Bacterium affects both livestock and people
A vaccine that could provide effective, antibiotic-free prevention of Fusobacterium infection has been developed by scientists at Kansas State University.
Fusobacterium necrophroum infection affects both livestock and people. Currently, antibiotics are used to control the bacterium, but researchers say the new vaccine takes an altogether different approach.
"The Food and Drug Administration has prevented the use of many antibiotics in cattle, especially those similar to ones with human applications, so this vaccine is an alternative,” commented Sanjeev K. Narayanan, professor of diagnostic medicine and pathobiology.
“This way, we don't expose people's food to as many antibiotics, so the vaccine protects both animals and humans."
The vaccine uses a two-pronged approach. It first immunises the animal against leukotoxins, which kill white blood cells and Kupffer cells - the liver’s natural weapons against bacteria.
The team found that Fusobacterium bacterium is able to survive in the liver because it produces leukotoxins. By immunising, if the bacterium enters the liver, there are antibodies built up against it, and the antibodies will neutralise the toxin.
The second element of the vaccine was developed in the lab, where the team identified the protein that allows the bacterium to attach to the walls of the rumen and the liver.
They were then able to identify a major protein in Fusobacterium necrophorum that is responsible for attaching to organs. Antibodies generated in the animal against the protein will prevent bacterial attachment.
"If you can prevent attachment, you can prevent infection," said T.G Nagaraja, a distinguished professor of microbiology. "That's why this patented vaccine uses a two-pronged approach."
The team says the vaccine is currently in testing for cattle, and may eventually be available also for sheep and for people.
Image (C) Kansas State University