Molecular Characteristics of Community-Acquired Methicillin-Resistant , Hospital-Acquired MRSA Isolates, and PVL in one of the Indian hospitals.

UNLABELLED

Community-acquired methicillin resistant (CA-MRSA) strains are increasingly replacing hospital-acquired MRSA (HA-MRSA) strains in hospitalized patients leading to poor clinical outcomes. Hence, this study aimed to characterize clinical isolates of MRSA (HA-MRSA and CA-MRSA) and to understand their clonal origin. A total of 400 consecutive clinical isolates were collected from the clinical bacteriology lab of a tertiary care hospital. All the isolates were screened for MRSA by cefoxitin disc diffusion test and A PCR, followed by SCC typing, antibiotic susceptibility testing, Panton Valentine Leukocidin (PVL) screening, and pulsed field gel electrophoresis (PFGE). Of the total 400 isolates, 134 categorized MRSA by cefoxitin, while 129 as A positive by PCR, of which 117 could be characterized into SCC types. SCCI and II were present in 1 isolate each, SCCIII in 36 (31%) representing HA-MRSA, While SCCIV in 51 (44%), and SCCV in 28 (24%) isolates representing CA-MRSA. Of all SCCIII isolates, 70% were multidrug resistant (MDR) while 59% of SCCIV and 29% of SCCV isolates were MDR. PVL (CA-MRSA virulence factor) positivity in III, IV, V isolates was 9%, 31%, 46% respectively. PFGE typing showed MRSA clones of multiple origins. In conclusion, study showed the evolving epidemiology of HA-MRSA and CA-MRSA. CA-MRSA constituted the majority of clinical isolates amongst both community and hospital MRSA isolates. Various MDR clones of IV and V were circulating and replacing III in hospital settings. SCCIV isolates were predominant and evolved as MDR, however, PVL was significantly associated with CA-MRSA.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12088-024-01195-9.