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Asgharzadeh M, Ozma MA, Rashedi J, Poor BM, Agharzadeh V, Vegari A, Shokouhi B, Ganbarov K, Ghalehlou NN, Leylabadlo HE, Kafil HS. False-Positive Mycobacterium tuberculosis Detection: Ways to Prevent Cross-Contamination. Tuberc Respir Dis (Seoul) 2020; 83:211-217. [PMID: 32578410 PMCID: PMC7362751 DOI: 10.4046/trd.2019.0087] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/30/2020] [Accepted: 03/02/2020] [Indexed: 01/17/2023] Open
Abstract
The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on falsepositive cultures of M. tuberculosis. Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, falsepositive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.
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Affiliation(s)
- Mohammad Asgharzadeh
- Biotechnology Research Center, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mahdi Asghari Ozma
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Jalil Rashedi
- Tuberculosis and Lung Diseases Research Center, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behroz Mahdavi Poor
- Tuberculosis and Lung Diseases Research Center, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Vahid Agharzadeh
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Vegari
- Department of Medical Physics, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Behrooz Shokouhi
- Connective Tissue Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | | | | | - Hossein Samadi Kafil
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Barac A, Karimzadeh-Esfahani H, Pourostadi M, Rahimi MT, Ahmadpour E, Rashedi J, Mahdavipoor B, Kafil HS, Spotin A, Abate KH, Mathioudakis AG, Asgharzadeh M. Laboratory Cross-Contamination of Mycobacterium tuberculosis: A Systematic Review and Meta-analysis. Lung 2019; 197:651-661. [PMID: 31203380 DOI: 10.1007/s00408-019-00241-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/24/2019] [Indexed: 11/29/2022]
Abstract
BACKGROUND Microbiological cultures are the mainstay of the diagnosis of tuberculosis (TB). False-positive TB results lead to significant unnecessary therapeutic and economic burden and are frequently caused by laboratory cross-contamination. The aim of this meta-analysis was to quantify the prevalence of laboratory cross-contamination. METHODS Through a systematic review of five electronic databases, we identified studies reporting rates of laboratory cross-contamination, confirmed by molecular techniques in TB cultures. We evaluated the quality of the identified studies using the National Institute of Health (NIH) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies, and conducted a meta-analysis using standard methodology recommended by the Cochrane Collaboration. RESULTS Based on 31 eligible studies evaluating 29,839 TB cultures, we found that 2% (95% confidence intervals [CI] 1-2%) of all positive TB cultures represent false-positive results secondary to laboratory cross-contamination. More importantly, we evaluated the rate of laboratory cross-contamination in cases where a single-positive TB culture was available in addition to at least one negative TB culture, and we found a rate of 15% (95% CI 6-33%). Moreover, 9.2% (91/990) of all patients with a preliminary diagnosis of TB had false-positive results and received unnecessary and potentially harmful treatments. CONCLUSIONS Our results highlight a remarkably high prevalence of false-positive TB results as a result of laboratory cross-contamination, especially in single-positive TB cultures, leading to the administration of unnecessary, harmful treatments. The need for the adoption of strict technical standards for mycobacterial cultures cannot be overstated.
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Affiliation(s)
- Aleksandra Barac
- Clinic for Infectious and Tropical Diseases, Clinical Centre of Serbia, Belgrade, Serbia.,Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Mahya Pourostadi
- Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Ehsan Ahmadpour
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. .,Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Jalil Rashedi
- Tuberculosis and Lung Disease Research Center, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Behroz Mahdavipoor
- Department of Laboratory Science, Faculty of Paramedicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Medical Parasitology, School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran
| | - Hossein Samadi Kafil
- Department of Microbiology, Tabriz University of Medical Sciences, Tabriz, Iran.,Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Adel Spotin
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Alexander G Mathioudakis
- Division of Infection, Immunity and Respiratory Medicine, The University of Manchester, Manchester, UK. .,North West Lung Centre, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, UK.
