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Emergence of a Globally Dominant IncHI1 Plasmid Type Associated with Multiple Drug Resistant Typhoid.

Authors :
Holt, Kathryn E.
Phan, Minh Duy
Baker, Stephen
Duy, Pham Thanh
Nga, Tran Vu Thieu
Nair, Satheesh
Keith Turner, A.
Walsh, Ciara
Fanning, Séamus
Farrell-Ward, Sinéad
Dutta, Shanta
Kariuki, Sam
Weill, François-Xavier
Parkhill, Julian
Dougan, Gordon
Wain, John
Source :
PLoS Neglected Tropical Diseases. Jul2011, Vol. 5 Issue 7, p1-13. 13p. 3 Diagrams, 5 Charts, 3 Graphs.
Publication Year :
2011

Abstract

Typhoid fever, caused by Salmonella enterica serovar Typhi (S. Typhi), remains a serious global health concern. Since their emergence in the mid-1970s multi-drug resistant (MDR) S. Typhi now dominate drug sensitive equivalents in many regions. MDR in S. Typhi is almost exclusively conferred by self-transmissible IncHI1 plasmids carrying a suite of antimicrobial resistance genes. We identified over 300 single nucleotide polymorphisms (SNPs) within conserved regions of the IncHI1 plasmid, and genotyped both plasmid and chromosomal SNPs in over 450 S. Typhi dating back to 1958. Prior to 1995, a variety of IncHI1 plasmid types were detected in distinct S. Typhi haplotypes. Highly similar plasmids were detected in cocirculating S. Typhi haplotypes, indicative of plasmid transfer. In contrast, from 1995 onwards, 98% of MDR S. Typhi were plasmid sequence type 6 (PST6) and S. Typhi haplotype H58, indicating recent global spread of a dominant MDR clone. To investigate whether PST6 conferred a selective advantage compared to other IncHI1 plasmids, we used a phenotyping array to compare the impact of IncHI1 PST6 and PST1 plasmids in a common S. Typhi host. The PST6 plasmid conferred the ability to grow in high salt medium (4.7% NaCl), which we demonstrate is due to the presence in PST6 of the Tn6062 transposon encoding BetU. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
19352727
Volume :
5
Issue :
7
Database :
Academic Search Index
Journal :
PLoS Neglected Tropical Diseases
Publication Type :
Academic Journal
Accession number :
77067244
Full Text :
https://doi.org/10.1371/journal.pntd.0001245