Hypervirulent Chlamydia trachomatis clinical strain is a recombinant between lymphogranuloma venereum (L(2)) and D lineages

Authors

Naraporn Somboonna, Children’s Hospital Oakland
Raymond Wan, Children’s Hospital Oakland
David M. Ojcius, University of California, MercedFollow
Matthew A. Pettengill, University of California, Merced
Sandeep J. Joseph, Emory University
Alexander Chang, Emory University
Ray Hsu, Children's Hospital Oakland
Timothy D. Read, Emory University
Deborah Dean, Emory University

ORCiD

David M. Ojcius: 0000-0003-1461-4495

Department

Biomedical Sciences

Document Type

Article

Publication Title

mBio

ISSN

2150-7511

Volume

2

Issue

3

DOI

10.1128/mBio.00045-11

First Page

e00045

Last Page

11

Publication Date

5-3-2011

Abstract

Chlamydia trachomatis is an obligate intracellular bacterium that causes a diversity of severe and debilitating diseases worldwide. Sporadic and ongoing outbreaks of lymphogranuloma venereum (LGV) strains among men who have sex with men (MSM) support the need for research on virulence factors associated with these organisms. Previous analyses have been limited to single genes or genomes of laboratory-adapted reference strain L₂/434 and outbreak strain L₂b/UCH-1/proctitis. We characterized an unusual LGV strain, termed L₂c, isolated from an MSM with severe hemorrhagic proctitis. L₂c developed nonfusing, grape-like inclusions and a cytotoxic phenotype in culture, unlike the LGV strains described to date. Deep genome sequencing revealed that L₂c was a recombinant of L₂ and D strains with conserved clustered regions of genetic exchange, including a 78-kb region and a partial, yet functional, toxin gene that was lost with prolonged culture. Indels (insertions/deletions) were discovered in an ftsK gene promoter and in the tarp and hctB genes, which encode key proteins involved in replication, inclusion formation, and histone H1-like protein activity, respectively. Analyses suggest that these indels affect gene and/or protein function, supporting the in vitro and disease phenotypes. While recombination has been known to occur for C. trachomatis based on gene sequence analyses, we provide the first whole-genome evidence for recombination between a virulent, invasive LGV strain and a noninvasive common urogenital strain. Given the lack of a genetic system for producing stable C. trachomatis mutants, identifying naturally occurring recombinants can clarify gene function and provide opportunities for discovering avenues for genomic manipulation.

Recommended Citation

Somboonna, N., Wan, R., Ojcius, D. M., Pettengill, M. A., Joseph, S. J., Chang, A., Hsu, R., Read, T. D., & Dean, D. (2011). Hypervirulent Chlamydia trachomatis clinical strain is a recombinant between lymphogranuloma venereum (L(2)) and D lineages. mBio, 2(3), e00045–11. DOI: 10.1128/mBio.00045-11
https://scholarlycommons.pacific.edu/dugoni-facarticles/45