Proteus spp in Horses (Equis) | Vetlexicon
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Proteus spp

ISSN 2398-2977

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Synonym(s): P. mirabilis, P. vulgaris

Introduction

Classification

Taxonomy

  • Genus:Proteus.
  • Family:Enterobacteriaceae.

Etymology

  • Gk:Proteus- an ocean God able to change himself into different shapes. Lat:mirabilis- wonderful;vulgaris- common.

Distribution

  • Worldwide.

Significance

  • Normal fecal flora of mammals.
  • Found in environment.
  • Opportunistic pathogen, occasionally causing infection in animals.

Active Forms

Active Form 1

Morphology

  • On blood agar   →   swarms, tends to turn agar chocolate brown color, powerful foul odor .
  • MacConkey agar   →   swarming inhibited; greyish colonies (non-lactose fermenter) .

Taxonomy

  • Triple sugar iron agar   →   same asSalmonellaspp   Salmonella spp  .
  • Lysine decarboxylase test = negative (Salmonellaspp positive).
  • Urease = positive (Salmonellaspp negative).
  • Indole = positive.
  • Ornithine = negative.
  • Gram's staining: gram-negative, medium-sized, non-sporing rods .
  • Aerobic and facultatively anaerobic.
  • Non-lactose fermenters.
  • Catalase = positive .
  • Oxidase = negative .
  • Motile.

Color

  • Grayish on blood agar.

Tolerances

Temperature
  • KiIled by drying.
Humidity
  • Can survive for many months in moist areas (if shaded), eg manure.
Ultraviolet
  • Susceptible to sunlight.
Other
  • Killed by pasteurization.

Development

Growth
  • Facultative anaerobe.
  • Ferments carbohydrates under anaerobic and aerobic conditions.
Reproduction
  • Binary fission.
  • Non-spore forming.
Longevity
  • Can survive for months in moist, shaded environments.

Resting Forms

Clinical Effects

Epidemiology

Habitat

  • Part of normal flora of gastrointestinal and urogenital tracts, and skin.

Lifecycle

  • Multiples by binary fission.
  • May undergo conjugation with otherEnterobactericeae, with transfer of plasmoids.

Transmission

  • Endogenous or exogenous infections.

Pathological effects

  • Compromise of immune system   →   opportunistic infections.

Other host effects

  • Part of normal gastrointestinal flora.
  • Part of normal skin flora in some dogs and cats.
  • Part of normal flora of urogenital tract in some horses.

Control

Control via chemotherapies

Susceptibility

Vaccination

  • None.

Diagnosis

Useful samples

  • Pus.
  • Tissue.
  • Mid-stream urine (for urinary tract infection).
  • Endoscopy   Respiratory: endoscopy  (for respiratory tract infection).

Specimen storage

  • Specimens should be refrigerated if not processed within 2 hours.

Transport of samples

  • If rapid processing is not possible, a swab or small portion of the sample should be put into bacteriologic transport media, such as:
    • Stuart.
    • Amies.
    • Cary-Blair.
    • Buffered glycerine-saline.
  • Package according to mailing regulations   Transportation of diagnostic specimens  .

Laboratory diagnosis

Direct microscopy of urine
  • May be significant bacterial count (more than 100,000 organisms/ml)   Urine: microbiology  .
    Gram staining
  • Gram-negative rods; smear from swarming growth may show long 'swarm cells' .
    Other tests
  • Blood agar : swarming with foul odor.
  • Hydrogen sulfide = positive .
  • Urease = positive .
  • Phenylalanine = positive .
  • Lysine = negative .
  • Proteus mirabilisandProteus vulgariscan be differentiated from each other by testing for indole production and maltose fermentation :
    • Proteus mirabilisindole -ve, maltose +ve.
    • Proteus vulgarisindole +ve, maltose -ve.

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • MacLeay J M et al (1998) Results of quantitative cultures of urine by free catch and catheterization from healthy adult horses. J Vet Intern Med 12 (2), 76-78 PubMed.
  • Ensink J M et al (1993) In-vitro susceptibility to antimicrobial drugs of bacterial isolates from horses in the Netherlands. Equine Vet J 25 (4), 309-313 PubMed.
  • Lakritz J et al (1993) Bronchointerstitial pneumonia and respiratory distress in young horses - clinical clinicopathologic, radiographic, and pathologic findings in 23 cases (1984-1989). J Vet Intern Med (5), 277-288 PubMed.
  • Brinsko S P, Varner D D, Blanchard T L, Relford R L & Johnson L (1992) Bilateral infectious epididymitis in a stallion. Equine Vet J 24 (4), 325-328 PubMed.
  • Orsini J A et al (1989) Resistance to gentamicin and amikacin of gram-negative organisms isolated from horses. Am J Vet Res 34 (3), 923-925 PubMed.
  • Divers T J, Byars T D, Murch O & Sigel C W (1981) Experimental induction of Proteus mirabilis cystitis in the pony and evaluation of therapy with trimethoprim-sulfadiazine. Am J Vet Res 42 (7), 1203-1205 PubMed.