Major genotype families and epidemic clones of Mycobacterium tuberculosis in Omsk region, Western Siberia, Russia, marked by a high burden of tuberculosis-HIV coinfection

Abstract

This population-based study characterized Mycobacterium tuberculosis isolates from HIV-positive and HIV-negative tuberculosis (TB) patients in the Omsk region in Western Siberia, Russia. We sought to gain insight into the major genotype families and epidemic and endemic clones of M. tuberculosis in the area with a high burden and adverse trend of TB/HIV coinfection. The study collection included M. tuberculosis isolates from 207 newly-diagnosed patients with pulmonary TB; 55 (26.5%) of patients were HIV-infected. The M. tuberculosis isolates were subjected to drug susceptibility testing and molecular typing based on spoligotyping and analysis of the robust genotype and cluster-specific markers. Patients with disseminated TB disease were more prevalent in the HIV-positive (34.5%) than in the HIV-negative group (4.6%) (P < .001). The Beijing genotype was predominant (62.3% of isolates), and its major subtypes were 94-32-cluster (Central Asian/Russian strain, n = 80) and B0/W148-cluster (successful Russian strain, n = 28). The main non-Beijing families were represented by Latin-American Mediterranean (14.5%), T family (11.1%), Ural (5.8%), and Haarlem (3.9%). Under multivariate logistic regression analysis, MDR was associated with Beijing genotype and not associated with HIV coinfection status (P < .001). Beijing genotype isolates were found more frequently in TB/HIV patients than in TB HIV-negative patients (74.5% versus 57.9%, respectively; P = .031). The non-Beijing genotypes were mainly drug susceptible except for the drug-resistant Ural SIT262 isolates. To summarize, the alarming situation in the Omsk region in Siberia regarding TB/HIV coinfection is seriously influenced by the active circulation of M. tuberculosis isolates of MDR-associated Beijing genotype. Among the non-Beijing families, emergence of the drug-resistant Ural family strains of spoligotype SIT262 warrants attention.