Vibrio, Aeromonas, Chromobacterium
Vibrio
- Motile (monotrichous) – SHOOTING STAR MOTILITY
- Oxidase (+), except for V. metschnikovii
- Halophilic except V. cholerae and V. mimicus
- LOA = ++-
- 0129 Susceptible vs. Aeromonas (R)
Vibrio cholerae
- Agent of cholera
- Hallmark: rice watery stools (caused by cholera toxin)
- Somatic antigens – O1 & O139
- Associated with V. cholerae envelope
- Positive markers for spread of pandemic and epidemic cholera
- Cholera toxin / Choleragen – increase cAMP — > dehydration, loss of water, Na and K.
| CLASSIFICATION OF VIBRIO CHOLERAE O1 (PANDEMIC TYPE) | ||
| Biotype | Classical | El Tor (Common Type) |
| Polymyxin Susceptibility | S | R |
| Lysis BY bacteriophage | + | – |
| Chicken RBC Agglutination | – | + |
| Hemolysis of Sheep RBC | – | + |
| Vogues-Proskauer Test | – | + |
| Serotype | Ogawa | Inaba | Hikojima |
| Anti – Ogawa | + | – | + |
| Anti – Inaba | – | + | + |
| Organism | Vibrio | Aeromonas | Plesiomonas |
| TSI | A/A (V. cholerae ) K/A (V. parahaemolyticus ) | A/A gas+ | K/A or A/A |
| NaCl | + | – | – |
| Oxidase | + | + | + |
| O129 Sensitivity / Vibrio Static Test | S | R | S/R |
| Motility | + | + | + |
| LOA | ++- | +-+ | +++ |
| DNAse | – | + | – |
| Esculin hydrolysis | – | + | – |
| Disease | 8% NaCl | TCBS | Other | |
| V. cholerae | Cholera (rice watery) | – | Yellow | String test + (0.5% Na desoxycholate) |
| V. alginolyticus | Wound and ear infection LEAST PATHOGENIC. Most frequently isolated | + | Yellow | Strict halophilic (1% NaCl; can tolerate up to 10%) |
| V. parahaemolyticus (O3:K6) | Gastroenteritis 2nd most common cause of gastroenteritis | + | Green | Arabinose + Kanagawa + Beta-hemolytic in Wagatsuma agar) |
| V. vulnificus | Primary septicemia, wound infection. Seen in blood cultures 2nd most serious type of infection | + | Green | Lactose + |
Aeromonas spp.
- Beta – hemolytic
- Grows on Modified Cefsulodin-Irgasan-Novobiocin (CIN)
C. violaceum
- Violacein
- ethanol soluble
- violet pigment (Room Temp.)
- Beta-hemolytic with almond like odor
