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Zhou Q, Li J, Luo L, Min S, Wang L, Peng L, Hou Y, He P, He S, Tang S, Chen H. Characterization of genital chlamydia trachomatis infection among women attending infertility and gynecology clinics in Hunan, China. BMC Infect Dis 2024; 24:405. [PMID: 38622501 PMCID: PMC11020174 DOI: 10.1186/s12879-024-09254-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 03/25/2024] [Indexed: 04/17/2024] Open
Abstract
BACKGROUND Genital infection with Chlamydia trachomatis (C. trachomatis) is a major public health issue worldwide. It can lead to cervicitis, urethritis, and infertility. This study was conducted to determine the characteristics of genital C. trachomatis infection among women attending to the infertility and gynecology clinics. METHODS Endocervical swabs were collected from 8,221 women for C. trachomatis nucleotide screening and genotyping, while serum samples were collected for C. trachomatis pgp3 antibody determination using luciferase immunosorbent assays. RESULTS High C. trachomatis DNA prevalence (3.76%) and seroprevalence (47.46%) rates were found, with genotype E (27.5%) being the most prevalent. C. trachomatis omp1 sense mutation was associated with cervical intraepithelial neoplasia (CIN) (odds ratio [OR] = 6.033, 95% confidence interval [CI] = 1.219-39.185, p = 0.045). No significant differences in C. trachomatis seroprevalence rates were observed between women with detectable C. trachomatis DNA in the infertility and routine physical examination groups (86.67% vs. 95%, p > 0.05); however, among women with negative C. trachomatis DNA, the former group had a markedly higher seroprevalence than the latter group (56.74% vs. 20.17%, p < 0.001). C. trachomatis DNA, but not pgp3 antibody, was significantly associated with CIN (OR = 4.087, 95% CI = 2.284-7.315, p < 0.001). CONCLUSION Our results revealed a high prevalence, particularly seroprevalence, of C. trachomatis among women with infertility. Furthermore, we found an association between C. trachomatis omp1 sense mutations and CIN. Therefore, C. trachomatis serves as a risk factor for CIN.
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Affiliation(s)
- Qianting Zhou
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Jiayan Li
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Lipei Luo
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
- Clinical Laboratory, Shenzhen Qianhai Shekou Free Trade Zone Hospital, Shenzhen, China
| | - Shuling Min
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Li Wang
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Lixiu Peng
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Yinglan Hou
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Ping He
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China
| | - Song He
- Clinical Laboratory, Shenzhen Qianhai Shekou Free Trade Zone Hospital, Shenzhen, China
| | - Shixing Tang
- Department of Epidemiology, School of Public Health, Southern Medical University, Guangzhou, China.
| | - Hongliang Chen
- Hengyang Medical School, The Affiliated Chenzhou Hospital, Chenzhou No. 1 People's Hospital, University of South China, Chenzhou, China.
