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 blaCTX-M-15 and blaCMY-2 resistance genes was observed in 11.6 % and 37 % of the isolates respectively. Overall, Salmonella enterica serovar Senftenberg was the predominant serovar carrying blaCTX-M-15 and blaCMY-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 blaCTX-M-15 gene. We also report for the first time from India, a case of gastroenteritis due to S. enterica serovar Thompson.