Mycobacterium lacus is a species of bacteria in the genus Mycobacterium known to be a causative agent in immunocompetent individuals.

Large, dispersed acid-fast bacilli with prominent beading

Colony characteristics

• Colonies on Löwenstein–Jensen medium were nonchromogenic, small, with a dry appearance.
• On Middlebrook 7H10 agar, colonies are small, non-pigmented and smooth to rough, with a slightly irregular edge. Younger colonies appeared slightly transparent.

• Growth was observed on Löwenstein–Jensen medium at two weeks at both 37 and 42 °C and at 3 weeks at 30 °C. At four weeks, very little growth was observed at 25 °C, and no growth was observed at 52 °C.

• The causative agent of bursitis in an immunocompetent individual.

• Isolated from synovial tissue from a 68-year-old female with bursitis of her right elbow. The likely exposure was in a lake.

Strain NRCM 00-255 = ATCC BAA-323 = DSM 44577

• Turenne et al. 2002. Mycobacterium lacus sp. nov., a novel slowly growing, non-chromogenic clinical isolate. Int. J. Syst. Evol. Microbiol., 52, 2135–2140. PMID 12508880

• Type strain of Mycobacterium lacus at BacDive - the Bacterial Diversity Metadatabase