June 24, 2014

Two moderate doses of a bacteria-derived protein fed to worm-infected swine in an experiment damaged or destroyed all intestinal roundworm larvae in the swine and nearly completely eliminated the infection, according to US Department of Agriculture (USDA) and University of California-San Diego scientists.

The parasitic roundworm that commonly infects pigs is Ascaris suum. During the experiments, the team used a crystal protein called "Cry5B," provided by Raffi Aroian and Yan Hu at the University of California-San Diego, which is derived from the soil bacterium Bacillus thuringiensis. Cry5B protein is considered nontoxic to vertebrates and mammals.

The dosage the team provided in the study is comparable to the dose range used in existing commercial antiparasitic drugs. The results show the potential of Cry5B to treat Ascaris infections in pigs and other livestock.

There is a need for more practical delivery systems for antiparasitic drug treatments, according to the scientists, and further cooperative research is planned.

The research team included microbiologist Joseph Urban and his colleagues at the USDA Agricultural Research Service (ARS) Beltsville Human Nutrition Research Center in Beltsville, Maryland, and Raffi Aroian and Yan Hu at the University of California-San Diego. ARS is USDA's chief intramural scientific research agency.