The genus Veillonella was first isolated by Veillon and Zuber in 1898. Prevot further described these bacteria in 1933. Morphology: • Gram-negative anaerobic cocci , 0.3-0.5 um in diameter • Non motile • non spore forming Habitat: • mouth • upper respiratory tract • Intestine • vagina Characteristic: • pH Optimum pH, 6.5-8.0. • Temperature Optimum temperature, 30-37`C. • usually isolated mixed with other bacteria (These organisms are hypothesised to form a cooperative metabolic system in which a waste product, lactic acid, produced by S. mutans is utilised by V. dispar.) • Chemoautotrophs (Chemoautotrophs obtain their energy as well as their carbon from inorganic sources; they do this by the oxidation of inorganic molecules such as sulphur or nitrite.) • Non-fermentative. • produce a highly endotoxic lipopolysaccharide • are generally resistant to tetracycline Species: Veillonella atypica, V. dispar are found in humans V. parvula V. caviae V. criceti in rodents. V. ratti V. rodentium Diseases: Dental caries Abscesses of teeth and gums. sinusitis Osteomyelitis Endocarditis Laboratory diagnosis:  Are small, spherical, gram-negative cocci appearing as pairs, masses, and short chains.  Non hemolytic  Growth may be improved by adding 1% sodium pyruvate and 0.1% potassium nitrate to the basal medium.  Colonies grow slowly on normal laboratory media, their growth being encouraged by factors such as lactate, pyruvate and nitrate.  enriched thioglycollate broth  Some form catalase.  Small white colonies.  Colony produce of a red fluorescence at a wavelength of 365 nm. This fluorescence is better observed in a Veillonella selective medium (Rogosa medium) and disappears in contact with oxygen.  Growth is usually visible after 48 hours in appropriate anaerobic conditions.  glucose or any other carbohydrate is not fermented;  indole -ve  nitrate is reduced.  H2S is produced  propionic and acetic acids, C02, and H2 are produced from lactate during growth. Lactate 2 propionate + acetate + CO2  Oxidase-negative. Catalase-negative, but some species produce an atypical catalase lacking porphyrin.

2. The genus Veillonella was
first isolated by Veillon and
Zuber in 1898.
Prevot further described
these bacteria in 1933.

3.  Gram-negative anaerobic cocci .
 0.3-0.5 um in diameter.
 Non motile.
 non spore forming.

4. Habitat:
 Mouth.
 upper respiratory tract.
 Intestine.
 vagina.

5. Characteristic:
 pH 6.5-8.0.
 Temperature 30-37`C.
 usually isolated mixed with other bacteria.
 Chemoautotroph's.
 Non-fermentative.
 produce a highly endotoxic
lipopolysaccharide.
 are generally resistant to tetracycline.

6. Species:
 Veillonella atypica
 V. dispar in humans
 V. parvula
 V. caviae
 V. criceti in rodents
 V. ratti
 V. rodentium

7. Diseases:
 Dental caries.
 Abscesses of teeth and gums.
 Sinusitis.
 Osteomyelitis.
 Endocarditis.

8. Laboratory diagnosis:
Culture media:
 Veillonella Agar Base with added antibiotic( vancomycin).
 Composition**
 Casein enzymic hydrolysate
 Yeast extract
 Sodium lactate .
 Sodium thioglycollate
 Basic fuchsin
 Rogosa agar .

9.  Are small, spherical, gram-negative cocci appearing as pairs,
masses, and short chains.

10. Small white colonies.
Growth is usually visible after 48 hours in appropriate
anaerobic conditions.

11.  Colony produce of a red fluorescence at a wavelength of 365
nm. This fluorescence is better observed in a Veillonella
selective medium .
Rogosa agar

12.  glucose or any other carbohydrate is not fermented.
 indole -ve .
 nitrate is reduced.
 H2S is produced.
 propionic and acetic acids, C02, and H2 are produced from lactate
during growth.
 Oxidase -ve.
 Catalase -ved.
 Non hemolytic.