Proteus vulgaris

Proteus vulgaris is a rod-shaped, nitrate-reducing, indole-positive and catalase-positive, hydrogen sulfide-producing, Gram-negative bacterium that inhabits the intestinal tracts of humans and animals. It can be found in soil, water, and fecal matter. It is grouped with the Morganellaceae and is an opportunistic pathogen of humans. It is known to cause wound infections and other species of its genera are known to cause urinary tract infections.
"P. vulgaris" was one of the three species Hauser isolated from putrefied meat and identified (1885).
Over the past two decades, the genus "Proteus", and in particular "P. vulgaris", has undergone a number of major taxonomic revisions. In 1982, "P. vulgaris" was separated into three biogroups on the basis of indole production. Biogroup one was indole negative and represented a new species, "P. penneri", while biogroups two and three remained together as "P. vulgaris".
Lab identification.
According to laboratory fermentation tests, "P. vulgaris" ferments glucose and amygdalin, but does not ferment mannitol or lactose. "P. vulgaris" also tests positive for the methyl red (mixed acid fermentation) test and is also an extremely motile organism.
When "P. vulgaris" is tested using the API 20E identification system it produces positive results for sulfur reduction, urease production, tryptophan deaminase production, indole production, sometimes positive gelatinase activity, and saccharose fermentation, and negative results for the remainder of the tests on the testing strip.
It is referenced in the Analytical Profile Index using the nine-digit code: 047602157.
The optimal growing conditions of this organism is in a facultative anaerobic environment with an average temperature of about 40 °C.
The Becton/Dickinson BBL Enterotube II system for identification of members of the order Enterobacterales inoculated with "P. vulgaris" may yield the following results:
"P. vulgaris" can test positive or negative for citrate. All combine for a Biocode ID of 31406, (Biocode ID 31402, 31404, 31407 all resulting in "P. vulgaris" with asymptomatic results) for use in the Interpretation Guide/Computer Coding and Identification System. "P. vulgaris" can also test urease negative in solid media (such as in Enterotube), but will be urease positive in liquid media. The CCIS code will still identify it with a negative urease test. When inoculated in a gelatin stab test, "P. vulgaris" is capable of hydrolysis of gelatin.
"Proteus" infections.
Clinical expression.
Enterobacterales (of which "Proteus "is a member) and "Pseudomonas" species are the micro-organisms most commonly responsible for Gram-negative bacteremia and sepsis.
The presence of the sepsis syndrome associated with a urinary tract infection (UTI) should raise the possibility of urinary tract obstruction. This is especially true of patients who reside in long-term care facilities, who have long-term indwelling urethral catheters, or who have a known history of urethral anatomic abnormalities.
Urease production leads to precipitation of organic and inorganic compounds, which leads to struvite stone formation. Struvite stones are composed of a combination of magnesium ammonium phosphate (struvite) and calcium carbonate-apatite. Struvite stone formation can be sustained only when ammonia production is increased and the urine pH is elevated to decrease the solubility of phosphate. Both of these requirements can occur only when urine is infected with a urease-producing organism such as "Proteus". Urease metabolizes urea into ammonia and carbon dioxide: urea 2 NH3 + CO2. The ammonia/ammonium buffer pair has a pK of 9.0, resulting in the combination of highly alkaline, ammonia-rich urine.
Symptoms attributable to struvite stones are uncommon. More often, women present with UTI, flank pain, or hematuria, and are found to have a persistently alkaline urine pH (>7.0).
Treatments.
Antibiotics to which "P. vulgaris" is known to be sensitive:
References.
“Proteus Vulgaris.” Thistle, Thistle.co, www.thistle.co.za/pdf_files/education/microbiology/microbiology_legends/Cycle_41/Cycle%2041%20Organism%203%20-%20Proteus%20Vulgaris.pdf.