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Blastocystis is the most common gastrointestinal protozoan parasite of humans and many vertebrates. This study was carried out to investigate the prevalence and determination subtype (ST) of Blastocystis in domestic ruminants of Shahrekord County, southwestern Iran. In this descriptive cross-sectional study, 330 ruminant fecal samples (107 cows, 115 sheep, and 108 goats) were evaluated by parasitological methods (direct wet mount microscopic examination and formalin-ether concentration), Giemsa staining, In vitro xenic culture (The modified Dobell and Laidlaw culture method), polymerase chain reaction, and sequencing from 2018 to 2019, then data were analyzed using SPSS software version 21. The overall Blastocystis positive in ruminants was 14.2% and the frequency of Blastocystis sp. in cattle, sheep, and goats were 0.93%, 17.4%, and 24.1% respectively. Molecular diagnosis techniques revealed that ruminants were infected with four STs (genotypes) of Blastocystis including ST5(21.3%), ST7(2.1%), ST10(17.1%) and ST14(57.4%). Also, the STs identified in cows were ST10, and the observed STs in sheep were ST5 (40%), ST7 (3%), ST10 (5%), ST14 (45%), and one unknown subspecies. Goats were infected by ST5 (7.7%), ST10 (23.1%), and ST14 (69.2%). In this study, ST14 was identified as the most common subtype of Blastocystis sp. that was not common between humans and livestock, meanwhile, ST5 and ST7 are common between humans and animals accounted 21.3% and 2.1% of the positive cases, respectively, and reinforces the hypothesis that ruminants are reservoirs of blastocystosis in humans., (© 2024. The Author(s).)

Background: Blastocystis, a widely distributed zoonotic protozoan infecting both humans and numerous animals, remains poorly understood with its potential medical and veterinary significance. This study examined the molecular occurrence and genetic variation of Blastocystis in children and calves in Bangladesh to explore cross-species transmission and disease burden., Methods: In total, 998 DNA samples were investigated, comprising 299 stool DNA from children and 699 fecal DNA from calves, using polymerase chain reaction and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene., Results: This study detected Blastocystis in 5.35% of the children and 14.74% of the calves. While slight variations in occurrence rates were observed across different study variables, none were statistically significant. The occurrence was highest among children under 5 years and calves aged 1-3 months. Regarding breed, the Holstein Friesian cross and the Jersey cross exhibited higher rates of infection. Conversely, occurrences were lower among children and calves in Gazipur district. The remaining parameters displayed nearly equivalent percentages of Blastocystis. The subtypes identified in children included ST1, ST3, and ST4, with ST1 comprising 50% of them. ST3 and ST4 were also found in calves, alongside ST10 (55.34%) being the most prevalent. Other subtypes found in calves were ST14, ST21, and ST24-ST26., Conclusions: This study found that Blastocystis is more common in calves than in children in Bangladesh, with genetic diversity of nine subtypes. The common occurrence of identical variants of two subtypes in both populations suggests potential zoonotic transmission, highlighting the necessity for further molecular investigations and comprehensive measures within the One Health framework to mitigate public health risks., (© 2024. The Author(s).)

Blastocystis sp. and Dientamoeba fragilis are intestinal protists, which are common worldwide, but the pathogenic role of these organisms in gastrointestinal diseases is still controversial. This study aimed to investigate the frequency of Blastocystis sp. and D. fragilis in stool samples from adult patients with celiac disease (CD) by using conventional and molecular methods. A total of 75 patients with CD and 75 healthy individuals were included in this study. Fresh stool specimens collected from each individual were analyzed by conventional and molecular methods. The overall prevalence of Blastocystis sp. and D. fragilis was 41.3% (31/75) and 24% (18/75) in patients with CD, and 46.7% (35/75) and 13.3% (10/75) in healthy controls, respectively. There was no statistically significant difference in the prevalence of Blastocystis sp. and D. fragilis between CD patients and healthy individuals. Blastocystis sp. subtypes were identified in 20 CD and 16 control patients and the overall subtype distribution was observed as ST1 13.9%, ST2 30.6%, and ST3 55.6%. The prevalence of Blastocystis sp. and D. fragilis in adults with CD is similar to the prevalence of protozoa in healthy adults. In this study, the most prevalent Blastocystis subtype was ST3 and the most frequent allele was a34 in both CD patients and healthy individuals. No significant difference was found between the two groups in terms of the detection rates of Blastocystis sp. and D. fragilis, and it is thought that both protists may be colonisers of the intestinal microbiome., Competing Interests: Declaration of competing interest Not applicable., (Copyright © 2024. Published by Elsevier B.V.)

