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 and leprosy in humans. The Greek prefix myco- means 'fungus', alluding to this genus' mold-like colony surfaces. Since this genus has cell walls with a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types.
Nontuberculous mycobacteria (NTM), also known as environmental mycobacteria, atypical mycobacteria and mycobacteria other than tuberculosis (MOTT), are mycobacteria which do not cause tuberculosis or leprosy/Hansen's disease. NTM are able to cause pulmonary diseases that resemble tuberculosis. Mycobacteriosis is any of these illnesses, usually meant to exclude tuberculosis. They occur in many animals, including humans and are commonly found in soil and water.
Scotochromogenic bacteria develop pigment in the dark. Runyon Group II nontuberculous mycobacteria such as Mycobacterium gordonae are examples but the term could apply to many other organisms.
Mycobacterium phlei is a species of acid-fast bacteria in the genus Mycobacterium. It is characterized as one of the fast-growing mycobacteria. M. phlei has only occasionally been isolated in human infections, and patients infected with M. phlei generally respond well to anti-mycobacterial therapy. M. phlei has an unusually high GC-content of 73%.
Mycobacterium botniense is a slowly growing Mycobacterium, which produces a yellow pigment. It was first isolated from a stream of water. M. botniense is most closely related to Mycobacterium xenopi. Etymology: botniense; of Botnia, referring to the Latin name of the province of Finland from which the isolation was made.
Mycobacteroides chelonae is a species of bacteria from the phylum Actinomycetota belonging to the genus Mycobacteroides. Mycobacteroides chelonae is a rapidly growing mycobacterium that is found all throughout the environment, including sewage and tap water. It can occasionally cause opportunistic infections of humans. It is grouped in Runyon group IV.
Mycobacterium elephantis, a bacterium of the family Mycobacteriaceae, was discovered and isolated from a deceased elephant near India and may be linked to respiratory dysfunction. Organisms in the genus Mycobacterium are known to be aerobic and non-motile. Organisms within Mycobacterium belong to either the rapid growing group or the slow growing group. M. elephantis is classified as a rapid grower and relates most closely to Mycobacterium confluentis and Mycobacterium phlei.
Mycobacterium flavescens is a species of the phylum Actinomycetota, belonging to the genus Mycobacterium.
Mycobacterium gadium is a species of the phylum Actinomycetota, belonging to the genus Mycobacterium.
Mycobacterium hassiacum is a rapid-growing thermophilic mycobacterium that was isolated in human urine in 1997 by researchers at the German University of Regensburg. It's a species of the phylum Actinomycetota, belonging to the genus Mycobacterium.
Mycobacterium avium complex is a group of mycobacteria comprising Mycobacterium intracellulare and Mycobacterium avium that are commonly grouped because they infect humans together; this group, in turn, is part of the group of nontuberculous mycobacteria. These bacteria cause Mycobacterium avium-intracellulare infections or Mycobacterium avium complex infections in humans. These bacteria are common and are found in fresh and salt water, in household dust and in soil. MAC bacteria usually cause infection in those who are immunocompromised or those with severe lung disease.
Mycobacterium kansasii is a bacterium in the Mycobacterium genus. It is an environmental bacteria that causes opportunistic infections in humans, and is one of the leading mycobacterial causes of human disease after tuberculosis and leprosy.
Mycobacterium tusciae is a slow-growing, scotochromogenic mycobacterium first isolated from a lymph node of an immunocompromised child and subsequently from tap water and from a respiratory specimen of a patient with chronic fibrosis. Etymology: tusciae referring to the Italian region of Tuscany, where the organisms were first isolated.
In microbiology, the phenotypic testing of mycobacteria uses a number of methods. The most-commonly used phenotypic tests to identify and distinguish Mycobacterium strains and species from each other are described below.
Mycolicibacter terrae is a slow-growing species of mycobacteria. It is an ungrouped member of the third Runyon. It is known to cause serious skin infections, which are "relatively resistant to antibiotic therapy".
Mycobacterium ulcerans is a species of bacteria found in various aquatic environments. The bacteria can infect humans and some other animals, causing persistent open wounds called Buruli ulcer. M. ulcerans is closely related to Mycobacterium marinum, from which it evolved around one million years ago, and more distantly to the mycobacteria which cause tuberculosis and leprosy.
Mycobacteroides franklinii is a species of bacteria from the phylum Actinomycetota belonging to the genus Mycobacteroides. Most of the original strains were isolated from clinical specimens in Pennsylvania, but some have been found in conduit water in the Netherlands. In general, human M. franklinii infections present with symptoms similar to an infection with Mycobacteroides abscessus, but it can also be associated with tattoo infections. M. franklinii is also associated with outbreaks of mycobacteriosis in farmed fish. M. fanklinii is susceptible to cefoxitin and bedaquiline.
Mycolicibacter algericus is a species of bacteria from the phylum Actinomycetota that was first isolated from the lung lesion of a goat. It is non-pigmented and grows slowly at 25–42 °C on Löwenstein–Jensen medium. It has also been isolated from freshwater fish, fresh produce, water treatment plant sludge, and a natural cave.
Mycolicibacter minnesotensis is a species of bacteria from the phylum Actinomycetota that was first isolated from a sphagnum peat bog. It is pink-pigmented and grows at 27–34 °C. It has also been isolated from fresh produce and water treatment plant sludge.
Mycolicibacterium aichiense is a species of bacteria from the phylum Actinomycetota that was first isolated from soil and from human sputum. It produces pigments when grow in the dark and grows rapidly at 25–37 °C on Ogawa egg medium or Sauton agar medium.
