First genotyping of Blastocystis in yaks from Qinghai Province, northwestern China

Comparative Analysis of Gut Bacterial Diversity in Wild and Domestic Yaks on the Qinghai-Tibetan Plateau

The gut microbiota is a diverse and complex population, and it has a key role in the host's health and adaptability to the environment. The present study investigated the fecal bacterial community of wild grazing (WG) and domestic grazing (DG) yaks on natural grazing pastures, analyzing the gut microbiota using 16S rRNA sequencing to assess bacterial diversity. A total of 48 yak fecal samples were selected from two different grazing habitats. The DG group had more crude proteins and non-fiber carbohydrates. The WG group had more OM, insoluble dietary fiber such as NDF, ADF, ether extract, and TC. There were 165 and 142 unique operational taxonomic units (OTUs) in the WG and DG groups, respectively. Shannon index analysis revealed a higher bacterial diversity in the WG group than in the DG group. At the phylum level, Firmicutes were the dominant bacterial taxa in both groups. The relative abundance of Firmicutes in the WG group was higher than in the DG group. At the family level, the WG group had a significantly higher abundance of Ruminococcaceae (p < 0.001) and Rikenellaceae (p < 0.001) than the DG group. The abundances of Alloprevotella and Succinivibrio were more pronounced in the DG group than in the WG group at the genus level. This study presents a novel understanding of the bacterial communities of ruminants and their potential applications for livestock production.

Molecular characterization of Blastocystis spp. in Hotan Black chickens in southern Xinjiang

To determine the infection status and assess the zoonotic potential of Blastocystis spp. in Hotan Black chickens in southern Xinjiang, China, fecal samples were collected from 617 chickens on 18 large-scale farms. The presence of Blastocystis spp. was determined using polymerase chain reaction based on the small subunit rRNA (SSU rRNA) locus. The results revealed an overall infection rate of 26.3% (162/617). Samples from Farm 1 in Luopu County showed the highest infection rate (76.3%, 29/38). The highest and lowest infection rates were detected in the <30-day (34.4%, 43/125) and > 90-day age groups (12.4%, 11/89), respectively. The infection rate decreased with increasing age. Statistical analysis showed significant differences in the infection rates of Blastocystis spp. among the different sampling sites (p < 0.05) and age groups (p < 0.05). Four Blastocystis spp. subtypes (ST6, ST7, ST10, and ST23) were identified. The infection rates of the zoonotic subtypes, ST6 and ST7, were 3.2% (20/617) and 22.2% (137/617), respectively. The presence of Blastocystis spp. and zoonotic subtypes provided evidence for the potential transmission of this pathogen between Hotan Black chickens and humans, especially in animal handlers in this area.

Molecular Identification and Genotyping of Cryptosporidium spp. and Blastocystis sp. in Cattle in Representative Areas of Shanxi Province, North China

Both Cryptosporidium spp. and Blastocystis sp. are common intestinal protozoa, which can cause zoonotic diseases and economic losses to livestock industry. To evaluate the prevalence and genetic population structure of Cryptosporidium spp. and Blastocystis sp. in beef and dairy cattle in Shanxi Province, north China, a total of 795 fecal samples were collected from beef and dairy cattle in three representative counties in Shanxi Province, and these fecal samples were examined using molecular approaches based on 18S small-subunit ribosomal RNA (SSU rRNA) of Cryptosporidium spp. and Blastocystis sp., respectively. Among 795 cattle fecal samples, 23 were detected as Cryptosporidium-positive and 103 were detected as Blastocystis-positive, and the overall prevalence of Cryptosporidium spp. and Blastocystis sp. in cattle in Shanxi Province was 2.9% and 13.0%, respectively. For Cryptosporidium spp., DNA sequence analysis indicated that all 23 positive samples were identified as C. andersoni. Furthermore, five known subtypes (ST1, ST10, ST14, ST21 and ST26) and three unknown subtypes of Blastocystis sp. were detected among 103 positive samples using DNA sequence analysis. This study reported the occurrence and prevalence of Cryptosporidium spp. and Blastocystis sp. in cattle in Shanxi Province for the first time, which extends the geographical distribution of these two zoonotic parasites and provides baseline data for the prevention and control of these two important zoonotic parasites in cattle in Shanxi Province.

