View
23
Download
0
Category
Tags:
Preview:
DESCRIPTION
VIBRIONACEAE. It contains 3 genera: Vibrio Aeromonas Plesiomonas VIBRIO: GENERAL CHARACTERS : Gram negative, rigid, curved rods. vibratory motility – charecteristic feature - PowerPoint PPT Presentation
Citation preview
VIBRIONACEAE
• It contains 3 genera: Vibrio Aeromonas Plesiomonas
• VIBRIO:• GENERAL CHARACTERS:
Gram negative, rigid, curved rods.
vibratory motility – charecteristic feature
asporogenous, non-capsulated
• VIBRIO SPECIES: V.cholerae V. mimicus
• HALOPHILIC VIBRIOS: V.parahaemolyticus V.alginolyticus V. vulnificus
GARDNER AND VENKATRAMAN’S CLASSIFICATION:
VIBRIO
GROUP A GROUP B
(biochemically and antigenically
heterogenous )
OSUB GROUP O1 Non-01(SERO GROUPS) (up to 0-13)(SERO VARS)
BIOTYPES : CLASSICAL El Tor
SEROTYPES : Ogawa Inaba Hikojima
• TEST CLASSICAL El Tor
• Hemolysis _ +
• VP test _ +
• Chick erythrocyte _ + agglutination • polymyxinB sensitivity + _
• GroupIV phage Susceptibility + _
• El Tor phage V Suceptibility _ +
VIBRIO CHOLERAE
MORPHOLOGY• Short ,curved ,cylindrical rods• V.comma• S-shaped or spiral forms• Pleomorphism• Fish in stream appearance• Darting motility• Swarm of gnats
CULTURAL CHARACTERISTICS• Strongly aerobic• Temp 16-40 C,PH :6.4-9.6• Requirement of Nacl• Grows well on ordinary media• Nutrient agar:
moist,translucent,rounddiscs,1-2mm in diameter with bluish tinge in transmitted light
Mac conkeys agar:- Late lactose fermenters
Blood agar:- hemodigestion
Gelatin stab culture:- infundibuliform or napiform
liquefaction
Peptone water:- forms surface pellicle-in
6hrs
• SPECIAL MEDIA:-1.Holding or transport media:- a.Venkatraman-Ramakrishnan
medium b.Cary-Blair medium c.Autoclaved sea water2.Enrichment media:- a.Alkaline peptone water b.Monsur’s taurocholate tellurite
peptone water3.Plating media:- a.alkaline bile salt agar b.monsur’s gelatin taurocholate
trypticase tellurite agar c.TCBS medium
• BIOCHEMICAL REACTIONS:- catalase -positive oxidase - positive Indole - positive methyl red -negative voges-proskauer test -negative citrate test - positive nitrate test - positive
• Sugar fermentation tests ferments glucose mannitol maltose mannose sucrose with the
production of acid only not ferments inositol arabinose or lactose• Vibrios decarboxylate lysine and
ornithine but not arginine• Vibrios elaborate several enzymes • CHOLERA RED REACTION
RESISTANCE• Susceptible to heat ,drying and acids
& disinfectants• Resist high alkalinity• Destroyed at 55 C in 15 min• Affected by vibriophages• Killed in the gastric juice of normal
acidity with in min• El Tor vibrios survive longer than
classical cholera vibrio
Recommended