Difference between revisions of "Taylorella equigenitalis"

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(New page: <big><center>'''BACK TO INFECTIOUS AGENTS AND PARASITES'''</center></big> <big><center>'''BACK TO BACTERIA'''</center></big>)
 
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<big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>
 
<big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>
 
<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
 
<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
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===Overview===
 +
 +
*Causes contagious equine metritis
 +
*Found in genital tracts of stallions, mares and foals
 +
*Found in urethral fossa of stallions and clitoral fossa of mares
 +
*Disrupts breeding programs on thouroughbred stud farms
 +
 +
 +
===Characteristics===
 +
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*Short, non-motile Gram-negative rod
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*Catalase, oxidase and phosphatase postitive
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*Microaerophilic
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*Grows slowly
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*Fastidious growth - requires chocolate agar and 5-10% carbon dioxide for growth
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*No growth on MacConkey
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 +
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===Pathogenesis and pathogenicity===
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 +
*Transmission during coitus or via contaminated instruments
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*Semenal fluid contaminated with ''T. equigenitalis'' from the urethral fossa
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*Deposition in uterus required for infection to establish
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*Bacteria replicate in uterus and cause acute endometritis
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*Initial influx of mononuclear cells and plasma cells, followed by  neutrophils, which cause a mucopurulent discharge
 +
*Acute endometrial changes only last a few days
 +
 +
 +
===Clinical infections===
 +
 +
*Contagious equine metritis
 +
*Highly contagious venereal disease of thorougbred horses
 +
*Infected stallions and mares are a reservoir of infection
 +
*Stallions and some mares asymptomatic
 +
*Mucopurulent vulval discharge and temporary infertility in mares after service with a carrier stallion
 +
*Discharge may continue for 2 weeks, and mares may remain infertile for several weeks
 +
*Mares may recover without treatment; 25% become carriers
 +
*Re-infection can occur
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*Foals become infected ''in utero'' or during parturition
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*Infected foals and mares that recover clinically may be a source of infection
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 +
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===Diagnosis===
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*Specimens for bacteriology:
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**Mares: swabs from clitoral fossa and sinuses and endometrium during oestrus
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**Fillies: swabs from clitoral fossa
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**Colts: penile sheath and tip of penis
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**Stallions: swabs from urethra, urethral fossa, penile sheath and pre-ejaculatory fluid
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*Place swabs in charcoal transport medium
 +
*Isolation on chocolate agar with amphotericin B, crystal violet and streptomycin
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*Small, smooth, yello-grey colonies
 +
*Slide agglutination test
 +
*Fluorescent antibody test
 +
*Latex agglutination
 +
*PCR
 +
*Serology only detects active infection
 +
 +
===Treatment and control===
 +
 +
*Wash external genitalia of mares and stallions with 2% chlorhexidine combined with antimicrobials
 +
*Lavage uterus with a penicillin-containing solution daily for 5-7 days in mares
 +
*Ablation of clitoral sinuses in persistently-infected mares
 +
*Notifiable disease
 +
*Laboratory detection of carrier animals and clinical infections
 +
*Hygiene
 +
*Stop breeding if CEM diagnosed on stud farm
 +
*Sample recovered animals to ensure free from disease
 +
*Test-mating of stallions to 2 maiden mares to detect infection

Revision as of 08:25, 20 July 2008

BACK TO INFECTIOUS AGENTS AND PARASITES
BACK TO BACTERIA

Overview

  • Causes contagious equine metritis
  • Found in genital tracts of stallions, mares and foals
  • Found in urethral fossa of stallions and clitoral fossa of mares
  • Disrupts breeding programs on thouroughbred stud farms


Characteristics

  • Short, non-motile Gram-negative rod
  • Catalase, oxidase and phosphatase postitive
  • Microaerophilic
  • Grows slowly
  • Fastidious growth - requires chocolate agar and 5-10% carbon dioxide for growth
  • No growth on MacConkey


Pathogenesis and pathogenicity

  • Transmission during coitus or via contaminated instruments
  • Semenal fluid contaminated with T. equigenitalis from the urethral fossa
  • Deposition in uterus required for infection to establish
  • Bacteria replicate in uterus and cause acute endometritis
  • Initial influx of mononuclear cells and plasma cells, followed by neutrophils, which cause a mucopurulent discharge
  • Acute endometrial changes only last a few days


Clinical infections

  • Contagious equine metritis
  • Highly contagious venereal disease of thorougbred horses
  • Infected stallions and mares are a reservoir of infection
  • Stallions and some mares asymptomatic
  • Mucopurulent vulval discharge and temporary infertility in mares after service with a carrier stallion
  • Discharge may continue for 2 weeks, and mares may remain infertile for several weeks
  • Mares may recover without treatment; 25% become carriers
  • Re-infection can occur
  • Foals become infected in utero or during parturition
  • Infected foals and mares that recover clinically may be a source of infection


Diagnosis

  • Specimens for bacteriology:
    • Mares: swabs from clitoral fossa and sinuses and endometrium during oestrus
    • Fillies: swabs from clitoral fossa
    • Colts: penile sheath and tip of penis
    • Stallions: swabs from urethra, urethral fossa, penile sheath and pre-ejaculatory fluid
  • Place swabs in charcoal transport medium
  • Isolation on chocolate agar with amphotericin B, crystal violet and streptomycin
  • Small, smooth, yello-grey colonies
  • Slide agglutination test
  • Fluorescent antibody test
  • Latex agglutination
  • PCR
  • Serology only detects active infection

Treatment and control

  • Wash external genitalia of mares and stallions with 2% chlorhexidine combined with antimicrobials
  • Lavage uterus with a penicillin-containing solution daily for 5-7 days in mares
  • Ablation of clitoral sinuses in persistently-infected mares
  • Notifiable disease
  • Laboratory detection of carrier animals and clinical infections
  • Hygiene
  • Stop breeding if CEM diagnosed on stud farm
  • Sample recovered animals to ensure free from disease
  • Test-mating of stallions to 2 maiden mares to detect infection