Background: Intestinal parasitic infections are the most common infectious diseases among Southeast Asian migrant workers in Taiwan, especially for infections with Blastocystis hominis. However, little is known about the impact of Blastocystis subtypes (STs) on the gut microbiota., Methods: We retrospectively evaluated the prevalence of intestinal parasites in a teaching hospital in Northern Taiwan in the period of 2015-2019. Blastocystis-positive stool specimens were collected for ST analysis by polymerase chain reaction in 2020. Intestinal microbiota analyses of different Blastocystis STs and Blastocystis-free individuals were conducted by 16S rRNA sequencing., Results: A total of 13,859 subjects were analyzed, of which 1802 cases (13%) were diagnosed with intestinal parasitic infections. B. hominis infections were the most prevalent (n = 1546, 85.7%). ST analysis of Blastocystis-positive samples (n = 150) indicated that ST1 was the most common type, followed by ST3, ST4, ST2, ST7, and ST5. Different Blastocystis STs (ST1, ST3, and ST4) were associated with distinct richness and diversity of the microbiota. Taxonomic profiles revealed that Akkermansia muciniphila was significantly enriched for all analyzed Blastocystis STs, whereas Holdemanella biformis was more abundant in the Blastocystis-free group. Additionally, Succinivibrio dextrinosolvens and Coprococcus eutactus were specifically more abundant in ST3 carriers than in non-infected individuals., Conclusion: This study demonstrates that A. muciniphila is positively associated with all Blastocystis STs, while H. biformis was negatively associated with them. Several bacteria were enriched in specific STs, highlighting the need for further microbiota analysis at the ST level to elucidate the pathogenicity of Blastocystis., Competing Interests: Conflict of interest The authors declare no conflicts of interest., (© 2023 The Authors. Published by Elsevier B.V. on behalf of Chang Gung University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Blastocystis is an intestinal protist frequently identified in humans and other animals, though its clinical significance remains controversial. This study aimed to determine the prevalence and genetic diversity of Blastocystis in faecal samples from symptomatic (n = 55) and asymptomatic (n = 50) individuals seeking medical care in Meknes, Morocco. Detection of the protist was accomplished through coproparasitological examination and culture in Jones medium. Culture-positive samples were subjected to molecular analyses (PCR and Sanger sequencing) based on sequences of the small subunit ribosomal RNA gene. Epidemiological questionnaires on demographics and potential risk factors were collected from participating patients. The overall Blastocystis infection rate was 51.4% (54/105), with no differences between symptomatic (52.7%, 29/55) and asymptomatic (50.0%, 25/50) individuals. Sequence analyses identified three Blastocystis subtypes, with ST3 being the most prevalent (42.0%), followed by ST1 (34.0%), and ST2 (12.0%). Regarding intra-subtype diversity, allele 4 was found within ST1; alleles 11/12 and alleles 34/36 (alone or in combination) were identified within ST2 and ST3 respectively. Allele 34 in ST3 (40.8%) and allele 4 in ST1 (34.7%) were the most common genetic variants circulating in the surveyed clinical population. A statistically significant association between ST2 and the presence of flatulence was observed. This is the first study assessing the epidemiology and genetic diversity of Blastocystis sp. in the Meknes region, Morocco., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Parasites Entamoeba spp., Enterocytozoon bieneusi and Blastocystis are prevalent pathogens causing gastrointestinal illnesses in animals and humans. Consequently, researches on their occurrence, distribution and hosts are crucial for the well-being of both animals and humans. Due to the confined spaces and frequent interaction between animals and humans, animal sanctuaries have emerged as potential reservoirs for these parasites. In this study, the wildlife sanctuary near the Huang Gorge of the Qinling Mountains in northwest China is chosen as an ideal site for parasite distribution research, considering its expansive stocking area and high biodiversity., Results: We collected 191 fecal specimens from 37 distinct wildlife species and extracted genomic DNA. We identified these three parasites by amplifying specific gene regions and analyzed their characteristics and evolutionary relationships. All the parasites exhibited a high overall infection rate, reaching 90.05%. Among them, seven Entamoeba species were identified, accounting for a prevalence of 54.97%, with the highest infection observed in Entamoeba bovis. In total, 11 Enterocytozoon bieneusi genotypes were discovered, representing a prevalence of 35.08%, including three genotypes of human-pathogenic Group 1 and two novel genotypes (SXWZ and SXLG). Additionally, 13 Blastocystis subtypes were detected, showing a prevalence of 74.87% and encompassing eight zoonotic subtypes. All of the above suggests significant possibilities of parasite transmission between animals and humans., Conclusions: This study investigated the occurrence and prevalence of three intestinal parasites, enhancing our understanding of their genetic diversity and host ranges in northwest China. Furthermore, the distribution of these parasites implies significant potential of zoonotic transmission, underscoring the imperative for ongoing surveillance and implementation of control measures. These efforts are essential to mitigate the risk of zoonotic disease outbreaks originating from wildlife sanctuary., (© 2024. The Author(s).)

