Blastocystis Subtype Distribution Research Articles

Molecular Epidemiology, Subtype Distribution, and Zoonotic Importance of Blastocystis sp. in Camelids (Camels and Alpacas): A Worldwide Systematic Review and Meta-Analysis.

Focusing on the global epidemiology and subtype distribution of Blastocystis sp. in camelids (camels and alpacas), the present systematic review and meta-analysis was conducted. Utilizing relevant keywords, a thorough search was conducted on four electronic databases (PubMed, Scopus, Google Scholar, and Web of Science) with no time constraints up to April 1, 2024. Total estimates and 95% confidence intervals (CIs) were subsequently calculated using a random-effects model. Finally, 11 studies with 18 datasets provided the required data. The global prevalence of Blastocystis sp. in camelids was estimated at 22%, with a 95% CI of 17.2-27.6%. Among 1061 camels, the pooled prevalence of Blastocystis sp. was 21.6% (95% CI: 16.6-27.6%) across 5 countries, which was lower than the 23.5% (95% CI: 12.2-43.1%) found in 449 tested alpacas across 3 countries. Camels were found to carry 15 genetically diverse subtypes (STs)of Blastocystis sp. (ST1-ST7, ST10, ST14, ST15, ST21, ST24, ST25, ST26, and ST30). Among these, ST10 exhibited the highest pooled prevalence [five datasets, 38.3% (95% CI: 22.4-57.1%)], followed by ST1 [three datasets, 24% (95% CI: 6-61.2%)] and ST14 [four datasets, 15.2% (95% CI: 6.7-31%)]. Alpacas exhibited three distinct STs (ST5, ST10, and ST14). Among these, ST10 [four datasets, 50.3% (95% CI: 33.3-67.3%)] had the greatest weighted frequency, with ST14 [four datasets, 40.2% (95% CI: 23.8-59.1%)] following closely behind. Of note, 9 zoonotic STs (ST1-ST7, ST10, and ST14) have been identified in camels and 3 in alpacas (ST5, ST10, and ST14) out of the 16zoonotic STs (ST1-ST10, ST12, ST14, ST16, ST23, ST35, and ST41)of Blastocystis sp. reported to date. Overall, camelids (camels and alpacas) can serve as a diverse reservoir for various Blastocystis sp. STs, potentially contributing to infections in humans, animals, and water sources. Nevertheless, research in this area is somewhat restricted, necessitating careful interpretation of the findings.

A Worldwide Systematic Review and Meta-Analysis of the Prevalence and Subtype Distribution of Blastocystis Sp. in Water Sources: A Public Health Concern.

Contaminated water sources can result in outbreaks of parasitic infections such as Blastocystis sp. in communities, creating a substantial strain on healthcare systems and affecting the general health of the population. To ascertain the prevalence and subtype distribution of Blastocystis sp. in water sources globally, a systematic review and meta-analysis of published papers up to May 19, 2024 were carried out. A thorough search of multiple electronic databases (PubMed, Scopus, Google Scholar, and Web of Science) identified 24 studies/28 datasets meeting the inclusion criteria, encompassing 2,451 water samples from 15 countries worldwide. Water samples comprised wastewater (six datasets, 285 samples), tap/drinking water (10 datasets, 253 samples), surface water (eight datasets, 1013 samples), and uncategorized water (four datasets, 900 samples). Total estimates and 95% confidence intervals (CIs) were computed using a random-effects model. This review found that 18.8% (95% CI: 12.8-26.9%) of examined water samples contained Blastocystis sp. Wastewater showed the highest Blastocystis sp. infection rate at 35.5% (95% CI: 13.5-66.1%), followed by tap/drinking water at 19.1% (95% CI: 9.5-34.5%), surface water at 17.6% (95% CI: 7.2-36.8%), and uncategorized water at 9.9% (95% CI: 4.1-21.8%). Sensitivity analysis assessed weighted prevalence variations following the exclusion of individual studies. Subgroup analysis of Blastocystis sp. prevalence was performed based on publication years, countries, continents, WHO regions, sample sizes, and diagnostic methods. Water samples can be the source of infection for nine Blastocystis sp. subtypes (STs) (ST1-ST4, ST6, ST8, ST10, ST21, and ST24), with seven STs (ST1-ST4, ST6, ST8, and ST10) capable of infecting humans. It is important to take preventative and control measures, improve the cleanliness and quality of water sources, and promote public health awareness due to the presence of different parasites such as Blastocystis sp. in water sources.

