Veillonella ppt

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.

1. Veillonella Prepared by: Ibtihal omer

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

3. Morphology: 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 -ve d . Non hemolytic.

13. Thanks for your attention