Prevalence and Subtype Distribution of Blastocystis in Tibetan Sheep in Qinghai Province, Northwestern China

Blastocystis is one of the most common intestinal protists in humans and a great number of animals, including sheep and goats. High prevalence and multiple subtypes of Blastocystis have been reported in sheep in several regions of China and elsewhere. However, there is a dearth of knowledge about Blastocystis in Tibetan sheep. A total of 761 fecal samples were collected from Tibetan sheep in seven counties of Qinghai Province, northwestern China, and were examined for the prevalence and subtypes of Blastocystis using molecular technology based on the partial small subunit ribosomal RNA gene of Blastocystis. The overall prevalence of Blastocystis in the investigated Tibetan sheep was 7.5% (57/761) using PCR and DNA Sanger sequencing, and differences in prevalence were observed among the ruminants from the seven counties (P < 0.01), and across four seasons (P < 0.01). Sequence analysis revealed five subtypes (ST14 (57.9%), ST10 (26.3%), ST12 (5.3%), ST21 (5.3%), and ST30 (5.3%)) of Blastocystis sp. in these Tibetan sheep, with ST14 as the predominant subtype. To our knowledge, this is the first report of Blastocystis colonization in Tibetan sheep.

"The Yak"-A remarkable animal living in a harsh environment: An overview of its feeding, growth, production performance, and contribution to food security

Yaks play an important role in the livelihood of the people of the Qinghai-Tibet Plateau (QTP) and contribute significantly to the economy of the different countries in the region. Yaks are commonly raised at high altitudes of ~ 3,000-5,400 m above sea level. They provide many important products, namely, milk, meat, fur, and manure, as well as social status, etc. Yaks were domesticated from wild yaks and are present in the remote mountains of the QTP region. In the summer season, when a higher quantity of pasture is available in the mountain region, yaks use their long tongues to graze the pasture and spend ~ 30-80% of their daytime grazing. The remaining time is spent walking, resting, and doing other activities. In the winter season, due to heavy snowfall in the mountains, pasture is scarce, and yaks face feeding issues due to pasture scarcity. Hence, the normal body weight of yaks is affected and growth retardation occurs, which consequently affects their production performance. In this review article, we have discussed the domestication of yaks, the feeding pattern of yaks, the difference between the normal and growth-retarded yaks, and also their microbial community and their influences. In addition, blood biochemistry, the compositions of the yaks' milk and meat, and reproduction are reported herein. Evidence suggested that yaks play an important role in the daily life of the people living on the QTP, who consume milk, meat, fur, use manure for fuel and land fertilizer purposes, and use the animals for transportation. Yaks' close association with the people's well-being and livelihood has been significant.

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

Blastocystis sp. is a common anaerobic protist with controversial pathogenicity that can infect various animals and humans. However, there are no reports of Blastocystis sp. infections in forest musk deer (Moschus berezovskii). The present study was designed to examine the occurrence, subtype distribution and genetic characterization of Blastocystis sp. in forest musk deer in southwestern China, and to assess the potential for zoonotic transmission. A total of 504 fresh stool samples were collected from captive forest musk deer in four distinct areas of southwestern China. Overall, 14.7% of the forest musk deer (74/504) were found to be infected with Blastocystis sp. The highest occurrence of Blastocystis sp. was observed in Dujiangyan (27.5%), followed by Maerkang (23.3%). The occurrence of Blastocystis sp. was 7.9% and 4.1% in Shimian and Hanyuan, respectively. Significant differences in the occurrence of Blastocystis sp. among different areas were observed (p < 0.05), while we did not observe significant differences among animals of different age and sex (p > 0.05). Two known zoonotic subtypes (ST1 and ST5) and three animal-predominant subtypes (ST10, ST13, and ST14) were identified, of which ST10 was the most common (36/74, 48.6%). Our findings highlight that forest musk deer may be potential reservoirs of zoonotic human Blastocystis sp. infections.

Prevalence and genotypes/subtypes of Enterocytozoon bieneusi and Blastocystis sp. in different breeds of cattle in Jiangxi Province, southeastern China