Molecular detection and subtype distribution of Blastocystis sp. from shelter dogs and cats in Van, Turkey: First report of ST10 in cats and ST1, ST10 and ST30 in dogs

Molecular detection and subtype distribution of Blastocystis sp. from shelter dogs and cats in Van, Turkey: First report of ST10 in cats and ST1, ST10 and ST30 in dogs

Existence of Blastocystis infection in bar–headed goose (Anser indicus)

Blastocystis is a common intestinal protist in humans and animals. Currently, Blastocystis infection in bar-headed geese is unknown. To understand the prevalence and distribution of Blastocystis subtypes in bar–headed geese, fecal samples were collected from 358 bar–headed geese in three regions. The total infection rate of Blastocystis in bar–headed in China was 5.9% (21/358), with 5.0% (6/120) in Aba (Ngawa) Tibetan and Qiang Autonomous Prefect, Sichuan province, 11.8% (14/119) in Maqu county, Gansu province, and 0.8% (1/119) in Caohai, Wei ning county, Guizhou province. The differences in prevalence rates by region were statistically significant. Sequences analyses showed that one known subtype (ST7, n = 16) and one potentially novel ST (n = 5) in bar–headed geese were detected in this study. This is the first report on the prevalence and subtype distribution of Blastocystis in bar–headed geese, which will improve our understanding of the epidemiology and public health implications of Blastocystis infection in wild migratory birds.

Subtype Distribution of Blastocystis spp. in Patients with Gastrointestinal Symptoms in Northern Spain.

Limited molecular data exist on the prevalence and subtype distribution of Blastocystis spp., the most prevalent parasite in human and animal feces worldwide. A total of 44 different subtypes (STs) of Blastocystis are currently recognized based on the sequence of the small subunit ribosomal RNA (SSU-rRNA) gene. This is a molecular study of Blastocystis spp. in hospitalized patients with gastrointestinal symptoms in northern Spain. We analyzed 173 Blastocystis-positive patients with gastrointestinal symptoms by using nested PCR for molecular detection, subtype identification, phylogenetic analyses, and genetic diversity assessment. ST2 (34.1%) and ST3 (34.7%) predominated, followed by ST1 (15.6%) and ST4 (15.6%). Mixed infections with different subtypes were observed in some patients. Sequence analysis revealed for the first time in European humans the allele 88 (a variant of ST1). In other cases, alleles commonly found in animal samples were detected (allele 9 in ST2, allele 34 in ST3, and allele 42 in ST4). Phylogenetic analysis showed high variability in ST1 and ST2, suggesting a polyphyletic origin, while both ST3 and ST4 exhibited higher genetic homogeneity, indicating a possible monophyletic origin and recent transmission to humans. These data confirm Blastocystis spp. subtype diversity and may help in understanding the evolutionary processes and potential zoonotic transmission of this parasite.

Identification of Blastocystis spp. in Urban Rodents of Different Districts in Southwestern Iran: Subtype Distribution and Possible Zoonotic Potential.

