Chlamydia trachomatis ompA variants in trachoma: what do they tell us?
BACKGROUND:Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious cause of blindness. Sequence-based analysis of the multiple strains typically present in endemic communities may be informative for epidemiology, transmission, response to treatment, and understanding the host respo...
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ftdoajarticles:oai:doaj.org/article:d4feb748dc0847b2bd0ad58eb4c4208c 2023-05-15T15:13:53+02:00 Chlamydia trachomatis ompA variants in trachoma: what do they tell us? Aura A Andreasen Matthew J Burton Martin J Holland Spencer Polley Nkoyo Faal David C W Mabey Robin L Bailey 2008-09-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0000306 https://doaj.org/article/d4feb748dc0847b2bd0ad58eb4c4208c EN eng Public Library of Science (PLoS) http://europepmc.org/articles/PMC2553491?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0000306 https://doaj.org/article/d4feb748dc0847b2bd0ad58eb4c4208c PLoS Neglected Tropical Diseases, Vol 2, Iss 9, p e306 (2008) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2008 ftdoajarticles https://doi.org/10.1371/journal.pntd.0000306 2022-12-31T03:59:37Z BACKGROUND:Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious cause of blindness. Sequence-based analysis of the multiple strains typically present in endemic communities may be informative for epidemiology, transmission, response to treatment, and understanding the host response. METHODS:Conjunctival and nasal samples from a Gambian community were evaluated before and 2 months after mass azithromycin treatment. Samples were tested for Ct by Amplicor, with infection load determined by quantitative PCR (qPCR). ompA sequences were determined and their diversity analysed using frequency-based tests of neutrality. RESULTS:Ninety-five of 1,319 (7.2%) individuals from 14 villages were infected with Ct at baseline. Two genovars (A and B) and 10 distinct ompA genotypes were detected. Two genovar A variants (A1 and A2) accounted for most infections. There was an excess of rare ompA mutations, not sustained in the population. Post-treatment, 76 (5.7%) individuals had Ct infection with only three ompA genotypes present. In 12 of 14 villages, infection had cleared, while in two it increased, probably due to mass migration. Infection qPCR loads associated with infection were significantly greater for A1 than for A2. Seven individuals had concurrent ocular and nasal infection, with divergent genotypes in five. CONCLUSIONS:The number of strains was substantially reduced after mass treatment. One common strain was associated with higher infection loads. Discordant genotypes in concurrent infection may indicate distinct infections at ocular and nasal sites. Population genetic analysis suggests the fleeting appearance of rare multiple ompA variants represents purifying selection rather than escape variants from immune pressure. Genotyping systems accessing extra-ompA variation may be more informative. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLoS Neglected Tropical Diseases 2 9 e306 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
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English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Aura A Andreasen Matthew J Burton Martin J Holland Spencer Polley Nkoyo Faal David C W Mabey Robin L Bailey Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
BACKGROUND:Trachoma, caused by Chlamydia trachomatis (Ct), is the leading infectious cause of blindness. Sequence-based analysis of the multiple strains typically present in endemic communities may be informative for epidemiology, transmission, response to treatment, and understanding the host response. METHODS:Conjunctival and nasal samples from a Gambian community were evaluated before and 2 months after mass azithromycin treatment. Samples were tested for Ct by Amplicor, with infection load determined by quantitative PCR (qPCR). ompA sequences were determined and their diversity analysed using frequency-based tests of neutrality. RESULTS:Ninety-five of 1,319 (7.2%) individuals from 14 villages were infected with Ct at baseline. Two genovars (A and B) and 10 distinct ompA genotypes were detected. Two genovar A variants (A1 and A2) accounted for most infections. There was an excess of rare ompA mutations, not sustained in the population. Post-treatment, 76 (5.7%) individuals had Ct infection with only three ompA genotypes present. In 12 of 14 villages, infection had cleared, while in two it increased, probably due to mass migration. Infection qPCR loads associated with infection were significantly greater for A1 than for A2. Seven individuals had concurrent ocular and nasal infection, with divergent genotypes in five. CONCLUSIONS:The number of strains was substantially reduced after mass treatment. One common strain was associated with higher infection loads. Discordant genotypes in concurrent infection may indicate distinct infections at ocular and nasal sites. Population genetic analysis suggests the fleeting appearance of rare multiple ompA variants represents purifying selection rather than escape variants from immune pressure. Genotyping systems accessing extra-ompA variation may be more informative. |
format |
Article in Journal/Newspaper |
author |
Aura A Andreasen Matthew J Burton Martin J Holland Spencer Polley Nkoyo Faal David C W Mabey Robin L Bailey |
author_facet |
Aura A Andreasen Matthew J Burton Martin J Holland Spencer Polley Nkoyo Faal David C W Mabey Robin L Bailey |
author_sort |
Aura A Andreasen |
title |
Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
title_short |
Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
title_full |
Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
title_fullStr |
Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
title_full_unstemmed |
Chlamydia trachomatis ompA variants in trachoma: what do they tell us? |
title_sort |
chlamydia trachomatis ompa variants in trachoma: what do they tell us? |
publisher |
Public Library of Science (PLoS) |
publishDate |
2008 |
url |
https://doi.org/10.1371/journal.pntd.0000306 https://doaj.org/article/d4feb748dc0847b2bd0ad58eb4c4208c |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 2, Iss 9, p e306 (2008) |
op_relation |
http://europepmc.org/articles/PMC2553491?pdf=render https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0000306 https://doaj.org/article/d4feb748dc0847b2bd0ad58eb4c4208c |
op_doi |
https://doi.org/10.1371/journal.pntd.0000306 |
container_title |
PLoS Neglected Tropical Diseases |
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2 |
container_issue |
9 |
container_start_page |
e306 |
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1766344394998284288 |