Development of a Multilocus Sequence Typing (MLST) scheme for Treponema pallidum subsp. pertenue: Application to yaws in Lihir Island, Papua New Guinea.

Charmie Godornes,Sheila A Lukehart,Alyssa E Barry,Oriol Mitja,Lorenzo Giacani,Steven J Norris

doi:10.1371/journal.pntd.0006113

Abstract

BackgroundYaws is a neglected tropical disease, caused by Treponema pallidum subsp. pertenue. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes.Methods and principal findingsPublished genome sequences of strains of T. pallidum subsp. pertenue and pallidum were compared to identify polymorphic genetic loci among the strains. DNA from a number of existing historical Treponema isolates, as well as a subset of samples from yaws patients collected in Lihir Island, Papua New Guinea, were analyzed using these targets. From these data, three genes (tp0548, tp0136 and tp0326) were ultimately selected to give a high discriminating capability among the T. pallidum subsp. pertenue samples tested. Intragenic regions of these three target genes were then selected to enhance the discriminating capability of the typing scheme using short readily amplifiable loci. This 3-gene multilocus sequence typing (MLST) method was applied to existing historical human yaws strains, the Fribourg-Blanc simian isolate, and DNA from 194 lesion swabs from yaws patients on Lihir Island, Papua New Guinea. Among all samples tested, fourteen molecular types were identified, seven of which were found in patient samples and seven among historical isolates or DNA. Three types (JG8, TD6, and SE7) were predominant on Lihir Island.ConclusionsThis MLST approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed.

Highlights

Yaws is a highly contagious treponemal infection caused by the bacterium Treponema pallidum subsp. pertenue (T.p. pertenue)
This multilocus sequence typing (MLST) approach allows molecular typing and differentiation of yaws strains. This method could be a useful tool to complement epidemiological studies in regions where T. pallidum subsp. pertenue is prevalent with the overall goals of improving our understanding of yaws transmission dynamics and helping the yaws eradication campaign to succeed
To assist in investigating the molecular epidemiology of yaws, we propose a new method for differentiating strains of the causative agent, Treponema pallidum subsp. pertenue

Summary

Introduction

Yaws is a highly contagious treponemal infection caused by the bacterium Treponema pallidum subsp. pertenue (T.p. pertenue). Yaws is a highly contagious treponemal infection caused by the bacterium Treponema pallidum subsp. In 2012, the World Health Organization (WHO) proposed a program to eradicate yaws by 2020 [3] using mass drug administration (MDA) with single dose azithromycin. Careful molecular epidemiological studies using typing can assist in understanding the dynamics of disease transmission to improve control of future outbreaks. Yaws is a neglected tropical disease, caused by Treponema pallidum subsp. The disease causes chronic lesions, primarily in young children living in remote villages in tropical climates. As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. Pertenue for disease control and epidemiological purposes As part of a global yaws eradication campaign initiated by the World Health Organization, we sought to develop and evaluate a molecular typing method to distinguish different strains of T. pallidum subsp. pertenue for disease control and epidemiological purposes

Methods

Results

Conclusion