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Villa L, Boga JA, Otero L, Vazquez F, Milagro A, Salmerón P, Vall-Mayans M, Maciá MD, Bernal S, Piñeiro L. Phenotypic and Genotypic Antimicrobial Susceptibility Testing of Chlamydia trachomatis Isolates from Patients with Persistent or Clinical Treatment Failure in Spain. Antibiotics (Basel) 2023; 12:975. [PMID: 37370294 DOI: 10.3390/antibiotics12060975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/23/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
The aim of this multicentre project (seven hospitals across the Spanish National Health Service) was to study the phenotypic and genotypic susceptibility of C. trachomatis to the main antimicrobials used (macrolides, doxycycline, and quinolones) in isolates from patients with clinical treatment failure in whom reinfection had been ruled out. During 2018-2019, 73 clinical isolates were selected. Sixty-nine clinical specimens were inoculated onto confluent McCoy cell monolayers for phenotypic susceptibility testing. The minimum inhibitory concentration for azithromycin and doxycycline was defined as the lowest concentration associated with an at least 95% reduction in inclusion-forming units after one passage in the presence of the antibiotic compared to the initial inoculum for each strain (control). Sequencing analysis was performed for the genotypic detection of resistance to macrolides, analysing mutations in the 23S rRNA gene (at positions 2057, 2058, 2059, and 2611), and quinolones, analysing a fragment of the gyrA gene, and searching for the G248T mutation (Ser83->Ile). For tetracyclines, in-house RT-PCR was used to test for the tet(C) gene. The phenotypic susceptibility testing was successful for 10 isolates. All the isolates had minimum inhibitory concentrations for azithromycin ≤ 0.125 mg/L and for doxycycline ≤ 0.064 mg/L and were considered sensitive. Of the 73 strains studied, no mutations were found at positions T2611C or G248T of the gyrA gene. We successfully sequenced 66 isolates. No macrolide resistance-associated mutations were found at positions 2057, 2058, 2059, or T2611C. None of the isolates carried the tet(C) gene. We found no evidence for genomic resistance in this large, clinically relevant dataset.
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Affiliation(s)
- Laura Villa
- Microbiology Department, Central University Hospital of Asturias and Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
| | - José Antonio Boga
- Microbiology Department, Central University Hospital of Asturias and Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
| | - Luis Otero
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Microbiology Department, Cabueñes University Hospital, and Health Research Institute of Asturias (ISPA), 33394 Gijón, Spain
| | - Fernando Vazquez
- Microbiology Department, Central University Hospital of Asturias and Health Research Institute of Asturias (ISPA), 33011 Oviedo, Spain
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Department of Functional Biology, Microbiology Area, Faculty of Medicine, University of Oviedo, 33003 Oviedo, Spain
| | - Ana Milagro
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Microbiology Department, Miguel Servet University Hospital, 50009 Zaragoza, Spain
| | - Paula Salmerón
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Microbiology Department, Vall d'Hebrón University Hospital, 08035 Barcelona, Spain
| | - Martí Vall-Mayans
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Vall'Hebron-Drassanes STI Unit, Infectious Diseases, Vall d'Hebrón University Hospital, 08035 Barcelona, Spain
| | - María Dolores Maciá
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Microbiology Department, Son Espases University Hospital, 07120 Palma de Mallorca, Spain
| | - Samuel Bernal
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Infectious Diseases and Microbiology Unit, Valme University Hospital, 41014 Seville, Spain
| | - Luis Piñeiro
- Sexually Transmitted Infections Study Group of the Infectious Diseases and Clinical Microbiology Spanish Society (GEITS-SEIMC), 28003 Madrid, Spain
- Microbiology Department, Donostia University Hospital-Biodonostia Health Research Institute, 20014 San Sebastian, Spain
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Pitt R, Alexander S, Ison C, Horner P, Hathorn E, Goold P, Woodford N, Cole MJ. Phenotypic antimicrobial susceptibility testing of Chlamydia trachomatis isolates from patients with persistent or successfully treated infections. J Antimicrob Chemother 2019; 73:680-686. [PMID: 29207004 DOI: 10.1093/jac/dkx454] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/03/2017] [Indexed: 12/30/2022] Open
Abstract
