Mycoplasma ovipneumoniae Diagnostics in Domestic and Wild Sheep and Goats
Mycoplasma ovipneumoniae is a respiratory pathogen of Caprinae, including domestic sheep, domestic goats, bighorn sheep, and mountain goats. M. ovipneumoniae causes atypical pneumonia and can also predispose to lung infections with many other bacterial species. M. ovipneumoniae infection is associated with pneumonia in all ages of bighorn sheep upon initial exposure, and often causes recurrent fatal lamb pneumonia outbreaks in subsequent years. M. ovipneumoniae infection of domestic sheep and goats is typically associated with mild disease, most often a ‘coughing syndrome’ of lambs and kids under 6 months of age. Less frequently, M. ovipneumoniae is associated with severe or fatal pneumonia in domestic lambs and adult and kid goats.
1. PCR detection of M. ovipneumoniae:
Animals with pneumonia: Swab the major bronchi and/or take a sample of consolidated lung tissues. If lungs are not available, M. ovipneumoniae can also usually be detected in swabs of the nose, middle ears, or sinuses, particularly if purulent exudate is seen.
Healthy or carrier animals: Swab the nose (deeply, both nares) .
A word about swabs: For M. ovipneumoniae PCR testing, use swabs made of synthetic materials (tip and shaft) and avoid swabs with agar-based transport media, as these are inhibitory to PCR. Swabs may be submitted dry in their sheath or other sterile containers, or may be placed in glycerol-containing media; swabs should be held frozen if delays are expected prior to testing.
2. cELISA detection of exposure to M. ovipneumoniae
Serology, using a monoclonal antibody based blocking ELISA test developed in WADDL, may be used to determine whether bighorn or domestic sheep herds / flocks have been exposed to M. ovipneumoniae. The test is not intended to (and will not work well to) determine whether individual animals are or are not infected (see below). The test is conducted on serum samples, but either extracted serum (0.5 ml) or clotted whole blood (1 ml) may be submitted; surplus serum volume received at WADDL will be discarded.
3. Which test should I use?
cELISA testing is a sensitive method for determining whether a sheep population has been exposed to M. ovipneumoniae. Seroprevalence varies among bighorn subspecies and domestic sheep; as a result, WADDL recommends sampling 10 or more mountain sheep, 15 or more desert sheep or 20 or more domestic sheep to reliably assess exposure status of the population. cELISA testing is not recommended for use in domestic goats.
PCR testing is necessary to determine the M. ovipneumoniae infection status of individual animals and for subsequently identifying its strain type. PCR is the most sensitive test for determining domestic sheep or goat flock/herd status because in those species PCR prevalence is typically higher than seroprevalence. If you are sampling domestic sheep to determine individual status for biosecurity purposes, WADDL recommends at least two negative results from samples taken a week (or more) apart before concluding the animal is not infected.
4. What documentation should I send with the samples?
We are switching from paper accession forms to an online ordering system which will expedite the sample testing process.
If you don’t have an online account, please go to https://w3.vetmed.wsu.edu/newaccounts.php to enroll (it takes 1-2 minutes). Once approved, you’ll receive an email with a link to submit your order, or you can go directly to the WADDL Client Portal.
This 4-step submission process will take you through a series of questions to ensure all required information is provided, so when your package arrives, samples are moved quickly to their testing section(s). Additionally, if you have multiple animals to test, there is an upload function which will save time.
Thereafter, you may log in at any time to view the status of your order, ensure it was received, and view/print results.
Page revised June 2019
Dr. Margaret Highland research: Identification of Host Factors and Immunopathogenesis of Pneumonia in Domestic and Bighorn Sheep