Mycobacterium vaccae is a nonpathogenic species of the Mycobacteriaceae family of bacteria that lives naturally in soil. Its name originates from the Latin word, vacca (cow), since it was first cultured from cow dung in Austria. Research areas being pursued with regard to killed Mycobacterium vaccae vaccine include immunotherapy for allergic asthma, cancer, depression, leprosy, psoriasis, dermatitis, eczema and tuberculosis.
There are scientists who believe that exposure to Mycobacterium vaccae may work as an antidepressant because it stimulates the generation of serotonin and norepinephrine in the brain. More specifically, it induces the neurogenesis of neurons that produce those two compounds.
M. vaccae is in the same genus as Mycobacterium tuberculosis, the bacterium which causes tuberculosis. Early trials indicated that exposure to M. vaccae would relieve tuberculosis symptoms. However, a 2002 review found no benefit from immunotherapy with M. vaccae in people with tuberculosis. There seems to be varying results because of two different forms of the bacterium ("smooth" and "rough"), plus individual response to vaccination from it.
Research, as of 24 May 2010[update], has shown that when Mycobacterium vaccae was injected into mice, it stimulated some growth of neurons. It also increased levels of serotonin and decreased levels of anxiety. "We found that mice that were fed live M. vaccae navigated the maze twice as fast and with less demonstrated anxiety behaviors as control mice", says Dorothy Matthews of The Sage Colleges in Troy, New York, who conducted the research with her colleague Susan Jenks.
There are two main variants of Mycobacterium vaccae according to their appearance in a culture dish. One is smooth and one is rough. Immunological response in mammals to the bacterium varies greatly according to which variant is used. In one study, Mycobacterium vaccae was cultured on "tryptone soy agar medium, collected, and heat killed at 121°C for 15 min."
AnHui Longcom Biologic Pharmacy Co., Ltd. (Longcom) produces a Mycobacterium vaccae vaccine with the trade name "Vaccae" for the treatment of tuberculosis. Immunitor Inc. reported success with its oral formulation of M. vaccae in treating tuberculosis.
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- AnHui Longcom Biologic Pharmacy Co., Ltd. (Longcom)
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- Can bacteria make you smarter?
- Google translated article from Spanish