Proteus mirabilis

Proteus mirabilis
P. mirabilis on an XLD agar plate.
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gamma Proteobacteria
Order:	Enterobacteriales
Family:	Enterobacteriaceae
Genus:	Proteus
Species:	P. mirabilis
Binomial name
Proteus mirabilis Hauser 1885

Proteus mirabilis is a Gram-negative, facultatively anaerobic, rod shaped bacterium. It shows swarming motility, and urease activity. P. mirabilis causes 90% of all Proteus infections in humans.

Diagnosis

An alkaline urine sample is a possible sign of P. mirabilis.

P. mirabilis can be diagnosed in the lab due to characteristic swarming motility, and inability to metabolize lactose (on a MacConkey agar plate, for example). Also P. mirabilis produces a very distinct odour.

Disease

This rod shaped bacterium has the ability to produce high levels of urease. Urease hydrolyzes urea to ammonia (NH₃) and thus makes the urine more alkaline. If left untreated, the increased alkalinity can lead to the formation of crystals of struvite, calcium carbonate, and/or apatite. The bacteria can be found throughout the stones, and these bacteria lurking in the stones can reinitiate infection after antibiotic treatment. Once the stones develop, over time they may grow large enough to cause obstruction and renal failure. Proteus can also cause wound infections, septicemia and pneumonias, mostly in hospitalized patients.

Treatment

P. mirabilis is generally susceptible to most antibiotics apart from tetracycline, however 10%–20% of P. mirabilis strains are also resistant to first generation cephalosporins and ampicillins.

Characteristics

P. mirabilis can utilize urea and citrate. It can produce hydrogen sulfide gas, and forms clear films on growth media. It is motile, possessing peritrichous flagella, and is known for its swarming ability. It is commonly found in the intestinal tract of humans. P. mirabilis is not pathogenic in guinea pigs or chickens. Noteworthy is the ability of this species to inhibit growth of unrelated strains resulting in a macroscopically visible line of reduced bacterial growth where two swarming strains intersect. This line is named Dienes line after its discoverer Louis Dienes.

The micro-organism tests:

• Indole negative and Nitrate reductase positive (no gas bubbles produced)
• Methyl Red positive and Voges-Proskauer negative
• Catalase positive and Cytochrome Oxidase negative
• Phenylalanine Deaminase positive
• Tryptophan test- negative (-)
• Urea test- positive
• Casein test-negative
• Starch test- negative
• Hydrogen sulfide test- positive
• Citrate agar test- positive

External links

• "Proteus mirabilis and Urinary Tract Infection" [1].
• Proteus Genome Projects from Genomes OnLine Database
• Bacteria of the species Proteus mirabilis are widely distributed in soil and water in the natural environment. In humans, Proteus is found as part of the normal flora of the gut....from http://www.biomedhtc.org.uk/ProteusMirabilis.htm BioMedHTC]

Further reading

• Esipov, Sergei E.; Shapiro, J. A. (1998). "Kinetic model of Proteus mirabilis swarm colony development". Journal of Mathematical Biology 36 (3): 249. doi:10.1007/s002850050100. 
• Frénod, Emmanuel (2006). "Existence result for a model of Proteus mirabilis swarm". Differential and integral equations 19 (6): 697–720. arXiv:math.FA/0702761. 
• Gué, Michaël; Dupont, Virginie; Dufour, Alain; Sire, Olivier (2001). "Bacterial swarming: A biological time-resolved FTIR-ATR study of Proteus mirabilis swarm-cell differentiation". Biochemistry 40 (39): 11938–11945. doi:10.1021/bi010434m. PMID 11570895. 
• Rauprich, O.; Matsushita, M.; Weijer, C. J.; Siegert, F.; Esipov, S. E.; Shapiro, J. A. (1 November 1996). "Periodic phenomena in Proteus mirabilis swarm colony development". Journal of Bacteriology 178 (22): 6525–6538. PMC 178539. PMID 8932309. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=178539.