Correlation between Ureaplasma subgroup 2 and genitourinary tract disease outcomes revealed by an expanded multilocus sequence typing (eMLST) scheme.

Andrew Mcdowell,Jun Zhang,Jingjuan Song,Yunsong Yu,Yan Jiang,Xinyou Xie,Yingying Kong,Jun Huang,Zhi Ruan,Tiejun Song

doi:10.1371/journal.pone.0104347

Andrew Mcdowell, Jun Zhang + Show 8 more

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https://doi.org/10.1371/journal.pone.0104347

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Journal: PloS one	Publication Date: Aug 5, 2014
Citations: 46	License type: CC BY 4.0

Affiliation: Zhejiang University, Sir Run Run Shaw Hospital

Abstract

The multilocus sequence typing (MLST) scheme of Ureaplasma based on four housekeeping genes (ftsH, rpL22, valS, and thrS) was described in our previous study; here we introduced an expanded MLST (eMLST) scheme with improved discriminatory power, which was developed by adding two putative virulence genes (ureG and mba-np1) to the original MLST scheme. To evaluate the discriminatory power of eMLST, a total of 14 reference strains of Ureaplasma serovars and 269 clinical strains (134 isolated from symptomatic patients and 135 obtained from asymptomatic persons) were investigated. Our study confirmed that all 14 serotype strains could successfully be differentiated into 14 eMLST STs (eSTs), while some of them could not even be differentiated by the MLST, and a total of 136 eSTs were identified among the clinical isolates we investigated. In addition, phylogenetic analysis indicated that two genetically significantly distant clusters (cluster I and II) were revealed and most clinical isolates were located in cluster I. These findings were in accordance with and further support for the concept of two well-known genetic lineages (Ureaplasma parvum and Ureaplasma urealyticum) in our previous study. Interestingly, although both clusters were associated with clinical manifestation, the sub-group 2 of cluster II had pronounced and adverse effect on patients and might be a potential risk factor for clinical outcomes. In conclusion, the eMLST scheme offers investigators a highly discriminative typing tool that is capable for precise epidemiological investigations and clinical relevance of Ureaplasma.

Highlights

Ureaplasma is a member of the class Mollicutes and one of the smallest free-living organisms
multilocus sequence typing (MLST) scheme represents basic clonal assignments based on the variation in several housekeeping genes [15,16,33], whereas virulence genes can be adopted to ‘‘zoom in’’ on clones and differentiate very closed strains
EMLST could provide a higher level of discrimination than MLST, based on the combination of housekeeping genes and virulence genes of this species, and may be more appropriate for studying the epidemiology

Summary

Introduction

Ureaplasma is a member of the class Mollicutes and one of the smallest free-living organisms. It lacks a cell wall, displays limited biosynthetic abilities, requires cholesterol and hydrolyzes urea as a metabolic substrate to generate ATP [1]. Ureaplasma is regarded as a commensal organism in the urogenital tract of sexually active adults and the colonization rate of Ureaplasma has been found between 40 to 80% in female [4]. It is always implicated in many diseases including inflammation, non-gonococcal urethritis, chorioamnionitis, adverse pregnancy outcomes, infertility, bronchopulmonary dysplasia in neonates, etc. It is always implicated in many diseases including inflammation, non-gonococcal urethritis, chorioamnionitis, adverse pregnancy outcomes, infertility, bronchopulmonary dysplasia in neonates, etc. [5,6,7,8,9,10]

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