Objectives Antimicrobial susceptibility data for Chlamydia trachomatis are lacking. Methodologies for susceptibility testing in C. trachomatis are not well-defined, standardized or performed routinely owing to its intracellular growth requirements. We sought to develop an assay for the in vitro susceptibility testing of C. trachomatis isolates from two patient cohorts with different clinical outcomes. Methods Twenty-four clinical isolates (11 from persistently infected and 13 from successfully treated patients) were overlaid with media containing two-fold serial dilutions of azithromycin or doxycycline. After incubation, aliquots were removed from the stock inoculum (SI) and each antimicrobial concentration for total RNA extraction, complementary DNA generation and real-time PCR. The MIC was defined as the lowest antimicrobial concentration where a 95% reduction in transcription was evident in comparison with the SI for each isolate. Results MICs of azithromycin were comparable for isolates from the two patient groups (82% ≤ 0.25 mg/L for persistently infected and 100% ≤ 0.25 mg/L for successfully treated patients). Doxycycline MICs were at least two-fold lower for isolates from the successfully treated patients (53.9% ≤ 0.064 mg/L) than for the persistently infected patients (100% ≥ 0.125 mg/L) (P = 0.006, Fisher's exact test). Overall, 96% of isolates gave reproducible MICs when re-tested. Conclusions A reproducible assay was developed for antimicrobial susceptibility testing of C. trachomatis. MICs of azithromycin were generally comparable for the two different patient groups. MICs of doxycycline were significantly higher in the persistently infected patients. However, interpretation of elevated MICs in C. trachomatis is extremely challenging in the absence of breakpoints, or wild-type and treatment failure MIC distribution data.
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Affiliation(s)
- Rachel Pitt
- Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.,The Sexually Transmitted Bacteria Reference Unit, Public Health England, London, UK
| | - Sarah Alexander
- The Sexually Transmitted Bacteria Reference Unit, Public Health England, London, UK
| | - Catherine Ison
- The Sexually Transmitted Bacteria Reference Unit, Public Health England, London, UK
| | - Patrick Horner
- Population Health Sciences, Bristol Medical School, University of Bristol, UK
| | - Emma Hathorn
- Whittal Street Clinic, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Penny Goold
- Whittal Street Clinic, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Neil Woodford
- Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK
| | - Michelle J Cole
- Antimicrobial Resistance and Healthcare Associated Infections (AMRHAI) Reference Unit, National Infection Service, Public Health England, London, UK.,The Sexually Transmitted Bacteria Reference Unit, Public Health England, London, UK
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Phillips S, Vodstrcil LA, Huston WM, Lawerence A, Timms P, Chen MY, Worthington K, McIver R, Bradshaw CS, Garland SM, Tabrizi SN, Hocking JS. Detection of Chlamydia trachomatis mRNA using digital PCR as a more accurate marker of viable organism. Eur J Clin Microbiol Infect Dis 2018; 37:2117-2122. [PMID: 30109584 DOI: 10.1007/s10096-018-3347-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/03/2018] [Indexed: 10/28/2022]
Abstract
Spontaneous resolution of urogenital Chlamydia trachomatis (CT) without treatment has previously been described, but a limitation of these reports is that DNA or RNA-based amplification tests used do not differentiate between viable infection and non-viable DNA. We modified a previously published CT mRNA detection (omp2) method to differentiate between viable infection and non-viable DNA in a sample of CT DNA PCR positive women. We modified a CT mRNA detection (omp2) method from reverse transcriptase qPCR (RTqPCR) to digital PCR (dPCR) and evaluated it in samples from CT DNA positive women. Firstly, CT infected McCoy B cells treated with azithromycin in vitro identified detectable mRNA levels disappeared <2 days, while DNA persisted up to 6 days. We used 55 self-collected vaginal swabs from a cohort of women diagnosed as DNA positive for chlamydia obtained pre- and 7 days of post-azithromycin treatment. Concordance with DNA results was higher for dPCR than RTqPCR (74.5% versus 65.5%). At visit 1, there was a strong linear relationship between DNA and mRNA (r = 0.9, p < 0.000); 24 samples had both mRNA and DNA detected (82.8%) and 5 had only DNA detected with a potential false positive proportion of 17.2% (95%CI: 5.8, 35.8). At visit 2, there was poor correlation between DNA and mRNA (r = 0.14, p = 0.55); eight specimens had only DNA detected (42.1%; 95%CI: 20.25, 66.50) and one had mRNA detected. DNA detection methods alone may detect non-viable DNA. Consideration should be given to further develop mRNA assays as ancillary tests to improve detection of viable chlamydia.
