, Srinivasan A, Phelan L, Garfinkel B, Boo T, McAllister S, Anderson J, Jensen B, Dodson D, Lonsway D, McDougal LK, Arduino M, Fraser VJ, Killgore G, Tenover FC, Cody S, Jernigan DB |title=A clone of methicillin-resistant ''Staphylococcus aureus'' among professional football players |journal=The New England Journal of Medicine |volume=352 |issue=5 |pages=468–75 |date=2005-02-03 |pmid=15689585 |doi=10.1056/NEJMoa042859 }}</ref> Three studies by the Texas State Department of Health found the infection rate among football players was 16 times the national average. In October 2006, a high-school football player was temporarily paralyzed from MRSA-infected turf burns. His infection returned in January 2007 and required three surgeries to remove infected tissue, as well as three weeks of hospital stay.<ref name=epstein1>{{cite news |url=https://www.bloomberg.com/apps/news?pid=newsarchive&sid=alxhrJDn.cdc |title=Texas Football Succumbs to Virulent Staph Infection From Turf |last=Epstein |first=Victor |date=21 December 2007 |publisher=[[Bloomberg L.P.|Bloomberg]] |accessdate=10 June 2010}}</ref> In 2013, [[Lawrence Tynes]], [[Carl Nicks (American football)|Carl Nicks]], and [[Johnthan Banks]] of the [[Tampa Bay Buccaneers]] were diagnosed with MRSA. Tynes and Nicks apparently did not contract the infection from each other, but it is unknown if Banks contracted it from either individual.<ref>{{cite web |url=http://espn.go.com/nfl/story/_/id/9808469/third-tampa-bay-buccaneers-player-tests-positive-mrsa-staph-infection |title=Third Tampa Bay Buccaneers player tests positive for MRSA staph infection |publisher=ESPN Internet Ventures |work=ESPN |date=11 October 2013 |accessdate=11 October 2013 |author=Yasinskas, Pat}}</ref> In 2015, [[Los Angeles Dodgers]]' infielder [[Justin Turner]] was infected while the team visited the [[New York Mets]].<ref>{{cite news |last=Hernandez|first=Dylan|url=http://www.latimes.com/sports/dodgers/dodgersnow/la-sp-dn-dodgers-justin-turner-nears-return-20150812-story.html|title=Dodgers' Justin Turner nears return from MRSA infection|work=[[Los Angeles Times]]|date=August 12, 2015|accessdate=August 13, 2015}}</ref> In October 2015, [[New York Giants]] tight end [[Daniel Fells]] was hospitalized with a serious MRSA infection.<ref>{{cite news |last=Rappoport |first=Ian |url=http://www.nfl.com/news/story/0ap3000000553694/article/mrsa-infection-leaves-giants-daniel-fells-in-dire-situation |title=MRSA infection leaves Giants' Daniel Fells in dire situation |work=[[NFL.com]] |date=October 11, 2015 |accessdate=October 12, 2015}}</ref> ===Children=== MRSA is becoming a critical problem in children;<ref>{{cite journal |author=Gray JW |title=MRSA: the problem reaches paediatrics |journal=Arch. Dis. Child. |volume=89 |issue=4 |pages=297–8 |date=April 2004 |pmid=15033832 |pmc=1719885 |doi=10.1136/adc.2003.045534 |url=http://adc.bmjjournals.com/cgi/content/full/89/4/297}}</ref> studies found 4.6% of patients in U.S. health-care facilities, (presumably) including hospital nurseries,<ref>{{cite journal |vauthors=Bratu S, Eramo A, Kopec R, Coughlin E, Ghitan M, Yost R, Chapnick EK, Landman D, Quale J |title=Community-associated methicillin-resistant ''Staphylococcus aureus'' in hospital nursery and maternity units |journal=Emerging Infect. Dis. |volume=11 |issue=6 |pages=808–13 |date=June 2005 |pmid=15963273 |pmc=3367583 |doi=10.3201/eid1106.040885 }}</ref> were infected or colonized with MRSA.<ref name=APIC> {{cite web |url= http://www.apic.org/Content/NavigationMenu/ResearchFoundation/NationalMRSAPrevalenceStudy/MRSA_Study_Results.htm |title= National Prevalence Study of Methicillin-Resistant ''Staphylococcus aureus'' (MRSA) in U.S. Healthcare Facilities |author= [http://www.apic.org Association for Professionals in Infection Control & Epidemiology] |date=June 25, 2007 |accessdate= 2007-07-14 |archiveurl= https://web.archive.org/web/20070907201425/http://www.apic.org/Content/NavigationMenu/ResearchFoundation/NationalMRSAPrevalenceStudy/MRSA_Study_Results.htm |archivedate=September 7, 2007}}</ref> Children (and adults, as well) who come in contact with day-care centers,<ref name = Gopal2017/> playgrounds, locker rooms, camps, dormitories, classrooms and other school settings, and gyms and workout facilities are at higher risk of getting MRSA. Parents should be especially cautious of children who participate in activities where sports equipment is shared, such as football helmets and uniforms.<ref>{{cite web |url=http://www.webmd.com/parenting/mrsa-and-staph-infections-in-children |title=Staph Infections and MRSA in Children: Prevention, Symptoms, and Treatment |work=webmd.com}}</ref> ==Mechanism== [[Antimicrobial resistance]] is genetically based; resistance is mediated by the acquisition of extrachromosomal genetic elements containing resistance genes. Examples include plasmids, transposable genetic elements, and [[genomic islands]], which are transferred between bacteria through [[horizontal gene transfer]].<ref name=jenson1>{{cite journal |vauthors=Jensen SO, Lyon BR |title=Genetics of antimicrobial resistance in ''Staphylococcus aureus'' |journal=Future Microbiol |volume=4 |issue=5 |pages=565–82 |date=June 2009 |pmid=19492967 |doi=10.2217/fmb.09.30 }}</ref> A defining characteristic of MRSA is its ability to thrive in the presence of [[penicillin]]-like antibiotics, which normally prevent bacterial growth by inhibiting synthesis of [[cell wall]] material. This is due to a resistance gene, ''mecA'', which stops β-lactam antibiotics from inactivating the enzymes (transpeptidases) critical for cell wall synthesis.<ref>{{Cite journal|last=Chambers|first=H. F.|date=February 2001|title=Methicillin-resistant Staphylococcus aureus. Mechanisms of resistance and implications for treatment|journal=Postgraduate Medicine|volume=109|issue=2 Suppl|pages=43–50|doi=10.3810/pgm.02.2001.suppl12.65|issn=1941-9260|pmid=19667557|doi-broken-date=2019-02-18}}</ref> ===SCC''mec''=== Staphylococcal [[gene cassette|cassette chromosome]] ''mec'' ([[SCCmec|SCC''mec'']]) is a genomic island of unknown origin containing the antibiotic resistance gene ''mecA''.<ref name=lowy1>{{cite journal |author= Lowy FD |title= Antimicrobial resistance: the example of ''Staphylococcus aureus'' |journal= J. Clin. Invest. |volume= 111 |issue= 9 |pages= 1265–73 |date= May 2003 |pmid= 12727914 |pmc= 154455 |doi= 10.1172/JCI18535}}</ref><ref name=monaco1>{{cite journal |vauthors=Pantosti A, Sanchini A, Monaco M |title= Mechanisms of antibiotic resistance in ''Staphylococcus aureus'' |journal= Future Microbiol |volume= 2 |issue= 3 |pages= 323–34 |date= June 2007 |pmid= 17661706 |doi= 10.2217/17460913.2.3.323 }}</ref> SCC''mec'' contains additional genes beyond ''mecA'', including the [[cytolysin]] gene ''psm-mec'', which may suppress virulence in HA-acquired MRSA strains.<ref>{{cite journal |vauthors= Kaito C, Saito Y, Nagano G, Ikuo M, Omae Y, Hanada Y, Han X, Kuwahara-Arai K, Hishinuma T, Baba T, Ito T, Hiramatsu K, Sekimizu K |title= Transcription and translation products of the cytolysin gene psm-mec on the mobile genetic element SCCmec regulate ''Staphylococcus aureus'' virulence |journal= PLoS Pathog. |volume= 7 |issue= 2 |pages= e1001267 |year= 2011 |pmid= 21304931 |pmc= 3033363 |doi= 10.1371/journal.ppat.1001267 |editor1-last= Cheung |editor1-first= Ambrose}}</ref> In addition this locus encodes strain dependent gene regulatory RNA called ''psm-mec''RNA.<ref>{{Cite journal|last=Cheung|first=Gordon Y. C.|last2=Villaruz|first2=Amer E.|last3=Joo|first3=Hwang-Soo|last4=Duong|first4=Anthony C.|last5=Yeh|first5=Anthony J.|last6=Nguyen|first6=Thuan H.|last7=Sturdevant|first7=Daniel E.|last8=Queck|first8=S. Y.|last9=Otto|first9=M.|date=2014-07-01|title=Genome-wide analysis of the regulatory function mediated by the small regulatory psm-mec RNA of methicillin-resistant Staphylococcus aureus|journal=International Journal of Medical Microbiology: IJMM|volume=304|issue=5–6|pages=637–644|doi=10.1016/j.ijmm.2014.04.008|issn=1618-0607|pmc=4087065|pmid=24877726}}</ref> SCC''mec'' also contains ''ccrA'' and ''ccrB''; both genes encode recombinases that mediate the site-specific integration and excision of the SCC''mec'' element from the ''S. aureus'' chromosome.<ref name="lowy1" /><ref name="monaco1" /> Currently, six unique SCC''mec'' types ranging in size from 21–67 kb have been identified;<ref name="lowy1" /> they are designated types I-VI and are distinguished by variation in ''mec'' and ''ccr'' gene complexes.<ref name="jenson1" /> Owing to the size of the SCC''mec'' element and the constraints of horizontal gene transfer, a minimum of five clones are thought to be responsible for the spread of MRSA infections, with clonal complex (CC) 8 most prevalent.<ref name="lowy1" /><ref>{{Cite journal|last=Enright|first=M.C.|last2=Robinson|first2=D.A.|date=2002|title=The evolutionary history of methicillin-resistant Staphylococcus aureus (MRSA).|journal=PNAS|volume=99|issue=11|pmid=12032344|doi=10.1073/pnas.122108599|pages=7687–92|pmc=124322|bibcode=2002PNAS...99.7687E}}</ref> SCC''mec'' is thought to have originated in the closely related ''S. sciuri'' species and transferred horizontally to ''S. aureus.'' <ref>{{Cite journal|last=Wu|first=S.W.|last2=de Lencastre|first2=H.|date=2001|title=Recruitment of the mecA gene homolog of Staphyoloccus sciuri into a resistance determinant and expression of the resistance phenotype in Staphylococcus aureus|journal=Journal of Bacteriology|volume=183}}</ref> Different SCC''mec'' genotypes confer different microbiological characteristics, such as different antimicrobial resistance rates.<ref name=kuo1>{{cite journal |vauthors=Kuo SC, Chiang MC, Lee WS, Chen LY, Wu HS, Yu KW, Fung CP, Wang FD |title= Comparison of microbiological and clinical characteristics based on SCCmec typing in patients with community-onset meticillin-resistant ''Staphylococcus aureus'' (MRSA) bacteraemia |journal= Int. J. Antimicrob. Agents |volume= 39 |issue= 1 |pages= 22–6 |date= January 2012 |pmid= 21982834 |doi= 10.1016/j.ijantimicag.2011.08.014 |url= http://linkinghub.elsevier.com/retrieve/pii/S0924-8579(11)00359-1}}</ref> Different genotypes are also associated with different types of infections. Types I-III SCC''mec'' are large elements that typically contain additional resistance genes and are characteristically isolated from HA-MRSA strains.