Enterocytozoon bieneusi and Blastocystis sp. are common zoonotic pathogens that parasitize in the small intestine of humans and animals, posing a threat to public health. However, little information is available on the prevalence and genotypes/subtypes of E. bieneusi and Blastocystis sp. in cattle in Jiangxi Province, southeastern China. In the present study, 556 fecal samples of cattle were collected from Nanchang city, Gao'an city, Xinyu city, and Ji'an city in Jiangxi Province. All samples were examined for the presence of E. bieneusi by nested PCR analysis of the ribosomal internal transcribed spacer (ITS) and Blastocystis sp. using PCR targeting the SSU rRNA gene. The overall prevalence of E. bieneusi and Blastocystis sp. was 5.4% (30/556) and 54.9% (305/556), respectively. The prevalence of E. bieneusi in dairy cattle, beef cattle, and buffaloes was 7.9% (13/165), 3.9% (11/283), and 5.6% (6/108), respectively. Eleven E. bieneusi genotypes were identified in this study, including six known genotypes, D (n = 10), I (n = 5), J (n = 4), IV (n = 4), N (n = 1), and BEB4 (n = 1), and five novel genotypes, JX-I to JX-V (n = 1), with genotype D as the predominant genotype in cattle. Phylogenetic analysis showed that six genotypes of E. bieneusi, D, IV, and JX-II to JX-V, were clustered into zoonotic group 1, whereas the remaining five genotypes belonged to group 2. Moreover, seven, seven, four, and five types were identified by multilocus sequence typing (MLST) at the MS1, MS3, MS4, and MS7 loci, respectively, forming three distinct multilocus genotypes (MLGs). In addition, the prevalence of Blastocystis sp. was 42.4% (70/165), 59.4% (168/283), and 62.0% (67/108) in dairy cattle, beef cattle, and buffaloes, respectively. Sequence analysis revealed that ST1, ST5, ST10, and ST14 of Blastocystis sp. were identified in these cattle, with ST10 being the major subtype. ST1 and ST5 are potential zoonotic subtypes. These findings have important implications for the control of E. bieneusi and Blastocystis sp. in cattle in Jiangxi Province.

Prevalence and molecular subtyping of Blastocystis in domestic pigeons in Henan Province, Central China

Blastocystis is an anaerobic intestinal protozoan parasite found in humans and many kinds of animals that mainly causes diarrhea, abdominal pain and other clinical symptoms. At present, research on the prevalence and subtype diversity of Blastocystis in domestic pigeons is very limited. The purpose of this study was to detect the infection rate and gene subtype distribution of Blastocystis in domestic pigeons in Henan Province, Central China, to provide a foundation for preventing and controlling Blastocystis in domestic pigeons. Fecal DNA was extracted from 504 fresh fecal samples of pigeons collected from 4 areas in Henan Province, Central China. All DNA samples were investigated by polymerase chain reaction (PCR), and positive samples were sequenced to analyze the gene subtypes based on small ribosomal subunit (SSU rRNA) gene. The overall infection rate of Blastocystis in pigeons in Henan Province was 7.7% (39/504). Four subtypes (STs) of Blastocystis were identified including ST1 (2/39, 5.1%), ST3 (16/39, 41.0%), ST4 (1/39, 2.6%) and ST7 (20/39, 51.3%), all of which belonged to zoonotic subtypes, and ST7 was the dominant gene subtype. The results show that Blastocystis infection is common in domestic pigeons in Henan Province, Central China, and the pathogen were zoonotic subtypes. Particular attention should be given to reducing the risk of transmission of Blastocystis from domestic pigeons to humans.

Molecular Characterization of Blastocystis from Beef Cattle in Northeastern China

Blastocystis is a common unicellular protist that lives in the intestines of humans and animals. Blastocystis infection and subtypes in cattle have been reported in several regions. However, the information of Blastocystis infection in cattle in China is still largely scant. To assess the prevalence and subtype distribution of Blastocystis in beef cattle in China, 803 fecal samples were collected from beef cattle farms in four cities of Northeast China, and were subjected to an analysis based on small subunit rRNA gene fragment. The overall prevalence of Blastocystis in beef cattle was 2.11% (17/803), with 2.15% in preweaning calves, 1.9% in postweaning calves, and 3.85% in breeding cattle, but absence in adult cattle (p > 0.05). Moreover, five Blastocystis subtypes were identified (ST10, ST21, ST23, ST25, and ST26), among which ST10 and ST26 subtypes were dominant subtypes in beef cattle. Mixed infections were detected in three specimens (ST10/ST25, ST10/ST23/ST25, and ST10/ST26). This is the first report showing Blastocystis infection in beef cattle in Northeast China. In addition, a variety of Blastocystis subtypes are reported in cattle in China for the first time. These results will benefit for better understanding the epidemiology and public health implications of Blastocystis.

