1
|
Wulandari DA, Hartati YW, Ibrahim AU, Pitaloka DAE, Irkham. Multidrug-resistant tuberculosis. Clin Chim Acta 2024; 559:119701. [PMID: 38697459 DOI: 10.1016/j.cca.2024.119701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/05/2024]
Abstract
One of predominant contributors to global mortality is tuberculosis (TB), an infection caused by Mycobacterium tuberculosis (MTB). Inappropriate and ineffectual treatment can lead to the development of drug-resistant TB. One of the most common forms of drug-resistant TB is multidrug-resistant tuberculosis (MDR-TB), caused by mutations in the rpoB and katG genes that lead to resistance to anti-TB drugs, rifampicin (RIF) and isoniazid (INH), respectively. Although culturing remains the gold standard, it is not rapid thereby delaying potential treatment and potentially increasing the incidence of MDR-TB. In contrast, molecular techniques provide a highly sensitive and specific alternative. This review discusses the classification of biomarkers used to detect MDR-TB, some of the commonly used anti-TB drugs, and DNA mutations in MTB that lead to anti-TB resistance. The objective of this review is to increase awareness of the need for rapid and precise detection of MDR-TB cases to decrease morbidity and mortality of this infectious disease worldwide.
Collapse
Affiliation(s)
- Dika Apriliana Wulandari
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, 45363, Indonesia
| | - Yeni Wahyuni Hartati
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, 45363, Indonesia
| | - Abdullahi Umar Ibrahim
- Department of Biomedical Engineering, Near East University, Mersin 10, Nicosia 99010, Turkey; Research Center for Science, Technology and Engineering (BILTEM), Near East University, 99138 Nicosia, TRNC, Mersin 10, Turkey
| | - Dian Ayu Eka Pitaloka
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, Universitas Padjadjaran, Bandung, Indonesia
| | - Irkham
- Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, 45363, Indonesia.
| |
Collapse
|
2
|
Rajendran A, Palaniyandi K. Mutations Associated with Pyrazinamide Resistance in Mycobacterium tuberculosis: A Review and Update. Curr Microbiol 2022; 79:348. [PMID: 36209317 DOI: 10.1007/s00284-022-03032-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 09/06/2022] [Indexed: 11/03/2022]
Abstract
Pyrazinamide (PZA) has remained a keystone of tuberculosis (TB) therapy, and it possesses high imperative sterilizing action that can facilitate reduction in the present chemotherapy regimen. The combination of PZA works both with first- and second-line TB drugs, notably fluoroquinolones, clofazimine, bedaquiline, delamanid and pretomanid. Pyrazinamide inhibits various targets that are involved in different cellular processes like energy production (pncA), trans-translation (rpsA) and pantothenate/coenzyme A (panD) which are required for persistence of the pathogen. It is well known that pncA gene encoding pyrazinamidase is involved in the transition of PZA into the active form of pyrazinoic acid, which implies that mutation in the pncA gene can develop PZA resistance in Mycobacterium tuberculosis (M. tuberculosis) strain leading to a major clinical and public health concern. Therefore, it is very crucial to understand its resistance mechanism and to detect it precisely to help in the management of the disease. Scope of this review is to have a deep understanding of molecular mechanism of PZA resistance with its multiple targets which would help study the association of mutations and its resistance in M. tuberculosis. This will in turn help learn about the resistance of PZA and develop more accurate molecular diagnostic tool for drug-resistant TB in future TB therapy.
Collapse
Affiliation(s)
- Ananthi Rajendran
- Department of Immunology, ICMR-National Institute for Research in Tuberculosis, #1, Mayor Sathyamoorthy Road, Chetpet, Chennai, 600031, India
| | - Kannan Palaniyandi
- Department of Immunology, ICMR-National Institute for Research in Tuberculosis, #1, Mayor Sathyamoorthy Road, Chetpet, Chennai, 600031, India.