<ref name=monaco1/><ref name=kuo1/> Conversely, CA-MRSA is associated with types IV and V, which are smaller and lack resistance genes other than ''mecA''.<ref name=monaco1/><ref name=kuo1/> These distinctions were thoroughly investigated by Collins et al. in 2001 and can be explained by the fitness differences associated with carriage of a large or small SCC''mec'' plasmid. Carriage of large plasmids, such as SCC''mec''I-III, is costly to the bacteria, resulting in compensatory decrease in virulence expression.<ref name=":0">{{Cite journal|last=Collins|first=J.|last2=Rudkin|first2=J.|date=2010|title=Offsetting virulence and antibiotic resistance costs by MRSA|journal=International Society for Microbial Ecology|volume=4}}</ref> MRSA is able to thrive in hospital settings with increased antibiotic resistance but decreased virulence- HA-MRSA targets immunocompromised, hospitalized hosts, thus a decrease in virulence is not maladaptive.<ref name=":0" /> In contrast, CA-MRSA tends to carry lower fitness cost SCC''mec'' elements to offset the increased virulence and toxicity expression required to infect healthy hosts.<ref name=":0" /> ===''mecA''=== [[MecA (gene)|''mecA'']] is a biomarker gene responsible for resistance to methicillin and other β-lactam antibiotics. After acquisition of ''mecA'', the gene must be integrated and localized in the ''S. aureus'' chromosome.<ref name=lowy1/> ''mecA'' encodes penicillin-binding protein 2a (PBP2a), which differs from other penicillin-binding proteins as its active site does not bind methicillin or other β-lactam antibiotics.<ref name=lowy1/> As such, PBP2a can continue to catalyze the transpeptidation reaction required for [[peptidoglycan]] cross-linking, enabling cell wall synthesis in the presence of antibiotics. As a consequence of the inability of PBP2a to interact with β-lactam moieties, acquisition of ''mecA'' confers resistance to all β-lactam antibiotics in addition to methicillin.<ref name=lowy1/><ref>Sahebnasagh R, Saderi H, Owlia P. Detection of methicillin-resistant Staphylococcus aureus strains from clinical samples in Tehran by detection of the mecA and nuc genes. The First Iranian International Congress of Medical Bacteriology; 4–7 September; Tabriz, Iran. 2011. 195 pp.</ref> ''mecA'' is under the control of two [[regulatory genes]], ''mecI'' and ''mecR1''. MecI is usually bound to the ''mecA'' promoter and functions as a repressor.<ref name=jenson1/><ref name=monaco1/> In the presence of a β-lactam antibiotic, MecR1 initiates a [[signal transduction cascade]] that leads to transcriptional activation of ''mecA''.<ref name=jenson1/><ref name=monaco1/> This is achieved by MecR1-mediated cleavage of MecI, which alleviates MecI repression.<ref name=jenson1/> ''mecA'' is further controlled by two co-repressors, BlaI and BlaR1. ''blaI'' and ''blaR1'' are homologous to ''mecI'' and ''mecR1'', respectively, and normally function as regulators of ''blaZ'', which is responsible for penicillin resistance.<ref name=lowy1/><ref name="berger-bachi">{{cite journal |author= Berger-Bächi B |title= Genetic basis of methicillin resistance in ''Staphylococcus aureus'' |journal= Cell. Mol. Life Sci. |volume= 56 |issue= 9–10 |pages= 764–70 |date= November 1999 |pmid= 11212336 |doi= 10.1007/s000180050023 |url= http://link.springer.de/link/service/journals/00018/bibs/90569-10/90560764.htm |archive-url= https://archive.is/20130212050521/http://link.springer.de/link/service/journals/00018/bibs/90569-10/90560764.htm |dead-url= yes |archive-date= 2013-02-12 }}</ref> The DNA sequences bound by MecI and BlaI are identical;<ref name=lowy1/> therefore, BlaI can also bind the ''mecA'' operator to repress transcription of ''mecA''.<ref name="berger-bachi"/> ===Arginine catabolic mobile element=== The [[arginine catabolic mobile element]] (ACME) is a virulence factor present in many MRSA strains but not prevalent in MSSA.<ref name= pmid17409207>{{cite journal |vauthors=Goering RV, McDougal LK, Fosheim GE, Bonnstetter KK, Wolter DJ, Tenover FC |title= Epidemiologic distribution of the arginine catabolic mobile element among selected methicillin-resistant and methicillin-susceptible Staphylococcus aureus isolates |journal= J. Clin. Microbiol. |volume= 45 |issue= 6 |pages= 1981–4 |year= 2007 |pmid= 17409207 |pmc= 1933090 |doi= 10.1128/JCM.00273-07}}</ref> {{cn span|SpeG-positive ACME compensates for the polyamine hypersensitivity of ''S. aureus'' and facilitates stable skin colonization, wound infection, and person-to-person transmission.|date=September 2017|reason=reference: added in the "Add more information" tab.|reference=Joshi GS, Spontak JS, Klapper DG, Richardson AR. Arginine catabolic mobile element encoded speG abrogates the unique hypersensitivity of Staphylococcus aureus to exogenous polyamines. Mol Microbiol 2011; 82:9–20}} ===Strains=== [[File:mecA Resistance.svg|thumb|right|Diagram depicting antibiotic resistance through alteration of the antibiotic's target site, modeled after MRSA's resistance to penicillin. Beta-lactam antibiotics permanently inactivate [[penicillin binding protein|PBP enzymes]], which are essential for bacterial life, by permanently binding to their active sites. Some forms of MRSA, however, express a PBP that will not allow the antibiotic into their active site.]] Acquisition of SCC''mec'' in methicillin-sensitive ''S. aureus'' (MSSA) gives rise to a number of genetically different MRSA lineages. These genetic variations within different MRSA strains possibly explain the variability in virulence and associated MRSA infections.<ref name=GordonLowy2008>{{cite journal |vauthors=Gordon RJ, Lowy FD |title= Pathogenesis of methicillin-resistant ''Staphylococcus aureus'' infection |journal= Clin. Infect. Dis. |volume= 46 |issue= Suppl 5 |pages= S350–9 |date= June 2008 |pmid= 18462090 |pmc= 2474459 |doi= 10.1086/533591 }}</ref> The first MRSA strain, ST250 MRSA-1 originated from SCC''mec'' and ST250-MSSA integration.<ref name=GordonLowy2008/> Historically, major MRSA clones: ST2470-MRSA-I, ST239-MRSA-III, ST5-MRSA-II, and ST5-MRSA-IV were responsible for causing hospital-acquired MRSA (HA-MRSA) infections.<ref name=GordonLowy2008/> ST239-MRSA-III, known as the Brazilian clone, was highly transmissible compared to others and distributed in Argentina, Czech Republic, and Portugal.<ref name=GordonLowy2008/> In the UK, the most common strains of MRSA are EMRSA15 and EMRSA16.<ref name="JAntimicrobChemother2001-Johnson">{{cite journal |vauthors=Johnson AP, Aucken HM, Cavendish S, Ganner M, Wale MC, Warner M, Livermore DM, Cookson BD |title= Dominance of EMRSA-15 and -16 among MRSA causing nosocomial bacteraemia in the UK: analysis of isolates from the European Antimicrobial Resistance Surveillance System (EARSS) |journal= J Antimicrob Chemother |volume= 48 |issue= 1 |pages= 143–4 |year= 2001 |pmid= 11418528 |doi= 10.1093/jac/48.1.143 |url= http://jac.oxfordjournals.org/cgi/content/full/48/1/143}}</ref> EMRSA16 has been found to be identical to the [[MLST|ST]]36:USA200 strain, which circulates in the United States, and to carry the SCC''mec'' type II, [[enterotoxin|enterotoxin A]] and [[toxic shock syndrome]] toxin 1 genes.<ref name=diep2006/> Under the new international typing system, this strain is now called MRSA252. EMRSA 15 is also found to be one of the common MRSA strains in Asia. Other common strains include ST5:USA100 and EMRSA 1.<ref name="StefaniChung2012">{{cite journal |vauthors=Stefani S, Chung DR, Lindsay JA, Friedrich AW, Kearns AM, Westh H, Mackenzie FM |title= Meticillin-resistant ''Staphylococcus aureus'' (MRSA): global epidemiology and harmonisation of typing methods |journal= International Journal of Antimicrobial Agents |volume= 39 |issue= 4 |pages= 273–82 |year= 2012 |pmid= 22230333 |doi= 10.1016/j.ijantimicag.2011.09.030 |issn= 0924-8579}}</ref> These strains are genetic characteristics of HA-MRSA.<ref name=calfee2011>{{cite journal |author= Calfee DP |title= The epidemiology, treatment, and prevention of transmission of methicillin-resistant ''Staphylococcus aureus'' |journal= J Infus Nurs |volume= 34 |issue= 6 |pages= 359–64 |year= 2011 |pmid= 22101629 |doi= 10.1097/NAN.0b013e31823061d6 |url= http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=1533-1458&volume=34&issue=6&spage=359}}</ref> Community-acquired MRSA (CA-MRSA) strains emerged in late 1990 to 2000, infecting healthy people who had not been in contact with health care facilities.<ref name=calfee2011/> Researchers suggest that CA-MRSA did not evolve from the HA-MRSA.<ref name=calfee2011/> This is further proven by molecular typing of CA-MRSA strains<ref name=daum2007>{{cite journal |author= Daum RS |title= Skin and Soft-Tissue Infections Caused by Methicillin-Resistant ''Staphylococcus aureus'' |journal= New England Journal of Medicine |volume= 357 |issue= 4 |pages= 380–390 |year= 2007 |pmid= 17652653 |doi= 10.1056/NEJMcp070747}}</ref> and genome comparison between CA-MRSA and HA-MRSA, which indicate that novel MRSA strains integrated SCC''mec'' into MSSA separately on its own.<ref name=calfee2011/> By mid 2000, CA-MRSA was introduced into the health care systems and distinguishing CA-MRSA from HA-MRSA became a difficult process.<ref name=calfee2011/> Community-acquired MRSA is more easily treated and more virulent than hospital-acquired MRSA (HA-MRSA).<ref name=calfee2011/> The genetic mechanism for the enhanced virulence in CA-MRSA remains an active area of research. Especially the [[Panton–Valentine leukocidin]] (PVL) genes are of interest because they are a unique feature of CA-MRSA.<ref name=GordonLowy2008/> In the United States, most cases of CA-MRSA are caused by a CC8 strain designated [[ST8:USA300]], which carries SCC''mec'' type IV, [[Panton–Valentine leukocidin]], [[phenol-soluble modulin|PSM-alpha]] and [[enterotoxin]]s Q and K,<ref name=diep2006>{{cite journal |vauthors=Diep BA, Carleton HA, Chang RF, Sensabaugh GF, Perdreau-Remington F |title= Roles of 34 virulence genes in the evolution of hospital- and community-associated strains of methicillin-resistant ''Staphylococcus aureus'' |journal= J Infect Dis |volume= 193 |issue= 11 |pages= 1495–503 |year= 2006 |pmid= 16652276 |doi= 10.1086/503777}}</ref> and [[ST1:USA400]].<ref>{{cite journal |vauthors=Wang R, Braughton KR, Kretschmer D, Bach TH, Queck SY, Li M, Kennedy AD, Dorward DW, Klebanoff SJ, Peschel A, DeLeo FR, Otto M |title= Identification of novel cytolytic peptides as key virulence determinants for community-associated MRSA |journal= Nat. Med. |volume= 13 |issue= 12 |pages= 1510–4 |date= December 2007 |pmid= 17994102 |doi= 10.1038/nm1656}}</ref> The ST8:USA300 strain results in skin infections, necrotizing fasciitis and toxic shock syndrome, whereas the ST1:USA400 strain results in necrotizing pneumonia and pulmonary sepsis.<ref name=GordonLowy2008/> Other community-acquired strains of MRSA are ST8:USA500 and ST59:USA1000. In many nations of the world, MRSA strains with different predominant genetic background types have come to predominate among CA-MRSA strains; USA300 easily tops the list in the U.S. and is becoming more common in Canada after its first appearance there in 2004. For example, in Australia ST93 strains are common, while in continental Europe ST80 strains, which carry SCC''mec'' type IV, predominate.<ref>{{cite journal |vauthors=Tristan A, Bes M, Meugnier H, Lina G, Bozdogan B, Courvalin P, Reverdy ME, Enright MC, Vandenesch F, Etienne J |title= Global distribution of Panton–Valentine leukocidin--positive methicillin-resistant Staphylococcus aureus, 2006 |journal= Emerging Infect. Dis. |volume= 13 |issue= 4 |pages= 594–600 |year= 2007 |pmid= 17553275 |pmc= 2725977 |doi= 10.3201/eid1304.061316 |url=}}</ref><ref name="GouldDavid2012">{{cite journal |vauthors=Gould IM, David MZ, Esposito S, Garau J, Lina G, Mazzei T, Peters G |title= New insights into meticillin-resistant ''Staphylococcus aureus'' (MRSA) pathogenesis, treatment and resistance |journal= Int. J. Antimicrob. Agents |volume= 39 |issue= 2 |pages= 96–104 |date= February 2012 |pmid= 22196394 |doi= 10.1016/j.ijantimicag.2011.09.028 |url= http://linkinghub.elsevier.com/retrieve/pii/S0924-8579(11)00459-6}}</ref> In Taiwan, ST59 strains, some of which are resistant to many non-beta-lactam antibiotics, have arisen as common causes of skin and soft tissue infections in the community. In a remote region of Alaska, unlike most of the continental U.S., USA300 was found rarely in a study of MRSA strains from outbreaks in 1996 and 2000 as well as in surveillance from 2004–06.<ref name="pmid18976551">{{cite journal |vauthors=David MZ, Rudolph KM, Hennessy TW, Boyle-Vavra S, Daum RS |title= Molecular epidemiology of methicillin-resistant Staphylococcus aureus, rural southwestern Alaska |journal= Emerging Infect. Dis. |volume= 14 |issue= 11 |pages= 1693–9 |year= 2008 |pmid= 18976551 |pmc= 2630737 |doi= 10.3201/eid1411.080381}}</ref> A MRSA strain, [[CC398]], is found in [[intensive animal farming|intensively reared]] production animals (primarily pigs, but also cattle and poultry), where it can be transmitted to humans as LA-MRSA (livestock-associated MRSA).<ref name="StefaniChung2012"/><ref>{{cite journal|last1=Panel on Biological Hazards|title=Joint scientific report of ECDC, EFSA and EMEA on meticillin resistant Staphylococcus aureus (MRSA) in livestock, companion animals and food.|journal=EFSA Journal|volume=7|issue=6|date=16 June 2009|doi=10.2903/j.efsa.2009.301r}}</ref><ref name="GravelandDuim2011">{{cite journal |vauthors=Graveland H, Duim B, van Duijkeren E, Heederik D, Wagenaar JA |title= Livestock-associated methicillin-resistant ''Staphylococcus aureus'' in animals and humans |journal= Int. J. Med. Microbiol. |volume= 301 |issue= 8 |pages= 630–4 |date= December 2011 |pmid= 21983338 |doi= 10.1016/j.ijmm.2011.09.004 |url= http://linkinghub.elsevier.com/retrieve/pii/S1438-4221(11)00090-7}}</ref> ==Diagnosis== [[File:MRSA on a selective choromogenic media plate.jpg|thumb|right|A selective and differential chromogenic medium for the qualitative direct detection of MRSA.]] [[File:MRSA on MHA media resistant to oxacillin antibiotic strip.jpg|thumb|right|The MRSA resistance to oxacillin being tested, the top s. aureus isolate is control and sensitive to oxacillin, the other three isolates are MRSA positive]] [[File:Muller Hinton agar with MRSA.jpg|thumb|[[Mueller-Hinton agar|Mueller Hinton agar]] showing MRSA resistant to oxacillin disk]] Diagnostic microbiology laboratories and reference laboratories are key for identifying outbreaks of MRSA. Normally, the bacterium must be cultured from blood, urine, [[sputum]], or other body-fluid samples, and in sufficient quantities to perform confirmatory tests early-on. Still, because no quick and easy method exists to diagnose MRSA, initial treatment of the infection is often based upon 'strong suspicion' and techniques by the treating physician; these include [[quantitative PCR]] procedures, which are employed in clinical laboratories for quickly detecting and identifying MRSA strains.<ref name= FrancoisP>{{cite book |chapterurl=http://www.horizonpress.com/staph|vauthors=Francois P, Schrenzel J|year=2008|chapter=Rapid Diagnosis and Typing of ''Staphylococcus aureus''|title=Staphylococcus: Molecular Genetics|publisher=Caister Academic Press |isbn=978-1-904455-29-5}}</ref><ref name=Mackay>{{cite book |editor= Mackay IM |title= Real-Time PCR in Microbiology: From Diagnosis to Characterization |publisher= Caister Academic Press |year= 2007 |url=http://www.horizonpress.com/rtmic |isbn=978-1-904455-18-9}}</ref> Another common laboratory test is a rapid [[agglutination (biology)|latex agglutination]] test that detects the PBP2a protein. PBP2a is a variant [[penicillin-binding protein]] that imparts the ability of ''S. aureus'' to be resistant to oxacillin.<ref name=Hardy>{{cite web |title=MRSA latex test for PBP2 |first=Denka |last=Seiken |url=http://www.hardydiagnostics.com/catalog2/hugo/MRSALatexTest.htm}}</ref> ===Microbiology=== Like all ''S. aureus'' (also abbreviated SA at times), methicillin-resistant ''S. aureus'' (MRSA) is a [[gram-positive]], spherical ([[coccus]]) [[bacterium]] that is about 1 [[micron]] in [[diameter]]. It does not form [[Endospore|spores]] and it is non-[[Motility|motile]]. It forms grape-like clusters or chains.<ref name=Murray>{{cite book | last = Murray | first = Patrick | title = Manual of clinical microbiology | publisher = [[ASM Press]] | location = Washington, D.C | year = 2007 | isbn = 9781555813710}}</ref>{{rp|390}} Unlike Methicillin-susceptible ''S. aureus'' (MSSA), MRSA is slower growing on a variety of media and has been found to exist in mixed colonies of MSSA. The mecA gene, which confers the resistance to a number of antibiotics is present in MRSA and not in MSSA. In some instances, the mecA gene is present in MSSA but is not expressed. Polymerase chain reaction (PCR) testing is the most precise method in identifying MRSA strains. Specialized culture media have been developed to better differentiate between MSSA and MRSA and in some cases, it will identify specific strains that are resistant to different antibiotics.<ref name=Murray/>{{rp|402}} Other strains of ''S. aureus '' have emerged that are resistant to [[oxacillin]], clindamycin, teicoplanin, and [[erythromycin]]. These resistant strains may or may not possess the mecA gene. ''S. aureus '' has also developed resistance to [[vancomycin]] (VRSA). One strain is only partially susceptible to vancomycin and is called vancomycin-intermediate ''S. aureus'' (VISA).<!--not the credit card--> GISA is a strain of resistant S. aureus and stands for glycopeptide-intermediate ''S. aureus'' and is less suspectible to vancomycin and teicoplanin. Resistance to antibiotics in ''S. aureus'' can be quantified. This done by determining the amount of the antibiotic in micrograms/milliliter must be used to inhibit growth. If S. aureus is inhibited at a concentration of vancomycin of less than or equal to 4 micrograms/milliliter, it is said to be susceptible. If a concentration of greater than 32 micrograms/milliliter is necessary to inhibit growth, it is said to be resistant.<!--note that MRSA can be resistant to vancomycin as well as can VRSA--><ref name=Winn>{{cite book | last = Winn | first = Washington | title = Koneman's color atlas and textbook of diagnostic microbiology | publisher = Lippincott Williams & Wilkins | location = Philadelphia | year = 2006 | isbn = 978-0781730143 }}</ref>{{rp|637}} ==Prevention== ===Screening === In health care settings, isolating those with MRSA from those without the infection is one method to prevent transmission. Rapid culture and sensitivity testing and molecular testing identifies carriers and reduces infection rates.<ref>{{cite journal |vauthors=Tacconelli E, De Angelis G, de Waure C, Cataldo MA, La Torre G, Cauda R |title= Rapid screening tests for meticillin-resistant ''Staphylococcus aureus'' at hospital admission: systematic review and meta-analysis |journal= Lancet Infect Dis |volume= 9 |issue= 9 |pages= 546–54 |date= September 2009 |pmid= 19695491 |doi= 10.1016/S1473-3099(09)70150-1 |url= http://linkinghub.elsevier.com/retrieve/pii/S1473-3099(09)70150-1}}</ref> MRSA can be identified by swabbing the nostrils and isolating the bacteria found inside the nostrils. Combined with extra sanitary measures for those in contact with infected people, swab screening people admitted to hospitals has been found to be effective in minimizing the spread of MRSA in hospitals in the United States, [[Denmark]], [[Finland]], and the [[Netherlands]].