| | - Mohammad Asgharzadeh
- Faculty of Paramedicine, Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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A case of Mycobacterium tuberculosis laboratory cross-contamination. J Infect Chemother 2019; 25:610-614. [PMID: 30982725 DOI: 10.1016/j.jiac.2019.03.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/08/2019] [Accepted: 03/13/2019] [Indexed: 11/23/2022]
Abstract
SETTING A laboratory cross-contamination event was suspected because Mycobacterium tuberculosis was unexpectedly detected at a high incidence in the cultures of several clinical specimens at the National Hospital Organization, Tokyo National Hospital, Japan. OBJECTIVE To describe a case of Mycobacterium tuberculosis laboratory cross-contamination. DESIGN We reviewed the medical records of 20 patients whose clinical specimens were suspected to have been contaminated by Mycobacterium tuberculosis. Variable number of tandem repeat analysis with 15 loci, the Japan Anti-Tuberculosis Association-12, and three additional hyper-variable loci, was performed to identify the cross-contamination event. RESULTS The clinical, laboratory, and variable number of tandem repeat data revealed that the cross-contamination had possibly originated from one strongly positive specimen, resulting in false-positive results in 11 other specimens, including a case treated with anti-tuberculosis drugs. CONCLUSION Clinical and laboratory data must be re-evaluated when cross-contamination is suspected and variable number of tandem repeat analysis should be used to confirm cross-contamination. Furthermore, original isolates should be stored appropriately, without sub-culturing and genotyping should be performed at the earliest possible for better utilization of variable number of tandem repeat for the identification of cross-contamination.
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Sensitivity and specificity of routine diagnostic work-up for tuberculosis in lung clinics in Yogyakarta, Indonesia: a cohort study. BMC Public Health 2019; 19:363. [PMID: 30940123 PMCID: PMC6444523 DOI: 10.1186/s12889-019-6658-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 03/14/2019] [Indexed: 11/10/2022] Open
Abstract
Background Establishing a correct diagnosis is challenging. We aimed to investigate the sensitivity and specificity of routine tuberculosis (TB) diagnostic work-up in lung clinics in Indonesia, a country with the third highest TB burden and the second highest gap between notifications of TB cases and the best estimate of incident cases in the world. Methods In the lung clinics of the Province of Yogyakarta, Indonesia, we recruited all consecutive patients with symptoms suggesting TB, aged ≥18 years. Routine TB examination consisted of clinical evaluation, sputum smear microscopy, and chest radiography. For research purposes, we added sputum culture, Human Immunodeficiency Virus (HIV) testing, and follow-up for 1.5 years or 2.5 years if culture results disagreed with the initial clinical diagnosis. The initial diagnosis was considered incorrect if patients did not respond to treatment. We calculated sensitivity and specificity of the TB routine examination using culture and a composite reference standard (CRS – a combination of routine examination, culture, and follow-up) as the reference standards. All analyses were conducted with IBM SPSS Statistics 25 (IBM Corp., Armonk, NY, USA). Results Between 2013 and 2015, we included 360 participants, and 21 were excluded due to incomplete data. Among those analyzed, 115 were initially diagnosed with smear-positive TB, 12 with smear-negative TB, and 212 non-TB. In 15 study participants, the diagnosis was changed after median 45 (range: 14–870) days; 14 participants initially not diagnosed with TB were later diagnosed with TB, while one subject initially diagnosed with TB actually did not have TB. Compared with culture and CRS, TB routine examination had sensitivity of 85% (95%CI: 77–91) and 90% (95%CI: 84–94), and specificity of 86.3% (95%CI: 81–91) and 99.5% (95%CI: 97–100), respectively. Conclusions A combination of clinical evaluation with sputum microscopy and chest radiography provided high sensitivity and specificity in diagnosing TB in lung clinics; in only 4.4% the diagnosis was incorrect. There is a need to improve routine TB diagnostic work by using clinical evaluation, sputum smear microscopy, and chest radiography all together in other settings, such as in primary health centers. Trial registration NCT02219945, clinicaltrials.gov. Registered 19 August 2014 (retrospectively registered).
