Multi-locus variable number tandem repeat analysis of 7th pandemic Vibrio cholerae

Connie Lam,Ruiting Lan,Peter R Reeves,Sophie Octavia

doi:10.1186/1471-2180-12-82

Connie Lam, Ruiting Lan + Show 2 more

Open Access

https://doi.org/10.1186/1471-2180-12-82

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Journal: BMC microbiology	Publication Date: May 24, 2012
Citations: 57	License type: cc-by

Affiliation: UNSW Sydney, University of Sydney

Abstract

BackgroundSeven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent. Cholera remains endemic in developing countries and is still a significant public health issue. In this study we use multilocus variable number of tandem repeats (VNTRs) analysis (MLVA) to discriminate between isolates of the 7th pandemic clone of Vibrio cholerae.ResultsMLVA of six VNTRs selected from previously published data distinguished 66 V. cholerae isolates collected between 1961–1999 into 60 unique MLVA profiles. Only 4 MLVA profiles consisted of more than 2 isolates. The discriminatory power was 0.995. Phylogenetic analysis showed that, except for the closely related profiles, the relationships derived from MLVA profiles were in conflict with that inferred from Single Nucleotide Polymorphism (SNP) typing. The six SNP groups share consensus VNTR patterns and two SNP groups contained isolates which differed by only one VNTR locus.ConclusionsMLVA is highly discriminatory in differentiating 7th pandemic V. cholerae isolates and MLVA data was most useful in resolving the genetic relationships among isolates within groups previously defined by SNPs. Thus MLVA is best used in conjunction with SNP typing in order to best determine the evolutionary relationships among the 7th pandemic V. cholerae isolates and for longer term epidemiological typing.

Highlights

Seven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent
MLVA is highly discriminatory in differentiating 7th pandemic V. cholerae isolates and MLVA data was most useful in resolving the genetic relationships among isolates within groups previously defined by Single Nucleotide Polymorphism (SNP)
MLVA is best used in conjunction with SNP typing in order to best determine the evolutionary relationships among the 7th pandemic V. cholerae isolates and for longer term epidemiological typing

Summary

Introduction

Seven pandemics of cholera have been recorded since 1817, with the current and ongoing pandemic affecting almost every continent. Cholera remains endemic in developing countries and is still a significant public health issue. In this study we use multilocus variable number of tandem repeats (VNTRs) analysis (MLVA) to discriminate between isolates of the 7th pandemic clone of Vibrio cholerae. Diarrhoeal diseases have been and continue to be a cause of mortality and morbidity, especially in developing countries. Only the O1 and O139 serogroups have been known to cause pandemic and epidemic level disease [2]. Since 1817, seven pandemics of cholera have been recorded [3]. The ongoing epidemic started in 1961 and has affected almost every continent, countries of Southeast Asia, Africa, and South America

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