''Mycobacterium haemophilum'' is a species of the phylum

Actinomycetota The ''Actinomycetota'' (or ''Actinobacteria'') are a phylum of all gram-positive bacteria. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soi ...

(

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to 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 ...

''.

Description

Short, occasionally curved,

gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bac ...

, nonmotile and strongly

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 ...

rods. Colony characteristics *Nonpigmented and rough to smooth colonies. Physiology *Media have to be supplemented with 0.4%

haemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...

or 60 μM

hemin Hemin (haemin; ferric chloride heme) is an iron-containing porphyrin with chlorine that can be formed from a heme group, such as heme B found in the hemoglobin of human blood. Chemistry Hemin is protoporphyrin IX containing a ferric iron (F ...

(factor X) or 15 mg/ml ferric ammonium citrate respectively, but not with FeCl₃ or

catalase Catalase is a common enzyme found in nearly all living organisms exposed to oxygen (such as bacteria, plants, and animals) which catalyzes the decomposition of hydrogen peroxide to water and oxygen. It is a very important enzyme in protecting t ...

. *Slow growth 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 ...

or Middlebrook 7H10 agar at 32 °C within 2 to 4 weeks. *Growth slower at 25 °C and 35 °C and absent at 37 °C. *Strictly intracellular growth in tissue cultures of fibroblasts. Differential characteristics *Unique among mycobacteria in its requirement for

or ferric ammonium citrate for growth. Distribution.

Pathogenesis

*Infects patients with suppressed

immune systems The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinter ...

. *Clinical presentation: multiple skin

nodules Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, p ...

occurring in clusters or without definitive pattern, commonly involving the extremities. Abscesses, draining

fistula A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...

s and

osteomyelitis Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the ...

may be associated with the nodules. Paediatric patients with localised cervical

lymphadenopathy Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In cl ...

. * Biosafety level 2

Type strain

First isolated in Israel from a

subcutaneous Subcutaneous may refer to: * Subcutaneous injection * Subcutaneous tissue The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The ...

granuloma A granuloma is an aggregation of macrophages that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such substances include infectious ...

from a patient with

Hodgkin's disease Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition ...

. An environmental reservoir is presumed. Strain ATCC 29548 = CCUG 47452 = CIP 105049 = DSM 44634 = NCTC 11185.

Notes

References

External links

Type strain of ''Mycobacterium haemophilum'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Acid-fast bacilli haemophilum Bacteria described in 1978 {{Mycobacterium-stub