OBJECTIVE: Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who presented positive cultures and to evaluate the genetic diversity of strains identified as Mycobacterium avium. METHODS: We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tuberculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. RESULTS: We found that NTM accounted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. CONCLUSIONS: These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic diversity of M. avium strains.
OBJECTIVE: Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who presented positive cultures and to evaluate the genetic diversity of strains identified as Mycobacterium avium. METHODS: We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tuberculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. RESULTS: We found that NTM accounted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. CONCLUSIONS: These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic diversity of M. avium strains.
Authors: Marta Majchrzak; Aleksandra Kaczmarkowska; Anna Didkowska; Sylwia Brzezińska; Blanka Orłowska; Daniel Klich; Ewa Augustynowicz-Kopeć; Krzysztof Anusz; Paweł Parniewski Journal: Pathogens Date: 2022-04-21
Authors: Aline Dos Santos Peixoto; Lílian Maria Lapa Montenegro; Andrea Santos Lima; Fábio Lopes Melo; Walter Lins Barbosa Júnior; Maria Madileuza Carneiro Neves; Jesus Pais Ramos; Haiana Charifker Schindler; Zulma Maria Medeiros Journal: Rev Soc Bras Med Trop Date: 2020-11-06 Impact factor: 1.581