Extended Spectrum and AmpC Beta-lactamase Producing Salmonella Rough Strains Associated with Gastroenteritis in Piglets of Meghalaya (India)

Abstract

Aim: An investigative study for gastroenteritis in unorganised private pig farms of Meghalaya, a North East State of India. Materials and Methods: Faecal samples were collected from 32 pigs including severely diarrhoeic piglets and were processed for detection of Escherichia coli, Salmonella, Clostridium spp., Rotavirus, as well as parasitic eggs and larvae. The isolates were screen by polymerase chain reaction (PCR) for rotavirus and the presence of virulence associated genes of E. coli and Salmonella. An antibiotic sensitivity test was performed on isolated Salmonella and screened for the presence of drug resistance beta-lactamase genes. Results: A total of 40 E. coli were isolated, all of which were found to be negative for any putative virulence genes of shigatoxigenic E. coli, enterotoxigenic E. coli, enterohaemorrhagic E. coli and enteropathogenic E. coli pathotypes. From severely diarrhoeic piglets, four salmonellae were isolated, which were recorded as Salmonella Rough strains. All the 4 isolates detected positivity for ESBL (blaTEM) and ampC β-lactamase (blaCMY-2) genes. However, no samples were found to be positive for viral and parasitic pathogens. Antibiotic susceptibility test revealed the Salmonella strains were resistant to commonly used drugs, such as enrofloxacin, cefalexin, tetracycline, amoxycillin, ampicillin and aztreonam. RAPD-PCR revealed the homogeneity of the strains associated with Salmonella infection in the area. Conclusion: The study indicated the involvement of Salmonella Rough strains with piglet diarrhoea in unorganised farms of Meghalaya. Detection of Salmonella possessing antibiotic resistance genes in food animal warranty immediate attention to hygienic practices and regulated use of antibiotics.