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Affiliation(s)
- Samuel Phillips
- Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia. .,Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Parkville, Victoria, 3052, Australia. .,University of Sunshine Coast, 90 Sippy downs drive, Sippy Downs, Queensland, 4556, Australia.
| | - Lenka A Vodstrcil
- Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia.,Melbourne School of Population and Global Health, University of Melbourne, Level 3, 207 Bouverie St, Carlton, Victoria, 3053, Australia.,Melbourne Sexual Health Centre, 580 Swanston Street, Carlton, Victoria, 3053, Australia
| | - Wilhelmina M Huston
- School of Life Sciences, University of Technology Sydney, City Campus, Broadway, Ultimo, New South Wales, 2007, Australia
| | - Amba Lawerence
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Ave, Kelvin Grove, Brisbane, Queensland, 4057, Australia
| | - Peter Timms
- University of Sunshine Coast, 90 Sippy downs drive, Sippy Downs, Queensland, 4556, Australia
| | - Marcus Y Chen
- Murdoch Children's Research Institute, Parkville, Victoria, 3052, Australia.,Melbourne Sexual Health Centre, 580 Swanston Street, Carlton, Victoria, 3053, Australia
| | - Karen Worthington
- Melbourne Sexual Health Centre, 580 Swanston Street, Carlton, Victoria, 3053, Australia
| | - Ruthy McIver
- Sydney Sexual Health Centre, Sydney Hospital, Macquarie Street, Sydney, New South Wales, 2001, Australia
| | - Catriona S Bradshaw
- Melbourne Sexual Health Centre, 580 Swanston Street, Carlton, Victoria, 3053, Australia
| | - Suzanne M Garland
- Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Parkville, Victoria, 3052, Australia.,Melbourne School of Population and Global Health, University of Melbourne, Level 3, 207 Bouverie St, Carlton, Victoria, 3053, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Carlton, Victoria, 3053, Australia
| | - Sepehr N Tabrizi
- Department of Microbiology and Infectious Diseases, The Royal Women's Hospital, Parkville, Victoria, 3052, Australia.,Melbourne School of Population and Global Health, University of Melbourne, Level 3, 207 Bouverie St, Carlton, Victoria, 3053, Australia.,Department of Obstetrics and Gynaecology, University of Melbourne, Carlton, Victoria, 3053, Australia
| | - Jane S Hocking
- Melbourne School of Population and Global Health, University of Melbourne, Level 3, 207 Bouverie St, Carlton, Victoria, 3053, Australia
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Janssen KJH, Dirks JAMC, Dukers-Muijrers NHTM, Hoebe CJPA, Wolffs PFG. Review of Chlamydia trachomatis viability methods: assessing the clinical diagnostic impact of NAAT positive results. Expert Rev Mol Diagn 2018; 18:739-747. [PMID: 29987959 DOI: 10.1080/14737159.2018.1498785] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Chlamydia trachomatis (chlamydia) is the most commonly diagnosed bacterial sexually transmitted infection (STI) worldwide. The advancement of molecular techniques has made chlamydia diagnostics infinitely easier. However, molecular techniques lack the information on chlamydia viability. Where in routine diagnostics the detection of chlamydia DNA or RNA might suffice, in other patient scenarios, information on the viability of chlamydia might be essential. Areas covered: In this review, the authors discuss the specific strengths and limitations of currently available methods to evaluate chlamydia viability: conventional cell culture, messenger RNA (mRNA) detection and viability-PCR (V-PCR). PubMed and Google Scholar were searched with the following terms: Chlamydia trachomatis, Treatment failure, Anal chlamydia, Microbial viability, Culture, Viability-PCR, Messenger RNA, and Molecular diagnostics Expert commentary: Several techniques are currently available to determine chlamydia viability and thus the clinical relevance of a positive test result in clinical samples. Depending on the underlying research question, all three discussed techniques have their merits when testing for viability. However, mRNA methods show the most promise in determining the presence of a true infection, in case the chlamydia reticulate body can be specifically detected. Further research is needed to understand how to best apply viability testing in current chlamydia diagnostics.