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Benamri I, Azzouzi M, Sanak K, Moussa A, Radouani F. An overview of genes and mutations associated with Chlamydiae species' resistance to antibiotics. Ann Clin Microbiol Antimicrob 2021; 20:59. [PMID: 34479551 PMCID: PMC8414684 DOI: 10.1186/s12941-021-00465-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 08/23/2021] [Indexed: 12/25/2022] Open
Abstract
Background Chlamydiae are intracellular bacteria that cause various severe diseases in humans and animals. The common treatment for chlamydia infections are antibiotics. However, when antibiotics are misused (overuse or self-medication), this may lead to resistance of a number of chlamydia species, causing a real public health problem worldwide. Materials and methods In the present work, a comprehensive literature search was conducted in the following databases: PubMed, Google Scholar, Cochrane Library, Science direct and Web of Science. The primary purpose is to analyse a set of data describing the genes and mutations involved in Chlamydiae resistance to antibiotic mechanisms. In addition, we proceeded to a filtration process among 704 retrieved articles, then finished by focusing on 24 studies to extract data that met our requirements. Results The present study revealed that Chlamydia trachomatis may develop resistance to macrolides via mutations in the 23S rRNA, rplD, rplV genes, to rifamycins via mutations in the rpoB gene, to fluoroquinolones via mutations in the gyrA, parC and ygeD genes, to tetracyclines via mutations in the rpoB gene, to fosfomycin via mutations in the murA gene, to MDQA via mutations in the secY gene. Whereas, Chlamydia pneumoniae may develop resistance to rifamycins via mutations in the rpoB gene, to fluoroquinolones via mutations in the gyrA gene. Furthermore, the extracted data revealed that Chlamydia psittaci may develop resistance to aminoglycosides via mutations in the 16S rRNA and rpoB genes, to macrolides via mutations in the 23S rRNA gene. Moreover, Chlamydia suis can become resistance to tetracyclines via mutations in the tet(C) gene. In addition, Chlamydia caviae may develop resistance to macrolides via variations in the 23S rRNA gene. The associated mechanisms of resistance are generally: the inhibition of bacteria’s protein synthesis, the inhibition of bacterial enzymes’ action and the inhibition of bacterial transcription process. Conclusion This literature review revealed the existence of diverse mutations associated with resistance to antibiotics using molecular tools and targeting chlamydia species’ genes. Furthermore, these mutations were shown to be associated with different mechanisms that led to resistance. In that regards, more mutations and information can be shown by a deep investigation using the whole genome sequencing. Certainly, this can help improving to handle chlamydia infections and healthcare improvement by decreasing diseases complications and medical costs. Supplementary Information The online version contains supplementary material available at 10.1186/s12941-021-00465-4.
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Affiliation(s)
- Ichrak Benamri
- Chlamydiae and Mycoplasma Laboratory, Institut Pasteur du Maroc, 20360, Casablanca, Morocco.,Systems & Data Engineering Team, National School of Applied Sciences, Abdelmalek Essaadi University, Tangier, Morocco
| | - Maryame Azzouzi
- Chlamydiae and Mycoplasma Laboratory, Institut Pasteur du Maroc, 20360, Casablanca, Morocco.,Laboratory of Microbiology, Pharmacology, Biotechnology and Environment, Faculty of Sciences Aîn-Chock, Hassan II University, Casablanca, Morocco
| | - Kholoud Sanak
- Chlamydiae and Mycoplasma Laboratory, Institut Pasteur du Maroc, 20360, Casablanca, Morocco.,IRDA Team, ENSIAS Mohammed V University, Rabat, Morocco
| | - Ahmed Moussa
- Systems & Data Engineering Team, National School of Applied Sciences, Abdelmalek Essaadi University, Tangier, Morocco
| | - Fouzia Radouani
- Chlamydiae and Mycoplasma Laboratory, Institut Pasteur du Maroc, 20360, Casablanca, Morocco.
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Ghasemian E, Inic-Kanada A, Collingro A, Mejdoubi L, Alchalabi H, Keše D, Elshafie BE, Hammou J, Barisani-Asenbauer T. Comparison of genovars and Chlamydia trachomatis infection loads in ocular samples from children in two distinct cohorts in Sudan and Morocco. PLoS Negl Trop Dis 2021; 15:e0009655. [PMID: 34370735 PMCID: PMC8376198 DOI: 10.1371/journal.pntd.0009655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 08/19/2021] [Accepted: 07/16/2021] [Indexed: 11/30/2022] Open
Abstract
