Genotyping and Drug Susceptibility Patterns of M. Tuberculosis Isolated from HIV Seropositive Patients in Tehran Iran

Abstract

Aim: To investigate the prevalence and drug-resistance M. tuberculosis isolated from HIV seropositive individuals in Tehran, Iran. Background: Human immunodeficiency virus (HIV) is one of the most important risk factors for developing active tuberculosis (TB). Objective: To determine the rate of transmission and drug resistant M. tuberculosis (MTB) strains isolated from HIV seropositive patients in Tehran province, Iran. Methods: This study consecutively enrolled 217 TB/HIV coinfected patients from April 2018 to August 2019 at Emam Khomeini referral hospital and 5 other health centers in Tehran province. The isolates were genotyped using 15 loci Mycobacterial interspersed repetitive unit-variable number tandem repeats (MIRU-VNTR). Minimum inhibitory concentration (MIC) was determined for 6 drugs. In addition, mutations were assessed in rpoB, katG, inhA, and ahpC genes using Reverse Blot Hybridization Assay System. Results: A 20 (9.2%) patients were culture-positive for M. tuberculosis and typed by MIRU-VNTR, 13 (65%) strains formed 5 clusters, but 6 (30%) isolates had a unique pattern. The total Hunter– Gaston discrimination index (HGDI) for all 15 loci was 0.846, and the cluster size was 2 to 4 patients. The estimated proportion of recent transmission was 45%. The mutation was identified in 1 isolate, lost inhAW1 and mutation in MT1 loci, which was resistant to isoniazid (INH). Moreover, 1 (5%) and 3 (15%) isolates were resistant to INH and ethambutol (EMB), respectively, of which 1 was resistant to INH and EMB. Conclusion: The transmission rate of TB in HIV patients was relatively high; however, the prevalence of drug-resistant strains and TB infection in females was insignificant in this study (p<0.05); none of the isolates was MDR strains.