L13 - Urogenital System I

What is the pathogen that causes contagious equine metritis (CEM)?

Taylorella equigenitalis

What type of pathogen is Taylorella equigenitalis?

• Gram -

• Rods

• Non-motile

• Microaerophilic (5-10% CO2 required)

What are the test results for Taylorella equigenitalis?

• Oxidase +

• Catalase +

• Phosphatase +

• Chocolate Agar: fast growth

• MacConkey Agar: no growth

What factor stimulates the growth of Taylorella equigenitalis?

Factor X

Where is Taylorella equigenitalis found? What about T. asinigenitalis

• Genital tracts of equines → urethral fossa of stallions and clitoral fossa of mares

• T. asinigenitalis in genital tract of donkeys → doesn’t cause dz

How to differentiate between Taylorella equigenitalis and T. asinigenitalis?

Fluorescent antibody test → T. asinigenitalis doesn’t react as much

What are the symptoms of Taylorella equigenitalis?

• Mucopurulent vaginal discharge w/ no systemic disturbance

• Temorary infertility in mares

• Stallions: asymptomatic

How is Taylorella equigenitalis transmitted?

• During coitus

• Contaminated instruments

• Foals born to infected dams → in utero or during parturition

• Bacteria must be deposited in the uterus for infection → cannot ascend

What is the pathogenesis of Taylorella equigenitalis?

1. Introduced to uterus

2. Replicates → acute endometritis

3. Mononuclear cells and plasma cells infiltrate

4. Neutrophils cause mucopurulent exudate

5. Up to 25% of mares remain a carrier of dz

6. Infection doesn’t induce protective immunity! Can reinfect!

How is Taylorella equigenitalis treated?

• Wash external genitalia with Chlorohex and nitrofurazone

• Daily intrauterine penicillin infusions in mares

What kind of pathogen is Brucella?

• Gram -

• Coccobacilli

• Aerobic

• Capnophilic

What are the test results for Brucella?

• Catalase +

• Oxidase +

• Urease + (except B. ovis)

• Modified Ziehl-Neelsen (MZN) Stain: Red

Where is Brucella usually found?

• Reproductive organs

• Infected wild animals serve as reservoirs

How is Brucella transmitted?

• Direct contact

• Abortion tissues/fluids → ingestion