Rodents are one of the most abundant and diverse species of mammals and have recently been identified as carriers of numerous human pathogens. The current study was conducted to assess the prevalence, subtype (STs) distribution, and zoonotic potential of Blastocystis spp. in various species of rodents in Shiraz, southwestern Iran. For this aim, a total of 120 fresh fecal samples were collected from Mus musculus (n = 40), Rattus norvegicus (n = 40), and Rattus rattus (n = 40) in various municipality districts of Shiraz (6 out of 10 districts) between February and November 2020. Upon detecting parasites using light microscopy, a DNA fragment of the Blastocystis SSU rDNA gene was amplified using conventional PCR. By employing direct wet mount examination, 8 out of 120 fecal samples (6.7%; 2 from house mice, 3 from black rats, and 3 from brown rats) tested positive. Similarly, 5% (2/40) of house mice, 7.5% (3/40) of black rats, and 7.5% (3/40) of brown rats tested positive using the molecular method. Phylogenetic analysis revealed that the Blastocystis infecting different rodent species in Shiraz belonged to two potentially zoonotic STs (ST1 and ST4). Accordingly, rodents should not be overlooked as potential reservoirs of zoonotic Blastocystis infections. Different sampled urban districts and their statistical association with reported prevalence rates were analyzed separately. Overall, the issue of the frequency and ST distribution of Blastocystis in urban rodents of Iran is still open to question and for a proper understanding, wider and more comprehensive studies are needed.

Molecular Prevalence and Subtypes Distribution of Blastocystis spp. in Humans of Latin America: A Systematic Review.

Blastocystis spp. are among the few enteric parasites with a prevalence that can reach up to approximately 80% in communities of developing countries. This systematic review updates and summarizes available literature on the molecular prevalence and subtype distribution of Blastocystis spp. in Latin American people. This work follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The literature revised covers from 1 January 2015 to 6 October 2023 in seven different scientific databases, and the material was selected through inclusion and exclusion criteria. According to data found in the 36 selected articles, the prevalence of Blastocystis spp. in Latin America ranged between 5.8% (Bolivian rural communities) and 94.0% (Colombian general public). Generally, genomic DNA was extracted from approximately 200 mg fecal sediments using commercial kits, such as the QIAamp Stool Mini Kit (QIAGEN, Hilden, Germany) or the Norgen Stool DNA Isolation Kit (Norgen Biotek Corporation, Thorold, ON, Canada). Subtype-specific primers (such as the couple of primers BhRDr-RD5) developed from unique sequences of the SSU rRNA gene were applied to Blastocystis subtyping. Ten specific subtypes (STs) were found as well as various mixed infections, and the most circulating Blastocystis STs were in the order ST3, ST1, ST2, and ST4. The most recent data about Blastocystis spp. molecular epidemiology and the STs in communities of Latin America are limited to studies from specific countries. Novel scientific data from the other countries are required to obtain a complete picture and truly understand the distribution and prevalence of Blastocystis spp. and the STs.

Molecular prevalence and subtype distribution of Blastocystis spp. among children who have diarrheia or are asymptomatic in Wenzhou, Zhejiang Province, China.

Blastocystis sp., a significant zoonotic parasite with a global distribution, was the focus of this study, which aimed to investigate its prevalence and genetic diversity among diarrheic and asymptomatic children in Wenzhou, China. We collected 1,032 fecal samples from Yuying Children's Hospital, Wenzhou, China, comprising 684 from children with diarrhea and 348 from asymptomatic children. Genomic DNA extracted from these samples was used to detect Blastocystis spp. by PCR, targeting the small subunit ribosomal RNA gene. Subsequently, a phylogenetic tree was constructed, applying the maximum likelihood method. Blastocystis spp. were detected in 67 (6.5%) of the fecal samples. The prevalence rate of Blastocystis spp. in diarrheic children (8.8%; 60/684) was significantly higher than that in asymptomatic children (2.0%; 7/348) (χ 2=17.3, p<0.001). Sequence analysis of the SSU rRNA gene identified five known Blastocystis spp. subtypes, ST1 (n=12), ST2 (n=5), ST3 (n=35), ST4 (n=12), and ST7 (n=3). ST1 and ST3 were present in both diarrheic and asymptomatic children, while ST2, ST4, and ST7 were exclusive to diarrheic children. Intra-subtype genetic polymorphisms were identified, comprising four variations in ST1 (ST1-1 to ST1-4), five in ST3 (ST3-1 to ST3-5), two in ST4 (ST4-1 and ST4-2), and two in ST7 (ST7-1 and ST7-2). Notably, ST1-2 to ST1-4, ST3-3 to ST3-5, and ST7-1 and ST7-2 represent newly identified variations. The composition and genetic characteristics of subtypes among children in this region suggest various sources of infection, including human-to-human and animal-to-human transmission.