| |
Collapse
|
3
|
Tagliani E, Nikolayevskyy V, Tortoli E, Cirillo DM. Laboratory diagnosis of tuberculosis. Tuberculosis (Edinb) 2018. [DOI: 10.1183/2312508x.10021318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
4
|
Baddam R, Kumar N, Wieler LH, Lankapalli AK, Ahmed N, Peacock SJ, Semmler T. Analysis of mutations in pncA reveals non-overlapping patterns among various lineages of Mycobacterium tuberculosis. Sci Rep 2018; 8:4628. [PMID: 29545614 PMCID: PMC5854631 DOI: 10.1038/s41598-018-22883-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/01/2018] [Indexed: 02/06/2023] Open
Abstract
Pyrazinamide (PZA) is an important first-line anti-tuberculosis drug, resistance to which occurs primarily due to mutations in pncA (Rv2043c) that encodes the pyrazinamidase enzyme responsible for conversion of pro-drug PZA into its active form. Previous studies have reported numerous resistance-conferring mutations distributed across the entire length of pncA without any hotspot regions. As different lineages of Mycobacterium tuberculosis display a strong geographic association, we sought to understand whether the genetic background influenced the distribution of mutations in pncA. We analyzed the whole genome sequence data of 1,480 clinical isolates representing four major M. tuberculosis lineages to identify the distribution of mutations in the complete operon (Rv2044c-pncA-Rv2042c) and its upstream promoter region. We observed a non-overlapping pattern of mutations among various lineages and identified a lineage 3-specific frame-shift deletion in gene Rv2044c upstream of pncA that disrupted the stop codon and led to its fusion with pncA. This resulted in the addition of a novel domain of unknown function (DUF2784) to the pyrazinamidase enzyme. The variant molecule was computationally modelled and physico-chemical parameters determined to ascertain stability. Although the functional impact of this mutation remains unknown, its lineage specific nature highlights the importance of genetic background and warrants further study.
Collapse
Affiliation(s)
- Ramani Baddam
- Robert Koch Institute, Berlin, 13353, Germany
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, Bangladesh
| | - Narender Kumar
- Department of Clinical Medicine, University of Cambridge, Cambridge, CB2 0QQ, United Kingdom
| | | | - Aditya Kumar Lankapalli
- Department of Biotechnology and Bioinformatics, Pathogen Biology Laboratory, School of Life Sciences, University of Hyderabad, Hyderabad, 500084, India
- Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Niyaz Ahmed
- Department of Biotechnology and Bioinformatics, Pathogen Biology Laboratory, School of Life Sciences, University of Hyderabad, Hyderabad, 500084, India
- Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, 1212, Bangladesh
| | - Sharon J Peacock
- Department of Clinical Medicine, University of Cambridge, Cambridge, CB2 0QQ, United Kingdom
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | | |
Collapse
|
5
|
Azam K, Cadir N, Madeira C, Gillespie SH, Sabiiti W. OMNIgene.SPUTUM suppresses contaminants while maintaining Mycobacterium tuberculosis viability and obviates cold-chain transport. ERJ Open Res 2018; 4:00074-2017. [PMID: 29479537 PMCID: PMC5814761 DOI: 10.1183/23120541.00074-2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 12/19/2017] [Indexed: 11/17/2022] Open
Abstract
Tuberculosis (TB) diagnostics are centralised, requiring long-distance transportation of specimens in most resource-limited settings. We evaluated the ability of OMNIgene.SPUTUM (OM-S) to obviate cold-chain transport of TB specimens. A two-arm (same-day and after 5 days sample processing) study was conducted to assess contamination rates and Mycobacterium tuberculosis viability in OM-S-treated samples against the standard decontamination procedure (SDP) in Mozambique, using Lowenstein Jensen (LJ) and mycobacterial growth indicator tube (MGIT) culture and molecular bacterial load assay. 270 specimens were processed using OM-S and SDP in same-day and 5-day arms. Contamination was lower in OM-S-treated than SDP-treated cultures: 12% versus 15% and 2% versus 27% in the same-day and 5-day arms, respectively. M. tuberculosis recovery in OM-S-treated LJ cultures was 10% and 56% higher in the same-day and 5-day arms, respectively, than SDP-treated cultures, but lower in MGIT (52% and 28% lower in the same-day and 5-day arms, respectively). M. tuberculosis viable count was 1log estimated CFU·mL-1 lower in 5-day OM-S-treated sputa. OM-S was more effective at liquefying sputum with a shorter sample processing time: 22 min for culture. OM-S is simple to use and has demonstrated a high potency to suppress contaminants, maintenance of viability at ambient temperatures and higher M. tuberculosis recovery, particularly in the solid LJ cultures. Optimisation of OM-S to achieve higher MGIT culture positivity and shorter time to result will increase its application and utility in the clinical management of TB.
