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Background: Mycobacterium tuberculosis genotyping has been crucial to determining the distribution and impact of different families on disease clinical presentation. The aim of the study was to evaluate the associations among sociodemographic and clinical characteristics and M. tuberculosis lineages from patients with pulmonary tuberculosis in Orizaba, Veracruz, Mexico. Methods: We analyzed data from 755 patients whose isolates were typified by 24-loci mycobacterial interspersed repetitive unit–variable number of tandem repeats (MIRU–VNTR). The associations among patient characteristics and sublineages found were evaluated using logistic regression analysis. Results: Among M. tuberculosis isolates, 730/755 (96.6%) were assigned to eight sublineages of lineage 4 (Euro-American). Alcohol consumption (adjusted odds ratio [aOR] 1.528, 95% confidence interval (CI) 1.041–2.243; p = 0.030), diabetes mellitus type 2 (aOR 1.625, 95% CI 1.130–2.337; p = 0.009), sputum smear positivity grade (3+) (aOR 2.198, 95% CI 1.524–3.168; p < 0.001) and LAM sublineage isolates (aOR 1.023, 95% CI 1.023–2.333; p = 0.039) were associated with the presence of cavitations. Resistance to at least one drug (aOR 25.763, 95% CI 7.096–93.543; p < 0.001) and having isolates other than Haarlem and LAM sublineages (aOR 6.740, 95% CI 1.704–26.661; p = 0.007) were associated with treatment failure. In a second model, multidrug resistance was associated with treatment failure (aOR 31.497, 95% CI 5.119–193.815; p < 0.001). Having more than 6 years of formal education was not associated with treatment failure. Conclusions: Knowing M. tuberculosis genetic diversity plays an essential role in disease development and outcomes, and could have important implications for guiding treatment and improving tuberculosis control. [ABSTRACT FROM AUTHOR]

Tuberculosis is a global human health threat, especially in developing countries. The present study aimed to describe the genetic diversity of Mycobacterium tuberculosis and to measure the transmission rates of primary and acquired resistance. A total of 755 M. tuberculosis isolates from a cohort study of patients with culture-confirmed pulmonary tuberculosis in Orizaba, Veracruz, performed between 1995 and 2010 were genotyped by the 24-locus mycobacterial interspersed repetitive unit–variable number of tandem repeats (MIRU-VNTR) method. Drug susceptibility was determined. Logistic regression models were constructed to identify the variables associated with resistance and clusters. The recent transmission index (RTI), the Hunter-Gaston discrimination index (HGDI) for the MIRU-VNTR test and allelic diversity (h) were calculated. The Haarlem and LAM lineages were the most common in the population. A total of 519 isolates were grouped into 128 clusters. The overall drug resistance rate was 19%, isoniazid monoresistance (10%) was the most common, and 3.4% of the isolates were multidrug resistant. Among the 116 isolates resistant to at least one drug, the primary and acquired resistance rates were 81.9% and 18.1%, respectively. Primary resistance was associated with belonging to a cluster (aOR 4.05, 95% CI 1.5–11.2, p = 0.007). Previous treatment history (aOR 9.05, 95% CI 3.6–22.5, p < 0.001) and LAM lineage (aOR 4.25, 95% CI 1.4–12.7, p = 0.010) were associated with multidrug-resistant tuberculosis (MDR-TB). The RTI was 51.7%, and the 24-locus MIRU-VNTR HGDI was 0.98. The alleles with the greatest diversity were 4056-QUB26 (h = 0.84), 2163b-QUB11b (h = 0.79), and 424-Mtub04 (h = 0.72). Primary resistance transmission, high LAM lineage prevalence and its association with MDR-TB represent public health problems. The implementation of molecular tools is needed to improve the existing control surveillance tuberculosis program. • Haarlem and LAM were the most prevalent M. tuberculosis lineages in Southern Mexico. • Recent Transmission Index (RTI) was high (51.7%). • Population was affected by high transmission rates of primary resistance. • LAM lineage isolates and patients previously treated were associated with MDR-TB. [ABSTRACT FROM AUTHOR]