The K-State researchers also want to understand why the presence of 0157 is higher during some months than in others, and why animals under stress shed more of the bacteria than other animals.
"If we find out answers to these questions, we can come up with intervention strategies," Nagaraja said. "The first part of the research is to look at the ecology, and the second part is to develop tests and practical intervention strategies."
For instance, Thomson is doing research with a company in Minnesota on a vaccine with antibodies that prevent the bacteria from getting iron, which they need to live. All three studies have shown a reduction in the prevalence of 0157 when the vaccine is used, Nagaraja said.
He also said that researchers are looking at what changes they could make in cattle diets that would make the animals' digestive systems less hospitable to 0157. Because the bacteria seem to congregate in the hindgut, Nagaraja said feeding cattle a diet that will reach the hindgut and produce acid will be effective in killing 0157. He also said that probiotics -- beneficial bacteria, like what humans can get though eating yogurt -- can reduce 0157 because they out compete the bacteria for resources.
Salmonella, one of the most common causes of gastroenteritis and which is spread through contaminated ground beef and manure-fertilized produce, also harms livestock. It causes bloody diarrhea in feedlot cattle and causes dairy cattle to abort. Renter's work centers on finding out why feedlot cattle that are being treated for other infections may show a higher rate of salmonella than healthy cattle. To find out the serotype of the salmonella, veterinarians and researchers have to send samples to a laboratory in Iowa. Narayanan is working to develop a rapid, molecular-based tes
|Contact: T.G. Nagaraja|
Kansas State University