Paraprobiotic-based treatment for control of nematodes in sheep

The U.S. Department of Agriculture’s Agriculture Research Service (ARS) has announced a new treatment for control of Haemonchus contortus in sheep.

ARS researchers partnered with Virginia Tech and the University of Massachusetts’ Medical School to develop the treatment, described in International Journal for Parasitology: Drugs and Drug Resistance.

“The H. contortus parasite has developed resistance to virtually all known classes of anti-parasitic drugs,” said ARS Researcher Dr. Joseph Urban, who lead the research team in testing and implementation of a paraprobiotic treatment.

Adult H. contortus produce eggs within sheep that are passed through faeces into the soil. The larvae then develop to re-infect other animals, spreading the infection throughout a pasture and creating a cycle of infection that hinders animal growth, development and production.

The newly-developed treatment is derived from the soil bacterium Bacillus thuringiensis that can produce a protein (crystal protein 5B) that binds to receptors in the intestine of the parasite.

“When the treatment was given to infected sheep at Virginia Tech there was a rapid and dramatic reduction of parasite reproduction and survival, without any negative effect observed in the sheep.” said Dr. Anne Zajac, professor of parasitology at Virginia Tech’s Virginia-Maryland College of Veterinary Medicine.

Paraprobiotics are “inactive probiotics”. Despite the growing interest in paraprobiotic use, these types of treatments are not commercially available. The treatments are currently under review by the U.S. Food and Drug Administration and will likely be commercially produced in large amounts once approved.

The project was supported by the National Institutes of Health/National Institute of Allergy and Infectious Diseases; and the Agriculture and Food Research Initiative Competitive Grant from the USDA’s National Institute of Food and Agriculture.

Article: Sanders, J., Xie, Y., Gazzola, D., Li, H., Abraham, A., Flanagan, K., Rus, F., Miller, M., Hu, Y., Guynn, S., Draper, A., Vakalapudi, S., Petersson, K. H., Zarlenga, D., Li, R. W., Urban, J. F., Jr, Ostroff, G. R., Zajac, A., Aroian, R. V. (2020). A new paraprobiotic-based treatment for control of Haemonchus contortus in sheep. InternationalJournal for Parasitology: Drugs and Drug Resistance, 14, 230-236, doi: 10.1016/j.ijpddr.2020.11.004