|Jenny, Maloney - US Department Of Agriculture (USDA)|
Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/6/2017
Publication Date: 4/26/2017
Citation: Maloney, J.G., Santin, M. 2017. Blastocystis prevalence and subtype distribution among pre-weaned dairy calves in the United States. BARC Poster Day.
Technical Abstract: Blastocystis is an enteric parasite commonly found in humans and many animals worldwide. Infection with Blastocystis has been associated with both mild and severe gastrointestinal manifestations and is linked to chronic spontaneous urticaria (hives). How Blastocystis is transmitted is still unclear, but studies support a fecal-oral transmission route via ingestion of contaminated food and water. Blastocystis has been divided into 17 subtypes (STs) based on SSU rDNA polymorphism. Several STs infect both humans and animals suggesting zoonotic transmission. Because of its status as an emerging pathogen, limited data exist on the prevalence and distribution of Blastocystis in food animals. Here we present the first large scale study of Blastocystis in dairy cattle in the United States. Fecal samples from 363 pre-weaned calves from 13 states were tested for Blastocystis. The presence of Blastocystis was detected by PCR, and all PCR positive specimens were sequenced to determine subtypes. Thirty-six (9.9%) samples were Blastocystis-positive. Calves from 7 states tested positive for Blastocystis. Two subtypes, ST-4 and ST-5, were identified in Blastocystis-positive calves, both of which have also been reported in humans. Given the prevalence, broad geographic distribution, and presence of zoonotic subtypes in Blastocystis infected calves, cattle could serve as important reservoirs of infection for humans and other domestic animals. This study highlights the potential risk of zoonotic transmission and suggests that the role of cattle in transmission of human infections requires further study.