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Affiliation(s)
- Kevin J H Janssen
- a Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI) , Maastricht University Medical Center (MUMC+) , Maastricht , The Netherlands
| | - Jeanne A M C Dirks
- a Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI) , Maastricht University Medical Center (MUMC+) , Maastricht , The Netherlands
| | - Nicole H T M Dukers-Muijrers
- a Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI) , Maastricht University Medical Center (MUMC+) , Maastricht , The Netherlands.,b Department of Sexual Health, Infectious Diseases and Environmental Health , South Limburg Public Health Service , Heerlen , The Netherlands
| | - Christian J P A Hoebe
- a Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI) , Maastricht University Medical Center (MUMC+) , Maastricht , The Netherlands.,b Department of Sexual Health, Infectious Diseases and Environmental Health , South Limburg Public Health Service , Heerlen , The Netherlands
| | - Petra F G Wolffs
- a Department of Medical Microbiology, Care and Public Health Research Institute (CAPHRI) , Maastricht University Medical Center (MUMC+) , Maastricht , The Netherlands
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Lau A, Kong F, Fairley CK, Donovan B, Chen M, Bradshaw C, Boyd M, Amin J, Timms P, Tabrizi S, Regan DG, Lewis DA, McNulty A, Hocking JS. Treatment efficacy of azithromycin 1 g single dose versus doxycycline 100 mg twice daily for 7 days for the treatment of rectal chlamydia among men who have sex with men - a double-blind randomised controlled trial protocol. BMC Infect Dis 2017; 17:35. [PMID: 28061753 PMCID: PMC5217553 DOI: 10.1186/s12879-016-2125-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 12/14/2016] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Rectal infection with Chlamydia trachomatis is one of the most common bacterial sexually transmissible infections among men who have sex with men (MSM) with diagnosis rates continuing to rise. Current treatment guidelines recommend either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. However, there are increasing concerns about treatment failure with azithromycin. We are conducting the first randomised controlled trial (RCT) to compare treatment efficacy of azithromycin versus doxycycline for the treatment of rectal chlamydia in MSM. METHODS/DESIGN The Rectal Treatment Study will recruit 700 MSM attending Australian sexual health clinics for the treatment of rectal chlamydia. Participants will be asked to provide rectal swabs and will be randomised to either azithromycin 1 g single dose or doxycycline 100 mg twice daily for 7 days. Participants will be asked to complete questionnaires about adverse drug reactions, sexual behaviour and drug adherence via short message service and online survey. The primary outcome is the treatment efficacy as determined by a negative chlamydia nucleic acid amplification test at 4 weeks post treatment. Secondary outcomes will utilise whole genome sequencing and mRNA assay to differentiate between treatment failure, reinfection or false positive results. DISCUSSION Rectal chlamydia is an increasing public health concern as use of pre-exposure prophylaxis against HIV becomes commonplace. Optimal, evidence-based treatment is critical to halting ongoing transmission. This study will provide the first RCT evidence comparing azithromycin and doxycycline for the treatment of rectal chlamydia. The results of this trial will establish which treatment is more efficacious and inform international management guidelines. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry ACTRN12614001125617.