Collapse
Affiliation(s)
- Khalide Azam
- Instituto Nacional de Saúde National Tuberculosis Reference Laboratory, Maputo, Mozambique
| | | | - Carla Madeira
- Instituto Nacional de Saúde National Tuberculosis Reference Laboratory, Maputo, Mozambique
| | | | - Wilber Sabiiti
- University of St Andrews School of Medicine, St Andrews, UK
| |
Collapse
|
6
|
Islam MM, Hameed HMA, Mugweru J, Chhotaray C, Wang C, Tan Y, Liu J, Li X, Tan S, Ojima I, Yew WW, Nuermberger E, Lamichhane G, Zhang T. Drug resistance mechanisms and novel drug targets for tuberculosis therapy. J Genet Genomics 2016; 44:21-37. [PMID: 28117224 DOI: 10.1016/j.jgg.2016.10.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/26/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
Drug-resistant tuberculosis (TB) poses a significant challenge to the successful treatment and control of TB worldwide. Resistance to anti-TB drugs has existed since the beginning of the chemotherapy era. New insights into the resistant mechanisms of anti-TB drugs have been provided. Better understanding of drug resistance mechanisms helps in the development of new tools for the rapid diagnosis of drug-resistant TB. There is also a pressing need in the development of new drugs with novel targets to improve the current treatment of TB and to prevent the emergence of drug resistance in Mycobacterium tuberculosis. This review summarizes the anti-TB drug resistance mechanisms, furnishes some possible novel drug targets in the development of new agents for TB therapy and discusses the usefulness using known targets to develop new anti-TB drugs. Whole genome sequencing is currently an advanced technology to uncover drug resistance mechanisms in M. tuberculosis. However, further research is required to unravel the significance of some newly discovered gene mutations in their contribution to drug resistance.
Collapse
Affiliation(s)
- Md Mahmudul Islam
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - H M Adnan Hameed
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Julius Mugweru
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chiranjibi Chhotaray
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changwei Wang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; Institute of Chemical Biology and Drug Discovery, Stony Brook University-State University of New York, Stony Brook, NY 11794-3400, USA
| | - Yaoju Tan
- State Key Laboratory of Respiratory Disease, Department of Clinical Laboratory, The Guangzhou Chest Hospital, Guangzhou 510095, China
| | - Jianxiong Liu
- State Key Laboratory of Respiratory Disease, Department of Clinical Laboratory, The Guangzhou Chest Hospital, Guangzhou 510095, China
| | - Xinjie Li
- State Key Laboratory of Respiratory Disease, Department of Clinical Laboratory, The Guangzhou Chest Hospital, Guangzhou 510095, China
| | - Shouyong Tan
- State Key Laboratory of Respiratory Disease, Department of Clinical Laboratory, The Guangzhou Chest Hospital, Guangzhou 510095, China
| | - Iwao Ojima
- Institute of Chemical Biology and Drug Discovery, Stony Brook University-State University of New York, Stony Brook, NY 11794-3400, USA
| | - Wing Wai Yew
- Stanley Ho Centre for Emerging Infectious Diseases, The Chinese University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Eric Nuermberger
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University, Baltimore, MD 21231-1002, USA
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins University, Baltimore, MD 21231-1002, USA
| | - Tianyu Zhang
- State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
7
|
Njire M, Tan Y, Mugweru J, Wang C, Guo J, Yew W, Tan S, Zhang T. Pyrazinamide resistance in Mycobacterium tuberculosis: Review and update. Adv Med Sci 2016; 61:63-71. [PMID: 26521205 DOI: 10.1016/j.advms.2015.09.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 07/29/2015] [Accepted: 09/17/2015] [Indexed: 11/28/2022]
Abstract
The global control and management of tuberculosis (TB) is faced with the formidable challenge of worsening scenarios of drug-resistant disease. Pyrazinamide (PZA) is an indispensable first-line drug used for the treatment of TB. It plays a key role in reducing TB relapse rates, shortening the course of the disease treatment from 9-12 months to 6 months, and the treatment of patients infected with bacillary strains that are resistant to at least isoniazid and rifampicin. Additionally, it is the only first-line anti-TB drug most likely to be maintained in all new regimens, which are aimed at reducing the treatment period of susceptible, multi-drug resistant and extensively drug-resistant TB. It has a preferential sterilizing activity against non-replicating persister bacilli with low metabolism at acid pH in vitro or in vivo during active inflammation where other drugs may not act so well. PZA seem to have a non-specific cellular target and instead, exerts its anti-mycobacterial effect by disrupting the membrane energetics, the trans-translation process, acidification of the cytoplasm and perhaps coenzyme A synthesis, which is required for survival of Mycobacterium tuberculosis (MTB) persisters. Indeed, the emergence of MTB strains resistant to PZA represents an important clinical and public health problem. The essential role of PZA in TB treatment underlines the need for accurate and rapid detection of its resistance. This article presents an updated review of the molecular mechanisms of drug action and resistance in MTB against PZA, commenting on the several research gaps and proposed drug targets for PZA.
