title: Mycobacterium lacus
text: # Mycobacterium lacus
  
  Mycobacterium lacus is a species of bacteria in the genus Mycobacterium known to be a causative agent in immunocompetent individuals.
  
  ## Description
  
  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.
  
  ### Physiology
  
  * 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.
  
  ## Pathogenesis
  
  * The causative agent of bursitis in an immunocompetent individual.
  
  ## Type strain
  
  * 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
  
  