The Presence of Blastocystis in Tibetan Antelope (Pantholops hodgsonii)

Blastocystis is a protozoan that parasitizes the intestines. A number of hosts of Blastocystis have been found, including human and animals. However, there has been no research on the prevalence of Blastocystis in Tibetan antelope. Here, a molecular test was performed using 627 Tibetan antelope fecal samples collected on Tibet in China from 2019 to 2020. The result showed that 30 (4.8%) samples were Blastocystis positive. The highest prevalence of Blastocystis was in Shuanghu County (25/209, 12.0%), followed by Shenza County (2/103, 1.9%), Nyima County (3/182, 1.6%), and Baigoin County (0/133, 0.0%). In addition, logistic regression analysis showed that the gender, sampling year, and area of Tibetan antelope were risk factors for Blastocystis prevalence. Three subtypes (ST10, ST13, and ST14) of Blastocystis were found in Tibetan antelope through a subtype sequence analysis, and ST13 was identified to be the dominant subtype. This is the first investigation for the infection of Blastocystis in Tibetan antelope. Collectively, the data in this study have expanded the host range of Blastocystis and provided basic information for the distribution of Blastocystis subtypes, which could support the prevention of Blastocystis infection in wild animals.

Molecular prevalence and subtype distribution of Blastocystis sp. in Asia and in Australia

Blastocystis is a prevalent protozoan parasite reported in humans, animals, and environmental samples. Over the past decade, numerous studies have investigated the prevalence and subtype distribution of Blastocystis sp. alongside with its genetic and biochemical features. However, studies on subtype distribution of this protozoan in humans, animals, and environmental samples represent the potential transmission routes. In this review, we evaluated studies performed in Asian countries and in Australia to provide an overview of environmental factors on the prevalence and subtype distribution of Blastocystis sp. among humans, animals, and the environment.

The Coexistence of Blastocystis spp. in Humans, Animals and Environmental Sources from 2010-2021 in Asia

Blastocystis spp. are controversial unicellular protists that inhabit the gastrointestinal tract of humans and a wide range of animals worldwide. This review provides an overview of the prevalence and distribution of Blastocystis spp. and their subtypes throughout Asia. Research articles reporting on the presence of Blastocystis spp. in locations within Asia, between 1 January 2010, and 10 May 2021, were obtained from Scopus, PubMed, and Google Scholar. In 427 articles, the prevalence of Blastocystis spp. in 31 countries within the last decade was revealed. Isolates were found in humans, various mammals, birds, reptiles, insects, water sources, vegetables, and ambient air. Prevalence of Blastocystis spp. varied widely across host categories. Subtypes identified throughout Asia were STs 1-14, and ST18-22 (novel subtypes). ST1, ST2, ST3, ST4 were the most frequently isolated in humans; ST5 in pigs; ST10 and ST14 in goats, sheep, and cattle; and ST6 and ST7 in chickens. ST1 and ST3 were most common in water samples. ST1, ST2, ST3, ST4, ST5 and ST6 were shared by humans, animals, and water sources. There is a growing interest in the study of Blastocystis spp. and their subtypes in Asia. Due to the isolation of Blastocystis spp. from biotic and abiotic sources in Asia, the application of the One Health (OH) approach to the study of Blastocystis spp. is proposed for improved perception of this organism.

Molecular epidemiology and genotype/subtype distribution of Blastocystis sp., Enterocytozoon bieneusi, and Encephalitozoon spp. in livestock: concern for emerging zoonotic infections

Intestinal parasitic infections have high prevalence rate in many regions especially in developing countries. The aim of this study was to determine the presence and genotype/subtype of some intestinal protozoa in livestock in Iran. Stool samples were collected from cattle, sheep, chickens, and horses. The presence of targeted parasites was evaluated using real-time PCR. Genotyping/subtyping of positive samples was characterized using sequencing of the ITS and barcoding region, respectively. Blastocystis sp., 27.7% (48/173) and Enterocytozoon bieneusi 26.0% (45/173) were the most frequent protozoa followed by Encephalitozoon spp., 0.57% (1/173). Cryptosporidium spp. were not detected among samples. Encephalitozoon spp., was detected only in chickens 2.2% (1/45). A statistically correlation was seen between animals and the prevalence of targeted protozoa. E. bieneusi genotypes I (9/38; 23.68%), BEB6 (22/38; 57.89%), D (6/38; 15.79%), and horse1 (1/38; 2.63%) were detected among samples. A statistically significant correlation was seen between the genotypes and animals (P ≤ 0.05). Blastocystis sp., ST1 (1/45; 2.22%), ST5 3/45; 6.66%), ST7 (1/45; 2.22%), ST10 (24/45; 53.33%), and ST14 (16/45; 35.55%) were characterized among samples. There was no significant correlation between certain subtypes and animals (P = 0.173). The presence of zoonotic potential genotypes of E. bieneusi in animals and zoonotic potential subtypes ST1 and ST7 among our samples provide a clue about the transmission dynamic of E. bieneusi and Blastocystis sp. between animals–animals and humans–animals.

