We characterized spa types, SCC. mec types, and antimicrobial resistance patterns of 516 methicillin-resistant Staphylococcus aureus (MRSA) isolates, collected between 2011 and 2014 from nares and blood cultures of United States patients. Among nares isolates, 45 spa types were observed; 29.9% were t002/SCC. mec II and 30.9% were t008/SCC. mec IV. Among blood isolates, 40 spa types were identified; 24.4% were t002/SCC. mec II and 39.9% were type t008/SCC. mec IV. Compared to data from our 2009-2010 survey, the percentage of t008/SCC. mec IV isolates from nares increased significantly (20.4%-30.9%; P = 0.004) while the percentage from positive blood cultures remained similar (39.2% versus 39.9%; P = 0.921). There were also significant changes in the overall antimicrobial resistance patterns observed, including the decrease of the clindamycin, erythromycin, levofloxacin and moxifloxacin multidrug resistance pattern, likely the result of t002/SCC. mec II strains being displaced by t008/SCC. mec IV strains. Rates of high-level mupirocin resistance did not change significantly from our past study (4.1% compared to 4.7%; P = 0.758) but an increase in low-level resistance, particularly among t002/SCC. mec II isolates, was observed.
|Original language||English (US)|
|Journal||Diagnostic Microbiology and Infectious Disease|
|State||Accepted/In press - Feb 1 2017|
All Science Journal Classification (ASJC) codes
- Microbiology (medical)
- Infectious Diseases