<ref>{{cite web |url=http://www.tufts.edu/med/apua/Patients/ridbooklet.pdf |title=Unnecessary Deaths: The Human and Financial Costs of Hospital Infections |accessdate=2007-08-05 |edition=2nd|author=McCaughey B|archiveurl= https://web.archive.org/web/20070711030535/http://www.tufts.edu/med/apua/Patients/ridbooklet.pdf |archivedate= July 11, 2007}}</ref> ===Hand washing=== The CDC offers suggestions for preventing the contraction and spread MRSA infection which are applicable to those in community settings, including incarcerated populations, childcare center employees, and athletes. To prevent the spread of MRSA the recommendations are to wash hands using soap and water or an alcohol-based sanitizer. Additional recommendations are to keep wounds clean and covered, avoid contact with other people's wounds, avoid sharing personal items such as razors or towels, shower after exercising at athletic facilities, and shower before using swimming pools or whirlpools.<ref>{{cite web |title= Personal Prevention of MRSA Skin Infections |publisher= CDC |accessdate = 25 May 2017 |date= 9 August 2010 |url= https://www.cdc.gov/infectioncontrol/guidelines/mdro/index.html}}{{CDC}}</ref> ===Isolation=== Excluding [[medical facility|medical facilities]], current US guidance does not require workers with MRSA infections to be routinely excluded from the general workplace.<ref name=NIOSH_MRSA>{{cite web |url= https://www.cdc.gov/niosh/topics/mrsa/ |title=NIOSH MRSA and the Workplace |accessdate=2017-05-25|publisher=United States National Institute for Occupational Safety and Health}}</ref> The National Institutes of Health recommends that those with wound drainage that cannot be covered and contained with a clean, dry bandage and those who cannot maintain good hygiene practices be reassigned.<ref name=NIOSH_MRSA/> Workers with active infections are excluded from activities where skin-to-skin contact is likely to occur.<ref name=CDC1998>{{cite web |url=https://www.cdc.gov/ncidod/dhqp/gl_hcpersonnel.html|title=Guidelines for Infection Control in Health Care Personnel, 1998|accessdate=December 18, 2007|publisher=[[Centers for Disease Control and Prevention]]|year=1998|author=CDC}}</ref> To prevent the spread of staph or MRSA in the workplace, employers make available adequate facilities that encourage good hygiene. In addition, surface and equipment sanitizing conforms to the Environmental Protection Agency (EPA)-registered disinfectants.<ref name="NIOSH_MRSA" /> Health Departments recommend that preventing the spread of MRSA in the home can be to: launder materials that have come into contact with infected person separately and with a dilute bleach solution; reduce the bacterial load in your nose and on your skin; clean those things in the house that people regularly touch like sinks, tubs, kitchen counters, cell phones, light switches, doorknobs, phones, toilets, and computer keyboards.<ref name=tpchd/> Among those in hospital, once between one and three cultures come back negative contact isolation can be stopped.<ref name=Ban2018>{{cite journal|last1=Banach|first1=David B.|last2=Bearman|first2=Gonzalo|last3=Barnden|first3=Marsha|last4=Hanrahan|first4=Jennifer A.|last5=Leekha|first5=Surbhi|last6=Morgan|first6=Daniel J.|last7=Murthy|first7=Rekha|last8=Munoz-Price|first8=L. Silvia|last9=Sullivan|first9=Kaede V.|last10=Popovich|first10=Kyle J.|last11=Wiemken|first11=Timothy L.|title=Duration of Contact Precautions for Acute-Care Settings|journal=Infection Control & Hospital Epidemiology|volume=39|issue=2|date=11 January 2018|pages=127–144|doi=10.1017/ice.2017.245|pmid=29321078}}</ref> ===Restricting antibiotic use=== [[Glycopeptide antibiotic|Glycopeptides]], [[cephalosporin]]s, and, in particular, [[quinolones]] are associated with an increased risk of colonisation of MRSA. Reducing use of antibiotic classes that promote MRSA colonisation, especially fluoroquinolones, is recommended in current guidelines.<ref name=tacconelli2008/><ref name=muto2003>{{cite journal |vauthors=Muto CA, Jernigan JA, Ostrowsky BE, Richet HM, Jarvis WR, Boyce JM, Farr BM |title= SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of ''Staphylococcus aureus'' and enterococcus |journal= [[Infect Control Hosp Epidemiol]] |volume= 24 |issue= 5 |pages= 362–86 |date= May 2003 |pmid= 12785411 |doi= 10.1086/502213|citeseerx= 10.1.1.575.8929 }}</ref> ===Public health considerations=== Mathematical models describe one way in which a loss of infection control can occur after measures for screening and isolation seem to be effective for years, as happened in the UK. In the "search and destroy" strategy that was employed by all UK hospitals until the mid-1990s, all hospitalized people with MRSA were immediately isolated, and all staff were screened for MRSA and were prevented from working until they had completed a course of eradication therapy that was proven to work. Loss of control occurs because colonised people are discharged back into the community and then readmitted; when the number of colonised people in the community reaches a certain threshold, the "search and destroy" strategy is overwhelmed.<ref>{{cite journal |vauthors=Cooper BS, Medley GF, Stone SP, Kibbler CC, Cookson BD, Roberts JA, Duckworth G, Lai R, Ebrahim S |title= Methicillin-resistant ''Staphylococcus aureus'' in hospitals and the community: stealth dynamics and control catastrophes |journal= [[Proc Natl Acad Sci USA]] |volume= 101 |issue= 27 |pages= 10223–8 |year= 2004 |pmid= 15220470 |pmc= 454191 |doi= 10.1073/pnas.0401324101}}</ref> One of the few countries not to have been overwhelmed by MRSA is the [[Netherlands]]: An important part of the success of the Dutch strategy may have been to attempt eradication of carriage upon discharge from hospital.<ref name=bootsma2006>{{cite journal |vauthors=Bootsma MC, Diekmann O, Bonten MJ |title= Controlling methicillin-resistant ''Staphylococcus aureus'': quantifying the effects of interventions and rapid diagnostic testing |journal= Proc Natl Acad Sci USA |volume= 103 |issue= 14 |pages= 5620–5 |year= 2006 |pmid= 16565219 |pmc= 1459403 |doi= 10.1073/pnas.0510077103}}</ref> ===Decolonization=== {{main|Decolonization (medicine)}} As of 2013 there had been no randomized clinical trials conducted to understand how to treat non-surgical wounds that had been colonized, but not infected, with MRSA,<ref name=CochraneNonSurg2013/> and insufficient studies had been conducted to understand how to treat surgical wounds that had been colonized with MRSA.<ref name = CochraneSurg2013/> As of 2013 it was not known whether strategies to eradicate MRSA colonization of people in nursing homes reduced infection rates.<ref name=CochraneNursHomeStop2013/> Care should be taken when trying to drain boils, as disruption of surrounding tissue can lead to larger infections, or even infection of the blood stream (often with fatal consequences).<ref name=NIH>{{cite web |title=MRSA (Methicillin-Resistant Staphylococcus aureus) |url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004520/|publisher=[[US National Institutes of Health]] |work=[[National Library of Medicine]] - [[PubMed Health]]|accessdate=20 November 2011}}</ref> [[Mupirocin]] 2% ointment can be effective at reducing the size of lesions. A secondary covering of clothing is preferred.<ref name=tpchd>{{cite web |title=Living With MRSA|url=http://www.tpchd.org/files/library/2357adf2a147d1aa.pdf|publisher=Group Health Cooperative/Tacoma-Pierce County Health Dept./Washington State Dept. of Health|accessdate=20 November 2011}}</ref> As shown in an animal study with diabetic mice, the topical application of a mixture of sugar (70%) and 3% povidone-iodine paste is an effective agent for the treatment of diabetic ulcers with MRSA infection.<ref>{{cite journal |vauthors=Shi CM, Nakao H, Yamazaki M, Tsuboi R, Ogawa H |title= Mixture of sugar and povidone-iodine stimulates healing of MRSA-infected skin ulcers on db/db mice |journal= Arch. Dermatol. Res. |volume= 299 |issue= 9 |pages= 449–56 |date= November 2007 |pmid= 17680256 |doi= 10.1007/s00403-007-0776-3}}</ref> ===Community settings=== It may be difficult for people to maintain the necessary cleanliness if they do not have access to facilities such as public toilets with handwashing facilities. In the United Kingdom, the [[Workplace (Health, Safety and Welfare) Regulations 1992]]<ref>{{cite web | url=http://www.legislation.gov.uk/uksi/1992/3004/contents/made | title=The Workplace (Health, Safety and Welfare) Regulations 1992 | publisher=[[The National Archives]]/[[Her Majesty’s Stationery Office]] | work=[[UK legislation]] | accessdate=January 12, 2018}}</ref> requires businesses to provide toilets for their employees, along with washing facilities including soap or other suitable means of cleaning. Guidance on how many toilets to provide and what sort of washing facilities should be provided alongside them is given in the Workplace (Health, Safety and Welfare) Approved Code of Practice and Guidance L24, available from [http://www.hsebooks.co.uk Health and Safety Executive Books]. But there is no legal obligation on local authorities in the United Kingdom to provide [[public toilet]]s, and although in 2008 the House of Commons [[Communities and Local Government Committee]] called for a duty on local authorities to develop a public toilet strategy<ref>{{cite web|url=http://www.communities.gov.uk/publications/localgovernment/publictoiletsresponse |title=[ARCHIVED CONTENT] UK Government Web Archive – The National Archives |first=Internet Memory |last=Foundation |publisher= |deadurl=bot: unknown |archiveurl=http://webarchive.nationalarchives.gov.uk/20120919132719/http://www.communities.gov.uk/publications/localgovernment/publictoiletsresponse |archivedate=2012-09-19 |df= }}</ref> this was rejected by the Government.<ref>{{cite web|url=http://www.communities.gov.uk/publications/localgovernment/publictoiletsresponse |title=Government Response to the Communities and Local Government Committee Report on the Provision of Public Toilets |publisher= |deadurl=yes |archiveurl=http://webarchive.nationalarchives.gov.uk/20120919132719/http://www.communities.gov.uk/publications/localgovernment/publictoiletsresponse |archivedate=2012-09-19 |df= }}</ref> ===Agriculture=== Some advocate regulations on the use of antibiotics in animal food to prevent the emergence of drug resistant strains of MRSA.