Molecular identification and subtype distribution of Blastocystis sp. in farm and pet animals in Turkey

A total of 1340 fresh fecal samples from farm and pet animals in Central Anatolia and the Middle Black Sea Region of Turkey were investigated using a PCR assay targeting the SSU rRNA of Blastocystis sp. An overall Blastocystis sp. prevalence of 19.4% (183/940) was found in farm animals, including cattle, sheep, water buffaloes, and chickens. Fecal samples of dogs, cats, and horses were negative. The highest prevalence of Blastocystis sp. was found in sheep (38.2%) among the farm animals. The SSU rRNA sequence analysis revealed two animal-specific subtypes, including ST10 in cattle and sheep and ST14 in water buffaloes. The zoonotic subtype ST7 was identified in chickens. Our results indicated a high prevalence of animal-specific subtypes in livestock and zoonotic subtype ST7 in chickens, highlighting the potential risk of chickens for zoonotic transmission of Blastocystis in the research area. This study is the first large-scale evaluation of Blastocystis in animal hosts in Turkey, and contributes to the molecular epidemiology and genetics of Blastocystis. Our results should be considered by authorities as an indication of the zoonotic importance of Blastocystis sp. and the need for surveillance in public health intervention programs.

Wide Genetic Diversity of Blastocystis in White-Tailed Deer (Odocoileus virginianus) from Maryland, USA

Blastocystis is a gastrointestinal protist frequently reported in humans and animals worldwide. Wildlife populations, including deer, may serve as reservoirs of parasitic diseases for both humans and domestic animals, either through direct contact or through contamination of food or water resources. However, no studies of the occurrence and subtype distribution of Blastocystis in wildlife populations have been conducted in the United States. PCR and next generation amplicon sequencing were used to determine the occurrence and subtypes of Blastocystis in white-tailed deer (Odocoileus virginianus). Blastocystis was common, with 88.8% (71/80) of samples found to be positive. Twelve subtypes were identified, ten previously reported (ST1, ST3, ST4, ST10, ST14, ST21, and ST23–ST26) and two novel subtypes (ST30 and ST31). To confirm the validity of ST30 and ST31, MinION sequencing was used to obtain full-length SSU rRNA gene sequences, and phylogenetic and pairwise distance analyses were performed. ST10, ST14, and ST24 were the most commonly observed subtypes. Potentially zoonotic subtypes ST1, ST3, or ST4 were present in 8.5% of Blastocystis-positives. Mixed subtype infections were common (90.1% of Blastocystis-positives). This study is the first to subtype Blastocystis in white-tailed deer. White-tailed deer were found to be commonly infected/colonized with a wide diversity of subtypes, including two novel subtypes, zoonotic subtypes, and subtypes frequently reported in domestic animals. More studies in wildlife are needed to better understand their role in the transmission of Blastocystis.

A systematic review and meta-analysis on the global prevalence and subtypes distribution of Blastocystis sp. infection in cattle: A zoonotic concern

Blastocystosis is an interesting parasitosis, since the parasitic infection is still seriously neglected and a considerable zoonotic evidence is emerging. Blastocystis sp. infects the intestinal lumen of humans and a wide range of animals, while there is a lack of comprehensive information on Blastocystis epidemiology in cattle worldwide. Thus, the present systematic review and meta-analysis were performed by exploring four electronic databases (PubMed, Web of Science, Scopus, and Google scholar) for relevant published papers up to 7th November 2020, utilizing a random-effects model to pool estimations and assign 95 % confidence intervals (CIs). Results of 28 studies (29 datasets) on cattle showed a 24.4 % (95 % CI: 16.9-33.9 %) prevalence for Blastocystis infection. Also, 16 out of 26 reported subtypes (STs) were isolated from cattle, with ST10 (18 datasets) as the highest-reported [32.3 % (95 % CI: 21.6-45.3)] as well as ST24 and ST25 (one study each) as the lowest-reported STs [1.4 % (95 % CI: 0.2-9.1)]. Additionally, among nine well-known zoonotic STs (ST1-ST8 and ST12), all STs except for ST8 were reported from cattle worldwide, demonstrating this animal species as a potential reservoir for human infections. Meanwhile, the overall prevalence of Blastocystis in various subgroups (publication year, WHO regions, countries, continents, and age groups) was analyzed separately. The finding of the present review article highlights the cattle as a significant source of zoonotic transmission of Blastocystis infection to humans, which must be considered for preventive measures.

