title: Characterisation and distribution of a cryptic Salmonella typhi plasmid pHCM2.
abstract: 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.
authors.affiliation: Centre for Molecular Microbiology and Infection, Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Kidgell
authors.forename: Derek
authors.initials: D
authors.lastname: Pickard
authors.forename: John
authors.initials: J
authors.lastname: Wain
authors.forename: Keith
authors.initials: K
authors.lastname: James
authors.forename: L T
authors.initials: LT
authors.lastname: Diem Nga
authors.forename: To Song
authors.initials: TS
authors.lastname: Diep
authors.forename: Myron M
authors.initials: MM
authors.lastname: Levine
authors.forename: Peadar
authors.initials: P
authors.lastname: O'Gaora
authors.forename: Michael B
authors.initials: MB
authors.lastname: Prentice
authors.forename: Julian
authors.initials: J
authors.lastname: Parkhill
authors.forename: Nicholas
authors.initials: N
authors.lastname: Day
authors.forename: Jeremy
authors.initials: J
authors.lastname: Farrar
authors.forename: Gordon
authors.initials: G
authors.lastname: Dougan
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D019295:Computational Biology; D004261:DNA Replication; D019143:Evolution, Molecular; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D012485:Salmonella typhi / Q000235:genetics*; D014435:Typhoid Fever / Q000382:microbiology; D014744:Vietnam