Identification and molecular analysis of Salmonella plasmid virulence genes (spv) on antibiotic resistance plasmid pR_(ST98) from S.typhi / 中华检验医学杂志

ABSTRACT

Objective To identify and analyze the plasmid (pR_ ST98 ) encoding multi-resistance to anti-microbial agents in S.typhi presenting the Salmonella plasmid virulence gene (spv).Methods Plasmid pR_ ST98 ,which could mediate virulence to its host bacteria, was used as the templete. The spv-specific PCR and Southern blot were employed to identify the spv virulence gene on this plasmid. The amplified spv fragments (spvR and spvB) were cloned into pGEM-T EASY.Then the DNA sequences were analysed. Results The date of PCR and Southern blot showed that spv,which had been found in other pathogenetic Salmonella spp. except S. typhi was also presented on pR_ ST98 . The ORF of spvR and spvB of pR_ ST98 were 894bp and 1 776bp respectively. They had more than 99% homologus with that of spvR and spvB on virulence plasmid in S.typhmurium.Conclusion From the results of PCR,Southern blot and nuclei acid sequencing, we concluded that this is the first report of revealing a mosaic-like plasmid carrying genes encoding not only drug resistance but also virulence in S.typhi.