Molecular detection and subtyping of Blastocystis sp. in pigs in Anhui Province

To investigate the prevalence and subtype distribution of Blastocystis sp. in pigs in Anhui Province. A total of 500 stool samples were collected from large-scale pig farms in Bozhou, Anqing, Chuzhou, Hefei, Fuyang, and Lu'an cities in Anhui Province from October to December 2015. Blastocystis was detected in pig stool samples using a PCR assay based on the small subunit ribosomal RNA (SSU rRNA) gene, and positive samples were subjected to sequencing and sequence analysis. Blastocystis subtypes were characterized in the online PubMLST database, and verified using phylogenetic tree created with the neighbor-joining algorithm in the Meta software. The prevalence of Blastocystis infection was 43.2% (216/500) in pigs in 6 cities of Anhui Province, and all pig farms were tested positive for Blastocystis. There was a region-specific prevalence rate of Blastocystis (17.2% to 50.0%) (χ2 = 26.084, P < 0.01), and there was a significant difference in the prevalence of Blastocystis sp. among nursery pigs (39.6%), preweaned pigs (19.1%), and growing pigs (62.3%) (χ2 = 74.951, P < 0.01). Both online inquiry and phylogenetic analysis revealed ST1, ST3, and ST5 subtypes in pigs, with ST5 as the predominant subtype. The prevalence of Blastocystis sp. is high in pigs in Anhui Province, with three zoonotic subtypes identified, including ST1, ST3, and ST5.

Prevalence of Blastocystis and Dientamoeba fragilis in diarrheal patients in Corum, Türkiye.

To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea patients and 50 healthy individuals were collected and evaluated using direct microscopy and molecular methods to screen for bacteria, protozoa, and viruses. The prevalence of Blastocystis was 24.6% in total and more frequent in the healthy group (30.0%). The commonly detected STs (subtypes) were ST3 (40.0%) and ST2 (34.2%). The distribution of Blastocystis STs in the healthy and diarrheal groups did not show any difference in sex and age, but ST3 was detected more frequently in patients aged from 40 to 59 years (p < 0.05). Alleles 4 (8/12) and 2 (4/12) were present in ST1; 9 (3/5) and 12 (2/5) in ST2; 34 (9/14), 36 (3/14), and 38 (2/14) in ST3; and only allele 42 (2/2) in ST4. D. fragilis was present in 8.4% of the population. However, there was no statistically significant difference between the healthy and diarrheic groups (12.0% and 6.5%, respectively), neither with respect to age nor sex. Co-infection was 58.3% and was more frequent in healthy individuals (33.3%) than in diarrhea patients (25.0%). Blastocystis ST3 was the most common subtype detected, with D. fragilis at 33.3%. Salmonella, Shigella, or helminth eggs were not observed in all groups, but Entamoeba histolytica, Giardia intestinalis, Cryptosporidium, Rotavirus, Adenovirus, and Clostridium difficile toxin were found only in diarrhea patients. These findings support the hypothesis that Blastocystis and D. fragilis may be part of the healthy human gut microbiome.

Distribution of Blastocystis subtypes isolated from various animal hosts in Thailand

Blastocystis is a parasitic protist of a variety of hosts, including humans. Mapping the distribution of Blastocystis and its genetic variants across different host species can help us understand the epidemiology of this organism and its role in health and disease. This study aimed to identify subtypes of Blastocystis detected in different animal hosts in Thailand. A total of 825 fecal samples belonging to 18 vertebrate orders, 36 families, 68 genera, and 80 species were collected. Of these, 111 specimens were Blastocystis-positive by culture. Seventy-nine samples were subjected to small subunit (SSU) ribosomal DNA amplification by PCR, and reliable subtype data were obtained for 61 specimens. At least 14 subtypes (ST), namely ST1 to ST10, ST14/ST24/ST25 complex, ST23, ST26, and ST29 were detected. In addition, Blastocystis was found in tortoises. ST1 (3.2%) and ST5 (11.5%) were found in pigs, ST2 (1.6%) and ST3 (3.2%) in non-human primates, ST4 (14.7%) in rodents and ruminants, ST6 (4.9%), ST7 (30%), ST9 (1.6%), and ST29 (1.6%) in birds, ST8 (6.6%) in Green peafowl and East Asian Porcupine, and ST10 (4.9%), ST14/ST24/ST25 (9.8%), ST23 (1.6%) and ST26 (1.6%) in ruminants. The sequence recovered from the elongated tortoises (Indotestudo elongata) (3.2%) was phylogenetically placed within the reptilian cluster of Blastocystis, for which no subtype system is available yet. Of note, we did not obtain Blastocystis sequences from any of the many canids and felids sampled in the study, and our data are in support of host specificity of Blastocystis, according to both colonization and subtype distribution.

