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| {{CMG}} | | {{CMG}} |
| ==Overview== | | ==Overview== |
| '''''Proteus''''' is a genus of [[Gram-negative]] [[Proteobacteria]], which includes [[pathogens]] responsible for many [[human]] [[urinary tract infection]]s.<ref name=Barron>{{cite book | author = Guentzel MN | title = Escherichia, Klebsiella, Enterobacter, Serratia, Citrobacter, and Proteus. ''In:'' Barron's Medical Microbiology ''(Barron S ''et al'', eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | id = [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.section.1472 (via NCBI Bookshelf)] ISBN 0-9631172-1-1 }}</ref> ''Proteus'' species do not usually ferment [[lactose]], but have shown to be capable lactose fermenters depending on the species in a [[TSI]] test, Triple Sugar Iron. They are [[oxidase]] negative, and [[urease]] positive; some species are [[Motility|motile]].<ref name=Sherris>{{cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004 | id = ISBN 0-8385-8529-9 }}</ref>
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| ==Pathogenesis== | | ==Microbiological Characteristics== |
| Three species—''[[Proteus vulgaris|P. vulgaris]]'', ''[[Proteus mirabilis|P. mirabilis]]'', and ''[[Proteus penneri|P. penneri]]''—are [[Opportunistic infection|opportunistic]] human [[pathogen]]s.
| | *''P. mirabilis'' is a urease-producing, motile, nitrite-reducing, hydrogen sulfide-producing, catalase-positive, facultatively anaerobic, Gram-negative bacillus. |
| ===Antimicrobial regimen===
| | *It grows optimally at 40 °C (104 °F). |
| :* '''Indole positive Proteus species'''<ref>{{cite book | last = Bartlett | first = John | title = Johns Hopkins ABX guide : diagnosis and treatment of infectious diseases | publisher = Jones and Bartlett Learning | location = Burlington, MA | year = 2012 | isbn = 978-1449625580 }}</ref>
| | *It produces [[hydrogen sulfide]] gas, and forms clear films on growth media. It is [[Motility|motile]], possessing peritrichous [[flagella]], and is known for its swarming ability. It is commonly found in the intestinal tracts of humans. ''P. mirabilis'' is not pathogenic in [[guinea pig]]s or chickens. |
| ::* Preferred regimen (1): [[Ceftriaxone]] 1 g IV q24h
| | *Characteristically, ''Proteus'' can inhibit the growth of other strains in culture media, resulting in a macroscopically visible line (Dienes line) of reduced bacterial growth where two swarming strains intersect. |
| ::* Preferred regimen (2): [[Imipenem]] 500 mg IV q6h
| | *The following table summarizes the microbiological characteristics of ''Proteus'': |
| ::* Preferred regimen (3): [[Ciprofloxacin]] 400 mg IV q12h or 250-500 mg PO bid
| | {| {{table}} |
| ::* Preferred regimen (4): [[Levofloxacin]] 500 mg IV/PO q24h
| | | align="center" style="background:#f0f0f0;"|'''Test''' |
| | | | align="center" style="background:#f0f0f0;"|'''Result''' |
| __NOTOC__
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| {{Taxobox
| | | Indole||Negative |
| | color = lightgrey
| | |- |
| | name = ''Proteus vulgaris''
| | | Nitrate reductase||Positive (no formation of gas bubbles) |
| | image = Proteus McConkey.jpg
| | |- |
| | image_caption = 24h old culture
| | | Methyl red||Positive |
| | regnum = [[Bacterium|Bacteria]]
| | |- |
| | phylum = [[Proteobacteria]]
| | | Voges-Proskauer||Negative (VP may be positive) |
| | classis = Gamma Proteobacteria
| | |- |
| | ordo = [[Enterobacteriaceae|Enterobacteriales]]
| | | Catalase||Positive |
| | familia = Enterobacteriaceae
| | |- |
| | genus = ''[[Proteus (bacterium)|Proteus]]''
| | | Cytochrome oxidase||Negative |
| | species = '''''P. vulgaris'''''
| | |- |
| | binomial = ''Proteus vulgaris''
| | | Phenylalanine deaminase||Positive |
| | binomial_authority = [[Gustav Hauser|Hauser]] 1885
| | |- |
| }}
| | | Tryptophan||Negative |
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| '''''Proteus vulgaris''''' is a [[Bacillus (shape)|rod-shaped]], nitrate-reducing, indole+ and catalase-positive, hydrogen sulfide-producing, [[gram-negative bacteria|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 [[Enterobacteriaceae]] and is an opportunistic pathogen of humans. It is known to cause [[urinary tract infection]]s and [[wound infection]]s.
| | | Urea (Harnstoff test) ||Positive |
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| The term [[Proteus]] signifies changeability of form, as personified in the Homeric poems in Proteus, "the old man of the sea", who tends the sealflocks of Poseidon and has the gift of endless transformation. The first use of the term “Proteus” in bacteriological nomenclature was made by Hauser (1885), who described under this term three types of organisms which he isolated from putrefied meat. One of the three species Hauser identified was ''Proteus vulgaris'', so this organism has a long history in microbiology.
