Evolution of methicillin-resistant S. aureus clones in the community and hospital setting, Argentina.

EGEA A.L.; CORSO A.; LAMBERGHINI R.O.; GAGETTI P.; FACCONE D.; LUCERO C.; GRUPO CA-MRSA ARGENTINA; BOCCO J.L.; SOLA C.

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

MRSA is a successful healthcare (HA) and community (CA) associated pathogen showing high virulence. We aimed to investigate the molecular epidemiology of MRSAinfections in both community and hospital setting in Argentina. Consecutive S.aureus clinical isolates were collected during Nov-2009 from 66 hospitals in 20 Argentina provinces and Buenos Aires city. Healthcare-onset (HO) infection was defined when MRSA was obtained after 48 hours of hospitalization.AMRSAwas considered an HAstrain if it was resistant to at least 2 non-beta-lactam antibiotics. MRSA were studied by local and global molecular typing. Out of 591 total isolates, 375 (63%) were from community-onset (CO) infections and 322 (54%) were MRSA (37% CA and 17% HA). MRSAproportion differed significantly between CO (58%) and HO (49%) infections. The molecular typing determined that most harbored SCCmecIV (74%) (IVc, 35%, IVa, 31% and minor variants) followed by SCCmecI (20%). CO-infections were associated mainly to PFGE type N-ST30-SCCmecIVc-t019-PVL+ (46%) and I-ST5-SCCmecIVa-t311-PVL+ (37%) clones. In contrast, HO-infections were associated mainly to PFGE type AST5-SCCmecI-t149 (46%) and I-ST5-SCCmecIVa-t311-PVL+ (20%) clones. The epidemiology ofMRSAis changing in Argentina, with higher rates in the CO- than in the HO-infections, mainly associated with the spread of two CA-MRSA clones harboring SCCmecIV.