Epidemiology and subtype distribution of Blastocystis among asymptomatic volunteers in Korea: a multicenter study

Background: Blastocystis is a genus of intestinal, anaerobic protozoan parasites that can be isolated from humans, animals, and the environment. We aimed to determine the distribution of Blastocystis and subtypes (STs) using stool samples obtained from healthy volunteers at collection centers in Korea. Methods: A total of 478 stool samples from volunteers were collected at five collection centers throughout Korea. The presence of Blastocystis was determined using PCR based on the small subunit (SSU) rRNA gene, and Blastocystis STs were confirmed through sequencing of the SSU rRNA gene. Results: Molecular analysis revealed the presence of Blastocystis in 27 (5.6%) of the enrolled participants. Two STs were identified: ST3 (66.7%) and ST1 (33.3%). The positive rates of Blastocystis varied by geographical region, ranging from 1.2%–12.0%. ST3 was the predominant subtype in all centers except one, where only ST1 was isolated. Phylogenic analysis showed clustering based on ST, but no significant differences were found among the regions. There was no association between Blastocystis colonization and either age or sex of the participants. Conclusions: The results of this multicenter study demonstrated colonization by Blastocystis, mainly ST3, in the gastrointestinal tracts of asymptomatic individuals in Korea.

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 frequency and subtype distribution of Blastocystis sp. in humans and domestic animals in households in Heilongjiang Province, China

Blastocystis is an enteric protozoan able to infect humans and a large variety of animal hosts worldwide. It exhibits significant genetic diversity, with at least 17 subtypes (STs) identified to date, most of which have low host specificity. In the present study, a cross-sectional survey was conducted on Blastocystis infection among humans and domestic animals sharing habitats in northeastern China's Heilongjiang Province, in order to investigate the frequency and subtype distribution and to evaluate the risk of the zoonotic transmission of Blastocystis sp..Results show that the frequency was 10.5% (6/57), and three subtypes (ST1, ST2, and ST3) were found in humans; in animals, the frequency was 17.9% (46/257), and six subtypes (ST1, ST3, ST5, ST7, ST10, and ST26) were detected. A significant association between Blastocystis sp. infection and eating unwashed vegetables and fruits was found (P = 0.007). We found no effect on gender, age and season on Blastocystis sp. colonization. Phylogenetic analysis showed that Blastocystis ST7 sequences from chicken in two geographical locations formed two distinct clades. Alleles were identified using the Blastocystis 18S database, and a total of 10 different alleles were found in seven STs. Overlap of STs in humans and domestic animals (pig or cattle) was observed in Dongfanghong village. The findings of potentially zoonotic subtypes in domestic animals suggest that these animals may serve as reservoirs of human Blastocystis sp. infections. Multisectoral cooperation is needed to slow down the transmission of Blastocystis in domestic animals, minimize environmental contamination by Blastocystis cysts, and increase molecular epidemiological surveillance of Blastocystis sp. in humans and animals.

