Molecular characterization of mycobacterium tuberculosis isolates from extrapulmonary tuberculosis EPTB patents at a tertiary care hospital of uttarakhand

Abstract

Extrapulmonary Tuberculosis (EPTB) has become an important entity newlinedue to its rising trend in last few years. The clinical presentation of EPTB, newlinepaucibacillary nature of specimens, inaccessible sites, non-uniform distribution of newlinebacilli are few challenges in disease diagnosis and management. Drug resistance in newlineEPTB cases is another challenge leading to high morbidity, mortality and increase in newlineburden of disease globally. newlineAim: The study was designed to explore the rate of EPTB cases and analyze the newlinemolecular profile of the recovered isolates. newlineMaterials and Methods: In this cross-sectional study 640 extrapulmonary samples were newlinecollected from 612 subjects clinically or radiologically suspected as EPTB. All newlineextrapulmonary samples were subjected to smear microscopy, culture and real time newlinepolymerase chain reaction (PCR) for microbiological confirmation. Molecular profile newlineof recovered isolates was done by PCR and reverse hybridization. newlineResults: Among 612 subjects suspected of EPTB 141 subjects (23.0%) were newlinemicrobiologically confirmed as EPTB. Almost half of the EPTB positive cases newline(45.0%) were from the 21 to 40 years of age group. The percentage of males and newlinefemales affected by the disease was equal i.e. males and females being 49.6% and newline50.4% respectively. The positivity rate of smear microscopy, culture and real time newlinePCR in various extrapulmonary samples was 5.3%, 13.1% and 25.8% respectively. newlinexxxiv newlineSensitivity and specificity of nucleic acid amplification tests (NAAT) and smear newlinemicroscopy comparing with gold standard was 100% and 87.7% and 40.5% and 100% newlinerespectively. The rate of drug resistant-EPTB (DR-EPTB) cases in our study was newline38.6% with the maximum resistant isolates recovered from samples of 21 to 40 years newlineage group. The most common mutation observed in Rifampicin (RIF) resistant and newlineIsoniazid (INH) resistant isolates were S531L codon in rpoand#946; gene and S315T codon newlinein katG gene of Mycobacterium tuberculosis (MTB) respectively. The highest EPTB newlinepositivity was observed from Dehradun whereas maximum