<ref name = Mehn2014/> MRSA is established in animals and birds.<ref name = Gopal2017/> ==Treatment== ===Antibiotics=== {{See also|Medications used to treat MRSA}} Treatment is urgent and delays can be fatal.<ref name=Ficalora>{{cite book | last = Ficalora | first = Robert | title = Mayo Clinic internal medicine board review | publisher = Oxford University Press | location = Oxford | year = 2013 | isbn = 9780199948949 }}</ref>{{rp|328}} The location and history related to the infection determines the treatment. The route of administration of an antibiotic varies. Antibiotics effective against MRSA can be given by IV, oral, or a combination of both and depends on the specific circumstances and patient characteristics.<ref name=IDSA2011/> The use of concurrent treatment with vancomycin other beta-lactam agents may have a synergistic effect.<ref name=Winn/>{{rp|637}} Both CA-MRSA and HA-MRSA are resistant to traditional anti-staphylococcal [[beta-lactam antibiotic]]s, such as [[cephalexin]]. CA-MRSA has a greater spectrum of antimicrobial susceptibility to [[sulfonamide (medicine)|sulfa drugs]] (like co-trimoxazole ([[trimethoprim/sulfamethoxazole]]), [[tetracycline antibiotics|tetracyclines]] (like [[doxycycline]] and [[minocycline]]) and [[clindamycin]] (for [[osteomyelitis]]).<ref name="IDSA2011" /> MRSA can be eradicated with a regimen of [[linezolid]],<ref name="GurusamyWilson2013" /> though treatment protocols vary and serum levels of antibiotics vary widely person to person and may affect outcomes.<ref name="ChooChambers2016">{{cite journal|last1=Choo|first1=Eun Ju|last2=Chambers|first2=Henry F.|title=Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia|journal=Infection & Chemotherapy|volume=48|issue=4|year=2016|pages=267–273|issn=2093-2340|doi=10.3947/ic.2016.48.4.267|pmid=28032484|pmc=5204005}}</ref> The effective treatment of MRSA with linezolid has been successful<ref name="GurusamyWilson2013">{{cite journal|last1=Gurusamy|first1=Kurinchi Selvan|last2=Wilson|first2=Peter|last3=Davidson|first3=Brian R|last4=Gurusamy|first4=Kurinchi Selvan|title=Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in non surgical wounds|year=2013|doi=10.1002/14651858.CD010427|journal=Cochrane Database of Systematic Reviews}}</ref> in 87% of people. Linezolid is more effective in soft tissue infections than vancomycin.<ref name="YueDong2016"/><ref name="CochraneSurg2013" /> This is compared to eradication of infection in those with MRSA treated with vancomycin. Treatment with vancomycin is successful in approximately 49% of people.<ref name="CochraneSurg2013" /> [[Linezolid]] belongs to the newer [[oxazolidinone]] class of antibiotics which has been shown to be effective against both CA-MRSA and HA-MRSA. The [[Infectious Disease Society of America]] recommends vancomycin, linezolid, or clindamycin (if susceptible) for treating those with MRSA pneumonia.<ref name="IDSA2011">{{cite journal|last1=Liu|first1=Catherine|last2=Bayer|first2=Arnold|last3=Cosgrove|first3=Sara E.|last4=Daum|first4=Robert S.|last5=Fridkin|first5=Scott K.|last6=Gorwitz|first6=Rachel J.|last7=Kaplan|first7=Sheldon L.|last8=Karchmer|first8=Adolf W.|last9=Levine|first9=Donald P.|last10=Murray|first10=Barbara E.|last11=Rybak|first11=Michael J.|last12=Talan|first12=David A.|last13=Chambers|first13=Henry F.|title=Clinical Practice Guidelines by the Infectious Diseases Society of America for the Treatment of Methicillin-Resistant Staphylococcus aureus Infections in Adults and Children|journal=[[Clinical Infectious Diseases]]|volume=52|issue=3|year=2011|pages=e18–e55|issn=1058-4838|doi=10.1093/cid/ciq146|pmid=21208910}}</ref> [[Ceftaroline]], a fifth-generation cephalosporin, is the first beta-lactam antibiotic approved in the US to treat MRSA infections in skin and soft tissue or community acquired pneumonia.<ref>{{cite web |url=http://www.fda.gov/newsevents/newsroom/pressannouncements/ucm231594.htm |title=FDA Approves Teflaro for Bacterial Infections |website= |accessdate=}}</ref> Vancomycin and [[teicoplanin]] are [[glycopeptide antibiotic]]s used to treat MRSA infections.<ref>{{cite journal |vauthors=Schentag JJ, Hyatt JM, Carr JR, Paladino JA, Birmingham MC, Zimmer GS, Cumbo TJ |title= Genesis of methicillin-resistant ''Staphylococcus aureus'' (MRSA), how treatment of MRSA infections has selected for vancomycin-resistant Enterococcus faecium, and the importance of antibiotic management and infection control |journal= Clin. Infect. Dis. |volume= 26 |issue= 5 |pages= 1204–14 |year= 1998 |pmid= 9597254 |doi= 10.1086/520287}}</ref> [[Teicoplanin]] is a structural [[congener (chemistry)|congener]] of vancomycin that has a similar activity spectrum but a longer [[biological half-life|half-life]].<ref>{{cite journal |vauthors=Rybak MJ, Lerner SA, Levine DP, Albrecht LM, McNeil PL, Thompson GA, Kenny MT, Yuh L |title= Teicoplanin pharmacokinetics in intravenous drug abusers being treated for bacterial endocarditis |journal= [[Antimicrob. Agents Chemother.]] |volume= 35 |issue= 4 |pages= 696–700 |year= 1991 |pmid= 1829880 |pmc= 245081 |doi= 10.1128/AAC.35.4.696}}</ref> Because the oral absorption of vancomycin and [[teicoplanin]] is very low, these agents can be administered intravenously to control systemic infections.<ref>{{cite journal |author= Janknegt R |title= The treatment of staphylococcal infections with special reference to pharmacokinetic, pharmacodynamic, and pharmacoeconomic considerations |journal= Pharmacy World & Science: PWS |volume= 19 |issue= 3 |pages= 133–41 |year= 1997 |pmid= 9259029 |doi= 10.1023/A:1008609718457}}</ref> Treatment of MRSA infection with vancomycin can be complicated, due to its inconvenient route of administration. Moreover, the efficacy of vancomycin against MRSA is inferior to that of anti-staphylococcal [[beta-lactam antibiotic]]s against methicillin-susceptible ''S. aureus'' (MSSA).<ref>{{cite journal |vauthors=Chang FY, Peacock JE, Musher DM, Triplett P, MacDonald BB, Mylotte JM, O'Donnell A, Wagener MM, Yu VL |title= ''Staphylococcus aureus'' bacteremia: recurrence and the impact of antibiotic treatment in a prospective multicenter study |journal= [[Medicine (Baltimore)]] |volume= 82 |issue= 5 |pages= 333–9 |year= 2003 |pmid= 14530782 |doi= 10.1097/01.md.0000091184.93122.09}}</ref><ref>{{cite journal |vauthors=Siegman-Igra Y, Reich P, Orni-Wasserlauf R, Schwartz D, Giladi M |title= The role of vancomycin in the persistence or recurrence of ''Staphylococcus aureus'' bacteraemia |journal= [[Scand J Infect Dis]] |volume= 37 |issue= 8 |pages= 572–8 |year= 2005 |pmid= 16138425 |doi= 10.1080/00365540510038488}}</ref> Several newly discovered strains of MRSA show [[antibiotic resistance]] even to vancomycin and [[teicoplanin]]. These new strains of the MRSA bacterium have been dubbed [[vancomycin-resistant Staphylococcus aureus|vancomycin intermediate-resistant ''S. aureus'' (VISA)]].<ref>{{cite journal |vauthors=Sieradzki K, Tomasz A |title= Inhibition of cell wall turnover and autolysis by vancomycin in a highly vancomycin-resistant mutant of ''Staphylococcus aureus'' |journal= J. Bacteriol. |volume= 179 |issue= 8 |pages= 2557–66 |year= 1997 |pmid= 9098053 |pmc= 179004|doi= 10.1128/jb.179.8.2557-2566.1997 }}</ref> <ref>{{cite journal |author= Schito GC |title= The importance of the development of antibiotic resistance in ''Staphylococcus aureus'' |journal= Clin Microbiol Infect |volume= 12 |issue= Suppl 1 |pages= 3–8 |year= 2006 |pmid= 16445718 |doi= 10.1111/j.1469-0691.2006.01343.x}}</ref> [[Linezolid]], [[quinupristin/dalfopristin]], [[daptomycin]], [[ceftaroline]], and [[tigecycline]] are used to treat more severe infections that do not respond to glycopeptides such as vancomycin.<ref>{{cite journal |vauthors=Mongkolrattanothai K, Boyle S, Kahana MD, Daum RS |title= Severe ''Staphylococcus aureus'' infections caused by clonally related community-associated methicillin-susceptible and methicillin-resistant isolates |journal= Clin. Infect. Dis. |volume= 37 |issue= 8 |pages= 1050–8 |year= 2003 |pmid= 14523769 |doi= 10.1086/378277}}</ref> Current guidelines recommend [[daptomycin]] for VISA bloodstream infections and endocarditis.<ref name="IDSA2011" /> This left [[vancomycin]] as the only effective agent available at the time. However, strains with intermediate (4–8&nbsp;μg/ml) levels of resistance, termed glycopeptide-intermediate ''S. aureus'' (GISA) or vancomycin-intermediate ''S. aureus'' (VISA), began appearing in the late 1990s. The first identified case was in Japan in 1996, and strains have since been found in hospitals in England, France and the US. The first documented strain with complete (>16&nbsp;μg/ml) resistance to vancomycin, termed [[Vancomycin-resistant Staphylococcus aureus|vancomycin-resistant ''S. aureus'']] (VRSA) appeared in the United States in 2002.<ref>{{cite journal |vauthors=Bozdogan B, Esel D, Whitener C, Browne FA, Appelbaum PC | title = Antibacterial susceptibility of a vancomycin-resistant Staphylococcus aureus strain isolated at the Hershey Medical Center | journal = Journal of Antimicrobial Chemotherapy | volume = 52 | issue = 5 | pages = 864–868 | year = 2003 | pmid = 14563898 | doi = 10.1093/jac/dkg457 }}</ref> However, in 2011, a variant of vancomycin has been tested that binds to the lactate variation and also binds well to the original target, thus reinstating potent antimicrobial activity.<ref>{{cite journal |vauthors=Xie J, Pierce JG, James RC, Okano A, Boger DL | title = A Redesigned Vancomycin Engineered for Dual d-Ala-d-Ala and d-Ala-d-Lac Binding Exhibits Potent Antimicrobial Activity Against Vancomycin-Resistant Bacteria | journal = J. Am. Chem. Soc. | volume = 133 | issue = 35 | pages = 13946–9 | year = 2011 | pmid = 21823662 | pmc = 3164945 | doi = 10.1021/ja207142h }}</ref> [[Linezolid|Oxazolidinones]] such as [[linezolid]], became available in the 1990s, and are comparable to vancomycin in effectiveness against MRSA. Linezolid resistance in ''S. aureus'' was reported in 2001,<ref>{{cite journal |vauthors=Tsiodras S, Gold HS, Sakoulas G, Eliopoulos GM, Wennersten C, Venkataraman L, Moellering RC, Ferraro MJ | title = Linezolid resistance in a clinical isolate of Staphylococcus aureus | journal = The Lancet | volume = 358 | issue = 9277 | pages = 207–208 | pmid = 11476839 | doi = 10.1016/S0140-6736(01)05410-1 | date=July 2001}}</ref> but infection rates have been at consistently low levels and in the United Kingdom and Ireland, no resistance was found in staphylococci collected from&nbsp;[[bacteremia]]&nbsp;cases between 2001 and 2006.