Molecular epidemiology, virulence gene profile and antibiogram of Listeria monocytogenes from foods of animal origin and ovines in Kashmir, India

The present investigation describes the prevalence, virulence gene profile, molecular epidemiology and antibiogram of Listeria monocytogenes (L. monocytogenes) from mutton (40), chicken (40), raw milk (40), pasteurized milk (40), and clinical cases of ovines (45) from the Kashmir Valley, India. The overall prevalence of L. monocytogenes from all sources was 6.34%, with the highest prevalence observed in ovine clinical cases (13.33%) followed by mutton (7.5%), chicken (5%) and raw milk (5%). Notably, no isolates were recovered from pasteurized milk. PCR targeting virulence genes (hlyA, plcA, plcB, and actA) identified hlyA in 13 (100%) isolates, plcA and actA in 11 (84.62%) isolates each, and plcB in 10 (76.92%) isolates. Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR was used to understand genetic relationships among the isolates. The results revealed that isolates from clinical cases formed a distinct cluster compared to food isolates. The antibiogram of the isolates revealed a high sensitivity to ampicillin (92.31%) and streptomycin (92.31%), while considerable resistance was observed against ceftriaxone (92.31%) and nalidixic acid (84.61%). The recovery of antimicrobial resistant L. monocytogenes from animal-derived foods and ovine clinical cases suggests its ubiquitous nature and potential link between the environment and animal/human infections, posing a significant public health concern.