''Mycobacterium lepromatosis'' is an aerobic,

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 sa ...

bacillus ''Bacillus'', from Latin "bacillus", meaning "little staff, wand", is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum ''Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-sh ...

(AFB), and the second known causative agent of

Hansen's disease Monster Beverage Corporation is an American beverage company that manufactures energy drinks including Monster Energy, Relentless (drink), Relentless, Reign (drink), Reign and Burn (energy drink), Burn. The company was originally founded as Ha ...

(

leprosy Leprosy, also known as Hansen's disease (HD), is a Chronic condition, long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the Peripheral nervous system, nerves, respir ...

). It was discovered in 2008. Analysis of the

16S rRNA 16S ribosomal RNA (or 16Svedberg, S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as ...

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

confirms that the species is distinct from ''

Mycobacterium leprae ''Mycobacterium leprae'' (also known as the leprosy bacillus or Hansen's bacillus) is one of the two species of bacteria that cause Hansen's disease (leprosy), a chronic but curable infectious disease that damages the peripheral nerves and ta ...

''.

Characteristics

Members of the ''

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 (''Mycobacterium tuberculo ...

'' genus are characterized by being

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. The Gram stain is ...

, non-motile, non-spore-forming, and possess a bacilliary cell shape. Bacteria in the ''Mycobacterium'' genus are characteristically known for possessing an outer membrane, a capsule, as well as a uniquely thick, waxy,

hydrophobic In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water. Hydrophobic molecules tend to be nonpolar and, thu ...

cell wall abundant in

mycolic acid Mycolic acids are long fatty acids found in the cell walls of Mycobacteriales taxon, a group of bacteria that includes ''Mycobacterium tuberculosis'', the causative agent of the disease tuberculosis. They form the major component of the cell wall ...

s. Many species of ''Mycobacterium'' are opportunistic pathogenic bacteria and can cause serious disease. The

16S ribosomal RNA 16S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S ...

(rRNA), a genetic marker of bacterial evolution is used in establishing phylogenetic relationships due to its highly conserved nature. 16S rRNA sequencing of ''M. lepromatosis'' displays a 2.1% genomic discrepancy from other Mycobacterium. The rpoB and hspa5 gene sequences were also analyzed, displaying speciation from its two most related ancestors of ''Mycobacterium,

M. leprae ''Mycobacterium leprae'' (also known as the leprosy bacillus or Hansen's bacillus) is one of the two species of bacteria that cause Hansen's disease (leprosy), a chronic but curable infectious disease that damages the peripheral nerves and targ ...

and

M. tuberculosis ''Mycobacterium tuberculosis'' (M. tb), also known as Koch's bacillus, is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' ha ...

.'' ''M. lepromatosis'' exemplifies a 9.1% deviance from ''M. leprae'' in nucleotide structure, evidence of a novel bacterium. A phylogenetic analysis of 20 genes and pseudogenes, isolated to 5 conserved protein genes, was used to construct phylogenetic trees displaying long terminal branches from the nodes, suggesting speciation occurred long ago.

Disease

''Mycobacterium lepromatosis'' can induce diffuse lepromatous leprosy (DLL), typically known to occur in Mexico and the Caribbean. * DLL is a severe form of leprosy which manifests through nerve invasion and extensive skin ulcerations due to massive AFB burden in internal organs. ''M. lepromatosis'', like ''M. leprae'', has not been cultured in the laboratory because they both lack genes necessary to grow outside their hosts. These genes are believed to have been lost through reductive evolution. The novel bacterium was discovered in 2008 following the autopsy of 2 deceased patients from Mexico. Similar to its close relative, ''Mycobacterium'' ''leprae'', ''M. lepromatosis'' is an

obligate intracellular parasite Intracellular parasites are microparasites that are capable of growing and reproducing inside the cells of a host. They are also called intracellular pathogens. Types There are two main types of intracellular parasites: Facultative and Obligate ...

that only reproduces in host cells, a fact that researchers have speculated is why bacterial culturing in the laboratory has been unsuccessful. Visually indistinguishable from its close relative, ''M. leprae'', ''M. lepromatosis'' is an

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

bacillus, requiring an oxygenated environment, is

rod-shaped Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archae ...

, consistent with all bacillus bacteria, and is resistant to acids due to the presence of mycolic acids in the cell wall. This prohibits the standard use of the

Gram stain Gram stain (Gram staining or Gram's method), is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. It may also be used to diagnose a fungal infection. The name comes ...

in characterization.

References

lepromatosis Leprosy Pathogenic bacteria {{bacteria-stub