Zoonotic and genetically diverse subtypes of Blastocystis in US pre-weaned dairy heifer calves
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Blastocystis is an emerging zoonotic pathogen with global distribution. However, limited data exist on the prevalence and genetic diversity of Blastocystis in the USA and in food animals. We conducted the first large-scale molecular investigation of Blastocystis in the USA by testing 2539 fecal samples from dairy heifer calves from 13 states. Blastocystis was detected in 73 (2.9%) fecal samples and in 10 of the 13 tested states. Molecular characterization showed a wide diversity of subtypes. Eleven subtypes were identified, seven previously reported (ST-3, ST-4, ST-5, ST-10, ST-14, ST-17, and ST-21) and four potentially novel subtypes (named ST-23 to ST-26). Zoonotic subtypes 3, 4, and 5 were found in 67% (49) of the positive specimens in this population. Our results suggest that cattle could serve as reservoirs of infection for humans and other domestic animals highlighting the potential risk of zoonotic transmission for Blastocystis.
KeywordsBlastocystis Zoonotic Subtypes Cattle
The authors thank Aleksey Molokin, Natalia Macarisin, Magnolia Alcantar, and Luis Pizarro Viera for technical services in support of this study. We additionally thank the dairy producers and their staff for participating in the study and the Federal and State Animal Health personnel who assisted in collecting the data and samples.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
“USDA is an equal opportunity provider and employer.”
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