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Methodological and Clinical Aspects of the Molecular Epidemiology of Mycobacterium tuberculosis and Other Mycobacteria. Clin Microbiol Rev 2016; 29:239-90. [PMID: 26912567 DOI: 10.1128/cmr.00055-15] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Molecular typing has revolutionized epidemiological studies of infectious diseases, including those of a mycobacterial etiology. With the advent of fingerprinting techniques, many traditional concepts regarding transmission, infectivity, or pathogenicity of mycobacterial bacilli have been revisited, and their conventional interpretations have been challenged. Since the mid-1990s, when the first typing methods were introduced, a plethora of other modalities have been proposed. So-called molecular epidemiology has become an essential subdiscipline of modern mycobacteriology. It serves as a resource for understanding the key issues in the epidemiology of tuberculosis and other mycobacterial diseases. Among these issues are disclosing sources of infection, quantifying recent transmission, identifying transmission links, discerning reinfection from relapse, tracking the geographic distribution and clonal expansion of specific strains, and exploring the genetic mechanisms underlying specific phenotypic traits, including virulence, organ tropism, transmissibility, or drug resistance. Since genotyping continues to unravel the biology of mycobacteria, it offers enormous promise in the fight against and prevention of the diseases caused by these pathogens. In this review, molecular typing methods for Mycobacterium tuberculosis and nontuberculous mycobacteria elaborated over the last 2 decades are summarized. The relevance of these methods to the epidemiological investigation, diagnosis, evolution, and control of mycobacterial diseases is discussed.
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Johnson MG, Lindsey PH, Harvey CF, Bradley KK. Recognizing Laboratory Cross-Contamination. Chest 2013; 144:319-322. [DOI: 10.1378/chest.12-2294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Moonan PK, Ghosh S, Oeltmann JE, Kammerer JS, Cowan LS, Navin TR. Using genotyping and geospatial scanning to estimate recent mycobacterium tuberculosis transmission, United States. Emerg Infect Dis 2012; 18:458-65. [PMID: 22377473 PMCID: PMC3309578 DOI: 10.3201/eid1803.111107] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
To determine the proportion of reported tuberculosis (TB) cases due to recent transmission in the United States, we conducted a cross-sectional study to examine culture-positive TB cases with complete genotype results (spoligotyping and 12-locus mycobacterial interspersed repetitive unit-variable-number tandem repeat typing) reported during January 2005-December 2009. Recently transmitted cases were defined as cases with matching results reported within statistically significant geospatial zones (identified by a spatial span statistic within a sliding 3-year window). Approximately 1 in 4 TB cases reported in the United States may be attributed to recent transmission. Groups at greatest risk for recent transmission appear to be men, persons born in the United States, members of a minority race or ethnic group, persons who abuse substances, and the homeless. Understanding transmission dynamics and establishing strategies for rapidly detecting recent transmission among these populations are essential for TB elimination in the United States.
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Affiliation(s)
- Patrick K Moonan
- US Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Lee MR, Chung KP, Chen WT, Huang YT, Lee LN, Yu CJ, Teng LJ, Hsueh PR, Yang PC, Luh KT. Epidemiologic surveillance to detect false-positive Mycobacterium tuberculosis cultures. Diagn Microbiol Infect Dis 2012; 73:343-9. [PMID: 22705229 DOI: 10.1016/j.diagmicrobio.2012.04.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 03/29/2012] [Accepted: 04/30/2012] [Indexed: 10/28/2022]
Abstract
This study was aimed to investigate the ability of potential indices from epidemiologic surveillance to detect false-positive cultures of Mycobacterium tuberculosis (MTB). All clinical specimens for mycobacterial culture from April 1 to August 31, 2010, were reviewed. Single-positive cultures without relevant clinical and pathologic information were categorized as suspected false-positive cultures. Genotyping methods were used to confirm false-positive cultures. The performance of epidemiologic surveillance indices to detect potential false-positive cultures was evaluated. A total of 14,462 specimens were sent to the laboratory and 214 batches were processed in 107 work days (average 67.6 specimens per batch, ranging from 21 to 130 specimens per batch). Seventy-one single-positive cultures were identified, among which 5 cultures of multidrug-resistant MTB in 1 batch were false-positive, confirmed by genotyping methods. Epidemiologic surveillance with statistical process control charts for single-positive cultures per day showed good performance in epidemiologic surveillance. The false-positive rate was 38.5% in the 13 potential false-positive cultures according to the statistical process control chart for single-positive cultures per day. Although the incidence of tuberculous disease is high in Taiwan, clustering of multidrug-resistant MTB in 1 batch or clustering of single-positive cultures still suggested the occurrence of false-positive MTB cultures. Therefore, epidemiologic surveillance for the clustering of single-positive cultures with the statistical process control chart could be used to monitor the occurrence of false-positive results.
