Infectious Disease Compendium



Aerobic gram negative rod; P. mirabilis, P. myxofaciens, P. vulgaris. They swarm on the plate.

Epidemiologic Risks

Part of normal flora. Also found in sewage. P. mirabilis is in water.


UTI predominates, although like Escherichia coli it can show up anywhere.


Resistance is increasing, I sure hope you know your local susceptibilities. Try quinolones OR third generation cephalosporins OR carbapenems empirically.


Likes to help cause struvite renal stones by altering pH of urine by alkalinization of the urine due to urease enzyme which splits urea into ammonia and carbon dioxide.

The cell wall O-antigenlike OX-2, OX-19, OX-k cross react with several species of Rickettsiae and are used for the Weil-Felix reaction.

Curious Cases

Relevant links to my Medscape blog


More Water

Last update: 05/05/18