Streptococcus bovis is a catalase

Catalase

Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...

- and oxidase

Oxidase

An oxidase is any enzyme that catalyzes an oxidation-reduction reaction involving molecular oxygen as the electron acceptor. In these reactions, oxygen is reduced to water or hydrogen peroxide ....

-negative, non-motile, non-sporulating

Endospore

An endospore is a dormant, tough, and temporarily non-reproductive structure produced by certain bacteria from the Firmicute phylum. The name "endospore" is suggestive of a spore or seed-like form , but it is not a true spore . It is a stripped-down, dormant form to which the bacterium can reduce...

, Gram-positive

Gram-positive

Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...

 lactic acid bacterium that grows as pairs or chains of cocci. It is a member of the Lancefield

Rebecca Lancefield

Rebecca Craighill Lancefield was a prominent American microbiologist. She joined the Rockefeller Institute for Medical Research in New York in 1918, and was associated with that institute throughout her long and outstanding career. Her bibliography comprises more than 50 publications published...

 group D streptococci. Most strains are non- or gamma-hemolytic

Hemolysis (microbiology)

Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species...

, but some also display alpha-hemolytic

Hemolysis (microbiology)

Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species...

 activity on ovine blood agar plates. S. bovis is commonly found in the alimentary tract of cows, sheep, and other ruminants.

Pathogenicity

S. bovis is a known human pathogen that has been implicated as a causative agent of endocarditis

Endocarditis

Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...

, and, more rarely, neonatal septicemia and meningitis

Meningitis

Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...

.

A correlative relationship

Correlation

In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence....

 exists between colon cancer and S. bovis proliferation in the large intestine. One study indicated that 15% of patients that were diagnosed with S. bovis bacteremia

Bacteremia

Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....

 had colonic neoplasms. However, research has not yet determined if this organism is a causative agent of colon cancer, or if pre-existing cancer makes the lumen

Lumen (anatomy)

A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...

 of the large intestine more hospitable to S. bovis outgrowth.

Ruminal effects

When ruminants consume diets high in starch

Starch

Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...

 or sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

, these easily fermentable carbohydrates promote the proliferation of S. bovis in the rumen. Because S. bovis is a lactic acid bacterium, fermentation of these carbohydrates to lactic acid

Lactic acid

Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...

 can cause a dramatic decline in ruminal pH, and subsequent development of adverse conditions such as ruminal acidosis or feedlot bloat.

External links

Streptococcus bovis