Molecular identification and genotyping of Blastocystis in farmed Cattle, Goats, and Pigs from Zhejiang Province, China

Abstract

Blastocystis is a genus of parasitic protozoa that parasitize/colonize humans and animals gastrointestinal tract. The current study performed a molecular survey of Blastocystis in farm cattle (Bos tarurs), goats (Capra hircus), and pigs (Susscrofa domestica) raised in different cities in Zhejiang Province of China to better understand the epidemiology of Blastocystis in the animals of this region. A total of 859 fresh fecal samples were collected from 265 cattle, 386 goats, and 208 pigs. All these samples were screened for the detection of Blastocystis by amplifying the small subunit ribosomal RNA (SSU rRNA) gene via PCR and Sanger sequencing. Of the 859 samples tested, 12.1 % (104) were positive for Blastocystis, with cattle showing a prevalence of 19.6 % (52/265), goats with 11.4 % (44/386), and pigs with 3.8 % (8/208). Eight different subtypes of Blastocystis were found: ST10 (n = 51), ST5 (n = 11), ST12 (n = 9), ST14 (n = 8), ST21 (n = 8), ST23 (n = 7), ST26 (n = 6), and ST4 (n = 4). Cattle carried seven (ST5, ST10, ST12, ST14, ST21, ST23, and ST26), whereas goats harbored eight (ST4, ST5, ST10, ST12, ST14, ST21, ST23, and ST26) subtypes. All pig-derived Blastocystis isolates belonged only to ST5. These results are significant as they indicate that cattle, goats, and pigs in Zhejiang Province, China, harbor various subtypes of Blastocystis, which enhances our understanding of the distribution of Blastocystis among these hosts in China.

Keywords: Blastocystis; Cattle; China; Genotypic variation; Goat; Pig.

Fig. 1

A map of the sampling locations in Zhejiang Province, China. This map was initially conceptualized and designed by the authors using ArcGIS 10.4 software. The original vector diagram imported into ArcGIS originated from the National Geomatics Center of China (http://www.ngcc.cn). The final version of the map, however, underwent modifications and assembly to meet specific attribution and permission guidelines. This was achieved using a combination of Microsoft PowerPoint 2003 and Adobe Photoshop CS6.

Fig. 2

Sequence variation in the SSU rRNA gene among of Blastocystis ST10. The sequences of three known (GenBank: PP572680 to PP572682) and seven novel (GenBank: PP572683 to PP572689) identified in this study were aligned. The three rows of numbers preceding the nucleotide sequence correspond to the nucleotide at position.

Fig. 3

Phylogenetic analysis based on partial sequences of the SSU rRNA gene of Blastocystis sp.. In the tree, subtypes are denoted by hollow and solid circles, indicating known and novel sequences identified in this study, respectively. The tree was constructed using the Neighbor-Joining method, with the Kimura 2-parameter model serving as the foundation. To evaluate the reliability of the tree, bootstrap values were calculated from 1000 replicates.