TAXONOMY: Bacteria -> Terrabacteria group -> Firmicutes -> Negativicutes -> Selenomonadales -> Veillonellaceae -> Veillonella
'Veillonella' are Gram-negative anaerobic cocci. This bacterium is well known for its lactate fermenting abilities. They are a normal bacterium in the intestines and oral mucosa of mammals. In humans they have been rarely implicated in cases of osteomyelitis and endocarditis, for example with the species Veillonella parvula.Babies with a higher risk of asthma presented lower levels of four bacteria in their feces samples in comparison with the infants who did not show any symptoms. Those bacteria were identified as Faecalibacterium, Lachnospira, Veillonella and Rothia - known all together as FLVR. [http://www.gutmicrobiotawatch.org/en/2015/11/25/four-types-of-gut-bacteria-may-protect-children-against-asthma-risk/]
Cocci, 0.3–0.5 μm in diameter; cells are usually arranged in pairs, masses, or short chains. Stains Gram negative. Nonmotile, nonsporeforming. Anaerobic. Optimum temperature, 30–37°C. Optimum pH, 6.5–8.0. Oxidase negative. Nitrate is reduced. Some species produce an atypical catalase lacking porphyrin. Gas is produced by most strains. Pyruvate, lactate, malate, fumarate, and oxaloacetate are fermented. Carbohydrates and polyols are not fermented by most strains. Major metabolic end products in trypticase-glucose-yeast extract (TGY, see below) broth are acetic and propionic acids. In addition, CO2 and H2 are produced from lactate (Rogosa, 1964). Resident of oral cavity, genito-urinary, respiratory, and intestinal tracts of humans and animals, but can also cause severe human infections such as bacteremia, endocarditis, osteomyelitis, and prosthetic joint infection.
DNA G+C content (mol%): 36–43 (Tm) or 40–44 (Bd).
Type species: Veillonella parvula
This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]