Background: Blastocystis is a unicellular eukaryote commonly found in the intestinal tract of humans and other animals. The prevalence of Blastocystis has been investigated in both developed and developing countries, yet its occurrence and distribution in rural locations has been less studied. Herein, we aimed to examine the distribution of Blastocystis colonization in Thai adults representing background populations along a rural/peri-urban gradient, as well as associations between colonization and personal characteristics., Methodology: A total of 238 participants were recruited from rural and peri-urban areas situated in three provinces. The presence of Blastocystis in feces was evaluated using PCR and qPCR. Information on gender, age, region (province), rural/peri-urban location, and body mass index (BMI) was collected., Principal Findings: The overall rate of Blastocystis carriage was 67.2%. Univariate analysis revealed significant associations between Blastocystis carriage and region (p<0.05), location (p<0.001) and age group (p<0.05). Logistic regression analysis revealed that rural/peri-urban location and BMI were significantly associated with Blastocystis carriage. Nine subtypes (ST1-ST7, ST10 and ST23) were identified with ST3, ST7 and ST1 as the most abundant ones, in this order. The greatest diversity of subtypes, in terms of numbers, was found in the middle aged group (nine subtypes), while the least diversity was found in the young adult and obese (three subtypes each) groups., Conclusions: This study increases the understanding of the epidemiology of Blastocystis colonization and its association with population parameters and characteristics in middle-income countries., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Jinatham et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Blastocystis inhabits the digestive tracts of a diverse range of hosts. Transmission patterns, including host specificity, and the clinical and public health significance of Blastocystis in humans remain poorly understood. This study aimed to investigate the distribution and genetic diversity of Blastocystis in herbivorous and carnivorous reptiles in Eastern Thailand. A total of 501 faecal samples were collected from 363 iguanas, 79 bearded dragons, 50 tortoises, and nine snakes in an animal breeding farm in Chonburi Province, Eastern Thailand. Detection and differentiation of Blastocystis was based on amplification, sequencing, and phylogenetic analysis of specific small subunit (SSU) ribosomal RNA genes from faecal DNA extracted from the samples. Altogether 101/501 samples (20 %) were polymerase chain reaction (PCR) and sequencing-positive for Blastocystis, 90 (89 %) of which were from iguanas; the remaining positive samples were from African spurred tortoise (n=6), Bearded dragon (n=3), Leopard tortoise (n=1), and Red-footed tortoise (n=1). Phylogenetic analysis revealed that most of the Blastocystis sequences from iguanas were largely similar, and they were distinct from those of the tortoises. Subtype 17 was found in the three bearded dragons and likely reflected Blastocystis from prey animals. This is the largest survey of Blastocystis in reptiles to date. Remarkable differences in Blastocystis colonization rates and genetic diversity were observed between iguanas and other reptile orders, and what was considered Blastocystis colonization was only observed in herbivorous reptiles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Migratory birds play an important role in the cross-regional transmission of zoonotic pathogens. Assessing the presence of zoonotic pathogens carried by migratory birds is critical for disease control. However, information about Blastocystis infection in the migratory birds is very limited. Thus, we conducted this study with the aim to explore the occurrence, prevalence and subtyping of Blastocystis in four breeds of migratory birds in northeastern China. From October 2022 to April 2023, a total of 427 fresh fecal samples were obtained from four breeds of