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Affiliation(s)
- Meng-Rui Lee
- Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
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Ou SM, Liu CJ, Teng CJ, Lin YT, Chang YS, Chiang SC, Tzeng CH, Chen TJ. Impact of pulmonary and extrapulmonary tuberculosis infection in kidney transplantation: a nationwide population-based study in Taiwan. Transpl Infect Dis 2012; 14:502-9. [PMID: 22571347 DOI: 10.1111/j.1399-3062.2012.00737.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Revised: 11/13/2011] [Accepted: 01/02/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Tuberculosis (TB) has been reported to increase morbidity after kidney transplantation and pose a therapeutic challenge. However, population-based research, specifically focused on the association between kidney transplantation and subsequent pulmonary or extrapulmonary TB, is lacking. METHODS A nationwide population-based study was conducted using Taiwan's National Health Insurance Research Database, which provided claims data belonging to kidney transplant recipients during 1997-2006. Multivariate analysis was used to identify independent risk factors for TB after kidney transplantation. Kaplan-Meier survival analysis was used to assess the outcome of patients with TB. RESULTS Among 4554 kidney transplant recipients over the 10-year period, 109 (2.4%) patients with newly diagnosed TB were identified: 75 patients with only pulmonary involvement, and 34 with extrapulmonary spread. The incidence of kidney transplant recipients developing TB was 638 per 100,000 person-years. The independent risk factors for post-transplant TB included cyclosporine-based immunosuppressant agents during the first year after kidney transplantation (odds ratio [OR]: 1.98, P = 0.001), hepatitis C infection (OR: 1.79, P = 0.024), and chronic obstructive pulmonary disease (OR: 1.50, P = 0.041). Kidney transplant recipients who developed TB had a lower 5-year survival rate than those who did not (78.6% vs. 93.4%, P = 0.001). CONCLUSIONS Kidney transplant recipients in Taiwan did have a high risk of TB infection, with high proportion of extrapulmonary spread. Physicians need to be vigilant in surveying for TB in kidney transplantation, especially in high-risk patients.
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Affiliation(s)
- S-M Ou
- Division of Nephrology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
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George G, Mony P, Kenneth J. Comparison of the efficacies of loop-mediated isothermal amplification, fluorescence smear microscopy and culture for the diagnosis of tuberculosis. PLoS One 2011; 6:e21007. [PMID: 21695047 PMCID: PMC3117872 DOI: 10.1371/journal.pone.0021007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Accepted: 05/16/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Despite the advent of novel diagnostic techniques, smear microscopy remains as the most practical test available in resource-limited settings for tuberculosis (TB) diagnosis. Due to the low sensitivity of microscopy and the long time required for culture, feasible and accessible rapid diagnostic methods are urgently needed. Loop-mediated Isothermal Amplification (LAMP) is a promising nucleic-acid amplification assay, which could be accessible, cost-effective and more suited for use with unpurified samples. METHODOLOGY/PRINCIPAL FINDINGS In the current study, the objective was to assess the efficacy of a LAMP assay for tuberculosis compared with fluorescence smear microscopy as well as Löwenstein-Jensen (LJ) and Mycobacteria Growth Indicator Tube (MGIT) cultures for the diagnosis of pulmonary tuberculosis using sputum samples. Smear microscopy and culture were performed for decontaminated and concentrated sputum from TB suspects and the LAMP was also performed on these specimens. The LAMP and smear microscopy were compared, in series and in parallel, to culture. LAMP and smear microscopy showed sensitivities of 79.5% and 82.1% respectively and specificities of 93.8% and 96.9% respectively, compared to culture. LAMP and smear in series had sensitivity and specificity of 79.5% and 100.0% respectively. LAMP and smear in parallel had sensitivity and specificity of 82.1% and 90.6% respectively. CONCLUSIONS/SIGNIFICANCE The overall efficacies of LAMP and fluorescence smear microscopy in the current study were high and broadly similar. LAMP and smear in series had high specificity (100.0%) and can be used as a rule-in test combination. However, the performance of LAMP in smear negative samples was found to be insufficient.