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Affiliation(s)
- Andrew Lau
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053 VIC Australia
| | - Fabian Kong
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053 VIC Australia
| | - Christopher K. Fairley
- Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053 VIC Australia
- Central Clinical School, Monash University, Clayton, 3800 VIC Australia
| | - Basil Donovan
- The Kirby Institute, UNSW Australia, Kensington, 2052 NSW Australia
| | - Marcus Chen
- Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053 VIC Australia
- Central Clinical School, Monash University, Clayton, 3800 VIC Australia
| | - Catriona Bradshaw
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053 VIC Australia
- Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053 VIC Australia
- Central Clinical School, Monash University, Clayton, 3800 VIC Australia
| | - Mark Boyd
- The Kirby Institute, UNSW Australia, Kensington, 2052 NSW Australia
| | - Janaki Amin
- The Kirby Institute, UNSW Australia, Kensington, 2052 NSW Australia
| | - Peter Timms
- University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, 4556 QLD Australia
| | - Sepehr Tabrizi
- Division of Laboratory Services, Department of Microbiology, University of Melbourne, Carlton, 3053 VIC Australia
| | - David G. Regan
- The Kirby Institute, UNSW Australia, Kensington, 2052 NSW Australia
| | - David A. Lewis
- Western Sydney Sexual Health Centre, 162 Marsden St, Parramatta, 2150 NSW Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity & Sydney Medical School-Westmead, University of Sydney, Sydney, 2000 NSW Australia
| | - Anna McNulty
- Sydney Sexual Health Centre, Level 3 Nightingale Wing, Sydney Hospital, Macquarie St, Sydney, 2000 NSW Australia
| | - Jane S. Hocking
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Carlton, 3053 VIC Australia
- Melbourne Sexual Health Centre, Alfred Health, 580 Swanston St, Carlton, 3053 VIC Australia
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Peuchant O, Duvert JP, Clerc M, Raherison S, Bébéar C, Bébéar CM, de Barbeyrac B. Effects of antibiotics on Chlamydia trachomatis viability as determined by real-time quantitative PCR. J Med Microbiol 2011; 60:508-514. [DOI: 10.1099/jmm.0.023887-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The objective of this study was to determine the effect of antibiotics on Chlamydia trachomatis viability by using a quantitative real-time PCR assay that measured DNA replication and mRNA transcription of the structural omp1 and omp2 genes, 16S rRNA and the groEL1 gene with and without antibiotics. Ofloxacin, moxifloxacin, azithromycin and doxycycline were tested against the serovar D and L2 reference strains and a derivative mutant resistant to fluoroquinolones, L2-OFXR, obtained by in vitro selection. Using DNA quantification, the antibiotic MIC was calculated when the number of DNA copies was equal to that of the chlamydial inoculum at time zero. This method allowed the easy determination of MICs by DNA quantification of the four selected genes and gave similar results to those obtained by immunofluorescence staining without biased interpretation. By using cDNA quantification, the lowest antibiotic concentration for which no RNA was transcribed corresponded to the minimum bactericidal concentration. C. trachomatis still transcribed the16S rRNA and groEL1 genes, even at concentrations well above the MIC, showing a bacteriostatic effect for all antibiotics tested. This method allows the study of antibiotic activity on growth and viability of C. trachomatis by DNA and RNA quantification at the same time without additional cell-culture passaging.