Trachoma is a blinding disease caused by repeated conjunctival infection with different Chlamydia trachomatis (Ct) genovars. Ct B genovars have been associated with more severe trachoma symptoms. Here, we investigated associations between Ct genovars and bacterial loads in ocular samples from two distinct geographical locations in Africa, which are currently unclear. We tested ocular swabs from 77 Moroccan children (28 with trachomatous inflammation-follicular (TF) and 49 healthy controls), and 96 Sudanese children (54 with TF and 42 healthy controls) with a Ct-specific real-time polymerase chain reaction (PCR) assay. To estimate bacterial loads, Ct-positive samples were further processed by multiplex real-time qPCR to amplify the chromosomal outer membrane complex B and plasmid open reading frame 2 of Ct. Genotyping was performed by PCR-based amplification of the outer membrane protein A gene (~1120 base pairs) of Ct and Sanger sequencing. Ct-positivities among the Moroccan and Sudanese patient groups were 60·7% and 31·5%, respectively. Significantly more Sudanese patients than Moroccan patients were genovar A-positive. In contrast, B genovars were significantly more prevalent in Moroccan patients than in Sudanese patients. Significantly higher Ct loads were found in samples positive for B genovars (598596) than A genovar (51005). Geographical differences contributed to the distributions of different ocular Ct genovars. B genovars may induce a higher bacterial load than A genovars in trachoma patients. Our findings emphasize the importance of conducting broader studies to elucidate if the noted difference in multiplication abilities are genovar and/or endemicity level dependent. We investigated the association between different Ct genovars, the approximate load of infection, and the distribution of Chlamydia genovars by comparing samples from one trachoma-endemic area (i.e., the city of El-Gadaref in Al Qadarif, Sudan) and one previously endemic area (i.e., the Zagora Province in Morocco), currently considered as non-endemic. This study is the first to reveal a significant difference between the genome copy numbers of Ct genovar A and B/Ba in children with TF. Evidence that Ct is still circulating in rural foci of countries like Morocco that are no longer considered endemic implies that the continuation of the trachoma surveillance must be warranted in future to avoid further spreading of Ct. The clinical significance of different infectious loads in the development of sequelae has to be determined as well as whether these differences are genovar specific or related to the given endemicity level.
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Affiliation(s)
- Ehsan Ghasemian
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Aleksandra Inic-Kanada
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Astrid Collingro
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Lamiss Mejdoubi
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Hadeel Alchalabi
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Darja Keše
- Institute of Microbiology and Immunology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | | | - Jaouad Hammou
- Medicine and Pharmacy Faculty, Mohammed V University, Rabat, Morocco
| | - Talin Barisani-Asenbauer
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Li X, Zhang S, Liang Q, Wang M, Hu A, Li X, Yang B, Zhang M, Wang N, Lu X. Molecular characteristics of the ompA gene of serotype B Chlamydia trachomatis in Qinghai Tibetan primary school students. SCIENCE CHINA-LIFE SCIENCES 2016; 59:561-70. [PMID: 27225260 DOI: 10.1007/s11427-016-5059-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2016] [Accepted: 04/15/2016] [Indexed: 11/30/2022]
Abstract
To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene (ompA) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was sequenced and compared with the same serotype in GenBank. In Jianshetang Primary School and Galeng Central Primary School in the Galeng Tibetan Township of Qinghai Haidong Sala Autonomous County, scraped samples were collected from the upper tarsal conjunctiva and lower conjunctival sac of both eyes of 45 students with trachoma, stored at 4°C, and transported to Beijing Tongren Hospital by air within 24 h. The samples were screened for C. trachomatis by real-time PCR. The ompA gene from the C. trachomatis-positive samples was amplified by nested PCR. The serotype was confirmed by National Center for Biotechnology Information (NCBI) BLAST search and homology analysis. The entire ompA gene sequence was compared with the corresponding gene sequences of serotype B strains available in GenBank. Of the 45 students aged 6-13 years with trachoma, 26 C. trachomatis-positive students were identified by the initial real-time PCR screening (average age, (9.09±1.63) years; sex ratio, 1.0), accounting for 57.78% (26/45). The cycle threshold values for real-time PCR were 16.79-37.77. Half (13/26) of C. trachomatis-positive students had a bacterial copy number of >10(5). The compliance rate of the ompA gene sequences with the C. trachomatis serotype B strains in GenBank was up to 99%. Two novel genetic mutations were found when the ompA gene was compared with those of the 11 serotype B strains in GenBank. The two non-synonymous mutations were located at (i) position 271 in the second constant domain, an adenine (A) to guanine (G) substitution (ACT→GCT), changing the amino acid at position 91 from threonine to alanine (Thr→Ala) in all 26 strains; and (ii) position 887 in the fourth variable domain, a cytosine (C) to thymine (T) substitution (GCA→GTA), changing the amino acid at residue 296 from alanine to valine (Ala→Val) in four of the 26 strains. Six mutations were identified relative to ATCC VR-573. The strains could be divided into two gene clusters according to the mutation at nucleotide position 887: CQZ-1 (China Qinghai Tibetan-1) and CQZ-2 (China Qinghai Tibetan-2). We thus detected two novel serotype B mutant strains of C. trachomatis among study subjects with trachoma.