migratory birds in five nature reserves in northeastern China, and screened for Blastocystis by PCR amplification. Twenty-one (4.92 %) of the studied samples were confirmed Blastocystis-positive, and two known zoonotic subtypes ST6 and ST7 were founded, with ST7 being the major subtype. Until now, we firstly reported the infection status and subtyping of Blastocystis in the migratory Greater White-Fronted Goose, White Stork, Oriental White Stork and Bean Goose in China. More importantly, these findings present further data on the genetic diversity and transmission routes of Blastocystis and further arouse public health concerns about this organism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Blastocystis is one of the most common zoonotic intestinal protozoa with global distribution and can cause gastrointestinal syndrome mainly characterized by diarrhea. School children are the main susceptible population. No epidemiological data on Blastocystis among school children in Hainan, the only tropical island province in China. Between March 2021 and June 2023, 1973 fecal samples were collected from school children across three regions in Hainan province. Blastocystis was examined by amplifying the small subunit ribosomal RNA (SSU rRNA) gene via polymerase chain reaction (PCR), and subtypes were identified through DNA sequencing and phylogenetic analysis. The overall prevalence of Blastocystis was 7.3 % (144/1973). The differences in infection rates across different regions, nationalities, and educational stages are statistically significant (P < 0.001). Five subtypes were identified, of which ST3 was the dominant subtype (60.4 %; 87/144), followed by ST1 (27.8 %; 40/144), ST7 (10.4 %; 15/144), ST6 (0.7 %; 1/144), and ST2 (0.7 %; 1/144). 42 known sequences and 15 novel sequences were identified including eight new variations of the ST1 (ST1-16∼ST1-23) with similarities ranging from 98.3 % to 99.78 % and seven new variations of the ST7 (ST7-7∼ST7-13) with similarities ranging from 97.7 % to 99.79 % by intra-subtype genetic polymorphisms analysis. The results evaluate the public health risks of Blastocystis among school children in Hainan and the sources of infection were discussed, providing important basic data for the effective prevention and control of intestinal parasitic diseases in Hainan., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objective: Recent studies determined that the amoeboid form of Blastocystis acts as a factor in stimulating the host's immune responses and ultimately results in urticaria and other skin disorders. The present study was conducted in order to determine the prevalence of Blastocystis in people referred to Bushehr city health centers and the relationship of this parasite with urticaria., Methods: Fecal samples were collected from 180 males and females referred to Bushehr health centers and a questionnaire containing demographic information was completed for each person. Samples were examined by preparing direct smear (wet mount) and then formalin-detergent sedimentation techniques. Data were analyzed using SPSS 22.0 software and chi-square test., Results: The results showed that 11.1% of cases infected with Blastocystis and 55% of patients with Blastocystis had various gastrointestinal symptoms. Statistical analysis showed that there was no significant relationship between infection with some demographic factors such as sex, age, literacy level and residence, but this was significant with some clinical symptoms such as itching and urticaria., Conclusion: Despite the existence of conflicting information and many ambiguities about the Blastocystis , this emerging pathogen is very important in terms of causing allergic and skin disorders in sufferers, therefore, it is necessary that patients with urticaria be evaluated for Blastocystis along with other diagnostic procedures and physicians should request a test before any medical intervention. Thus, diagnosis and treatment of these people can play an important role in improving the health of society.

