title: High degree of multi-drug resistance and hetero-resistance in pulmonary TB patients from Punjab state of India.
abstract: Line Probe Assays (LPAs) have been recommended for rapid screening of MDR-TB. Aims of this study were (1) to compare the performance of LPA with standard Bactec MGIT 960 system and (2) to ascertain the pattern of genetic mutations in the resistance isolates. In phase I, a total of 141 Mycobacterium tuberculosis isolates from our routine laboratory were tested by LPA and Bactec MGIT 960 for DST. In phase II, 578 sputum specimens of suspected DR-TB patients were received from the Punjab state of India. Of them 438 specimens or their cultures were subjected to LPA. The presence of mutant bands with their corresponding wild type band was identified as "hetero-resistance". In phase I, LPA showed high concordance with 96.4% positive agreement and 97.6% negative agreement with Bactec MGIT 960-DST. In phase II, 12 (2.7%) specimens were detected as invalid by LPA. Of the remaining 426 specimens, 184 (43.1%) had resistance to RIF and 142 (33.3%) to INH while 103 (24.1%) specimens showed resistance to both INH and RIF (MDR-TB) by LPA. Of the 142 INH resistant, 113 (79.5%) showed mutations in katG and 29 (20.4%) in inhA. A high rate of hetero-resistance pattern was observed in rpoB gene (28.8%) and katG gene (9.8%). The most frequent mutation was S531L (81.1%) in rpoB region and S315T1 (100%) in katG gene.
authors.affiliation: Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi 110 029, India.
authors.forename: Parveen
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi 110 029, India.
authors.forename: Veena
authors.initials: V
authors.lastname: Balooni
authors.affiliation: Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi 110 029, India.
authors.forename: Brijesh Kumar
authors.initials: BK
authors.lastname: Sharma
authors.affiliation: Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi 110 029, India.
authors.forename: Virender
authors.initials: V
authors.lastname: Kapil
authors.affiliation: Central TB Division, Directorate General of Health Services, Ministry of Health and Family Welfare, Government of India, New Delhi, India.
authors.forename: K S
authors.initials: KS
authors.lastname: Sachdeva
authors.affiliation: Division of Clinical Microbiology and Molecular Medicine, All India Institute of Medical Sciences, New Delhi 110 029, India. Electronic address: sarman_singh@yahoo.com.
authors.forename: Sarman
authors.initials: S
authors.lastname: Singh
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D002374:Catalase / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D008826:Microbial Sensitivity Tests; D025202:Molecular Diagnostic Techniques; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D013183:Sputum / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000235:genetics* / Q000276:immunology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000235:genetics* / Q000276:immunology; D044465:White People / Q000235:genetics
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; C505805:rpoB protein, Mycobacterium tuberculosis; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; D012321:DNA-Directed RNA Polymerases
keywords: Isoniazid; Line Probe Assay; MTBDRplus; Mycobacterium tuberculosis; Rifampicin