Characterisation and distribution of a cryptic Salmonella typhi plasmid pHCM2.
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.
Kidgell
Claire
C
Centre for Molecular Microbiology and Infection, Department of Biological Sciences, Imperial College of Science, Technology and Medicine, London SW7 2AY, UK.
Pickard
Derek
D
Wain
John
J
James
Keith
K
Diem Nga
L T
LT
Diep
To Song
TS
Levine
Myron M
MM
O'Gaora
Peadar
P
Prentice
Michael B
MB
Parkhill
Julian
J
Day
Nicholas
N
Farrar
Jeremy
J
Dougan
Gordon
G
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