First detection of Blastocystis sp. in migratory whooper swans (Cygnus cygnus) in China

Blastocystis is a usual intestinal protist that always found in humans and various animals. Currently, the prevalence of Blastocystis in the migratory whooper swan (Cygnus cygnus) is unknown. In our research, we aimed to determine the occurrence, prevalence, subtype distribution and dynamic transmission mechanisms of Blastocystis in the migratory whooper swan in China. We also assessed the zoonotic potential of Blastocystis isolates, as well as possible routes of transmission and impact of this organism on One Health perspective. Fecal samples (n = 770) were collected from whooper swans inhabiting the Sanmenxia Swan Lake National Urban Wetland Park, China. The overall prevalence of Blastocystis was 11.6% (89/770). We identified 9 subtypes of Blastocystis sp., including 5 zoonotic subtypes [ST1 (Cakir et al., 2019 (8)), ST4 (Selma and Karanis, 2011 (4)), ST5 (Stensvold et al., 2009 (1)), ST6 (Fare et al., 2019 (5)) and ST7(58)] and 3 host-specific subtypes [ST10 (Zhao et al., 2018 (7)), ST14 (Tan et al., 2010 (2)), ST23 (Wang et al., 2018 (3)), and ST25 (Stensvold et al., 2009 (1))]. Subtypes ST4, ST5, ST6, ST10, ST14, ST23, and ST25 were first identified in the whooper swan. Among these subtypes, ST23 and ST25 were identified in birds for the first time, indicating that these subtypes are expanding their host range. So far, this is the first research reporting on the prevalence and subtypes distribution of Blastocystis in the migratory whooper swan in China. The findings obtained in this study will provide new insights into the genetic diversity and transmission routes of Blastocystis, and the possible public health concerns posed by this organism.

Prevalence and Subtype Distribution of Blastocystis Isolated from School-Aged Children in the Thai-Myanmar Border, Ratchaburi Province, Thailand

Blastocystis is one of the most common enteric protozoa that inhabits the intestinal tract of humans and different animals. Moreover, it has a worldwide geographic distribution. Its main mode of transmission is via the fecal-oral route. At present, 26 subtypes are widely distributed across both humans and animals. The current study aimed to determine the prevalence and subtype distribution of Blastocystis among school-aged children living on the Thai-Myanmar border, Ratchaburi province, Thailand. In total, 508 samples were collected from children at six schools. The prevalence of Blastocystis infection was amplified and sequenced in the 600 bp barcode region of the small-subunit ribosomal RNA (SSU rRNA). The overall prevalence of Blastocystis infection was 3.35% (17/508). ST3 (11/17) was the most predominant subtype, followed by ST1 (5/17) and ST2 (1/17). A phylogenetic tree was constructed based on the Tamura92+G+I model using the maximum-likelihood algorithm. Surprisingly, all sequences of the ST3-positive samples were closely correlated with the cattle-derived sequence. Meanwhile, all sequences of the Blastocystis ST1-positive samples were closely correlated with the human-derived sequence. Nevertheless, further studies should be conducted to validate the zoonotic transmission of Blastocystis. Based on our findings, personal hygiene and sanitation should be improved to promote better health in children in this area.

An update on the distribution of Blastocystis subtypes in the Americas

Blastocystis is an intestinal protist that presents worldwide distribution, colonizes animal and human hosts, and is classified into at least 34 ribosomal subtypes (STs). Herein, we conducted an update based on studies reporting Blastocystis-positive samples obtained from diverse hosts in the Americas. We described the distribution throughout the continent by assembling maps representing the distribution of STs and the most important 18S-rRNA alleles. Thirty-nine articles from the previous study, “A summary of Blastocystis subtypes in North and South America,” and forty-one additional articles from March 2019 to March 2022 were considered. The most common subtype described was ST3, representing the highest percentage of positive samples. Other recently identified STs include ST12, ST13, and ST16 in humans, and ST10, ST14, and ST17 in animals. Novel subtypes have also been described in this continent. We assembled and updated the distribution of Blastocystis in the Americas. We hope this delivers new understandings and knowledge of this microorganism’s prevalence and genetic diversity.

Prevalence and molecular subtyping of Blastocystis sp. in rabbits in Henan, Central China.

