Temporal Fluctuation of Multidrug Resistant Salmonella Typhi Haplotypes in the Mekong River Delta Region of Vietnam


Holt, KE; Dolecek, C; Chau, TT; Pham, TD; Tran, TPL; Nguyen, VMH; Tran, VTN; Campbell, JI; Bui, HM; Nguyen, VVC; Tran, TH; Farrar, J; Dougan, G; Baker, S; (2011) Temporal Fluctuation of Multidrug Resistant Salmonella Typhi Haplotypes in the Mekong River Delta Region of Vietnam. PLoS neglected tropical diseases, 5 (1). ISSN 1935-2727 DOI: https://doi.org/10.1371/journal.pntd.0000929

[img]
Preview
Text - Published Version
License:

Download (2MB) | Preview

Abstract

Background: Typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi), which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina) assay to type 1,500 single nucleotide polymorphisms (SNPs) and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005. Principal Findings: The population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Song Hau branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene. Significance: The H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2) observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam.

Item Type: Article
Keywords: ENTERICA SEROVAR TYPHI, CLINICAL-RESPONSE, SEROTYPE TYPHI, RISK-FACTORS, DNA PROBES, FEVER, PLASMIDS, NAM, SUSCEPTIBILITY, OUTBREAKS
Faculty and Department: Faculty of Infectious and Tropical Diseases > Dept of Pathogen Molecular Biology
PubMed ID: 21245916
Web of Science ID: 286596000007
URI: http://researchonline.lshtm.ac.uk/id/eprint/1311

Statistics


Download activity - last 12 months
Downloads since deposit
893Downloads
345Hits
Accesses by country - last 12 months
Accesses by referrer - last 12 months
Impact and interest
Additional statistics for this record are available via IRStats2

Actions (login required)

Edit Item Edit Item