DISSEMINATION OF THE CA-MRSA PEDIATRIC CLONE (ST5-IV-t002-pvl+) IN SOUTHERN ISRAEL

Methicillin resistant Staphylococcus aureus (MRSA) isolates of clonal complex 5 (CC5), SCCmec type IV, spa type t002 have been reported globally as the Pediatric Clone associated with CA-MRSA outbreaks. This MRSA strain, first described in 1992 in Portugal, infects mainly children and newborns. We aimed to determine the presence of this clone in Israel among MRSA strains of spa type t002 analyzed at the national reference center.

Staphylococcus aureus, spa type t002, pvl^-, is a common HA-MRSA in bacteremia patients. Analysis of strains, received during 2015-2017, revealed 52 MRSA isolates of spa type t002, pvl⁺ confirmed as the pediatric clone. Most of the strains (33) were isolated in southern Israel, among them 24 children with mean age of 3.4yr, 23/24 (96%) Bedouins. The majority of cases were community associated (22/24, 91.6%) with no identified risk factors for MRSA infection. The predominant presenting symptom was skin and soft tissue infection (SSTI) (21/24, 87.5%), 2 children had bacteremia one with septic shock that required ICU admission. Treatment failure was recorded in 25% of patients with no mortality.

PFGE analysis revealed 2 major restriction patterns, representative isolates were confirmed as ST5, SCCmec type IV (pediatric clone). Antimicrobial resistance was observed for erythromycin (29%), and clindamycin (29%). In southern Israel, CA-MRSA clones accounted for 39% of MRSA from SSTIs. The pediatric clone was the predominant pvl+ CA-MRSA in southern Israel (46%) in comparison with other regions (5%).

This pediatric MRSA clone is a significant cause of community onset SSTI in southern Israel. The proven dissemination potential of CA-MRSA and this clone in particular warrants further investigation.