Serotype profile and molecular characterization of antimicrobial resistance in non-typhoidal Salmonella isolated from gastroenteritis cases over nine years

Resistance to third-generation cephalosporins in non-typhoidal Salmonella (NTS) is emerging worldwide. We report the occurrence of extended-spectrum beta-lactamase (ESBL) phenotypes in 53.4% of NTS isolated over a period of nine years from gastroenteritis cases. ESBL and AmpC co-production was observed in 21% of the isolates. Occurrence of bla(CTX-M-15) and bla(CMY-2) resistance genes was observed in 11.6% and 37% of the isolates respectively. Overall, Salmonella enterica serovar Senftenberg was the predominant serovar carrying bla(CTX-M-15) and bla(CMY-2) resistance genes. We report for the first time from India, one isolate each of S. enterica serovar Thompson, S. enterica serovar Infantis and S. enterica serovar Newport, carrying the bla(CTX-M-15) gene. We also report for the first time from India, a case of gastroenteritis due to S. enterica serovar Thompson.