Spoligotyping of Mycobacterium tuberculosis in Ziehl-Neelsen-stained slides from Belém, Pará State, Brazil

Abstract

Spoligotyping is a molecular method based on the amplification of a polymorphic direct repeat locus, which allows for the detection and identification of Mycobacterium tuberculosis. Samples of M. tuberculosis obtained from material fixed in Ziehl-Neelsen-stained slides from public laboratories in Belém, Pará State, Brazil, were genotyped in this study. The molecular characterization of M. tuberculosis through spoligotyping of samples from 102 patients showed high sensitivity, with 90 complete and matching hybridization patterns. The genotypes were classified based on a comparison of the results obtained with data available in the SITVITWEB international database. Of the 45 different genotypes observed, 35 had already been reported and 11 had never been reported. Sixty-one genotypes were observed in 2 to 15 samples, and 29 genotypes did not match. LAM, T, H and EAI were the most common families. The districts with the highest concentration of cases were Guamá, Jurunas and Terra Firme. Spoligotyping is considered an important tool to follow up isolates in distinct epidemiologic contexts. Genetic and demographic characterization of these microorganisms contributes to a better understanding of the distribution of tuberculosis in this population, its transmission process, the occurrence of cross contaminations, and the implementation of controlling measures of the disease.