Characterisation and distribution of a cryptic Salmonella typhi plasmid pHCM2

Claire Kidgell, Derek Pickard, John Wain, Keith James, L. T. Diem Nga, To Song Diep, Myron M. Levine, Peadar O'Gaora, Michael B. Prentice, Julian Parkhill, Nicholas Day, Jeremy Farrar, Gordon Dougan

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31 Citations (Scopus)


pHCM2 is a 106 kbp cryptic plasmid harboured by Salmonella typhi CT18, originally isolated from a typhoid patient in Vietnam. The genome of S. typhi CT18, including pHCM2, has recently been completely sequenced and annotated. Bioinformatic analysis revealed that 57% of the coding sequences (CDSs) encoded on pHCM2 display over 97% DNA sequence identity to the virulence-associated plasmid of Yersinia pestis, pFra. pHCM2 encodes no obvious virulence-associated determinants or antibiotic resistance genes but does encode a wide array of putative genes directly related to DNA metabolism and replication. PCR analysis of a series of S. typhi isolates from Vietnam detected pHCM2-related DNA sequences in some S. typhi isolated before, but not after, 1994. Similar pHCM2-related sequences were also detected in S. typhi isolated from other regions of South East Asia and Pakistan but not elsewhere in the world.
Original languageEnglish
Pages (from-to)159-171
Number of pages13
Issue number3
Publication statusPublished - May 2002

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