Genetic characterization and genotyping of β -lactamase producing Salmonella enterica serovars Enteritidis and Typhimurium isolated from livestock and poultry samples

The present study was designed to detect the presence of β-lactamase producing Salmonella enterica Serovars Enteritidis and Typhimurium from faecal (60 cattle rectal, 108 sheep rectal, 163 pig rectal and 186 poultry cloacal swabs) and meat (55 beef, 98 mutton, 120 pork and 126 chicken) samples of different livestock and poultry. The isolates were detected by cultural isolation and further confirmed by PCR. Further these isolates were subjected to phenotypic detection and genotypic confirmation of different β-lactamases by PST and PCR, respectively. Out of 916 samples analysed, 18 Enteritidis and 14 Typhimurium were isolated, out of which β-lactamase producing S. Enteritidis and S. Typhimurium were detected in 14 (10 poultry cloacal, 2 chicken, 1 pork and 1 pig rectal) and 12 (10 chicken, 1 pork and 1 mutton) samples, respectively. Of 14 β-lactamase positive S. Enteritidis, 7 showed presence of TEM, 3 OXA, 2 SHV, one each for CTXM-1 and CTXM-9. Out of 12 β-lactamase positive S. Typhimurium, 8 showed presence of TEM, 2 for CTXM-9 and one each for OXA and CTXM-2. Genotyping of these Salmonella isolates by ERIC & REP-PCR has differentiated all the isolates.