Proteus species

Background:

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Enterobacteriaceae (Gram Negative Bacilli)
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>Citrobacter species:
     1] Citrobacter koseri
     2] Citrobacter freundii
>Enterobacter species:
     1] Enterobacter cloacae,
     2] Enterobacter aerogenes)
>Escherichia coli
>Klebsiella species:
     1] Klebsiella ozaenae
     2] Klebsiella pneumoniae
     3] Klebsiella rhinoscleromatis
>Morganella species
     1] (Morganella morganii)
>Proteus species:

     1] Proteus mirabilis
     2] Proteus vulgaris
>Providencia species:
     1] Providencia_rettgeri
     2] Providencia stuartii
>Salmonella species:
     1] Salmonella enteritidis
     2] Salmonella typhi
     3] Other
>Serratia marcescens
>Shigella species:
     1] Shigella dysenteriae (serogroup A)
     2] Shigella flexneri
     3] Shigella boydii
     4] Shigella sonnei
     5] Other

Proteus:

Gram-negative, oxidase-negative, catalase- and nitrate-positive, and urease positive.
Widely distributed in nature as saprophytes, being found in decomposing animal matter, in sewage, in manure soil, and in human and animal feces.
They are opportunistic pathogens, commonly responsible for urinary and septic infections, often nosocomial. Three species – P. vulgaris, P. mirabilis, and P. penneri – are opportunistic human pathogens.
On the species level, indole is considered reliable, as it is positive for Proteus vulgaris but negative for Proteus mirabilis.
Most strains produce a powerful urease enzyme, which rapidly hydrolyzes urea to ammonia and carbon monoxide.

Therapy:

Important considerations: The choice of an agent should be based on local antimicrobial sensitivities, site of infection, cost, and comorbid conditions. Generally, the most common agents/regimens are listed first. Listed dosages may need to be adjusted for renal dysfunction.

Proteus mirabilis:

Ceftin (cefuroxime oral) 250-500mg orally twice daily
Augmentin 875/125 mg orally twice daily
Ciprofloxacin 500-750 mg orally q12h or 400mg IV q12h
Levofloxacin 500mg – 750 mg IV/PO once daily
Ceftriaxone 1-2 grams IV q24h

Proteus vulgaris:

Ciprofloxacin 500-750 mg orally q12h or 400mg IV q12h
Levofloxacin 500mg – 750 mg IV/PO once daily
Ceftriaxone 1-2 grams IV q24h
Cefepime 1-2 grams IV every 8-12 hours
Imipenem 500mg IV every 6 hours [Range: 250-1000 mg q6-8h]