Randy Shirbroun talks pathology and prevention of diseases caused by Mycoplasma bovis
WORTHINGTON, Minn. – Veterinarian Randy Shirbroun of Newport Laboratories Inc. addressed more than 200 bison producers regarding the pathology and prevention of diseases caused by Mycoplasma bovis. The producers had gathered for the 2016 National Bison Association Summer Conference held in June at Elk River, Minnesota. Shirbroun specializes in ruminant health issues including those seen in the American bison, which became the official U.S. national mammal in May.
Mycoplasma bovis is a bacterium responsible for a number of diseases. "Each animal species tends to have its own Mycoplasma species," Shirbroun said, "but multiple strains of Mycoplasma bovis can affect cattle and bison." The morbidity and mortality rates associated with Mycoplasma infections in bison, however, are higher than other species.
Shirbroun explained: "It's actually a very common pathogen in domestic cattle, present in up to 86 percent of pneumonia cases according to reports from some diagnostic laboratories. But bison tend to be much more susceptible to Mycoplasma than domestic cattle are. Whether it's because of different strains or some other reason, we haven't been able to answer that yet."
When Shirbroun asked who among the assembly had dealt with Mycoplasma, hands shot up around the room.
Transmission of the bacteria is primarily through an individual animal's contact with an infected animal's respiratory secretions, perhaps while nosing a fence or drinking from a communal water supply. But treatment of Mycoplasma is complicated by several of the highly adaptable organism's distinct characteristics. "As amazing an animal as the bison is," Shirbroun said, "Mycoplasma bovis is at least as amazing an organism."
For one, it's smaller than other bacteria, and it lacks a cell wall. Plus, "it is a 'plastic' organism" Shirbroun said. "It has a very high rate of change and is highly immunogenic." The combination makes Mycoplasma bovis difficult to treat with conventional antibiotics used for other bacterial infections.
Newport Laboratories first got involved in seeking a solution for the bison industry seven years ago when Turner Ranches sought their help. A total of more than 51,000 head of bison are managed by the subsidiary of Turner Enterprises at 16 of its properties.
Shirbroun said the result of the Turner-Newport collaboration was a custom-engineered formula derived from antigens of the producer's herd using "autogenous biologics." Autogenous formulations are not generic remedies. Not only can Newport create vaccines that precisely match bison as a species but for the exact strains affecting the producers' herds.
"An autogenous approach is ideal when there is no vaccine or the existing vaccine is ineffective," Shirbroun said. "They are specifically created for bison."
Shirbroun said the autogenous process always begins with a licensed veterinarian, who is responsible for collecting tissue samples. Veterinarians can send the samples directly to Newport Laboratories or any diagnostic lab of their choice.
Once the disease organism has been cultured and identified, gene sequencing is performed. Virulent factors are identified and coded, "There's significant genetic variation between the wide range of isolates we see," Shirbroun said. "And each pathogen-specific vaccine product is manufactured in a USDA facility," Shirbroun said.
Located in Worthington, Minnesota, Newport Laboratories, Inc. is the nation's leading manufacturer of autogenous biologics. Newport Laboratories assists veterinarians and livestock producers in their efforts to address animal health problems through diagnostic testing and production of high-quality, evidence-based, autogenous veterinary biologics. Newport Laboratories is owned by Merial, Inc. For further information call 800-220-2522, email Newportlabs@boehringer-ingelheim.com or visit the Newport website at http://www.newportlabs.com