Skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus USA300 clone.
Until recently, methicillin-resistant Staphylococcus aureus (MRSA) has caused predominantly healthcare-associated infections. We studied MRSA infections and overall skin and soft tissue infections (SSTIs) in outpatients receiving care at the Baltimore Veterans Affairs Medical Center Emergency Care Service during 2001-2005. We found an increase in MRSA infections, from 0.2 to 5.9 per 1,000 visits (p < 0.01); most were community-associated SSTIs. Molecular typing showed that > 80% of MRSA infections were caused by USA300. In addition, SSTI visits increased from 20 to 61 per 1,000 visits (p < 0.01). The proportion of SSTI cultures that yielded MRSA increased from 4% to 42% (p < 0.01), while the proportion that yielded methicillin-sensitive S. aureus remained the same (10% to 13%, p = 0.5). The increase in community-associated MRSA infections and the overall increase in SSTIs in our population suggest that USA300 is becoming more virulent and has a greater propensity to cause SSTIs.
Johnson
Jennifer K
JK
Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA. jkjohnson@som.umaryland.edu
Khoie
Tina
T
Shurland
Simone
S
Kreisel
Kristen
K
Stine
O Colin
OC
Roghmann
Mary-Claire
MC
D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008396:Maryland / Q000453:epidemiology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D018461:Soft Tissue Infections / Q000188:drug therapy / Q000382:microbiology*; D013207:Staphylococcal Skin Infections / Q000188:drug therapy / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification*