Occurrence and Genetic Diversity of the Zoonotic Enteric Protozoans and Enterocytozoon bieneusi in Père David's Deer (Elaphurus davidianus) from Beijing, China

Marked genetic diversity within Blastocystis in Australian wildlife revealed using a next generation sequencing-phylogenetic approach

Blastocystis is a genus of intestinal stramenopiles that infect vertebrates, and may cause disease of the alimentary tract. Currently, at least 40 genotypes ("subtypes") of Blastocystis are recognised worldwide based on sequence data for the small subunit of the nuclear ribosomal RNA (SSU-rRNA) gene. Despite the numerous studies of Blastocystis worldwide, very few studies have explored Blastocystis in wild animals, particularly in Australia. Here, we used a PCR-based next generation sequencing (NGS)-phylogenetic approach to genetically characterise and classify Blastocystis variants from selected wildlife in the Australian state of Victoria. In total, 1658 faecal samples were collected from nine host species, including eastern grey kangaroo, swamp wallaby, common wombat, deer, European rabbit, canines and emu. Genomic DNA was extracted from these samples, a 500 bp region of the SSU-rRNA gene amplified by polymerase chain reaction (PCR) and, then, a subset of samples sequenced using Illumina technology. Primary PCR detected Blastocystis in 482 of the 1658 samples (29%), with the highest percentage in fallow deer (63%). Subsequent, Illumina-based sequencing of a subset of 356 samples revealed 55 distinct amplicon sequence variants (ASVs) representing seven currently-recognised subtypes (STs) [ST13 (prominent in marsupials), ST10, ST14, ST21, ST23, ST24 and ST25 (prominent in deer)] and two novel STs (ST45 and ST46) in marsupials. Mixed infections of different STs were observed in macropods, deer, emu and canids (fox, feral dog or dingo), but no infection was detected in rabbits or wombats. This study reveals marked genetic diversity within Blastocystis in a small number of species of wild animals in Australia, suggesting complexity in the genetic composition and transmission patterns of members of the genus Blastocystis in this country.

Molecular identification and genotyping of Blastocystis sp. in sheep and goats from some areas in Inner Mongolia, Northern China

Blastocystis sp. is a kind of unicellular intestinal commensal which is widely distributed in humans and animals, and frequently found in the people who are in close contact with animals. To investigate the prevalence and evaluate the zoonotic potential of Blastocystis sp. in sheep and goats from Inner Mongolia, China, a total of 1037 samples were collected from them, and subjected to nested PCR amplification based on the small subunit ribosomal RNA (SSU rRNA) gene of Blastocystis sp. The sanger sequencing was used for Blastocystis sp. subtype identification. The results indicated that the average infection rate of Blastocystis sp. was 10.70% [95CI: 8.82%-12.58%] (111/1037), including 11.30% [95CI: 7.96%-14.64%] for sheep (39/345) and 10.40% [95CI: 8.13%-12.67%] for goats (72/692). Five Blastocystis subtypes (ST5, ST10, ST14, ST21 and ST26) were identified in the present study. Among them, ST10 was the most dominant subtype in sheep and goats, accounting for 70.27% (78/111) of the total identified positive samples. This is the first report regarding Blastocystis sp. subtypes ST21 and ST26 in goats in China. This study has provided a detail epidemiological data on the prevalence and subtypes distribution of Blastocystis sp. in sheep and goats in Inner Mongolia, China. Our results indicated that sheep and goats could be reservoir host for multiple Bastocystis subtypes, including the zoonotic subtypes. Further studies among humans, livestock and wild animals are needed to better understand their role in the spread of Blastocystis sp.