Contagious Equine Metritis (CEM)
Etiologic agent: Taylorella equigenitalis bacterium

Test codes:
B0017 - Ultrasensitive qualitative detection of Taylorella equigenitalis by real time polymerase chain reaction
P0024 - Equine breeding panel (includes CEM and other pathogens)

Contagious equine metritis (CEM), caused by Taylorella equigenitalis, a Gram-negative eubacterium, is a sexually transmitted disease of horses. CEM is characterized by discharge of large amounts of mucopurulent fluid from the vagina and can result in infertility or early abortion. Nevertheless, only 30-40% of mares infected by this bacterium have clinical signs. Some mares may become long-term asymptomatic carriers and these, together with infected stallions, may spread infection during mating.

Diagnosis of CEM is often attempted by bacterial isolation from the cervix of the uterus, the clitoral sinus, and the clitoral fossa of mares, and the urethral orifice, the urethral fossa and the penile sheath of stallions. This approach, however, is often not sensitive enough to detect the infection because T. equigenitalis is microaerophilic, drug sensitive and slow growing. Visible colony formation usually takes 4 to 6 days and is often obscured by the presence of other fast-growing bacteria in the sample. Molecular detection of this bacterium is often preferred for its higher sensitivity, specificity and rapid turnaround time. Molecular detection is especially useful in identifying asymptomatic carriers (Parlevliet, 1977).

Utilities:

• Confirm the disease causing agent
• Shorten the time required to confirm a clinical diagnosis of T. equigenitalis infection.
• Ensure that horse populations are free of T. equigenitalis
• Early prevention of spread of this bacterium
• Minimize personnel exposure to this bacterium
• Safety monitoring of biological products that derive from horses

References:
Parlevliet, J.M. (1997) Epidemiologic aspects of Taylorella equigenitalis. Theriogenology 47, pp. 1169–1177.

Specimen requirements: 1 ml semen, amniotic fluid, CSF, vaginal swab, clitoral fossa swab or culture, shipped overnight at room temperature.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time PCR

Normal range: Nondetected