Background: As opposed to the CA-MRSA epidemic in the USA, CA-MRSA in Europe is clonally heterogeneous; ST80 being most common. We characterized community-onset MRSA infections in Israel.
Methods: During 4/2010-10/2013, all community-onset MRSA clinical isolates from a major HMO in Israel, representing ~30% of the population, were collected prospectively. Demographic and clinical data were collected and antibiotic susceptibility determined. PCR was performed for mecA, SCCmec and PVL. SCCmecIV/V isolates were further characterized by PCR for arcA, tsst1, eta, etb, and sequenced for spa type.
Results: MRSA isolates were detected in 270 patients, mainly from wounds. SCCmecI-III, IV and V were found in 128(47%), 116(43%) and 26(10%) of patients respectively. SCCmecIV patients were younger (p<0.0001) (77% of all children had SCCmecIV isolates). Almost all isolates were tmp/smx susceptible (98%). Clindamycin resistance rate was lower in SCCmecIV/V compared with SCCmecI-III isolates (34%/23% vs. 95% respectively, p<0.0001); SCCmecIV had the lowest MDR rate (8%,p<0.0001). The 3 major spa types of SCCmecIV were t032 (EMRSA15)(13%), t008 (USA300)(13%) and t991 (10%) and were distributed throughout Israel. Strain t991 was eta+/PVL-, isolated mainly from children (75%), and quinolone susceptible (92%). PVL+ strains (n=29) included mainly USA300 (52%) and ST30 (14%). Recent hospitalization was recorded in 40%/50% of patients with SCCmecIV/V isolates, respectively; within SCCmecIV: 70%/17%/8% of EMRSA15, USA300 and t991 patients were recently hospitalized respectively.
Conclusions: Among community-onset MRSA, multiple genetic lineages are evident. Approximately third are typical CA-MRSA clones; the two major being USA300 and t991. CA-MRSA isolates were detected throughout Israel particularly from wounds.
