Molecular epidemiology and drug resistance of Mycobacterium tuberculosis in a tertiary care hospital in northeastern Mexico

Introduction: Tuberculosis (TB) is a re-emerging disease considered a public health concern. In the present study, we analyzed the epidemiology and drug resistance of Mycobacterium tuberculosis strains isolated from patients with pulmonary TB. Methodology: Mycobacterium tuberculosis isolates (n = 190) were obtained from patients with pulmonary TB admitted to Dr. Jose Eleuterio Gonzalez University Hospital (UH). Each M. tuberculosis isolate was analyzed by spoligotyping (spacer oligonucleotide typing) and MIRUVNTR (Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat). Drug resistance was evaluated using the AnyplexTM II MTB/MDR/XDR assay. Results: The predominant spoligotypes observed were X1 (SIT 119, n = 46), T1 (SIT 53, n = 40), H3 (SIT 50, n = 13), Beijing (SIT 1, n = 11), and EAI2-Manila (SIT 19, n = 8). MIRU-VNTR analysis showed that the locus QUB-26 had the highest allelic variability. The observed drug resistance included monoresistance to rifampicin (2.6%; n = 5), isoniazid (3.2%; n = 6), and fluoroquinolones (1.6%; n = 3) as well as multidrug resistance (5.3%; n = 10). All of the Beijing strains were susceptible. Regarding comorbidities, 13.7% (26/190) of the patients were co-infected with TB and HIV (TB+HIV+), and 31.6% (55/190) had TB along with diabetes (TB + diabetes). Conclusions: The most prevalent lineages were X1 (SIT 119; 24.3%) and T1 (SIT 53; 21%). An alarming proportion (12.6%) of M. tuberculosis isolates presented drug resistance. To effectively manage TB, continuous surveillance of regional strain dissemination, drug resistance profiles, and TB-associated comorbidities is crucial.