Pulmonary infection by non-tuberculous mycobacteria in an endemic region for tuberculosis in Northeast Brazil.

Abstract

A wide range of non-tuberculous mycobacteria (NTM) species have been identified worldwide, with increasing recognition of their clinical importance in pulmonary disease. To evaluate the diversity, frequency, antimicrobial resistance profile, and clinical characteristics of pulmonary NTM cases in Pernambuco, Brazil, we conducted a descriptive clinical-epidemiological and comparative cross-sectional study of pulmonary NTM (PNTM) along with pulmonary tuberculosis (PTB). Pulmonary biological samples were obtained and analyzed by bacilloscopy, culture, and biochemical tests for PNTM and PTB diagnosis. Molecular analysis for hsp65 and rpoB genes was also performed to confirm NTM species and classified as slowly growing mycobacteria (SGM) or rapidly growing mycobacteria (RGM). Antimicrobial susceptibility tests were also performed with 13 different drugs. Twenty-one PNTM cases were identified. They were significantly associated with a previous history of TB (66.7%) and occurred more frequently in males (67.7%). The age of the PNTM group (52.0±14.7 years) was significantly higher than PTB group (44.0±14.8 years; P=0.006). Six different NTM species were detected (three SGM and three RGM): M. kansasii (57.1%), M. intracellulare (9.5%), M. abscessus subsp. abscessus (9.5%), M. abscessus subsp. bolletii (9.5%), M. fortuitum (9.5%), and M. asiaticum (4.8%). Among the cases, 15 specimens demonstrated antimicrobial resistance to at least one drug. This is the first study to describe the frequency, diversity, and antimicrobial resistance of NTM species associated with pulmonary disease in Pernambuco, providing relevant epidemiological data to support diagnosis and management in this endemic region for tuberculosis.