First identification of Blastocystis sp. subtypes in Rex rabbits in China.

Blastocystis sp. is a common protist that colonizes the intestinal tract in both humans and animals worldwide. A total of 666 fecal samples of Rex rabbits were collected from 12 farms in three administrative regions in Henan, China. Blastocystis sp. was screened and subtyped by PCR amplification of the small subunit ribosomal DNA. The results indicated that 31 (4.7%, 31/666) rabbits were positive for Blastocystis sp. across three farms (25.0%, 3/12). The infection rate of Blastocystis sp. in Rex rabbits was highest in Jiyuan at 9.1% (30/331), followed by Luoyang (0.5%, 1/191), with no positive infections found in Zhengzhou. The Blastocystis sp. infection rate in adults (10.2%, 14/287) was higher than that in young rabbits (4.5%, 17/379) (χ = 0.0027, P > 0.50). Four Blastocystis sp. subtypes (ST1, ST3, ST4, and ST17) were identified in rabbits in the present study. Among them, the subtypes ST1 (n = 15) and ST3 (n = 14) were dominant, followed by ST4 (n = 1) and ST17 (n = 1). Blastocystis sp. ST1 was the dominant subtype in adult rabbits, and ST3 was the dominant subtype in young rabbits. This study enriches the data on the prevalence and subtype distributions of Blastocystis sp. in rabbits. More studies are needed among humans, domestic animals, and wild animals to obtain a better understanding of their role in the spread of Blastocystis sp.