Journal article
In vitro rescue of genital strains of Chlamydia trachomatis from interferon-y and tryptophan depletion with indole-positive, but not indole-negative Prevotella spp.
BMC Microbiology, Vol.16, 286
2016
Abstract
Background: The natural course of sexually transmitted infections caused by Chlamydia trachomatis varies between individuals. In addition to parasite and host effects, the vaginal microbiota might play a key role in the outcome of C. trachomatis infections. Interferon-gamma (IFN-γ), known for its anti-chlamydial properties, activates the expression of indoleamine 2,3-dioxygenase (IDO1) in epithelial cells, an enzyme that catabolizes the amino acid L- tryptophan into N-formylkynurenine, depleting the host cell's pool of tryptophan. Although C. trachomatis is a tryptophan auxotroph, urogenital strains (but not ocular strains) have been shown in vitro to have the ability to produce tryptophan from indole using the tryptophan synthase (trpBA) gene. It has been suggested that indole producing bacteria from the vaginal microbiota could influence the outcome of Chlamydia infection. Results: We used two in vitro models (treatment with IFN-γ or direct limitation of tryptophan), to study the effects of direct rescue by the addition of exogenous indole, or by the addition of culture supernatant from indole-positive versus indole-negative Prevotella strains, on the growth and infectivity of C. trachomatis. We found that only supernatants from the indole-positive strains, P. intermedia and P. nigrescens, were able to rescue tryptophan-starved C. trachomatis. In addition, we analyzed vaginal secretion samples to determine physiological indole concentrations. In spite of the complexity of vaginal secretions, we demonstrated that for some vaginal specimens with higher indole levels, there was a link to higher recovery of the Chlamydia under tryptophan-starved conditions, lending preliminary support to the critical role of the IFN-γ-tryptophan-indole axis in vivo. Conclusions: Our data provide evidence for the ability of both exogenous indole as well as supernatant from indole producing bacteria such as Prevotella, to rescue genital C. trachomatis from tryptophan starvation. This adds weight to the hypothesis that the vaginal microbiota (particularly from women with lower levels of lactobacilli and higher levels of indole producing anaerobes) may be intrinsically linked to the outcome of chlamydial infections in some women.
Details
- Title
- In vitro rescue of genital strains of Chlamydia trachomatis from interferon-y and tryptophan depletion with indole-positive, but not indole-negative Prevotella spp.
- Authors
- Noa Ziklo (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and EngineeringWilhelmina M Huston (Author) - University of Technology SydneyKuong Taing (Author) - Sexual Health and HIV ServiceMohammad Katouli (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and EngineeringPeter Timms (Author) - University of the Sunshine Coast - Faculty of Science, Health, Education and Engineering
- Publication details
- BMC Microbiology, Vol.16, 286; 10
- Publisher
- BioMed Central Ltd.
- Date published
- 2016
- DOI
- 10.1186/s12866-016-0903-4
- ISSN
- 1471-2180; 1471-2180
- Copyright note
- Copyright © The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Organisation Unit
- School of Science and Engineering - Legacy; University of the Sunshine Coast, Queensland; School of Health and Sport Sciences - Legacy; School of Science, Technology and Engineering; Centre for Bioinnovation
- Language
- English
- Record Identifier
- 99451030602621
- Output Type
- Journal article
- Research Statement
- false
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