ST8:USA300

{{Short description|Strain of bacteria}}

{{Infraspeciesbox special

| image = MRSA7820.jpg

| image_caption = Electron micrograph of MRSA

| genus = Staphylococcus

| species = aureus

| infraspecies_rank1_name = Strain

| infraspecies_rank1 = ST8:USA300

}}

ST8:USA300 is a strain of community-associated methicillin-resistant Staphylococcus aureus (MRSA) that has emerged as a particularly antibiotic resistant epidemic that is responsible for rapidly progressive, fatal diseases including necrotizing pneumonia, severe sepsis and necrotizing fasciitis.{{cite journal |vauthors=Boyle-Vavra S, Daum RS |title=Community-acquired methicillin-resistant Staphylococcus aureus: the role of Panton-Valentine leukocidin |journal=Lab. Invest. |volume=87 |issue=1 |pages=3–9 |year=2007 |pmid=17146447 |doi=10.1038/labinvest.3700501|doi-access=free }} The epidemiology of infections caused by MRSA is rapidly changing: in the past 10 years, infections caused by this organism have emerged in the community (whereas previously MRSA infections were almost exclusively hospital-acquired). The two MRSA clones in the United States most closely associated with community outbreaks, USA400 (MW2 strain, ST1 lineage) and USA300, often contain Panton-Valentine leukocidin (PVL) genes and, more frequently, have been associated with skin and soft tissue infections. Outbreaks of community-associated (CA)-MRSA infections have been reported in correctional facilities, among athletic teams, among military recruits, in newborn nurseries, and among sexually active men who have sex with men, CA-MRSA infections now appear to be endemic in many urban regions and cause most MRSA infections.{{cite journal |vauthors=Maree CL, Daum RS, Boyle-Vavra S, Matayoshi K, Miller LG |title=Community-associated methicillin-resistant Staphylococcus aureus isolates causing healthcare-associated infections |journal=Emerging Infect. Dis. |volume=13 |issue=2 |pages=236–42 |year=2007 |pmid=17479885 |doi= 10.3201/eid1302.060781|pmc=2725868}}{{cite journal |vauthors=Diep BA, Chambers HF, Graber CJ, etal |title=Emergence of multidrug-resistant, community-associated, methicillin-resistant Staphylococcus aureus clone USA300 in men who have sex with men |journal=Ann. Intern. Med. |volume=148 |issue=4 |pages=249–57 |date=February 2008 |pmid=18283202 |doi= 10.7326/0003-4819-148-4-200802190-00204|s2cid=20491386 |doi-access= }}