| | | Casein||Negative |
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| 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''.
| | | Starch||Negative |
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| == Lab identification ==
| | | Hydrogen sulfide||Positive |
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| 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.
| | | Citrate agar||Negative |
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| When ''P. vulgaris'' is tested using the API 20E identification system<ref>{{cite web |url=http://www.rlc.dcccd.edu/mathsci/reynolds/micro/lab_manual/API.html |archiveurl=http://web.archive.org/web/20081107051850/http://www.rlc.dcccd.edu/mathsci/reynolds/micro/lab_manual/API.html |archivedate=7 November 2008 |title=API Test Strips}}</ref> 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.
| | | Ornithine decarboxylase||Positive |
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| It is referenced in the [[Analytical Profile Index]] using the nine-digit code: 047602157
| | | Lysine decarboxylase||Negative |
| | | |- |
| The optimal growing conditions of this organism is in a facultative anaerobic environment with an average temperature of about 40°C.
| | | Glucose fermentation||Positive |
| | | |- |
| The Becton/Dickinson BBL Enterotube II system for identification of members of the family Enterobacteriaceae inoculated with ''P. vulgaris'' may yield the following results: | | |Amygdalin fermentation||Positive |
| *Positive for glucose fermentation (with gas production)
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| *Negative for lysine and ornithine
| | |Mannitol fermentation||Negative |
| *Positive for hydrogen sulfide production and indole production
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| *Negative for adonitol and lactose
| | |Lactose fermentation||Negative |
| *Negative for arabinose, sorbitol and dulcitol
| | |} |
| *Positive for the phenylalanine test and the Harnstoff urea test
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| ''P. vulgaris'' can test positive or negative for citrate. All combine for a "Biocode ID of 31407" 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.
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| == ''Proteus'' infections ==
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| === Etiology and epidemiology === | |
| *Nosocomial infections
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| *''P. mirabilis'' causes 90% of ''Proteus'' infections.
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| *''P. vulgaris'' and ''P. penneri'' are easily isolated from individuals in long-term care facilities and hospitals and from patients with underlying diseases or compromised immune systems.
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| *Patients with recurrent infections, those with structural abnormalities of the urinary tract, those who have had urethral instrumentation, and those whose infections were acquired in the hospital have an increased frequency of infection caused by ''Proteus'' and other organisms (e.g., ''Klebsiella'', ''Enterobacter'', ''Pseudomonas'', enterococci, and staphylococci)
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| <!-- format convert to text or at least readable === Pathogenesis and virulence ===
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| ''motility''
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| '''flagella'''
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| ''adherence factors''<br />
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| '''Fimbriae'''—facilitate adherence and thus enhance the capacity of the organism to produce disease
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| ''inflammatory response''<br />
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| '''IL-6/IL-8 secretion'''—attachment to uroepithelial cells initiates secretion
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| '''apoptosis and epithelial cell desquamation'''
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| '''pyelonephritis'''—Bacterial production of urease increases risk
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| '''bacteremia & sepsis'''—bacterial endotoxin (LPS)
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| ''Survival''
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| '''urease production'''—alkalinize the urine by hydrolyzing urea to ammonia makes proteus effective in producing an environment in which it can survive. -->
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| === Clinical expression ===
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| Enterobacteriaceae (of which ''Proteus ''is a member) and ''Pseudomonas'' species are the micro-organisms most commonly responsible for Gram-negative bacteremia and sepsis.
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| 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.
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| ;UTI obstruction
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| 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 NH<sub>3</sub> + CO<sub>2</sub>. The ammonia/ammonium buffer pair has a pK of 9.0, resulting in the combination of highly alkaline, ammonia-rich urine.
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| 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).
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| == Treatments ==
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| Known antibiotics to which ''P. vulgaris'' is sensitive:
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| Ciprofloxacin<br />
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| Ceftazidime<br />
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| Netilmicin<br />
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| Sublactam or cefoperazone<br />
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| Meropenem<br />
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| Piperacillin/tazobactam<br />
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| Unasyn
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| Antibiotics should be introduced in much higher doses than "normal" when ''P. vulgaris'' has infected the sinus or respiratory tissues; for example, ciprofloxacin should be introduced at a level of at least 2000 mg per day orally in such a situation, rather than the "standard" 1000 mg per day.
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| [[Category:Infectious Disease Project]]
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| ==See also==
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| * [[Proteus OX19|''Proteus'' OX19]]
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| * [[Swarming motility]]
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| {{Gram-negative bacterial diseases}}
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| {{DEFAULTSORT:Proteus Vulgaris}}
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| [[Category:Enterobacteria]]
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| | ===Natural Rerervoir=== |
| | *''Proteus'' can be found in soil, water, and fecal matter. |
| | * It inhabits the intestinal tracts of humans and animals, and is considered an opportunistic pathogen of humans |
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| ==References== | | ==References== |
| {{reflist|2}} | | {{reflist|2}} |
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| [[Category:Enterobacteria]]
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| [[Category:Gram negative bacteria]]
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| {{SIB}}
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