Characterization of clinical isolates of Mycobacterium tuberculosis from indigenous peoples of Colombia

Introduction Tuberculosis continues to be a public health priority. Indigenous peoples are vulnerable groups with cultural determinants that increase the risk of the disease. Objective To determine molecular epidemiology and phenotypical features and of Mycobacterium tuberculosis isolates from indigenous people in Colombia during the period from 2009 to 2014. Materials and methods We conducted an analytical observational study; we analyzed 234 isolates to determine their patterns of sensitivity to antituberculosis drugs and their molecular structures by spoligotyping. Results The isolates came from 41 indigenous groups, predominantly the Wayúu (13.10%) and Emberá Chamí (11.35%). We found 102 spoligotypes distributed among seven genetic families (37.2% LAM, 15.8% Haarlem, 8.1% T, 3.4% U, 2.6% S, 2.1% X, and 0.9%, Beijing). The association analysis showed that the non-clustered isolates were related to prior treatment, relapse, orphan spoligotypes, and the Beijing family. The H family presented an association with the Arhuaco and Camëntŝá indigenous groups, the U family was associated with the Wounaan group, and the T family was associated with the Motilón Barí group. Conclusions This is the first national study on M. tuberculosis characterization in indigenous groups. The study evidenced that diagnosis in indigenous people is late. We described 53% of orphan patterns that could be typical of the Colombian indigenous population. The high percentage of grouping by spoligotyping (62%) could indicate cases of active transmission, a situation that should be corroborated using a second genotyping marker. A new Beijing spoligotype (Beijing-like SIT 406) was identified in Colombia.