Collapse
|
8
|
Miotto P, Cirillo DM, Migliori GB. Drug resistance in Mycobacterium tuberculosis: molecular mechanisms challenging fluoroquinolones and pyrazinamide effectiveness. Chest 2015; 147:1135-1143. [PMID: 25846529 DOI: 10.1378/chest.14-1286] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Physicians are more and more often challenged by difficult-to-treat cases of TB. They include patients infected by strains of Mycobacterium tuberculosis that are resistant to at least isoniazid and rifampicin (multidrug-resistant TB) or to at least one fluoroquinolone (FQ) and one injectable, second-line anti-TB drug in addition to isoniazid and rifampicin (extensively drug-resistant TB). The drug treatment of these cases is very long, toxic, and expensive, and, unfortunately, the proportion of unsatisfactory outcomes is still considerably high. Although FQs and pyrazinamide (PZA) are backbone drugs in the available anti-TB regimens, several uncertainties remain about their mechanisms of action and even more remain about the mechanisms leading to drug resistance. From a clinical point of view, a better understanding of the genetic basis of drug resistance will aid (1) clinicians to provide quality clinical management to both drug-susceptible and drug-resistant TB cases (while preventing emergence of further resistance), and (2) developers of new molecular-based diagnostic assays to better direct their research efforts toward a new generation of sensitive, specific, cheap, and easy-to-use point-of-care diagnostics. In this review we provide an update on the molecular mechanisms leading to FQ- and PZA-resistance in M tuberculosis.
Collapse
Affiliation(s)
- Paolo Miotto
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Daniela M Cirillo
- Emerging Bacterial Pathogens Unit, Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Giovanni Battista Migliori
- WHO Collaborating Centre for TB and Lung Diseases, Fondazione S. Maugeri, Care and Research Institute, Tradate, Italy.
| |
Collapse
|
9
|
Martinez E, Holmes N, Jelfs P, Sintchenko V. Genome sequencing reveals novel deletions associated with secondary resistance to pyrazinamide in MDR Mycobacterium tuberculosis. J Antimicrob Chemother 2015; 70:2511-4. [PMID: 25977398 DOI: 10.1093/jac/dkv128] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/16/2015] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVES Detection of pyrazinamide resistance in Mycobacterium tuberculosis isolates presents significant challenges in settings with no dominant clonal lineages, such as Australia. We assessed the utility of WGS versus standard PCR amplification assays for the characterization of pyrazinamide resistance in MDR-TB isolates identified in New South Wales, Australia, over an 8 year period. METHODS PCR amplicon sequencing was used to identify molecular markers associated with antibiotic resistance in pyrazinamide-resistant MDR-TB isolates recovered by the New South Wales Mycobacterium Reference Laboratory between 2007 and 2014. WGS was subsequently performed on two isolates for which pncA amplification failed. RESULTS WGS identified two novel genomic deletions associated with in vitro resistance to pyrazinamide in MDR-TB. One isolate also carried a second deletion involving the genes dfrA and thyA associated with resistance to para-aminosalicylic acid. CONCLUSIONS Steadily decreasing sequencing costs are increasing the appeal of WGS as an alternative approach for detecting complex patterns of pyrazinamide resistance in MDR-TB.