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Affiliation(s)
- Xue Li
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Shaoya Zhang
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Mei Wang
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Ailian Hu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Xiuyuan Li
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Benshan Yang
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Mingxin Zhang
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
| | - Ningli Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Xinxin Lu
- Department of Laboratory Medicine, Beijing Tongren Hospital, Capital Medical University, Beijing 100730, China
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Nunes A, Gomes JP. Evolution, phylogeny, and molecular epidemiology of Chlamydia. INFECTION GENETICS AND EVOLUTION 2014; 23:49-64. [PMID: 24509351 DOI: 10.1016/j.meegid.2014.01.029] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/16/2014] [Accepted: 01/19/2014] [Indexed: 10/25/2022]
Abstract
The Chlamydiaceae are a family of obligate intracellular bacteria characterized by a unique biphasic developmental cycle. It encompasses the single genus Chlamydia, which involves nine species that affect a wide range of vertebral hosts, causing infections with serious impact on human health (mainly due to Chlamydia trachomatis infections) and on farming and veterinary industries. It is believed that Chlamydiales originated ∼700mya, whereas C. trachomatis likely split from the other Chlamydiaceae during the last 6mya. This corresponds to the emergence of modern human lineages, with the first descriptions of chlamydial infections as ancient as four millennia. Chlamydiaceae have undergone a massive genome reduction, on behalf of the deletional bias "use it or lose it", stabilizing at 1-1.2Mb and keeping a striking genome synteny. Their phylogeny reveals species segregation according to biological properties, with huge differences in terms of host range, tissue tropism, and disease outcomes. Genome differences rely on the occurrence of mutations in the >700 orthologous genes, as well as on events of recombination, gene loss, inversion, and paralogous expansion, affecting both a hypervariable region named the plasticity zone, and genes essentially encoding polymorphic and transmembrane head membrane proteins, type III secretion effectors and some metabolic pathways. Procedures for molecular typing are still not consensual but have allowed the knowledge of molecular epidemiology patterns for some species as well as the identification of outbreaks and emergence of successful clones for C. trachomatis. This manuscript intends to provide a comprehensive review on the evolution, phylogeny, and molecular epidemiology of Chlamydia.
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Affiliation(s)
- Alexandra Nunes
- Reference Laboratory of Bacterial Sexually Transmitted Infections and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal
| | - João P Gomes
- Reference Laboratory of Bacterial Sexually Transmitted Infections and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016 Lisbon, Portugal.