<ref>{{Cite journal|year=2008|title=Non-susceptibility trends among staphylococci from bacteraemias in the UK and Ireland, 2001– 06|url=http://jac.oxfordjournals.org/content/62/suppl_2/ii65.full.pdf|journal=Journal of Antimicrobial Chemotherapy|volume=62|pages=ii65–ii74|via=|doi=10.1093/jac/dkn353|pmid=18819981|last1=Hope|first1=R.|last2=Livermore|first2=D. M.|last3=Brick|first3=G.|last4=Lillie|first4=M.|last5=Reynolds|first5=R.}}</ref> ===Skin and soft-tissue infections === In skin abscesses, the primary treatment recommended is removal of dead tissue, incision, and drainage. More data is needed to determine the effectiveness of specific antibiotics therapy in SSIs.<ref name=IDSA2011/> Examples of soft tissue infections from MRSA include: ulcers, [[impetigo]], abscesses, and surgical site infections.<ref name="YueDong2016">{{cite journal|last1=Yue|first1=Jirong|last2=Dong|first2=Bi Rong|last3=Yang|first3=Ming|last4=Chen|first4=Xiaomei|last5=Wu|first5=Taixiang|last6=Liu|first6=Guan J|last7=Dong|first7=Bi Rong|title=Linezolid versus vancomycin for skin and soft tissue infections| year=2016|doi=10.1002/14651858.CD008056.pub3|pmid=26758498|journal=Cochrane Database of Systematic Reviews|issue=1|pages=CD008056}}</ref> In surgical wounds, there is weak evidence (high risk of [[bias]]) that [[Linezolid]] may be better than [[Vancomycin]] to eradicate MRSA surgical site infections.<ref>{{cite journal|last1=Gurusamy|first1=KS|last2=Koti|first2=R|last3=Toon|first3=CD|last4=Wilson|first4=P|last5=Davidson|first5=BR|title=Antibiotic therapy for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in surgical wounds.|journal=The Cochrane Database of Systematic Reviews|date=20 August 2013|issue=8|pages=CD009726|doi=10.1002/14651858.CD009726.pub2|pmid=23963687}}</ref> MRSA colonization is also found in non surgical wounds such as traumatic [[wound]]s, [[burn]]s, and chronic [[ulcer]]s (i.e.: [[diabetic ulcer]], [[pressure ulcer]], [[arterial insufficiency ulcer]], [[venous ulcer]]). There is no conclusive evidence about the best antibiotic regimen to treat MRSA colonization.<ref name="CochraneNonSurg2013"/> ===Children=== In skin infections and in secondary infection sites topical [[mupirocin]] is used successfully. For bacteremia and endocarditis, vancomycin or daptomycin is considered. For children with MRSA infected bone or joints, treatment is individualized and long-term. Neonates can develop Neonatal pustulosis as a result of topical infection with MRSA.<ref name=IDSA2011/> Clindamycin is not approved for the treatment of MRSA infection it is still used in children for soft tissue infections.<ref name=IDSA2011/> ===Endocarditis and bacteremia === Evaluation for the replacement of a prosthetic valve is considered. Appropriate antibiotic therapy may be administered for up to six weeks. Four to six weeks of antibiotic treatment is often recommended, and is dependent upon the extent of MRSA infection.<ref name=IDSA2011/> ===Respiratory infections=== CA-MRSA in hospitalized patients pneumonia treatment begins before culture results. After the susceptibility to antibiotics is performed, the infection may be treated with vancomycin or linezolid for up to 21 days. If the pneumonia is complicated by the accumulation of pus in the pleural cavity surrounding the lungs, drainage may be done along with antibiotic therapy.<ref name=IDSA2011/> People with cystic fibrosis may develop respiratory complications related to MRSA infection. The incidence of MRSA in those with cystic fibrosis increased during 2000 to 2015 by five times. Most of these infections were HA-MRSA. MRSA accounts for 26% of lung infections in those with cystic fibrosis.<ref name="MaselliKeyt2017">{{cite journal|last1=Maselli|first1=Diego|last2=Keyt|first2=Holly|last3=Restrepo|first3=Marcos|title=Inhaled Antibiotic Therapy in Chronic Respiratory Diseases (Review)|journal=International Journal of Molecular Sciences|volume=18|issue=5|year=2017|pages=1062|issn=1422-0067|doi=10.3390/ijms18051062|pmid=28509852|pmc=5454974}}</ref> ===Bone and joint infections=== Cleaning the wound of dead tissue and draining abscesses is the first action to treat the MRSA infection. Administration of antibiotics is not standardized and is adapted by a case-by-case basis. Antibiotic therapy can last up to 1 to 3 months and sometimes even longer.<ref name=IDSA2011/> ===Infected implants=== MRSA infection can occur associated with implants and joint replacements. Recommendations on treatment are based upon the length of time the implant has been in place. In cases of a recent placement of a surgical implant or artificial joint, the device may be retained while antibiotic therapy continues. If the placement of the device has occurred over 3 weeks ago, the device may be removed. Antibiotic therapy is used in each instance sometimes long-term.<ref name=IDSA2011/> ===Central nervous system=== MRSA can infect the central nervous system and form brain abscess, subdural empyema, and spinal epidural abscess. Excision and drainage can be done along with antibiotic treatment. Septic thrombosis of cavernous or [[dural venous sinus]] can sometimes be a complication.<ref name=IDSA2011/> ===Other infections=== Treatment is not standardized for other instances of MRSA infection in a wide range of tissues. Treatment varies for MRSA infections related to: subperiosteal abscesses, necrotizing pneumonia, cellulitis, pyomyositis, necrotizing fasciitis, mediastinitis, myocardial, perinephric, hepatic, and splenic abscesses, septic thrombophlebitis, and severe ocular infections, including endophthalmitis.<ref name=IDSA2011/> Pets can be reservoirs and pass on MRSA to people. In some cases, the infection can be symptomatic and the pet can suffer a MRSA infection. Health departments recommend that the pet be taken to the veterinarian if MRSA infections keep occurring in the people who have contact with the pet.<ref name=tpchd/> == Epidemiology == Worldwide, an estimated 2&nbsp;billion people carry some form of ''S. aureus''; of these, up to 53&nbsp;million (2.7% of carriers) are thought to carry MRSA.<ref>{{cite web |url= http://www.keepkidshealthy.com/welcome/infectionsguide/mrsa.html |title= MRSA Infections |publisher= Keep Kids Healthy| archiveurl=https://web.archive.org/web/20071209022625/https://keepkidshealthy.com/welcome/infectionsguide/mrsa.html| archivedate=December 9, 2007 |deadurl=yes}}</ref> ===HA-MRSA=== In a US cohort study of 1300 healthy children, 2.4% carried MRSA in their nose.<ref name="auto">{{cite journal |vauthors=Fritz SA, Garbutt J, Elward A, Shannon W, Storch GA |title= Prevalence of and risk factors for community-acquired methicillin-resistant and methicillin-sensitive ''Staphylococcus aureus'' colonization in children seen in a practice-based research network |journal= Pediatrics |volume= 121 |issue= 6 |pages= 1090–8 |year= 2008 |pmid= 18519477 |doi= 10.1542/peds.2007-2104}}</ref> Bacterial sepsis occurs with most (75%) of cases of invasive MRSA infection.<ref name=IDSA2011/> In 2009, there were an estimated 463,017 hospitalization due to MRSA or a rate of 11.74 per 1,000 hospitalizations.<ref name=klein2013>{{cite journal |author1=Eili Y. Klein |author2=Lova Sun |author3=David L. Smith |author4=Ramanan Laxminarayan |title=The Changing Epidemiology of Methicillin-Resistant Staphylococcus aureus in the United States: A National Observational Study |journal=American Journal of Epidemiology|volume=177 |issue=7 |date=2013 |doi= 10.1093/aje/kws273 |pmid=23449778 |pages=666–674}}</ref> Many of these infections are less serious, but the Centers for Disease Control and Prevention (CDC) estimates that there are 80,461 invasive MRSA infections and 11,285 deaths due to MRSA annually.<ref>{{cite web|url=https://www.cdc.gov/drugresistance/threat-report-2013/|title=Antibiotic Resistance Threats in the United States, 2013 - Antibiotic/Antimicrobial Resistance - CDC|publisher=}}{{CDC}}</ref> In 2003, the cost for a hospitalization due to a MRSA was $92,363. A hospital stay for MSSA was $52,791 (USD).<ref name="YueDong2016"/> Infection after surgery is relatively uncommon, but occurs as much as 33% in specific types of surgeries. Infections of surgical sites range from 1% to 33%. MRSA sepsis that occurs within 30 days has a 15-38% mortality rate. MRSA sepsis that occurs within one year following a surgical infection has a mortality rate of around 55%. There may be increased mortality associated with cardiac surgery. There is a rate of 12.9% in those infected with MRSA while only a 3% infected with other organisms. SSIs infected with MRSA had longer hospital stays than those who did not.<ref name= CochraneSurg2013/> Globally, MRSA infection rates are dynamic and vary year to year.<ref>{{cite web|url=https://resistancemap.cddep.org/AntibioticResistance.php|title=ResistanceMap - Antibiotic Resistance|publisher = Center for Disease Dynamics, Economics & Policy | date = 2017|website=resistancemap.cddep.org|accessdate=27 May 2017}} note: a search must be performed on the website; it is interactive and the statistics are based upon the most current information,</ref> According to The 2006 SENTRY Antimicrobial Surveillance Program report, the incidence of MRSA blood stream infections was 35.9 per cent in North America. MRSA blood infections in Latin America was 29%. European incidence was 22.8%. The rate of all MRSA infections in Europe ranged from 50% per cent in Portugal down to 0.8 per cent in Sweden. Overall MRSA infection rates varied in Latin America: Colombia and Venezuela combined had 3%, Mexico had 50%, Chile 38%, Brazil 29%, and Argentina 28%.