We launched a new series on the blog in October. Once a month, we are sharing with you a presentation given at the 2017 Allen D. Leman swine conference, on topics that the swine group found interesting, innovative or that lead to great discussions.
Our seventh presentation is by Dr. Paul Yeske from Swine Vet Center regarding the likelihood of lateral transmission of Mycoplasma hyopneumoniae.
To listen to this talk, please click on the image below.
Today we are sharing a review article regarding the acclimation strategies in gilts to control Mycoplasma hyopneumoniae infection published in Veterinary Microbiology by the University of Barcelona in collaboration with Dr. Maria Pieters.
The article first covers how to assess the M. hyopneumoniae health status of the herd. Various methods of monitoring and diagnosis are detailed and compared with each other.
Proposed farm classification according to M. hyopneumoniae health status. (aELISA results (negative/positive) could depend on infection pattern in the farm and sampling time point.)
| Classification
|
Clinical signs | Lung lesions | ELISA resulta | PCR result | |
|---|---|---|---|---|---|
| Negative | Not observed | Not observed | Negative | Negative | |
| Provisional negative | Not observed | Not observed | Positive | Negative | |
| Positive | Subclinical infected I | Not observed | Not observed | Positive/Negative | Positive |
| Subclinical infected II | Not observed | Observed | Positive/Negative | Positive | |
| Clinical affected | Observed | Observed | Positive/Negative | Positive | |
Vaccination against M. hyopneumoniae, using commercial vaccines, is the most commonly used strategy to control its associated diseases in worldwide swine production systems.
However, since protection against M. hyopneumoniae infection by commercial vaccines is not complete, antimicrobial treatments are frequently required to control disease outcome. Several antibiotic classes are effective in reducing the incidence and severity of M. hyopneumoniae compatible lung lesions: macrolides, lincosamides, tetracycline, and fluoroquinolones among others.
The most common replacement origin used in Europe was external and that most respondents knew M. hyopneumoniae health status of replacement on arrival, being in most of the cases seropositive. Nevertheless, only 28% of respondents verified this theoretical M. hyopneumoniae status given as ELISA test results. Additionally, the most used strategy to acclimate gilt was vaccination alone (58%).
Gilt Development Units are utilized to allow ample time to incoming gilt to gradually adopt the health status of the recipient herd. These acclimation facilities are in most of the cases continuous flow allowing an effective gilt exposure to M. hyopneumoniae. Gilt vaccination in North American swine industry was also recognized as the most common practice used at acclimation.
Natural exposure was also used in both continents to help acclimate the incoming gilts to M.hyopneumoniae. However, taking into account that pig-to-pig transmission of this bacterium has proven to be extremely slow , the ratio of infected and naïve gilts as well as the time of exposure are crucial and should be considered to achieve an effective exposure.
Mycoplasma hyopneumoniae (M. hyopneumoniae) is the primary causative agent of enzootic pneumonia (EP), one of the most economically important infectious disease for the swine industry worldwide. M. hyopneumoniae transmission occurs mainly by direct contact (nose-to-nose) between infected to susceptible pigs as well as from infected dams to their offspring (sow-to-piglet). Since disease severity has been correlated with M. hyopneumoniae prevalence at weaning in some studies, and gilts are considered the main bacterial shedders, an effective gilt acclimation program should help controlling M. hyopneumoniae in swine farms. The present review summarizes the different M. hyopneumoniae monitoring strategies of incoming gilts and recipient herd and proposes a farm classification according to their health statuses. The medication and vaccination programs against M. hyopneumoniae most used in replacement gilts are reviewed as well. Gilt replacement acclimation against M. hyopneumoniae in Europe and North America indicates that vaccination is the main strategy used, but there is a current trend in US to deliberately expose gilts to the pathogen.
Controlling Mycoplasma hyopneumoniae in the field can be challenging. After summarizing the best sample types and diagnostic methods to detect mycoplasma infections early, Dr. Maria Pieters wrote an article for pig333 recapitulating the existing options for a producer struggling with enzootic pneumonia on her farm.
No single strategy will confer total protection. A well-orchestrated combination of various methods adjusted to a single production unit or system will be needed.
Indeed, Dr. Pieters reminds us that 3 different approaches can be combined to achieve greater disease control:
No single strategy will confer total protection from infection with M. hyopneumoniae or disease elimination. However, a well-orchestrated combination of various methods, not only directed at clinical signs, but to the root of disease spread and transmission, adjusted to the unique characteristics of a production unit or system, is necessary to reach the goal of controlling M. hyopneumoniae infections and improving overall swine production around the world.
The entire article on Controlling Mycoplasma hyopneumoniae in the field is available on the pig333 website.
In lieu of the Science Page today, we are bringing you our most popular articles on the blog this past year: a publication by Dr. Maria Pieters, head of the MycoLab called Sample and diagnostic types for early detection of Mycoplasma hyopneumoniae.
Mycoplasma hyopneumoniae is the causative agent enzootic pneumonia, an economically significant disease in pigs. In this study published by Drs. Pieters and Rovira from the University of Minnesota, pigs experimentally inoculated with M.hyopneumoniae were sampled 0, 2, 5, 9, 14, 21, and 28 post-inoculation.
Different sample types were compared:
Using different diagnostic tests:
Laryngeal swab samples tested by PCR were highly sensitive for detection of Mycoplasma hyopneumoniae in live pigs. Various commercial ELISA kits for detection of Mycoplasma hyopneumoniae antibodies showed similar sensitivity. Oral fluids showed a low sensitivity for detection of Mycoplasma hyopneumoniae in experimentally infected pigs.
We launched a new series on the blog last month. Once a month, we are sharing with you a presentation given at the 2017 Allen D. Leman swine conference, on topics that the swine group found interesting, innovative or that lead to great discussions.
Our second presentation today is from Dr. Paul Yeske from Swine Vet Center, who is coming back on his experience with Mycoplasma hyopneumoniae elimination and giving us an update if the herds stayed negative.
To listen to this presentation, please click on the picture below:
Happy Thanksgiving to you and your loved ones!
