''Mycolicibacter terrae'' (formerly ''Mycobacterium terrae'') is a slow-growing species of

mycobacteria ''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 ...

. It is an ungrouped member of the third Runyon (nonchromatogenic mycobacteria). It is known to cause serious skin infections, which are "relatively resistant to antibiotic therapy".

Discovery

Richmond and Cummings were the first to isolate ''Mycobacterium terrae'', which they described as "an acid‐fast saprophyte". It is sometimes called the "radish bacillus", because it was isolated from radish water.

Pathology

This bacterium was originally injected into

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy (), is a species of rodent belonging to the genus '' Cavia'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ...

s, and did not cause apparent illness, leading to the misconception that this strain was nonpathogenic. In reality, however, infection by this organism can cause disease of the joints, tendons, lungs, gastrointestinal tract, and genitourinary tract. In humans, symptoms of infection include swelling, lesions, and inflammation, and may mimic the symptoms of

osteoarthritis Osteoarthritis (OA) is a type of degenerative joint disease that results from breakdown of joint cartilage and underlying bone which affects 1 in 7 adults in the United States. It is believed to be the fourth leading cause of disability in the ...

Uses

This bacterium is used to study effectiveness of disinfection processes for reusable medical instruments. ''Mycobacterium terrae'' is used during validations of reprocessing procedures of surgical instruments, more specifically as a test organism in determining disinfection efficiency. In order to establish a microbial count the extraction media is filtered and the filters are then placed onto

agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori ('' Gracilaria'') and "tengusa" ('' Gelidiaceae''). As found in nature, agar ...

plates for an incubation of up to 21 days at 37°± 2 °C. At the end of the incubation period the number of

colony forming unit In microbiology, colony-forming unit (CFU, cfu or Cfu) is a unit which estimates the number of microbial cells (bacteria, fungi, viruses etc.) in a sample that are viable, able to multiply via binary fission under the controlled conditions. Count ...

s are counted. This count is used to calculate the

log reduction Log reduction is a measure of how thoroughly a decontamination process reduces the concentration of a contaminant. It is defined as the common logarithm of the ratio of the levels of contamination before and after the process, so an increment of 1 ...

to determine disinfection efficiency. The

Association for the Advancement of Medical Instrumentation The Association for the Advancement of Medical Instrumentation (AAMI) is an organization for advancing the development, and safe and effective use of medical technology Health technology is defined by the World Health Organization as the "appli ...

(AAMI) Technical Information Report TIR30 lists acceptance criteria for this test.

References

External links

Type strain of ''M. terrae'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6947101 terrae Acid-fast bacilli Bacteria described in 1966