<ref name="YueDong2016"/> The [[Centers for Disease Control and Prevention]] (CDC) estimated that about 1.7&nbsp;million nosocomial infections occurred in the United States in 2002, with 99,000 associated deaths.<ref>{{cite journal |vauthors=Klevens RM, Edwards JR, Richards CL, Horan TC, Gaynes RP, Pollock DA, Cardo DM |title= Estimating health care-associated infections and deaths in U.S. hospitals, 2002 |journal= [[Public Health Rep]] |volume= 122 |issue= 2 |pages= 160–6 |year= 2007 |pmid= 17357358 |pmc= 1820440|doi= 10.1177/003335490712200205 }}</ref> The estimated incidence is 4.5 nosocomial infections per 100 admissions, with direct costs (at 2004 prices) ranging from $10,500 (£5300, €8000 at 2006 rates) per case (for bloodstream, urinary tract, or respiratory infections in immunocompetent people) to $111,000 (£57,000, €85,000) per case for antibiotic-resistant infections in the bloodstream in people with transplants. With these numbers, conservative estimates of the total direct costs of nosocomial infections are above $17&nbsp;billion. The reduction of such infections forms an important component of efforts to improve healthcare safety. (BMJ 2007){{Citation needed|reason=proper citing|date=February 2009}} MRSA alone was associated with 8% of nosocomial infections reported to the CDC National Healthcare Safety Network from January 2006 to October 2007.<ref name="pmid18947320">{{cite journal |vauthors=Hidron AI, Edwards JR, Patel J, Horan TC, Sievert DM, Pollock DA, Fridkin SK |title= NHSN annual update: antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006-2007 |journal= Infect Control Hosp Epidemiol |volume= 29 |issue= 11 |pages= 996–1011 |date= November 2008 |pmid= 18947320 |doi= 10.1086/591861}}</ref> The [[British National Audit Office]] estimated that the incidence of nosocomial infections in Europe ranges from 4% to 10% of all hospital admissions. As of early 2005, the number of deaths in the United Kingdom attributed to MRSA has been estimated by various sources to lie in the area of 3,000 per year.<ref>{{cite journal |vauthors=Johnson AP, Pearson A, Duckworth G |title= Surveillance and epidemiology of MRSA bacteraemia in the UK |journal= [[J Antimicrob Chemother]] |volume= 56 |issue= 3 |pages= 455–62 |year= 2005 |pmid= 16046464 |doi= 10.1093/jac/dki266}}</ref> In the United States, 95&nbsp;million carry ''S. aureus'' in their noses; of these, 2.5&nbsp;million (2.6% of carriers) carry MRSA.<ref>{{cite journal |vauthors=Graham PL, Lin SX, Larson EL |title= A U.S. population-based survey of ''Staphylococcus aureus'' colonization |journal= [[Annals of Internal Medicine]] |volume= 144 |issue= 5 |pages= 318–25 |year= 2006 |pmid= 16520472 |doi= 10.7326/0003-4819-144-5-200603070-00006}}</ref> A population review conducted in three U.S. communities showed the annual incidence of CA-MRSA during 2001–2002 to be 18–25.7/100,000; most CA-MRSA isolates were associated with clinically relevant infections, and 23% of people required hospitalization.<ref>{{cite conference |vauthors=Jernigan JA, Arnold K, Heilpern K, Kainer M, Woods C, Hughes JM |title= Methicillin-resistant ''Staphylococcus aureus'' as community pathogen |booktitle= Symposium on Community-Associated Methicillin-resistant ''Staphylococcus aureus'' (Atlanta, Georgia, U.S.). Cited in Emerg Infect Dis |publisher= Centers for Disease Control and Prevention |date=2006-05-12 |url= https://www.cdc.gov/ncidod/EID/vol12no11/06-0911.htm |accessdate= 2007-01-27}}</ref> ===CA-MRSA=== In a US cohort study of 1300 healthy children, 2.4% carried MRSA in their nose.<ref name="auto"/> There are concerns that the presence of MRSA in the environment may allow resistance to be transferred to other bacteria through phages (viruses that infect bacteria). The source of MRSA could come from hospital waste, farm sewage, and other waste water.<ref name=IDSA2011/> ===LA-MRSA=== Livestock associated MRSA (LA-MRSA) has been observed in Korea, Brazil, Switzerland, Malaysia, India, Great Britain, Denmark, and China.<ref name = Gopal2017/> ==History== [[File:EARSS MRSA 2008-en.svg|thumb|Incidence of MRSA in human blood samples in countries which took part in the study in 2008]] In 1961 the first known MRSA isolates were reported in a British study, and from 1961 to 1967 there were infrequent hospital outbreaks in Western Europe and Australia,<ref name= "The University of Chicago Medical Center">{{cite web |url=http://mrsa-research-center.bsd.uchicago.edu/timeline.html |publisher=The University of Chicago Medical Center |title=MRSA History Timeline: The First Half-Century, 1959–2009 |year=2010}}</ref> with [[methicillin]] then being licensed in England to treat resistant infections. Other reports of MRSA began to be described in the 1970s.<ref name = CochraneSurg2013/> Resistance to other antibiotics was documented in some strains of S. aureus. In 1996, vancomycin resistance was reported in Japan.<ref name=Winn/>{{rp|637}} In many countries, outbreaks of MRSA infection was reported to be transmitted between hospitals.<ref name=Murray/>{{rp|402}} The rate had increased to 22% by 1995, and by 1997 the percent of hospital ''S. aureus'' infections attributable to MRSA had reached 50%. The first report of community-associated MRSA (CA-MRSA) occurred in 1981, and in 1982 there was a large outbreak of CA-MRSA among intravenous drug users in Detroit, Michigan.<ref name= "The University of Chicago Medical Center"/> Additional outbreaks of CA-MRSA were reported through the 1980s and 1990s, including outbreaks among Australian Aboriginal populations that had never been exposed to hospitals. In the mid-1990s there were scattered reports of CA-MRSA outbreaks among US children. While HA-MRSA rates stabilized between 1998 and 2008, CA-MRSA rates continued to rise. A report released by the University of Chicago Children's Hospital comparing two time periods (1993–1995 and 1995–1997) found a 25-fold increase in the rate of hospitalizations due to MRSA among children in the United States.<ref>{{cite web|url=http://mrsa-research-center.bsd.uchicago.edu/JAMA_02_25_1998_issue.pdf|title=Community-acquired MRSA in Children with no predisposing risk|publisher=}}</ref> In 1999 the University of Chicago reported the first deaths from invasive MRSA among otherwise healthy children in the United States.<ref name= "The University of Chicago Medical Center"/> By 2004, the genome for various strains of MRSA were described.<ref>{{cite journal |vauthors=Holden MT, Feil EJ, Lindsay JA, Peacock SJ, Day NP, Enright MC, Foster TJ, Moore CE, Hurst L, Atkin R, Barron A, Bason N, Bentley SD, Chillingworth C, Chillingworth T, Churcher C, Clark L, Corton C, Cronin A, Doggett J, Dowd L, Feltwell T, Hance Z, Harris B, Hauser H, Holroyd S, Jagels K, James KD, Lennard N, Line A, Mayes R, Moule S, Mungall K, Ormond D, Quail MA, Rabbinowitsch E, Rutherford K, Sanders M, Sharp S, Simmonds M, Stevens K, Whitehead S, Barrell BG, Spratt BG, Parkhill J |title= Complete genomes of two clinical ''Staphylococcus aureus'' strains: Evidence for the rapid evolution of virulence and drug resistance |journal= Proc Natl Acad Sci USA |volume= 101 |issue= 26 |pages= 9786–91 |year= 2004 |pmid= 15213324 |pmc= 470752 |doi= 10.1073/pnas.0402521101}}</ref> It has been argued that the observed increased mortality among MRSA-infected people may be the result of the increased underlying [[morbidity]] of these people. Several studies, however, including one by Blot and colleagues, that have adjusted for underlying disease still found MRSA bacteremia to have a higher attributable mortality than methicillin-susceptible ''S. aureus'' (MSSA) bacteremia.<ref>{{cite journal |vauthors=Blot SI, Vandewoude KH, Hoste EA, Colardyn FA |title= Outcome and attributable mortality in critically Ill patients with bacteremia involving methicillin-susceptible and methicillin-resistant ''Staphylococcus aureus'' |journal= Arch Intern Med |volume= 162 |issue= 19 |pages= 2229–35 |year= 2002 |pmid= 12390067 |doi= 10.1001/archinte.162.19.2229}}</ref> A population-based study of the incidence of MRSA infections in [[San Francisco]] during 2004–05 demonstrated that nearly 1 in 300 residents suffered from such an infection in the course of a year and that greater than 85% of these infections occurred outside of the healthcare setting.<ref>{{cite journal |vauthors=Liu C, Graber CJ, Karr M, Diep BA, Basuino L, Schwartz BS, Enright MC, O'Hanlon SJ, Thomas JC, Perdreau-Remington F, Gordon S, Gunthorpe H, Jacobs R, Jensen P, Leoung G, Rumack JS, Chambers HF |title= A population-based study of the incidence and molecular epidemiology of methicillin-resistant ''Staphylococcus aureus'' disease in San Francisco, 2004–2005 |journal= Clin. Infect. Dis. |volume= 46 |issue= 11 |pages= 1637–46 |date= June 2008 |pmid= 18433335 |doi= 10.1086/587893 }}</ref> A 2004 study showed that people in the United States with ''S. aureus'' infection had, on average, three times the length of hospital stay (14.3 vs. 4.5 days), incurred three times the total cost ($48,824 vs. $14,141), and experienced five times the risk of in-hospital death (11.2% vs 2.3%) than people without this infection.<ref>{{cite journal |vauthors=Noskin GA, Rubin RJ, Schentag JJ, Kluytmans J, Hedblom EC, Smulders M, Lapetina E, Gemmen E |title= The Burden of ''Staphylococcus aureus'' Infections on Hospitals in the United States: An Analysis of the 2000 and 2001 Nationwide Inpatient Sample Database |journal= Arch Intern Med |volume= 165 |issue= 15 |pages= 1756–1761 |year= 2005 |pmid= 16087824 |doi= 10.1001/archinte.165.15.1756}}</ref> In a meta-analysis of 31 studies, Cosgrove ''et al.'',<ref>{{cite journal |vauthors=Cosgrove SE, Qi Y, Kaye KS, Harbarth S, Karchmer AW, Carmeli Y |title= The impact of Methicillin Resistance in ''Staphylococcus aureus'' Bacteremia on Patient Outcomes: Mortality, Length of Stay, and Hospital Charges |journal= Infection Control and Hospital Epidemiology |volume= 26 |issue= 2 |pages= 166–174 |year= 2005 |pmid= 15756888 |doi= 10.1086/502522}}</ref> concluded that MRSA bacteremia is associated with increased mortality as compared with MSSA bacteremia (odds ratio= 1.93; 95% {{nowrap|CI {{=}} 1.93 ± 0.39}}).