''Mycobacterium vaccae'' is a nonpathogenic species of the

Mycobacteriaceae ''Mycobacteriaceae'' is a family of bacteria in 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 ...

family of

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 among ...

that lives naturally in

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

. Its generic name originates from the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word, ''vacca'' (

cow Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

), since the first ''Mycobacterium'' strain was cultured from

cow dung Cow dung, also known as cow pats, cow pies or cow manure, is the waste product (faeces) of bovine animal species. These species include domestic cattle ("cows"), bison ("buffalo"), yak, and water buffalo. Cow dung is the undigested residue ...

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

. ''Mycobacterium vaccae'' was first isolated from the

Ugandan }), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The southe ...

Lang'o District, where locals claimed that a "muddy substance had the power to cure a number of ailments". Research areas being pursued with regard to killed ''Mycobacterium vaccae'' vaccine include

immunotherapy Immunotherapy or biological therapy is the treatment of disease by activating or suppressing the immune system. Immunotherapies designed to elicit or amplify an immune response are classified as ''activation immunotherapies,'' while immunotherap ...

for allergic

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

, depression,

leprosy Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve damag ...

psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete ...

dermatitis Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved can v ...

eczema Dermatitis is inflammation of the Human skin, skin, typically characterized by itchiness, erythema, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become lichenification, thick ...

and

tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...

. A research group at Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, England, UK has shown that ''Mycobacterium vaccae'' stimulated a newly discovered group of

neurons A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. N ...

, increased levels of serotonin and decreased levels of anxiety in mice. Other researchers fed live ''Mycobacterium vaccae'' to mice, then measured their ability to navigate a maze compared to control mice not fed the bacteria. "Mice that were fed live ''M. vaccae'' navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice", according to Dorothy Matthews, who conducted the research with Susan Jenks at the Sage Colleges, Troy, New York, USA. ''Mycobacterium vaccae'' is in the same

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

as ''

Mycobacterium tuberculosis ''Mycobacterium tuberculosis'' (M. tb) 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'' has an unusual, waxy coating on its c ...

'', the bacterium which causes

. Numerous trials have indicated that exposure to oral and injectable products derived from ''M. vaccae'' bacteria can have positive effects in treating tuberculosis. Although a 2002 review of selected clinical trials failed to find any consistent benefit of certain dosage regimens of injectable ''Mycobacterium'' products in people with tuberculosis, a more recent meta-analysis of 54 clinical studies of M. vaccae products for tuberculosis showed treatment resulted in improved sputum conversion and radiological (X-ray) assessment. Medical researchers at Kharkiv National Medical University, Kharkiv, Ukraine have reported two clinical trials with oral formulations of Immunitor Inc's killed ''Mycobacterium vaccae'' oral vaccine and An Hui Longcom's killed ''Mycobacterium vaccae'' oral vaccine in treating tuberculosis, including drug resistant TB (MDR-TB). The research team reported greater success with the Immunitor vaccine than the An Hui Longcom vaccine. A successful Phase III clinical trial of Tubivac is published. A team of researchers at the Genetics and Microbiology Department of the Autonomous University of Barcelona, Barcelona, Spain discovered that ''Mycobacterium vaccae'' changes from its "smooth" type to its "rough" type (referring to how colonies of this organism appear under a microscope) at thirty degrees Celsius. They discovered that the "smooth" type of ''Mycobacterium vaccae'' has a substance on the outside of its cell wall which interferes with the production of Th-1

cytokines Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...

, responsible for some kinds of T-helper cell

immune response An immune response is a reaction which occurs within an organism for the purpose of defending against foreign invaders. These invaders include a wide variety of different microorganisms including viruses, bacteria, parasites, and fungi which could ...

. The team also found that the

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

cells of mice inoculated with "rough" ''Mycobacterium vaccae'' produced more Th-1 cytokines than those inoculated with "smooth" ''Mycobacterium vaccae''. The researchers say this may explain why different vaccines made from ''Mycobacterium vaccae'' vary in their effectiveness in increasing immune response to other organisms during

clinical trials Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...

. A study conducted in 2017-2018 revealed that ''Mycobacterium vaccae'' lysate may prevent the development of atopic dermatitis symptoms when applied topically. in In a 2019 study, scientists identified a lipid called 10(Z)-hexadecenoic acid found in ''Mycobacterium vaccae'', and discovered that inside stimulated immune cells (

macrophages Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer ce ...

), the lipid binds to the peroxisome proliferator-activated receptor, inhibiting a number of key pathways which drive inflammation.

References

External links

Bacteria and depression -- Bad is good (The Economist)
* ttps://www.google.com/patents?id=cLaFAAAAEBAJ&dq=%22Treatment+of+conditions+of+the+central+nervous+system+using+mycobacteria%22 U.S. Patent 10258550 - (Google Patents)br>
Compositions Derived From Mycobacterium Vaccae and Methods for Their Use (Patentscope)
Can bacteria make you smarter?Google translated article from SpanishType strain of ''Mycobacterium vaccae'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q655983 Antidepressants vaccae