Species of Blastocystis Alexieff, 1911 are anaerobic intestinal protists found in humans and many kinds of animals that mainly cause diarrhea, abdominal pain and other clinical symptoms. At present, data on the prevalence and subtype diversity of species of Blastocystis in domestic rabbits are very limited. The purpose of this study was to characterise the infection rate and gene subtype distribution of Blastocystis sp. in domestic rabbits in Henan Province, Central China, and provide foundation for prevention and control of the disease caused by Blastocystis sp. in domestic rabbits. DNA was extracted from 286 fresh rabbit faecal samples collected from four areas of Henan Province, Central China. All DNA samples were screened using PCR and positive samples were sequenced to identify individual subtypes based on the small ribosomal subunit (SSU rRNA) gene. The overall infection rate of Blastocystis sp. in domestic rabbits in Henan Province was 15% (43/286). Three subtypes were identified, including ST1 (26/43, 60%), ST3 (5/43, 12%) and ST7 (12/43, 28%), all of which belonged to potentially zoonotic subtypes, ST1 was the dominant gene subtype. These results showed that infection with Blastocystis sp. was common in domestic rabbits in Henan Province, Central China, and was represented by zoonotic subtypes. Therefore, special attention should be paid to reduce the risk of transmission of Blastocystis sp. from domestic rabbits to humans.

Diversity of Blastocystis Subtypes in Horses in Colombia and Identification of Two New Subtypes

Blastocystis is a common intestinal protist in humans and animals worldwide. Wild and domestic animals are thought to be reservoirs of Blastocystis subtypes that also infect humans. There are limited studies on the prevalence and subtype distribution of Blastocystis in horses. In this study, 185 fecal samples were collected from horses (1 month to 17 years of age) in four regions of Colombia (Sabana de Bogotá, Costa Atlántica, Llanos Orientales, and Bogotá D.C.). Blastocystis presence and subtypes were determined by PCR and next generation amplicon sequencing. Eighty-one (43.8%) horses were positive for Blastocystis, with positive horses in all four regions. Molecular characterization identified 12 Blastocystis subtypes, 10 known subtypes (ST1, ST3–ST6, ST10, ST14, ST25, ST26), and 2 novel subtypes (ST33 and ST34). The validity of the novel subtypes was confirmed via phylogenetic and pairwise distance analyses of the full-length SSU rRNA gene sequences. Mixed subtype infections were common (55.6% of Blastocystis-positive horses). ST10 was the most prevalent subtype, present in 82.8% of Blastocystis-positive horses. Potentially zoonotic subtypes were identified in 88.9% of the Blastocystis-positive horses. This constitutes the most comprehensive study of Blastocystis in horses. Our findings indicate that horses harbor potentially zoonotic subtypes and could contribute to the transmission of Blastocystis to humans.

First Report ofBlastocystisspp. Infection in Pet Birds in Henan Province, Central China

Blastocystis spp. are common intestinal parasites found in humans and many kinds of animals. Blastocystis spp. infection is associated with a variety of symptoms, including diarrhea, abdominal pain, and chronic urticaria, among which asymptomatic infection is the most common. Among the 11 potentially zoonotic subtypes of Blastocystis spp., 9 subtypes have been reported in bird species. The purpose of this study was to detect the infection rate and gene subtype distribution of Blastocystis spp. in pet birds in Henan Province, Central China, to provide a foundation for preventing and controlling Blastocystis spp. in pet birds. Fecal DNA was extracted from 382 fresh fecal samples of pet birds collected from five areas in Henan Province, Central China. Twenty-three species of pet birds from four orders, from local pet trading markets, parks, and individuals, were sampled. All DNA samples were investigated by PCR, and positive samples were sequenced to analyze the gene subtypes based on the small ribosomal subunit (SSU rRNA) gene. Blastocystis spp. was detected in 0.8% of the samples. Further DNA sequencing and phylogenetic analyses resulted in the identification of two known zoonotic subtypes, ST1 (n = 2) and ST7 (n = 1). As far as we know, this is the first time that ST1 subtype has been reported in Chinese birds. It is found that pet birds may be the hosts of zoonotic Blastocystis spp. subtypes, and the role of birds in transmitting Blastocystis spp. to humans needs to be further studied.