Molecular detection of Blastocystis in black bears and sika deer in northern China

Protists of the Blastocystis genus are distributed worldwide and can infect a range of hosts. However, data concerning Blastocystis infection are limited for sika deer and are not available for black bears. Therefore, in the present study, a total of 312 black bears (Ursus thibetanus) from Heilongjiang Province and 760 sika deer (Cervus nippon) from four different northern Chinese provinces were investigated. Blastocystis infection in these animals was detected via PCR amplification of the small subunit rRNA gene in fecal samples. The prevalence of Blastocystis infection in black bears and sika deer was 14.4% (45/312 positive samples) and 0.8% (6/760 positive samples), respectively. Young black bears (18.3%) had a significantly higher Blastocystis prevalence than adult bears (9.1%). The prevalence of Blastocystis was significantly higher in black bears raised outdoors (24.6%) than in bears raised indoors (12.2%). Blastocystis-positive sika deer were only found in Jilin Province (1.3%, 6/480). Female sika deer (0%, 0/61) had a significantly lower Blastocystis prevalence than males (0.9%, 6/699). Sanger sequencing was used to determine the small subunit rRNA gene sequences of the Blastocystis-positive PCR products. A neighbor-joining phylogenetic tree based on the small subunit rRNA gene sequences showed that only Blastocystis subtype (ST)1 was identified in black bears, whereas ST10 and ST14 were found in sika deer. This is the first report of Blastocystis ST1 infection in black bears. These findings also extend the distribution information of Blastocystis subtypes, which will provide a foundation for further study of Blastocystis in different hosts in China.

Epidemiology of Blastocystis infection from 1990 to 2019 in China

Background

Blastocystis is ubiquitous presence in animals and humans worldwide and has a high level genetic diversity. The aim of this study was to conduct a summary of Blastocystis prevalence, subtypes (STs) in humans and animals in China and depict their distribution.

Methods

We searched for the articles related to epidemiology of Blastocystis in humans and animals throughout China which published from January 1, 1990, to July 31, 2019 in the following databases: PubMed, China National Knowledge Infrastructure (CNKI) and Wanfang database. The keywords were Blastocystis and one of the following ones: STs, subtypes, distribution, epidemiology, prevalence, infection, molecular, geographic, intestinal parasites, genetic diversity and characterization.

Results

In recent years, various molecular epidemiological studies have been carried out in some provinces/regions of China to identify subtypes of Blastocystis. Infants and young children, school students, hospitalized diarrhea patients, HIV/AIDS patients, tuberculosis patients, and cancer patients as respondents had been included. ST1–ST7 and ST12 were the main subtypes in Chinese population. Moreover, surveys of Blastocystis infection in animal were also conducted in some provinces of China. A variety of animals were investigated including pigs, cattle, sheep, yak, giant panda, and crested ibis (Nipponia nippon) with the main subtypes of ST1–ST8, ST10, ST12–ST14.

Conclusions

In recent years, some provinces/regions in China have conducted various molecular epidemiological studies to identify the Blastocystis subtypes. It is important to focus on new subtypes and mixed subtypes of infection, while increasing data on ribosomal alleles. We encourage the scientific community to start research on humans and surrounding animals (including domestic and wild animals) to better understand the possibility of Blastocystis transmission between humans and animals. We call for action among researchers studying intestinal parasitic diseases (Blastocystis), start drawing the subtype of Blastocystis and increase the subtype related to its clinical symptoms.

Blastocystis infection and subtype distribution in domestic animals in the Qinghai-Tibetan Plateau Area (QTPA) in China: A preliminary study

Blastocystis is a common intestinal protozoan parasite of humans and a variety of animal species. To date, the prevalence of Blastocystis and major subtypes distribution in the domestic animals inhabiting in the Qinghai-Tibetan Plateau Area (QTPA) of China is yet poorly studied. In this study, we investigated the distribution and genetic diversity of Blastocystis in seven animal species in QTPA in China. Four hundred and five fresh fecal samples were collected from domestic animals in Qinghai, Yunnan, and Tibet of China and analyzed using nested PCR and SSU rRNA gene sequencing. It was found that the overall prevalence of Blastocystis infection was 40.2% (163/405) in the animals studied. The most predominant subtype of Blastocystis was ST10 (57.7%) followed by ST14 (28.8%) and ST2 (13.5%). These results reveal the epidemiological features of Blastocytis infection in animals in the high altitude plateau area. The finding of presence of ST2 in a number of animal species suggests a zoonotic nature of Blastocystis and might be of importance of public health.

