Search

A total of 480 samples, comprising 429 faecal samples from healthy adult birds and 51 tissue samples from dead birds, were collected from four government poultry farms in the Kashmir valley from September 2007 to April 2008. In all, 33 Salmonella isolates were obtained. Of these, 28 (84.85%) isolates were Salmonella Gallinarum, 3 (9.09%) were Salmonella Enteritidis and the remaining 2 (6.06%) were Salmonella Typhimurium. All the isolates harboured the invA, sefA, stn and spvC virulence-specific genes. However, the sopB gene was found in only 90.9% of the isolates. Pulsed-field gel electrophoresis analysis of representative isolates revealed that the majority were related but a few belonged to different clones. The majority of the isolates were resistant to cefpodoxime, nalidixic acid and sulphadiazine and sensitive to chloramphenicol, cefotaxime and tetracycline. Isolation of multidrug-resistant Salmonella, including the zoonotically important serovars, revealed a potential threat not only to poultry but also to human health in Kashmir.

Twenty-four strains of Salmonella enteritidis, isolated from several outbreaks of salmonellosis from different poultry farms in India, were checked for the plasmid profile and detection of virulence gene(s) by PCR. Most of the strains contained only a single plasmid of 55 kb. Additional plasmids of 23.2 kb and 8.7 kb were seen in one of the strains, and another strain carried only two plasmids of 23.2 kb and 8.7 kb. Four strains did not carry any plasmid. PCR amplification showed the presence of virulence-associated genes in all the isolates harbouring the 55 kb plasmid. Intraperitoneal inoculation of mice, with most of the strains carrying the 55 kb plasmid, caused 100% mortality. Most strains lacking the 55 kb plasmid were avirulent. In chickens, oral inoculation of the S. enteritidis strains carrying the 55 kb plasmid produced 40-100% mortality, with characteristic signs of salmonellosis. Oral inoculation of strains lacking the 55 kb plasmid did not cause any mortality. Hence, it appears that the large plasmid of S. enteritidis probably contributes towards virulence in mice and chickens.