Introduction: Mycobaterium colombiense, a slow-growing mycobacterium, belongs to the complex of Mycobaterium avium (MAC). It was isolated for the first time in Colombia, in 2006, in an HIV patient. To report the first case of a brazilian HIV/AIDS patient in whom M. colombiense was identified.

Methods 51 year old male, heavy drinker and smoker, COPD, waste picker. HIV+, poorly adherent to ART, CD4 count of 14 and VL 3,960 in 2015. He was treated for M. kansasii infection from 2007 to 2009, when ART was also started. In 2015, he had several sputa collected, and results were intermittently positive for AFB testing. GeneXpert was negative in all of samples. He had a positive culture for M. intracellulare in January; but sputum culture was positive for atypical mycobacteria in September and November. BAL in November had a positive culture for MAC, later identified as M. colombiense. The clinical specimen was treated by the NALC-NaOH method, and was seeded in LJ medium. Growth of smooth, creamy colonies with yellow pigment was observed after 30 days of incubation. Sequencing of the rpoB gene for identification showed similarity of 99% with the CIP 108962 strain M. colombiense. The gene sequence was analysed by BLAST V2.0. All blood cultures for fungus, mycobacteria and bacteria were negative in the same time.

Discussion and conclusion This patient with advanced AIDS, COPD and alcoholism had been treated years before for M. kansasii and for M. avium. Six years later, due to respiratory and consumptive syndrome, he was hospitalised for investigation and there was growth of M. colombiense in bronchoalveolar lavage - BAL. To our knowledge, this is the first isolate of this species in Brazil. In 2015, M. intracellulare and MAC were grown in sputum culture; these mycobacteria, being closely related, are very difficult to distinguish, with the possibility that M. colombiense was the etiological agent early on. Due to the unavailability of modern moleculares tools to describe emerging MAC species, the true prevalence of M. colombiense in Brazil is probably underestimated.