Blastocystis in domesticated and wild mammals and birds

Blastocystis is a ubiquitous parasite that infects a broad range of vertebrate hosts including humans and domestic and wild animals. While human infections have been occasionally associated with gastrointestinal illnesses and/or urticaria, animal infections are not usually associated with disease. However, from a public health perspective, most subtypes isolated in humans have also been isolated from animals raising the question of the importance of animal reservoirs in the epidemiology of this parasite. The identification of Blastocystis in water supplies suggests water can be a potential vehicle in the transmission of this parasite not only for humans but also for animals. In addition, Blastocystis has been detected in retail fresh produce. Knowledge of this parasite has greatly expanded in the last two decades from simple microscopic observations to the application of molecular tools to explore Blastocystis taxonomy and epidemiology. This review provides a comprehensive overview of Blastocystis in animals highlighting the subtype diversity of this widespread and genetically diverse parasite in different animal groups. This information will be useful in understanding the current status of taxonomy, epidemiology, zoonotic potential, and public health importance of Blastocystis.

First Report of Blastocystis Infection in Pigs from Large Farms in Xinjiang, China

Blastocystis is a common intestinal protozoan in humans and various animals worldwide. A few studies have reported the genetic characterization of Blastocystis in pigs in China, but no epidemiological data are available from the Xinjiang Uygur Autonomous Region. In this study, 801 fecal samples were collected from seven scale pig farms in Xinjiang and tested by polymerase chain reaction and sequence analysis of the partial SSU rRNA gene. The average infection rate of Blastocystis was 21.7% (174/801), with 7.1% in preweaning piglets, 10.0% in postweaning piglets, 31.8% in fattening pigs, and 41.9% in sows (χ²  = 104.89; P < 0.01). Blastocystis subtypes ST1 (7/174), ST3 (2/174), and ST5 (165/174) were identified, with subtype ST5 being predominant in each of the pig farms and in each of the age groups. ST3 and ST5 were identified in preweaning piglets, and ST1, ST3, and ST5 were identified in postweaning piglets. In contrast, only the subtype ST5 was observed in fattening pigs and sows. Genetic polymorphisms were observed at the intrasubtype level, including two variations of ST1 (ST1A, ST1B), and seven of ST5 (ST5A to ST5G), by sequence alignment analysis and phylogenetic analysis. More studies are needed to elucidate the transmission and public health significance of Blastocystis in pigs in various areas.

First molecular subtyping and phylogeny of Blastocystis sp. isolated from domestic and synanthropic animals (dogs, cats and brown rats) in southern Iran

BACKGROUND

Blastocystis sp. is a common intestinal protist that infects humans and many animals globally. Thus far, 22 subtypes (STs) have been identified in mammalian and avian hosts. Since various STs are common to humans and animals, it was suggested that some human infections might arise from zoonotic transmission. Therefore, the aim of this study was to assess the presence of Blastocystis sp. in domestic (dogs and cats) and synanthropic animals (rats) of Fars Province, Iran, and to genetically characterize the samples.

METHODS

A total of 400 fresh faecal samples from 154 dogs, 119 cats, and 127 rats were inspected by direct microscopy, Wheatley's trichrome staining, in vitro culture, and 18S rRNA gene nested-PCR. Finally, sequencing and phylogenetic analyses were performed.

RESULTS

Out of 400 samples, 47 (11.8%) and 61 (15.3%) samples were detected as positive by direct wet mount and culture, respectively. Molecular analysis detected a larger number of positive samples (n = 70, 17.5%): nested-PCR showed that 29 (18.8%) dogs, 21 (17.7%) cats, and 20 (15.8%) rats were infected by Blastocystis sp. Sequence analysis of positive samples indicated the presence of zoonotic STs in all investigated host species. Specifically, ST2 (allele 9), ST3 (allele 34), ST4 (allele 94), ST7 (allele 99), ST8 (allele 21), and ST10 (allele 152) were detected in dogs; ST1 (allele 2), ST3 (allele 34), ST4 (allele 94), ST10 (allele 152), and ST14 (allele 159) were detected in cats; and ST1 (allele 2), ST3 (allele 34), and ST4 (allele 92) were detected in rats.

CONCLUSIONS

Our data suggest that domestic dogs and cats can serve as possible reservoirs for in-contact humans, especially those who handle shelter-resident and client-owned animals. Moreover, rats as synanthropic animals can function as a potential source of human infections. Conversely, humans can act as a source of infections to animals. These results should be reinforced in future molecular epidemiological studies.

