In recent years have been seen increased reports of nontuberculous mycobacteria (NTM)
infections in the world. However, data on frequency and NTM species associated with
pulmonary infections are still limited in Brazil, especially in states of Northern Brazil. The
knowledge of species associated with NTM lung infections has clinical and epidemiological
importance, being molecular techniques efficient tools to provide diagnostic species-specific,
which is necessary for choice of appropriate therapy. This study describes the diversity of
NTM isolated from respiratory specimens at the Evandro Chagas Institute between 1999 and
2011. The NTM were initially characterized by PCR-restriction analysis (PRA-hsp65) and reidentificated
by sequencing of 16S rRNA, hsp65, rpoB and ITS1 targets. According to ours
findings, the PRA-hsp65 method proved to be a convenient tool for identifying NTM,
allowing distinction of a variety of species quickly, simply and inexpensively, as compared to
the sequencing. Moreover, as suggested in this study, according to local species diversity, this
method can be subject to modifications to provide greater discriminatory power. Sequence
analysis of the rpoB gene of Mycobacterium avium complex (MAC) revealed that this target
is not a suitable alternative for discrimination of isolates from State of Para, because it
generated discrepant results with low taxonomic resolution. M. chelonae, M. avium and M.
simiae complexes were the most frequent NTM. Two potential species were detected, M.
paraensis sp. nov. and M. amazoniensis sp. nov., being proposed as new members of the M.
simiae complex. Among the patients with NTM disease, the main characteristics found were
women older than 50 years, pardo ethnic group and previous tuberculosis. Although this study
does not show the real magnitude of NTM lung infections in State of Para, it describes the
diversity of species and clearly reveals the importance of this group in the region, which has
accounted 13.5% of mycobacterial isolates in a reference laboratory. The findings highlight
the need for bacteriological confirmation of cases presumptively diagnosed as TB with
primary resistance to therapy for TB.
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