The Bactérie S of the Vibrio belong to the family of the Vibrionaceae . They are small bacilli, frequently curved forms known as “in comma”, extremely mobiles. The most known of the kind Vibrio is Vibrio cholerae : agent responsible for the Cholera. There is a score of species of the kind Vibrio .

Ecology

Habitat

They are Bactérie S alive in the Eau. Many lives in Saprophyte S in fresh water, but they are also common in the salted watery habitats (sea water, estuaries, intestines of the marine animals). Their resistance to sea salt is explained by their halophilie.

Pathogenic capacity

Some species have a “capacity Pathogène”, the ones against the man S, the others against the aquatic animals like the Poisson S or the Batracien s.
The species Vibrio cholerae is responsible for a serious exclusively human pathology, famous in the history for its epidemic S world: the Cholera which remains, today, a heavy threat for certain countries in particular the Africa and the sub-continent Indien.
Vibrio parahaemolyticus causes digestive infections following consumption of shells (oysters), shellfish, fish of water Saline believed or insufficiently cooked, this bacterium is responsible for many Toxi-infection S with the Japan where the believed fish consumption is very courante.
Thus the pathogenic Vibrio have more specifically a “capacity Toxique”: capacity of the bacterium to secrete a Toxin responsible for disorder in the operation of a higher organization.

Bacteriological characters

Microscopic aspect

The vibrios appear as bacilli negative Gram S ends, frequently of form curved, 2 to 3 µm length. They are characterized by a great mobility related to the presence of a single Flagelle: polar ciliature. Thus their displacements are very fast, and follow a rectilinear trajectory.

Macroscopic aspect and of culture

Vibrio give on GTS (gélose trypticase soya) of the colonies from 2 to 3 mms in diameter, circulars on regular board, enough punts, légèrements convex, transparent in general in 24:00. Then the colonies are opacified; smooth colonies, luisantes of the type S.

Conditions of culture

Aerobe preferably, they develop little or not in anaérobiose. They of course cultivate the ordinary mediums between 10°C and 40°C (Psychrophile S and Mésophile S), a pH a little above 7 will be optimal for their culture (Neutrophile and Alcalophile). On simple peptones medium their culture will be fast and abundant (“not-demanding” germ)

The Vibrio have properties which allow their “electivity” on the various mediums:

• They are cultivated with a pH Alcalin between 7,5 and 9
• They are cultivated with strong NaCl concentration (10 to 30 g/l), because of their character Halophile. However certain species of Vibrio are unable to push in absence of NaCl it are known as halophilous obligatory.
• Their growth is not blocked by the addition of different Inhibiteur S such as the biliary Sels, Citrate of Sodium, Thiosulfate of sodium…
• what makes them potential sources of misidentifyings with the Entérobactérie S, whose selective mediums are favourable with the development of the Vibrio .

Characteristics of the cultures

• “Aspect in bubble”: homogeneous disorder with a veil on the surface.
• “Aspect in gélose”: small or average colonies (from 1 to 2 mms in diameter for 12 midnight) semi-curvature, smooth, round: of type smooth ; transparent or translucent.

Culture media

Nonselective mediums:

• ordinary Medium
• Medium Mueller-Hinton

Selective mediums:

• Medium TCBS (thiosulfate-citrate-bile-saccharose)

Biochemical characters

The characters biochemical of the Vibrio are studied in traditional gallery for enterobactery or Api 20 for bacillus gram - non-entérobactérie.
A test makes it possible to differentiate the kinds Vibrio from the kind Aeromonas in the family of the Vibrionaceae : it is about the test of vibriostase , a sensibilté test of the bacteria to a compound vibriostatic O129. knowing that the kind Vibrio is sensitive.

Identification antigenic

The stocks Pathogène S of Vibrio are identified by a Sérogroupage in particular the antigens of wall.

Species belonging to the kind Vibrio

• Vibrio cholerae
• Vibrio parahaemolyticus
• Vibrio alginolyticus
• Vibrio anguillarum
• Vibrio ordalli
• Vibrio damsela
• Vibrio carchariae
• Vibrio vulnificus
• Vibrio salmonicida
• Vibrio fisheri

See too

• the negative Gram S
• the Cholera

Random links:

Nicolas Louis de Lacaille | Peumérit | Delicatessen | Yataca | Lepidoblepharis oxycephalus