<ref>{{cite journal |vauthors=Hardy KJ, Hawkey PM, Gao F, Oppenheim BA |title= Methicillin resistant ''Staphylococcus aureus'' in the critically ill |journal= British Journal of Anaesthesia |volume= 92 |issue= 1 |pages= 121–30 |year= 2004 |pmid= 14665563 |doi= 10.1093/bja/aeh008}}</ref> In addition, Wyllie ''et al.'' report a death rate of 34% within 30 days among people infected with MRSA, a rate similar to the death rate of 27% seen among MSSA-infected people.<ref>{{cite journal |vauthors=Wyllie DH, Crook DW, Peto TE |title= Mortality after ''Staphylococcus aureus'' bacteraemia in two hospitals in Oxfordshire, 1997–2003: cohort study |journal= BMJ |volume= 333 |issue= 7562 |page= 281 |year= 2006 |pmid= 16798756 |pmc= 1526943 |doi= 10.1136/bmj.38834.421713.2F |url= http://bmj.bmjjournals.com/cgi/content/abstract/333/7562/281}}</ref> In the US, the Centers for Disease Control and Prevention issued guidelines on October 19, 2006, citing the need for additional research, but declined to recommend such screening.<ref>{{cite web|url=https://www.cdc.gov/ncidod/dhqp/pdf/ar/mdroGuideline2006.pdf|title=Healthcare-associated infections—HAI—CDC|work=cdc.gov}}</ref> According to the CDC, the most recent estimates of the incidence of healthcare-associated infections that are attributable to MRSA in the United States indicate a decline in such infection rates. Incidence of MRSA central line-associated blood stream infections as reported by hundreds of intensive care units decreased 50–70% from 2001–2007.<ref name="mrsa-surveillance">{{cite web|url=https://www.cdc.gov/mrsa/statistics/MRSA-Surveillance-Summary.html|title=MRSA Surveillance|date=April 8, 2011|publisher=Centers for Disease Control and Prevention}}</ref> A separate system tracking all hospital MRSA bloodstream infections found an overall 34% decrease between 2005–2008.<ref name="mrsa-surveillance"/> In 2010, vancomycin was the drug of choice.<ref name=IDSA2011/> Across Europe, based mostly on data from 2013 seven countries (Iceland, Norway, Sweden, Netherlands, Denmark, Finland, and Estonia, from lowest to higher) had low levels of hospital-acquired MRSA infections compared to the others,<ref name=EHCI2015>{{cite news |title=Outcomes in EHCI 2015|url=http://www.healthpowerhouse.com/files/EHCI_2015/EHCI_2015_report.pdf |accessdate=27 January 2016|publisher=Health Consumer Powerhouse|date=26 January 2016}}</ref>{{rp|92–93}} and among countries with higher levels significant improvements had been made only in Bulgaria, Poland and the British Isles.<ref name=EHCI2015/>{{rp|40}} A 1,000-year-old [[collyrium|eye salve]] recipe found in the medieval [[Bald's Leechbook]] at the [[British Library]], one of the earliest known medical textbooks, was found to have activity against MRSA ''in vitro'' and in skin wounds in mice.<ref>{{cite web |last1=Thompson|first1=Nick|last2=Smith-Spark|first2=Laura|title=Thousand-year-old Anglo-Saxon potion kills MRSA superbug|url=http://edition.cnn.com/2015/03/31/health/anglo-saxon-potion-mrsa/index.html|website=CNN News|publisher=CNN/Time Warner|accessdate=1 April 2015}}</ref> ==Popular culture== MRSA is frequently a media topic, especially if well-known personalities have announced that they have or have had the infection.<ref>{{cite web|url=http://www.tampabay.com/sports/football/bucs/bucs-carl-nicks-lawrence-tynes-have-mrsa-infections/2137793|title=Bucs' Nicks, Tynes have MRSA infections|website=Tampa Bay Times|accessdate=3 June 2017}}</ref><ref>{{cite web|url=http://www.cnn.com/2015/10/12/health/mrsa-bacteria/index.html|title=MRSA: The tiny bacteria that can tackle giants|first=Elizabeth Cohen, Senior Medical|last=Correspondent|website=CNN|accessdate=3 June 2017}}</ref><ref>{{cite web|url=https://gizmodo.com/this-australian-says-he-and-his-dead-friend-invented-bi-1746958692|title=This Australian Says He and His Dead Friend Invented Bitcoin|first=Sam Biddle and Andy|last=Cush|publisher=|accessdate=3 June 2017}}</ref> Outbreaks of infection appear regularly in newspapers and television news programs. A report on skin and soft tissue infections in the [[Cook County]] jail in Chicago in 2004–05 demonstrated MRSA was the most common cause of these infections among those incarcerated there.<ref name=":2">{{Cite journal|last=Singh|first=Jatinder|last2=Johnson|first2=Ryan C.|last3=Schlett|first3=Carey D.|last4=Elassal|first4=Emad M.|last5=Crawford|first5=Katrina B.|last6=Mor|first6=Deepika|last7=Lanier|first7=Jeffrey B.|last8=Law|first8=Natasha N.|last9=Walters|first9=William A.|date=2016-10-26|title=Multi-Body-Site Microbiome and Culture Profiling of Military Trainees Suffering from Skin and Soft Tissue Infections at Fort Benning, Georgia|journal=mSphere|language=en|volume=1|issue=5|pages=e00232–16|doi=10.1128/mSphere.00232-16|issn=2379-5042|pmc=5064451|pmid=27747300}}</ref> Lawsuits that are filed against those who are accused of infecting others with MRSA are also popular stories in the media.<ref>{{cite web|url=http://www.aboutlawsuits.com/hospital-infection-lawsuits-are-on-the-rise-1914/|title=Hospital Infection Lawsuits are on the Rise - AboutLawsuits.com|website=www.aboutlawsuits.com|accessdate=3 June 2017}}</ref><ref>{{cite web|url=http://www.nydailynews.com/news/mrsa-superbug-doctor-named-misdiagnosis-lawsuits-article-1.259477|title=Doc who treated superbug vic was sued before|publisher=|accessdate=3 June 2017}}</ref> MRSA will be included in experiments and cultured on the International Space Station to observe the effects of zero gravity on its evolution.<ref>{{cite web|url=http://www.popularmechanics.com/space/rockets/a25084/spacex-carrying-msra-to-iss/|title=The Next SpaceX Launch Will Carry Deadly Bacteria|date=7 February 2017|publisher=|accessdate=3 June 2017}}</ref><ref>{{cite web|url=http://www.kdcprojects.com/news/417-deadly-delivery-for-the-iss|title=KDC Projects|website=www.kdcprojects.com|accessdate=3 June 2017}}</ref> National Public Radio broadcast an episode of Fresh Air with MRSA as the topic.<ref>{{cite web|url=https://www.npr.org/2010/03/23/124999740/mrsa-the-drug-resistant-superbug-that-wont-die|title=MRSA: The Drug-Resistant 'Superbug' That Won't Die|website=NPR.org|accessdate=3 June 2017}}</ref> MRSA is the topic of television shows<ref>{{cite web|url=https://www.imdb.com/title/tt0771556/?ref_=fn_al_tt_1|title="Should I Worry About...?" MRSA (TV Episode 2004)|publisher=|accessdate=3 June 2017}}</ref><ref>{{cite web|url=https://www.wired.com/2015/02/resistance-release/|title=Resistance: The Movie That Will Make You Care About Antibiotic Misuse|first=Maryn|last=McKenna|publisher=|accessdate=3 June 2017}}</ref><ref>{{cite web|url=http://www.digitalspy.com/tv/line-of-duty/feature/a805973/line-of-duty-series-4-release-date-cast-and-everything-you-need-to-know-as-it-moves-to-bbc-one/|title=Line of Duty series 4: Everything you need to know|date=24 April 2017|publisher=|accessdate=3 June 2017}}</ref> books<ref>{{cite book|title=Superbug: The Fatal Menace of MRSA|first=search|last=results|date=1 February 2011|publisher=Free Press|isbn = 978-1416557289}}</ref> and movies.<ref>{{cite web|url=http://www.huffingtonpost.co.uk/juliet-gellatley/facing-the-future-of-anti_b_10927382.html|title=Facing the Future of Antibiotic Resistance - The Change Starts Here|website=HuffPost UK|accessdate=3 June 2017}}</ref> ==Research== Various antibacterial chemical extracts from various species of the Sweetgum tree, (genus ''[[Liquidambar]]'') have been investigated for their activity in inhibiting MRSA. Specifically these are: [[cinnamic acid]], [[cinnamyl cinnamate]], [[ethyl cinnamate]], [[benzyl cinnamate]], [[styrene]], [[vanillin]], [[cinnamyl alcohol]], [[2-phenylpropyl alcohol]] and [[3-phenylpropyl cinnamate]].<ref name="CrandallLingbeck2015">{{cite journal|last1=Crandall|first1=PhilipG|last2=Lingbeck|first2=JodyM|last3=O′Bryan|first3=CorlissA|last4=Martin|first4=ElizabethM|last5=Adams|first5=JoshuaP|title=Sweetgum: An ancient source of beneficial compounds with modern benefits|journal=Pharmacognosy Reviews|volume=9|issue=17|year=2015|pages=1–11|issn=0973-7847|doi=10.4103/0973-7847.156307|pmid=26009686|pmc=4441155}}</ref> The delivery of inhaled antibiotics along with systematic administration to treat MRSA are being developed. It's believed that this will improve the outcomes of those with cystic fibrosis and other respiratory infections.<ref name="MaselliKeyt2017"/> [[Phage therapy]] has been used for years in MRSA in eastern countries and studies are ongoing in western countries.<ref>{{Cite journal|last=Reardon|first=Sara|date=2014-06-03|title=Phage therapy gets revitalized|journal=Nature|language=en|volume=510|issue=7503|pages=15–16|doi=10.1038/510015a|pmid=24899282|issn=0028-0836|bibcode=2014Natur.510...15R}}</ref><ref>{{Cite web|url=http://www.bbc.com/future/story/20161115-the-viruses-that-may-save-humanity|title=The viruses that may save humanity|last=Robson|first=David|language=en|access-date=2018-09-25}}</ref> ==References== {{Reflist}} ==Further reading== {{Commons category|Methicillin-resistant Staphylococcus aureus|MRSA}} *[https://www.cdc.gov/mrsa/ The Centers for Disease Control and Prevention] information, prevention, statistics, at risk groups, causes, educational resources, and environmental factors. *[https://www.cdc.gov/niosh/topics/mrsa/ National Institute for Occupational Safety and Health] information on the bacteria, exposure in the workplace, and reducing risks of being infected. {{Gram-positive firmicutes diseases}} {{Taxonbar|from=Q595158}} {{DEFAULTSORT:Methicillin-Resistant Staphylococcus Aureus}} [[Category:Antibiotic-resistant bacteria]] [[Category:Bacterial diseases]] [[Category:Healthcare-associated infections]] [[Category:Staphylococcaceae]] [[Category:Staphylococcus|*]] [[Category:Infection-related cutaneous conditions]] [[Category:Bacterium-related cutaneous conditions]] [[Category:Cat diseases]] [[Category:Pathovars]]'