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Kese D, Potocnik M, Maticic M, Kogoj R. Genotyping of Chlamydia trachomatis directly from urogenital and conjunctiva samples using an ompA gene pyrosequencing-based assay. ACTA ACUST UNITED AC 2011; 63:210-6. [DOI: 10.1111/j.1574-695x.2011.00843.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Darja Kese
- Institute of Microbiology and Immunology; Medical Faculty Ljubljana; University of Ljubljana; Ljubljana; Slovenia
| | - Marko Potocnik
- Department of Dermatovenereology; University Medical Centre Ljubljana; Ljubljana; Slovenia
| | - Mojca Maticic
- Department of Infectious Diseases and Febrile Illnesses; University Medical Centre Ljubljana; Ljubljana; Slovenia
| | - Rok Kogoj
- Institute of Microbiology and Immunology; Medical Faculty Ljubljana; University of Ljubljana; Ljubljana; Slovenia
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Andreasen AA, Burton MJ, Holland MJ, Polley S, Faal N, Mabey DC, Bailey RL. Chlamydia trachomatis ompA variants in trachoma: what do they tell us? PLoS Negl Trop Dis 2008; 2:e306. [PMID: 18820750 PMCID: PMC2553491 DOI: 10.1371/journal.pntd.0000306] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Accepted: 09/04/2008] [Indexed: 11/22/2022] Open
Abstract
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. Trachoma is an important cause of blindness resulting from transmission of the bacterium Chlamydia trachomatis. One way to understand better how this infection is transmitted and how the human immune system controls it is to study the strains of bacteria associated with infection. Comparing strains before and after treatment might help us learn if someone has a new infection or the same one as before. Identifying differences between disease-causing strains should help us understand how infection leads to disease and how the human host defences work. We chose to study variation in the chlamydial gene ompA because it determines the protein MOMP, one of the leading candidates for inclusion in a vaccine to prevent trachoma. If immunity to MOMP is important in natural trachoma infections, we would expect to find evidence of this in the way the strains varied. We did not find this, but instead found that two common strains seemed to cause different types of disease. Although their MOMPs were very slightly different, this did not really explain the differences. We conclude that methods of typing strains going beyond the ompA gene will be needed to help us understand the interaction between Chlamydia and its human host.
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Affiliation(s)
- Aura A. Andreasen
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Matthew J. Burton
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Medical Research Council Laboratories, Fajara, The Gambia
| | - Martin J. Holland
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Medical Research Council Laboratories, Fajara, The Gambia
| | - Spencer Polley
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Nkoyo Faal
- Medical Research Council Laboratories, Fajara, The Gambia
| | - David C.W. Mabey
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Robin L. Bailey
- London School of Hygiene & Tropical Medicine, London, United Kingdom
- Medical Research Council Laboratories, Fajara, The Gambia
- * E-mail:
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Zheng HP, Jiang LF, Fang DY, Xue YH, Wu YA, Huang JM, Ou ZY. Application of an oligonucleotide array assay for rapid detecting and genotyping of Chlamydia trachomatis from urogenital specimens. Diagn Microbiol Infect Dis 2007; 57:1-6. [PMID: 16872784 DOI: 10.1016/j.diagmicrobio.2006.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Revised: 05/04/2006] [Accepted: 05/07/2006] [Indexed: 10/24/2022]
Abstract
An oligonucleotide array technology was established for rapidly detecting and genotyping Chlamydia trachomatis in urogenital infections. The VS1-VS2 region of the omp1 gene was used to design oligonucleotide probes. Eleven serovar-specific probes to serovars A, B, C, D, E, F, G, H, I, J, and K, and 3 group-specific probes to group B (B, Ba, D, E, L1, and L2), group C (A, C, H, I, J, K, and L3), and an intermediate group (F and G) were synthesized and spotted onto the nylon membrane. Two pairs of universal primers were designed for the nested polymerase chain reaction (PCR) amplification of the VS1-VS2 gene. Digoxigenin-labeled amplicons of the VS1-VS2 gene of C. trachomatis were hybridized to the membrane array. Hybridization signals were read by the nitroblue tetrazolium/5-bromo-4-chloro-3-indolylphosphate color development. The assay developed was tested with reference strains of C. trachomatis serovars and clinical samples. The sensitivity was evaluated for 57 samples previously found to be positive for C. trachomatis by using plasmid PCR, and 98.2% (56/57) concordance was obtained. Fourteen oligonucleotide probes were optimized by trying different reaction conditions, showing specific hybridization with the corresponding reference strains, but no cross-reactions with other urogenital microorganisms. Using this procedure, a total of 59 strains were detected from 56 chlamydial samples. Eight genotypes were found, and type D, E, F, and H were the most frequently observed types (77.9%). Three cases (5.4%) had multiple infections with serovars: 1.D/E, 2.D/F, and 3.F/K. To validate the reference strains and confirm the genotype identity as determined by the oligonucleotide array technology, we sequenced all reference strains and 10 selected specimens across variable sequence VS1 and VS2. No discrepancies were found between the array typing and the genotype identity confirmed by nucleotide sequencing of the PCR product. The findings from this study indicated that the oligonucleotide array is a simple, fast, and specific assay for directly detecting and genotyping C. trachomatis from clinical samples.
