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

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

that lives naturally in

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

. Its name originates from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word, ''vacca'' ( cow), since the first ''Mycobacterium'' strain was cultured from cow dung in

Austria Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine Federal states of Austria, states, of which the capital Vienna is the List of largest cities in Aust ...

. ''Mycobacterium vaccae'' was first isolated from the Ugandan 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 common 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 wh ...

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

, depression,

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 ...

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

dermatitis Dermatitis is a term used for different types of skin inflammation, 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 ...

eczema Dermatitis is a term used for different types of skin inflammation, 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 ...

and

tuberculosis Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can al ...

. A research group at Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology,

University of Bristol The University of Bristol is a public university, public research university in Bristol, England. It received its royal charter in 1909, although it can trace its roots to a Merchant Venturers' school founded in 1595 and University College, Br ...

Bristol Bristol () is a City status in the United Kingdom, cathedral city, unitary authority area and ceremonial county in South West England, the most populous city in the region. Built around the River Avon, Bristol, River Avon, it is bordered by t ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

, UK has shown that heat-killed ''Mycobacterium vaccae'' injected into mice stimulated a newly discovered group of

neurons A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

, increased levels of serotonin and decreased levels of anxiety. 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 (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

as ''

Mycobacterium 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 ...

'', 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 2003 review of selected clinical trials failed to find any consistent benefit of certain dosage regimens of injectable ''Mycobacterium'' products in people with tuberculosis, a subsequent 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 Kharkiv, also known as Kharkov, is the second-largest List of cities in Ukraine, city in Ukraine.

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

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 produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

, responsible for some kinds of T-helper cell

immune response An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellula ...

. The team also found that the

spleen The spleen (, from Ancient Greek '' σπλήν'', splḗn) is an organ (biology), organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The spleen plays important roles in reg ...

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 subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

. 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 MPhi, φ, MΦ or MP) are a type of white blood cell of the innate immune system that engulf and digest pathogens, such as cancer cells, microbes, cellular debris and foreign substances, which do not have proteins that ...

), 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)
* ttp://www.physorg.com/news193928997.html Can bacteria make you smarter?br>Google translated article from Spanish
{{Taxonbar, from=Q655983 Antidepressants vaccae