NAME: Proteus spp. (human pathogens include P. mirabilis, P. vulgaris, P. penneri, and P. hauseri)
SYNONYM OR CROSS REFERENCE: Sometimes referred as members of the Proteeae tribe Footnote 1. Former species of genus Proteus now homotypic synonyms with other species: P. inconstans with Providencia alcalifaciens, P. morganii with Morganella morganii, and P. rettgeri with Providencia rettgeri Footnote 2.
CHARACTERISTICS: Proteus spp. consist of Gram-negative, motile, aerobic rod-shaped bacilli belonging to the family Enterobacteriaceae Footnote 3, Footnote 4. Members of the Enterobacteriaceae family generally range from 0.3 to 1.0 mm in width and 0.6 to 6.0 mm in length Footnote 3. They are urease positive and form swarmer cells which allow for swarming motility on solid media. They are part of normal flora of human gastrointestinal tract.
PATHOGENICITY/TOXICITY: Proteus spp. are commonly associated with complicated urinary tract infections (UTIs) Footnote 1, Footnote 3-Footnote 5. They generally affect the upper urinary tract (common site of infection), causing infections such as urolithiasis (stone formation in kidney or bladder) Footnote 3, Footnote 4, cystitis Footnote 4, and acute pyelonephritis. Rare cases of bacteraemia, associated with UTIs, with Proteus spp. have also been reported Footnote 1. Other infections include septicaemia and wound infections. After attachment and colonization within the urinary tract, Proteus spp. release urease, which catalyzes the conversion of urea into ammonia and CO2 Footnote 3, Footnote 5. This causes a decrease in the urine pH and may eventually lead to the formation of kidney or bladder stones. P. mirabilis causes the most infections among all Proteus spp.
EPIDEMIOLOGY: Proteus spp. infections occur worldwide and Proteus spp. are part of the human intestinal flora Footnote 1, Footnote 3-Footnote 5. They are also widespread in the environment, including animals, soil, and polluted water. They are important causative agents in community-acquired and nosocomial UTIs; within Europe and North America, 4 to 6% of Proteus infections are community-acquired and 3 to 6% are nosocomial Footnote 3. Proteus spp. are generally considered pathogenic for young individuals and opportunistic pathogens for the elderly Footnote 4. The rate of infection is highest among the elderly, particularly those with indwelling catheters (long-term catheterization) or under frequent antibiotic therapy Footnote 1, Footnote 4, Footnote 5. Other target groups include prepubescent males and females, with higher rate of infection reported among uncircumcised males Footnote 4. Individuals with long-term catheterization or structural abnormalities of the urinary tract are more susceptible to infection with Proteus spp. Footnote 1, Footnote 4, Footnote 5. Nosocomial outbreaks with antibiotic-resistant Proteus spp. have been reported Footnote 4.
HOST RANGE: Humans Footnote 3.
INFECTIOUS DOSE: Unknown.
MODE OF TRANSMISSION: Proteus spp. are part of the human intestinal flora Footnote 1, Footnote 3-Footnote 5 and can cause infection upon leaving this location. They may also be transmitted through contaminated catheters (particularly urinary catheters) Footnote 1, Footnote 4, Footnote 5 or by accidental parenteral inoculation. The specific mode of transmission, however, has not been identified.
INCUBATION PERIOD: Unknown.
COMMUNICABILITY: Proteus spp. are not known to be transmitted from person-to-person.
RESERVOIR: Humans Footnote 1, Footnote 3, Footnote 4, animals, birds Footnote 3, and fish. Proteus spp. are widespread within the environment, including soil, water, and sewerage Footnote 1, Footnote 4.
DRUG SUSCEPTIBILITY: Proteus spp. are generally susceptible to broad-spectrum cephalosporins, aminoglycosides, and imipenem Footnote 3. P. mirabilis is also susceptible to trimethoprim-sulfamethoxazole, ampicillin, amoxicillin, and piperacillin. P. vulgaris and P. penneri are also susceptible to cefoxitin, cefepime, and aztreonam. P. mirabilis is resistant to nitrofurantoin. Resistance to ciprofloxacin may develop with unrestricted use. P. vulgaris and P. penneri are resistant to piperacillin, amoxicillin, ampicillin, cefoperazone, cefuroxime, and cefazolin. P. penneri is more resistant to penicillin than P. vulgaris. Resistance to β-lactamases among Proteus spp. is emerging Footnote 4. Carbapenem resistance, including pan-resistant isolates, have been described in India Footnote 6.
SUSCEPTIBILITY TO DISINFECTANTS: Gram-negative bacteria are generally susceptible to a number of disinfectants including phenolic compounds, hypochlorites (1% sodium hypochlorite), alcohols (70% ethanol), formaldehyde (18.5 g/L; 5% formalin in water), glutaraldehyde, and iodines (0.075 g/L) Footnote 7.
PHYSICAL INACTIVATION: Bacteria are generally sensitive to moist heat (121 °C for at least 15 minutes) and dry heat (160 to 170 °C for at least 1 hour) Footnote 8.
SURVIVAL OUTSIDE HOST: Proteus spp. survive only for a few days on inanimate surfaces; and only 1 to 2 days in the case of P. vulgaris Footnote 9. They also survive well within the environment in soil, water, and sewage Footnote 3.
SURVEILLANCE: Monitor for symptoms. Proteus spp. can be diagnosed by isolation and differentiation with chromogenic media (i.e. by means of cultured organisms from urine and bloods samples) Footnote 3.
LABORATORY-ACQUIRED INFECTIONS: No cases of laboratory-acquired infection have reported to date.
SOURCES/SPECIMENS: Samples from urine tract, wounds, and blood samples Footnote 3. Specific sources identified include:
P. mirabilis: Urinary tract, blood, and cerebrospinal fluid.
P. penneri: Urinary tract, blood, wound, feces, eye.
P. vulgaris: Urinary and respiratory tract, wound, and stool.
PRIMARY HAZARDS: Use of contaminated catheters (particularly urinary catheters) in medical procedures Footnote 1, Footnote 4, Footnote 5, and accidental parenteral inoculation and/or ingestion of contaminated material.
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk Group 2 Footnote 10. The risk group associated with “Proteus spp.” reflects the genus as a whole, but does not necessarily reflect the risk group classification of every species within the genus.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 11. These containment requirements apply to the genus as a whole, and may not apply to each species within the genus.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk to splashes Footnote 10.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited Footnote 10. Additional precautions should be considered with work involving animals or large scale activities.
SPILLS: Allow aerosols to settle. While wearing protective clothing, gently cover the spill with absorbent paper towel and apply appropriate disinfectant, starting at perimeter and working towards the centre. Allow sufficient contact time before clean up Footnote 11.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism before disposing by autoclave, chemical disinfection, gamma irradiation, or incineration Footnote 11.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled Footnote 11.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: September 2011
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2011