Geographical location and genotyping analysis of pulmonary tuberculosis in the state of Nuevo Leon, Mexico

Tuberculosis, caused by Mycobacterium tuberculosis, is a major global health problem. In Mexico, the State of Nuevo Leon is among the top ten in tuberculosis morbidity. Information about transmission patterns and case clustering for tuberculosis in Nuevo Leon is limited. The spoligotypes of 151 isolates from newly diagnosed pulmonary tuberculosis patients were obtained and its phenotypic drug susceptibility pattern for streptomycin, isoniazid, rifampin, ethambutol, and pyrazinamide was determined by using the Mycobacteria Growth Indicator Tube fluorometric method. Geographical data of isolates were mapped using geographic information systems. Nineteen M. tuberculosis sublineages were identified. The most frequent lineages were: T1 at 35% (n = 53), X1 at 19.2% (n = 29), and LAM at 10.2% (n = 15). Additionally, we identified the Beijing lineage (3.3%, n = 5) and orphan strains (9.9%, n = 15). Drug resistant strains were 25 (16.55%) DR-TB, 15 (9.93%) MDR/RR-TB and 6 (3.97%) Hr-TB. Regarding TB comorbidities, diabetes mellitus II affected 21.85% of patients, while four patients were HIV-positive (2.65%). Despite the large number of tuberculosis cases in Monterrey, no definitive correlation with clusters and comorbidities was found. However, our results suggest a potential TB transmission hotspot for the T1 lineage within the Monterrey metropolitan area.