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Affiliation(s)
- He-ping Zheng
- Department of Microbiology, School of Medicine, Sun Yat-sen University, Guangzhou 510089, China
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Halse TA, Musser KA, Limberger RJ. A multiplexed real-time PCR assay for rapid detection of Chlamydia trachomatis and identification of serovar L-2, the major cause of Lymphogranuloma venereum in New York. Mol Cell Probes 2006; 20:290-7. [PMID: 16644182 DOI: 10.1016/j.mcp.2006.02.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Accepted: 02/17/2006] [Indexed: 11/26/2022]
Abstract
Lymphogranuloma venereum (LGV) is caused by a rare form of Chlamydia trachomatis that is difficult to diagnose, since culture is not readily available, and since other methods are not reliable or lack sensitivity. We report here a rapid, sensitive, and specific real-time multiplex polymerase chain reaction (PCR) assay capable of detecting C. trachomatis and identifying serovar L-2 in the same reaction, directly from rectal swabs. The analytical sensitivity of the assay was 25 genome copies for C. trachomatis, and 50 genome copies for L-2. The analytical specificity was 100%, as demonstrated with a diverse range of C. trachomatis serovars and other site-specific bacterial pathogens. With the use of a rapid DNA extraction method, a blinded validation of spiked rectal swabs correctly identified 30 samples containing C. trachomatis cells, L-2 DNA, or negative samples. The multiplexed PCR assay also identified serovar L-2 in 13 of 70 rectal swab samples taken from symptomatic patients. Twelve additional samples were positive for C. trachomatis only, and omp1 sequencing determined these samples as either serovar D, E, G, J, or K. This assay represents the first real-time PCR method capable of detecting C. trachomatis DNA, and of simultaneously identifying C. trachomatis infection as serovar L-2.
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Affiliation(s)
- Tanya A Halse
- New York State Department of Health, Wadsworth Center-David Axelrod Institute, 120 New Scotland Avenue, Albany, NY 12208, USA
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Millman K, Black CM, Johnson RE, Stamm WE, Jones RB, Hook EW, Martin DH, Bolan G, Tavaré S, Dean D. Population-based genetic and evolutionary analysis of Chlamydia trachomatis urogenital strain variation in the United States. J Bacteriol 2004; 186:2457-65. [PMID: 15060049 PMCID: PMC412158 DOI: 10.1128/jb.186.8.2457-2465.2004] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis is a major cause of ocular and sexually transmitted diseases worldwide. While much of our knowledge about its genetic diversity comes from serotyping or ompA genotyping, no quantitative assessment of genetic diversity within serotypes has been performed. To accomplish this, 507 urogenital samples from a multicenter U.S. study were analyzed by phylogenetic and statistical modeling. No B, Da, or I serotypes were represented. Based on our analyses, all but one previous urogenital B serotype was identified as Ba. This, coupled with the lack of B serotypes in our population, suggests that B has specific tropism for ocular mucosa. We identified a Ba/D recombinant (putative crossover nucleotide 477; P < 0.0001) similar to a B/D mosaic we described previously from an African trachoma patient. Computational analyses of the Ba/D recombinant indicated that upstream changes were less important for tissue tropism than downstream incorporation of the D sequence. Since most serotypes had nonsynonymous/synonymous ratios of <1.0, the major outer membrane protein, encoded by ompA, has many functional constraints and is under purifying selection. Surprisingly, all serotype groups except for J had a unimodal population structure indicating rapid clonal expansion. Of the groups with a unimodal structure, E and Ia and, to a lesser extent, G and K were prevalent, had infrequent incorporation of mutations, and, compared to other groups, had a relatively greater degree of diversifying selection, consistent with a selective sweep of mutations within these groups. Collectively, these data suggest a diverse evolutionary strategy for different serogroups of the organism.
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Affiliation(s)
- Kim Millman
- Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California 90033, USA
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