''Mycobacterium lacus'' is a species of bacteria in the genus ''

Mycobacterium ''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (''M. tuberculosis'') and l ...

'' known to be a causative agent in immunocompetent individuals.

Description

Large, dispersed

acid-fast Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Once stained as part of a s ...

bacilli Bacilli is a taxonomic class of bacteria that includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens such as ''Bacillus anthracis'' (the cause of anthrax). ''Bacilli'' are almost exclusively gram-posit ...

with prominent beading Colony characteristics *Colonies on

Löwenstein–Jensen medium Löwenstein–Jensen medium, more commonly known as LJ medium, is a growth medium specially used for culture of ''Mycobacterium'' species, notably ''Mycobacterium tuberculosis''. When grown on LJ medium, ''M. tuberculosis'' appears as brown, gra ...

were

nonchromogenic In chemistry, the term chromogen refers to a colourless (or faintly coloured) chemical compound that can be converted by chemical reaction into a compound which can be described as "coloured". There is no universally agreed definition of the term. ...

, 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

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 Bursitis is the inflammation of one or more bursae (fluid filled sacs) of synovial fluid in the body. They are lined with a synovial membrane that secretes a lubricating synovial fluid. There are more than 150 bursae in the human body. The bursae ...

in an

immunocompetent In immunology, immunocompetence is the ability of the body to produce a normal immune response following exposure to an antigen. Immunocompetence is the opposite of immunodeficiency (also known as ''immuno-incompetence'' or being ''immuno-comp ...

individual.

Type strain

*Isolated from synovial tissue from a 68-year-old female with

of her right elbow. The likely exposure was in a lake. Strain NRCM 00-255 = ATCC BAA-323 = DSM 44577

References

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

External links

Type strain of ''Mycobacterium lacus'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Acid-fast bacilli lacus Bacteria described in 2002 {{Mycobacterium-stub