Proteus mirabilis

Basic description of microbe:

• Straight rods

• 0.4-0.8 μm x 1-3 μm

• Motile

• Facultatively anaerobic

• Optimal temperature: 37°C

What it looks like on the agar:

• Whole Colony***                                Round

• Margin***                                           Smooth

• Elevation                                              Growth into medium

• Color                                                   turns agar dark yellow color

*** Colonies produce a swarming growth pattern which make it difficult to see the individual colonies.

Biochemical Tests:

• Oxidase                                               negative

• Catalase                                               positive

• Methyl Red                                          positive

• Indole                                                  negative

• Lysine Decarboxylase                          negative

• Reduction of Nitrate                             positive

Interesting Facts:

• Occur in intestines of humans and a wide variety of animals

• Occur in manure, soil, and polluted waters

• Human pathogens and secondary invaders (urinary tract infections; septic lesions in burn patients)