Identification of Salmonella enterica serovar typhi genotypes by use of rapid multiplex ligation-dependent probe amplification

Duy Pham Thanh, Nga Tran Vu Thieu, Chau Tran Thuy, Martin Lodén, Kiki Tuin, James I. Campbell, Nguyen Van Minh Hoang, Phat Voong Vinh, Jeremy Farrar, Kathryn E Holt, Gordon Dougan, Stephen Baker

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9 Citations (Scopus)

Abstract

Salmonella enterica serovar Typhi, the causative agent of typhoid fever, is highly clonal and genetically conserved, making isolate subtyping difficult. We describe a standardized multiplex ligation-dependent probe amplification (MLPA) genotyping scheme targeting 11 key phylogenetic markers of the S. Typhi genome. The MLPA method demonstrated 90% concordance with single nucleotide polymorphism (SNP) typing, the gold standard for S. Typhi genotyping, and had the ability to identify isolates of the H58 haplotype, which is associated with resistance to multiple antimicrobials. Additionally, the assay permitted the detection of fluoroquinolone resistance-associated mutations in the DNA gyrase-encoding gene gyrA and the topoisomerase gene parC with a sensitivity of 100%. The MLPA methodology is simple and reliable, providing phylogenetically and phenotypically relevant genotyping information. This MLPA scheme offers a more-sensitive and interpretable alternative to the nonphylogenetic subgrouping methodologies that are currently used in reference and research laboratories in areas where typhoid is endemic.

Original languageEnglish
Pages (from-to)2950-2958
Number of pages9
JournalJournal of Clinical Microbiology
Volume51
Issue number9
DOIs
Publication statusPublished - Sep 2013

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