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Affiliation(s)
- Geojith George
- Division of Infectious Disease, St. John's Research Institute, Bangalore, India
| | - Prem Mony
- Division of Epidemiology and Biostatistics, St. John's Research Institute, Bangalore, India
| | - John Kenneth
- Division of Infectious Disease, St. John's Research Institute, Bangalore, India
- * E-mail:
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Kato-Maeda M, Metcalfe JZ, Flores L. Genotyping of Mycobacterium tuberculosis: application in epidemiologic studies. Future Microbiol 2011; 6:203-16. [PMID: 21366420 DOI: 10.2217/fmb.10.165] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Genotyping is used to track specific isolates of Mycobacterium tuberculosis in a community. It has been successfully used in epidemiologic research (termed 'molecular epidemiology') to study the transmission dynamics of TB. In this article, we review the genetic markers used in molecular epidemiologic studies including the use of whole-genome sequencing technology. We also review the public health application of molecular epidemiologic tools.
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Affiliation(s)
- Midori Kato-Maeda
- University of California, San Francisco, Francis J Curry National Tuberculosis Center, Division of Pulmonary & Critical Care Medicine, San Francisco General Hospital, 1001 Potrero Avenue, Building 100, Room 109, Mail box 0841, San Francisco, CA 94110-0111, USA
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Geojith G, Dhanasekaran S, Chandran SP, Kenneth J. Efficacy of loop mediated isothermal amplification (LAMP) assay for the laboratory identification of Mycobacterium tuberculosis isolates in a resource limited setting. J Microbiol Methods 2010; 84:71-3. [PMID: 21047534 DOI: 10.1016/j.mimet.2010.10.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 10/05/2010] [Accepted: 10/21/2010] [Indexed: 10/18/2022]
Abstract
Current methods of TB diagnosis are time consuming and less suited for developing countries. The LAMP (loop mediated isothermal amplification) is a rapid method more suitable for diagnosis in resource limited settings and has been proposed as a viable test requiring further evaluation for use as a laboratory method as well. We evaluated two LAMP assays, using culture lysates of clinical sputum samples (from Southern India) and compared it to a proprietary multiplex PCR reverse-hybridization line probe assay ('GenoType MTBC' from HAIN Lifescience GmbH, Germany). The LAMP procedure was modified to suit the local conditions. The Mycobacterium tuberculosis specific LAMP assay ('MTB LAMP') showed sensitivity and specificity, of 44.7% and 94.4% respectively in a 60 min format, 85.7% and 93.9% respectively in a 90 min format and 91.7%, and 90.9% respectively in a 120 min format. The Mycobacteria universal LAMP assay ('Muniv LAMP') showed a sensitivity of 99.1%. The LAMP was shown to be a rapid and accessible assay for the laboratory identification of M. tuberculosis isolates. Initial denaturation of template was shown to be essential for amplification in unpurified/dilute samples and longer incubation was shown to increase the sensitivity. The need for modification of protocols to yield better efficacy in this scenario needs to be addressed in subsequent studies.
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Affiliation(s)
- G Geojith
- Infectious disease unit, St. John's Research Institute, Bangalore, India
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