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Affiliation(s)
- Olivia Peuchant
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Jean Philippe Duvert
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Maïthé Clerc
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Sophie Raherison
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Christiane Bébéar
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Cécile M. Bébéar
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
| | - Bertille de Barbeyrac
- Laboratoire de Bactériologie EA 3671, Infections Humaines à Mycoplasmes et Chlamydiae, Centre National de Référence des Infections à Chlamydiae, Université Victor Segalen Bordeaux 2, Bordeaux, France
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Wooters MA, Kaufhold RM, Field JA, Indrawati L, Heinrichs JH, Smith JG. A real-time quantitative polymerase chain reaction assay for the detection of Chlamydia in the mouse genital tract model. Diagn Microbiol Infect Dis 2008; 63:140-7. [PMID: 19026505 DOI: 10.1016/j.diagmicrobio.2008.10.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 10/11/2008] [Indexed: 11/18/2022]
Abstract
Chlamydia trachomatis is a human pathogen that infects genital tracts in women. Disease control may be achieved through development of an efficacious vaccine. A mouse genital tract model serves as a tool for evaluation of vaccine candidates. Currently, assessment of infection in mice is performed by enumeration of inclusion-forming units (IFUs) through microscopic counting of fluorescently stained bacteria. We have developed a highly sensitive real-time quantitative polymerase chain reaction (RT-qPCR) assay for enumeration of Chlamydia from mouse genital tracts to increase assay sensitivity, remove subjectivity, and improve sample throughput. The qPCR assay uses a 16S ribosomal gene sequence that is conserved across Chlamydia species and serovars, resulting in detection of multiple serovars of C. trachomatis, as well as Chlamydia muridarum and Chlamydia pneumoniae. The PCR assay provided results similar to IFU enumeration (94% agreement between the 2 assays) and is highly sensitive and specific with less inherent subjectivity than traditional enumeration methods.
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Affiliation(s)
- Melissa A Wooters
- Vaccine Basic Research, Merck Research Laboratories, West Point, PA 19486-0004, USA.
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Jalal H, Stephen H, Curran MD, Burton J, Bradley M, Carne C. Development and validation of a rotor-gene real-time PCR assay for detection, identification, and quantification of Chlamydia trachomatis in a single reaction. J Clin Microbiol 2006; 44:206-13. [PMID: 16390971 PMCID: PMC1351959 DOI: 10.1128/jcm.44.1.206-213.2006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A multitarget real-time PCR (MRT-PCR) for detection of Chlamydia trachomatis DNA was developed and validated. There were three targets for amplification in a single reaction: the cryptic plasmid (CP), the major outer membrane protein (MOMP) gene, and an internal control. The assay had the following characteristics: (i) detection and confirmation of the presence of C. trachomatis DNA in a single reaction, (ii) detection of all genovars of C. trachomatis without any cross-reactivity with pathogenic bacteria or commensal organisms of the oropharynx and genital tract, (iii) a 95% probability of detection with three copies of MOMP and one copy of CP per reaction mixture, (iv) identification of the inhibition of amplification, (v) a quantitative dynamic range of 25 to 250,000 genome copies per reaction mixture, (vi) high intra- and interassay reproducibilities, and (vii) correct identification of all samples in the validation panel. There were 146 COBAS Amplicor PCR (Amplicor PCR)-positive samples and 122 Amplicor PCR-negative samples in the panel. MRT-PCR detected CP DNA alone in 6 (4%) Amplicor PCR-positive samples and both CP and MOMP DNAs in 140 (96%) of 146 Amplicor PCR-positive samples. The quantity of MOMP DNA in 95 (68%) of 140 samples was within the dynamic range of the assay. The median C. trachomatis load in these samples was 321 genome copies per reaction mixture (range, 26 to 40,137 genome copies per reaction mixture). Due to the inclusion of two different C. trachomatis-specific targets, the assay confirmed 259 (97%) of 268 results in a single reaction. This assay could be used in the qualitative format for the routine detection of C. trachomatis and in the quantitative format for study of the pathogenesis of C. trachomatis-associated diseases. The assay demonstrated the potential to eliminate the need for confirmatory testing in almost all samples, thus reducing the turnaround time and the workload.
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Affiliation(s)
- Hamid Jalal
- Clinical Microbiology & Public Health Laboratory, Addenbrooke's Hospital, Cambridge, UK.
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