Aeromonas hydrophila

Basic description of microbe:

• Straight rods with rounded ends, some spherical in shape
• 0.3-1.0 μm diameter x 1.0-3.5 μm long
• Pairs or short chains
• Motile
• Facultatively anaerobic
• Optimal temperature: 22-28°C; some grow well at 37°C

What it looks like on the agar:

• Whole Colony                                      Round
• Margin                                                 Smooth
• Elevation                                              Umbonate
• Color                                                   Beige, opaque
• Colony Texture                                     Moist

Biochemical Tests:

• Oxidase                                               positive
• Catalase                                               positive
• DNase                                                 positive
• Indole                                                  positive
• Methyl Red                                          positive
• Voges-Proskauer                                 positive
• H₂S                                                     positive
• Urea Hydrolysis                                   negative
• Phenylalanine Deaminase                      negative
• Reduction of Nitrate                             positive

Interesting Facts:

• Some are pathogenic to frogs, fish, and humans (diarrhea and bacteremia in humans).