Diversidad genética de Mycobacterium tuberculosis circulando en la jurisdicción V de Jalapa, Veracruz, México / Genetic diversity of Mycobacterium tuberculosis circulating in the jurisdiction V from Jalapa, Veracruz, Mexico

ANTECEDENTES: El estado de Veracruz se ubica en el sureste de México y presenta una alta prevalencia de tuberculosis (TBC) y drogo resistencia. Sin embargo, la composición de los genotipos circulantes es poco conocida. OBJETIVO: Caracterizar la diversidad genética de la TBC en la jurisdicción sanitaria V del estado de Veracruz. MÉTODOS: Estudio transversal realizado en aislados clínicos de pacientes con TBC residentes de la jurisdicción V. Se determinó la sensibilidad a medicamentos de primera línea. La genotipificación se realizó mediante espoligotipificación y MIRU-VNTR 15 loci. RESULTADOS: Entre los 74 aislados analizados se observó resistencia a un fármaco en 44 (59%) aislados. Linaje L4 (EuroAmericano) se presentó en 73 aislados. Se identificaron cinco sublinajes; H (40%), T (22%), LAM (16%), X (13%) y U (7%). El 32% de los aislados se agrupó mediante su espoligotipo y 40% en 10 complejos clonales. CONCLUSIONES: Es la primera descripción sobre la estructura genética de TBC en la región central de Veracruz. La diversidad de genotipos podría contribuir a su dispersión en la región. Esta información será útil para el desarrollo de intervenciones y reducir el impacto de TBC en la población.

BACKGROUND: The state of Veracruz is placed in southeastern Mexico and has a high prevalence of tuberculosis (TB) and drug resistance. Nevertheless, the composition of circulating genotypes in the central region of the state is partially known. AIM: To characterize the genetic diversity of TB in the sanitary jurisdiction V of the state of Veracruz. METHODS: A cross-sectional study was conducted among clinical isolates from patients with TB living in the jurisdiction V, in Jalapa Ver., Mexico. Sensitivity to first-line drugs was determined, and genotyping was performed by spoligotyping and MIRU-VNTR 15 loci. RESULTS: Among the 74 isolates analyzed, resistance to one drug was observed in 44 isolates. L4 (EuroAmerican) was the major lineage identified. Five sublineages were the most abundant; H (40%), T (22%), LAM (16%), X (13%) and U (7%). Only 32% of the isolates were clustered by spoligotype and 40% were placed in ten clonal complexes. CONCLUSIONS: This is the first description of the genetic structure of TB in the central region of Veracruz. The diversity of genotypes could contribute to its dispersion. This information will be useful for the development of interventions to reduce the impact of TB in the population.

Genotyping Mycobacterium bovis from cattle in the Central Pampas of Argentina: temporal and regional trends

Mycobacterium bovis is the causative agent of bovine tuberculosis (TB), a disease that affects approximately 5% of Argentinean cattle. Among the molecular methods for genotyping, the most convenient are spoligotyping and variable number of tandem repeats (VNTR). A total of 378 samples from bovines with visible lesions consistent with TB were collected at slaughterhouses in three provinces, yielding 265 M. bovis spoligotyped isolates, which were distributed into 35 spoligotypes. In addition, 197 isolates were also typed by the VNTR method and 54 combined VNTR types were detected. There were 24 clusters and 27 orphan types. When both typing methods were combined, 98 spoligotypes and VNTR types were observed with 27 clusters and 71 orphan types. By performing a meta-analysis with previous spoligotyping results, we identified regional and temporal trends in the population structure of M. bovis. For SB0140, the most predominant spoligotype in Argentina, the prevalence percentage remained high during different periods, varying from 25.5-57.8% (1994-2011). By contrast, the second and third most prevalent spoligotypes exhibited important fluctuations. This study shows that there has been an expansion in ancestral lineages as demonstrated by spoligotyping. However, exact tandem repeat typing suggests dynamic changes in the clonal population of this microorganism.