• Saraj Uddin Sajid
  • Stefan Schwarz


Background: Salmonella enterica serovar Enteritidis is an important frequently reported zoonoticpathogen and a common cause of human gastroenteritis worldwide. The highly conserved Serospecific plasmids (SSPs) and Salmonella plasmid virulence (Spv) genes have been shown tomediate extra-intestinal colonization and systemic infection. The objective of current study was todocument the presence of SSPs and SpvB/SpvC genes prevailing in the indigenous population ofserovar Enteritidis. Methods: A total of 48 epidemiologically unrelated strains of Salmonellaenteritidis were included in the study. Preparation of plasmids DNA suitable for endonucleasedigestion and separation of respective fragments by agarose gel electrophoresis followedpreviously described protocols. The plasmids of Escherichia coli V517, 1-kbp ladder, and λ DNAHindIII fragments served as DNA size standards. Transfer of DNA fragments from agarose gels tonitrocellulose membranes was achieved by capillary blot procedure. An ECL labeled 3.6 kbpHindIII fragment of plasmid PRQ 51 was used as probe for SpvB/SpvC gene detection. Results:Plasmid DNA fingerprinting revealed the presence of two different profiles of approximately 55kbp and 90 kbp and were identified as virulence plasmids by DNA hybridization. The SpvB/SpvCgenes were located on HindIII fragments of 3.6 kbp in each of the two types of virulence plasmids.Conclusion: The study confirms the presence of SSPs and SpvB/SpvC genes in indigenous strainsof S. enteritidis isolated from Northern Punjab area of Pakistan and substantiate the previous dataon such findings from other parts of the world.Keywords: Salmonella enteritidis; virulence plasmids, SpvB/SpvC genes


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