Occurrence, genetic diversity and zoonotic potential of Blastocystis sp. in forest musk deer (Moschus berezovskii) in Southwest China

High prevalence of Blastocystis sp. in farmed sika deer (Cervus nippon) in Northern China

Introduction

Blastocystis sp. is a widespread intestinal protist, that threatens the health of humans and animals. However, epidemiological data on Blastocystis sp. in sika deer are still scarce in China and globally. This study aimed to reveal the infection rate, and subtype distribution of Blastocystis sp. in farmed sika deer across China.

Methods

A total of 466 fresh fecal samples were collected from farmed sika deer in northern China. A 600 bp fragment of the SSU rRNA was amplified to detect the presence of Blastocystis sp. in samples.

Results

The results revealed an overall infection rate of Blastocystis sp. at 65.02% (303/466). The highest infection rate was found in Shandong (98%, 49/50), followed by Heilongjiang (95.51%, 85/89), while the lowest infection rate was found in Jilin (36.31%, 61/168). Additionally, within the seasonal group, the infection rate was significantly higher in autumn (69.04%) than in summer (43.06%). In the age group, although the infection rate in young animals (68.38%) was higher than in adults (63.90%), no statistical difference was observed. Ten subtypes were identified from 303 Blastocystis sp.-positive samples, including ST1, ST5, ST10, ST14, ST21, ST23, ST24, ST26, ST30 and ST42. Among these, ST10 was the dominant subtype with an infection rate of 43.23% (131/303), and ST1 and ST5 were zoonotic subtypes. Notably, this study is the first to report the presence of ST42 in sika deer.

Discussion

These findings suggest that sika deer may be a potential source of human Blastocystis sp. infection. In addition, this study reveals the high infection rate of Blastocystis sp. in farmed sika deer and reports for the first time the presence of ST42 subtype, providing valuable data for the epidemiological study of Blastocystis sp. in sika deer.

Epidemiology, molecular characterization, and risk factors of Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. infections in snakes in China

Snakes are widely farmed in China for medicinal purposes and as pets worldwide. Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. are significant zoonotic pathogens frequently discovered in various animals, causing diseases with global public health implications. However, their prevalence and zoonotic potential in snakes remain poorly understood. In this study, 812 snake faecal samples were collected across 28 China provinces. The partial small subunit (SSU) rRNA gene was amplified using polymerase chain reaction (PCR) to assess evolutionary relationships and genetic characterization. Detection rates for Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. were 6.40 %, 3.33 %, and 2.71 %, respectively. Sequencing and phylogenetic analysis revealed that Cyclospora isolates were closely related to those found in humans and cattle. Subtyping for Blastocystis species identified two zoonotic subtypes (ST4, ST6) and four host-specific subtypes (ST10, ST15, ST21, ST42). Multiple Acanthamoeba genotypes were detected, including T4, T11, and T13. Furthermore, species, age, and living conditions are key risk factors. This study provides valuable insights into these infections in snakes and underscores the need for proper hygiene and One Health measures to reduce zoonotic transmission and environmental contamination.

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.