Molecular prevalence and subtypes of Blastocystis sp. in primates in northern China

Blastocystis sp. is a common enteric protist that colonizes humans and a wide range of animals. Although some studies have reported incidences of Blastocystis sp. in humans and animals in China, there are limited data available concerning the prevalence among people and non-human primates. The aims of the present study were to determine the prevalence, subtype distribution and genetic characteristics of Blastocystis sp. in primates, and to investigate the potential for zoonotic transmission between human and non-human primates. A total of 185 faecal samples from non-human primates and 1,118 samples from human volunteers were collected in Hebei province. The overall prevalence of Blastocystis sp. in non-human primates was 32.97% (61/185) based on polymerase chain reaction (PCR) amplification of the barcode region of the SSU rRNA gene. Rates of prevalence were highest among Cercopithecus neglectus (100%, 5/5) and were absent in Cebus apella and Colobus guereza. The prevalence of Blastocystis sp. in humans was 34.88% (390/1,118), and the highest rates were 41.24% in children three years of age. There was a higher detection rate in humans with diarrhoea (53.68%). Five potentially zoonotic subtypes (ST1, ST2, ST3, ST5 and ST9) were identified; among these, ST1 and ST2 were more prevalent than others in non-human primates. Similarly, two subtypes (ST2 and ST5) were detected in humans and ST2 was also the most prevalent. To the best of our knowledge, this is the first report of the prevalence and subtype composition of Blastocystis sp. in Hebei province, and the first study concerning the relationship of Blastocystis sp. among primates in China. The findings of the study will improve our understanding of the genetic diversity and public health potential of Blastocystis sp. enteric infections in addition to providing a profile of subtype characteristics of Blastocystis sp. in primates of northern China.

Molecular characterization of Blastocystis sp. in captive wildlife in Bangladesh National Zoo: Non-human primates with high prevalence and zoonotic significance

Blastocystis sp. is a protozoan parasite, commonly found in the gastrointestinal tracts of animals and humans globally. The parasitic species has wide genetic diversity. Currently the mammalian and avian isolates of the parasite are grouped into 17 well known subtypes (STs), of which ten (ST1-ST9, ST12) are reported in humans. To assess the genetic diversity of Blastocystis sp. in wildlife, a total of 200 fresh fecal samples were collected from 32 mammalian wildlife species in Bangladesh National Zoo. Blastocystis sp. was screened and subtyped by PCR amplification and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene. The minimum prevalence of Blastocystis sp. infection was 15.5% (31/200) in zoo animals. Eight out of 32 wildlife animal species (25.0%) were infected with Blastocystis sp. Among them, the occurrence of Blastocystis sp. was higher in non-human primates (NHPs) (31.8%) than that in herbivores (4.9%) and carnivores (0). Nucleotide sequence analysis of the SSU rRNA gene revealed seven different Blastocystis sp. subtypes, such as ST1, ST2, ST3, ST10, ST11, ST13 and ST14 in the wild animals. ST3 was the dominant subtype (41.9%, 13/31) being detected in NHPs. Of the 31 Blastocystis sp. isolates from the wild animals, 24 (77.4%) isolates belonged to the most common subtypes (ST1 to ST3) found in humans. This is the first molecular study of Blastocystis sp. in wild animals in Bangladesh. This study highlights the remarkable genetic diversity in Blastocystis sp. isolates from zoo animals and provides the first molecular evidence from spotted deer, gayal and grey langur. Due to circulation of large percentage of potentially zoonotic subtypes in the wild animals, there is a higher risk of zoonotic transmission of Blastocystis sp. in the zoo keepers and visitors.

Prevalence and subtype distribution of Blastocystis in ethnic minority groups on both sides of the China-Myanmar border, and assessment of risk factors

Blastocystis is one of the most common intestinal parasites in humans worldwide. To understand its prevalence and to explore the risk factors for Blastocystis in humans in developing countries, a molecular epidemiological investigation of Blastocystis was conducted in ethnic minority groups on both sides of the China-Myanmar border. A total of 461 fecal specimens were collected from 289 Yao people in China and 172 Wa people in Myanmar, together with a questionnaire for each participant. Based on sequence analysis of the partial small subunit of ribosomal RNA (SSU rRNA) gene (barcode region or 260 bp region), an average prevalence of 6.29% (29/461) was observed, with 4.50% (13/289) in Yao people and 9.30% (16/172) in Wa people. Twenty-two Blastocystis isolates were successfully subtyped by sequence analysis of the barcode region. Three subtypes were identified: ST1 (n = 7), ST3 (n = 13) and ST4 (n = 2). A statistical difference in the prevalence of Blastocystis was only observed between children (12.37%, 12/97) and adults (4.95%, 16/323), and between not washing hands (11.02%, 14/127) and washing hands (4.76%, 15/315) after using toilets, emphasizing the importance and necessity of health education in people in the investigated areas, especially in children.