Salmonella typhimurium

Basic description of microbe:

• Rods (0.7-1.5 mm x 2-5 mm)

• Motile

• Anaerobic

• Optimal temperature: 37 ˚C

What it looks like on the agar:

• Whole Colony                                      Round

• Margin                                                 Irregular colonies

• Elevation                                              Convex

• Color                                                   White-yellow

Biochemical tests: 

• Oxidase                                               negative

• Catalase                                               positive

• Indole                                                  negative

• Voges-Proskauer                                 negative

• Methyl Red                                          positive

• Simmons Citrate                                   positive

• H₂S production                                    positive

• Urease                                                 negative

• Phenylalanine Deaminase                      negative

• Reduction of Nitrate                             positive

Interesting Facts:

• Can occur in humans, warm and cold blooded animals, foods and the environment.

• Causative agent of typhoid fever, enteric fevers, gastroenteritis, and septicemia.