Collapse
Affiliation(s)
- Elena Martinez
- Centenary Institute, Sydney, Australia Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia NSW Mycobacterium Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research-Pathology West, Sydney, Australia Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| | - Nadine Holmes
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia NSW Mycobacterium Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research-Pathology West, Sydney, Australia Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| | - Peter Jelfs
- NSW Mycobacterium Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research-Pathology West, Sydney, Australia Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| | - Vitali Sintchenko
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Sydney, Australia NSW Mycobacterium Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research-Pathology West, Sydney, Australia Centre for Infectious Diseases and Microbiology-Public Health, Westmead Hospital, Western Sydney Local Health District, Sydney, Australia
| |
Collapse
|
10
|
Genetic determinants involved in p-aminosalicylic acid resistance in clinical isolates from tuberculosis patients in northern China from 2006 to 2012. Antimicrob Agents Chemother 2014; 59:1320-4. [PMID: 25421465 DOI: 10.1128/aac.03695-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
p-Aminosalicylic acid (PAS) is an important compound for treating multidrug-resistant tuberculosis (TB). Previous studies showed that thyA mutations are often related to PAS resistance in clinical isolates. We performed a systematic analysis of isolate genotypes and detected mutations in three folate pathway genes (folC, thyA, and ribD) in 61.1% (127/208) of PAS-resistant isolates, including 11 double mutants. This result expands our knowledge about the distribution and frequency of mutations related to PAS resistance in mycobacterial clinical isolates.
Collapse
|
11
|
Abstract
Pyrazinamide (PZA) is a prodrug that is converted to pyrazinoic acid by the enzyme pyrazinamidase, encoded by the pncA gene in Mycobacterium tuberculosis. Molecular identification of mutations in pncA offers the potential for rapid detection of pyrazinamide resistance (PZAr). However, the genetic variants are highly variable and scattered over the full length of pncA, complicating the development of a molecular test. We performed a large multicenter study assessing pncA sequence variations in 1,950 clinical isolates, including 1,142 multidrug-resistant (MDR) strains and 483 fully susceptible strains. The results of pncA sequencing were correlated with phenotype, enzymatic activity, and structural and phylogenetic data. We identified 280 genetic variants which were divided into four classes: (i) very high confidence resistance mutations that were found only in PZAr strains (85%), (ii) high-confidence resistance mutations found in more than 70% of PZAr strains, (iii) mutations with an unclear role found in less than 70% of PZAr strains, and (iv) mutations not associated with phenotypic resistance (10%). Any future molecular diagnostic assay should be able to target and identify at least the very high and high-confidence genetic variant markers of PZAr; the diagnostic accuracy of such an assay would be in the range of 89.5 to 98.8%. Conventional phenotypic testing for pyrazinamide resistance in Mycobacterium tuberculosis is technically challenging and often unreliable. The development of a molecular assay for detecting pyrazinamide resistance would be a breakthrough, directly overcoming both the limitations of conventional testing and its related biosafety issues. Although the main mechanism of pyrazinamide resistance involves mutations inactivating the pncA enzyme, the highly diverse genetic variants scattered over the full length of the pncA gene and the lack of a reliable phenotypic gold standard hamper the development of molecular diagnostic assays. By analyzing a large number of strains collected worldwide, we have classified the different genetic variants based on their predictive value for resistance which should lead to more rapid diagnostic tests. This would assist clinicians in improving treatment regimens for patients.
Collapse
|
12
|
Köser CU, Ellington MJ, Peacock SJ. Whole-genome sequencing to control antimicrobial resistance. Trends Genet 2014; 30:401-7. [PMID: 25096945 PMCID: PMC4156311 DOI: 10.1016/j.tig.2014.07.003] [Citation(s) in RCA: 187] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/10/2014] [Accepted: 07/14/2014] [Indexed: 11/18/2022]
Abstract
Following recent improvements in sequencing technologies, whole-genome sequencing (WGS) is positioned to become an essential tool in the control of antibiotic resistance, a major threat in modern healthcare. WGS has already found numerous applications in this area, ranging from the development of novel antibiotics and diagnostic tests through to antibiotic stewardship of currently available drugs via surveillance and the elucidation of the factors that allow the emergence and persistence of resistance. Numerous proof-of-principle studies have also highlighted the value of WGS as a tool for day-to-day infection control and, for some pathogens, as a primary diagnostic tool to detect antibiotic resistance. However, appropriate data analysis platforms will need to be developed before routine WGS can be introduced on a large scale.
Collapse
Affiliation(s)
- Claudio U Köser
- Department of Medicine, University of Cambridge, Cambridge, UK.
| | - Matthew J Ellington
- Clinical Microbiology and Public Health Laboratory, Public Health England, Cambridge, UK
| | - Sharon J Peacock
- Department of Medicine, University of Cambridge, Cambridge, UK; Clinical Microbiology and Public Health Laboratory, Public Health England, Cambridge, UK; Cambridge University Hospitals National Health Service Foundation Trust, Cambridge, UK; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| |
Collapse
|