Introduction and Objective: Intestinal parasitoses are important causes of morbidity and mortality, especially in immunocompromised individuals. In patients with chronic renal insufficiency (CRI), the accumulation of non-excreted metabolites leads to uraemia, which induces a state of immunodeficiency, increasing the incidence of infections. The aim of the study was molecular screening for enteric protozoa in patients with chronic renal insufficiency., Material and Methods: A total of 53 samples were collected in January 2023 from patients undergoing dialysis at Logman Ltd. Nephrodialysis Centre in Košice, Slovakia. Samples were examined by polymerase chain reaction (PCR) for the presence of Cryptosporidium parvum / Cryptosporidium hominis , Giardia intestinalis , Microsporidia spp., and Blastocystis sp., Results: From the 53 samples, the only pathogen identified by PCR was Blastocystis sp., in 13 patients (24.5 %). Sequence analyses confirmed that the most prevalent subtype (ST) among patients was ST 3 (n=9, 69.2%), followed by ST 1 (n=3, 23.1%) and ST 2 (n=1, 7.7%)., Conclusions: Molecular methods for the detection of microscopic enteric parasites are not used as a first-line diagnostic method in Slovakia. In immunocompromised patients, diarrhoea can be caused not only by a chronic disease or therapy but can also be a result of an ongoing underdiagnosed infection. Early diagnosis leads to targeted therapy and subsequent partial improvement of the quality of life. This study also shows the first insights into Blastocystis sp. subtype distribution in humans in Slovakia.

Urticaria is a skin rash with several etiologic factors, including infectious agents. Blastocystis hominis is an intestinal protozoan parasite that has been linked to urticaria and skin lesions. The aim of this work was to investigate the association between B. hominis infection and chronic urticaria. In a case-control study, stool samples were obtained from 94 patients with chronic urticaria as case group and 285 healthy individuals as control group. Urticaria activity score 7 (UAS7) was used to score the severity of urticaria, classified as mild, moderate and intense. All stool samples underwent routine stool examinations, as well as polymerase chain reaction (PCR) for the detection of B. hominis. Molecular detection was carried out using the small subunit ribosomal RNA (SSU-rRNA) gene and the parasite subtypes were determined by sequencing. The rate of B. hominis infection was 21.3% (20 out of 94) and 17.2% (49 out of 285) between the case and control groups, respectively (p = 0.463). Three subtypes of B. hominis, including ST-1, ST-2 and ST-3, were detected in the case and control groups (ST-1 = 30% vs. 8.3%, ST-2 = 40% vs. 25% and ST-3 = 30% vs. 66.6% in the case and control group, respectively), which was statistically significant (p = 0.00001). However, no statistical differences were found between the severity of the urticaria and the B. hominis subtypes (p = 0.533). This study revealed a higher prevalence (but not significant) of B. hominis infection among patients with urticaria than healthy individuals. However, the results did not find a significant association between the subtypes of B. hominis and the severity of urticaria., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Domestic dogs and cats can serve as a source of environmental contamination with Toxocara spp. and Blastocystis spp., and this represents a neglected public and veterinary health problem. We assessed the microscopic and molecular prevalence of these species in a locality in Algeria and identified the associated risk factors. The faeces of 225 dogs and 78 cats were collected in Mitidja between March and July 2022. The samples were analysed by coproscopy and by polymerase chain reaction (PCR) targeting the Internal Transcribed Spacer 2 (ITS2) and Small Subunit Ribosomal (SSU-RNA) of T. canis and Blastocystis spp. respectively. The overall microscopic prevalence of Toxocara spp. in dogs and cats was 9.78 ± 1.98% and 12.82 ± 7.42%, respectively. The rate of Blastocystis spp. was 15.11 ± 2.39% and 15.38 ± 4.08% in dogs and cats, respectively while the molecular prevalence of T. canis in dogs was 4.89 ± 1.44% and in cats 1.28 ± 1.27%; the prevalence of Blastocystis spp. was 41.78 ± 3.29% and 34.62 ± 5.39% in dogs and cats, respectively. Phylogenetic and phylogeographic analyses identified the presence of the H1 subtype of T. canis in dogs, and the ST1 subtype of Blastocystis in dogs and cats. Dogs with clinical signs were more likely to be infected with T. canis (OR 6.039, P < 0.05) than healthy dogs. This study demonstrates that dogs and cats are carriers of Toxocara spp. and Blastocystis spp. and are therefore a source of environmental contamination. Veterinarians and human health professionals should work together to implement control strategies as part of a "One Health" approach to improving animal health and reducing the risk of transmission to humans., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A total of 360 fecal samples were randomly collected from 150 cattle, 150 sheep, and 60 humans (30 people with close animal contact and 30 individuals without close animal contact) at 10 farms in Ilam, western Iran from June 2022 to August 2023. All samples were directly examined for Blastocystis by zinc sulfate flotation, followed by microscopic observation. Positive samples were further subtyped using conventional PCR and sequencing methods. A mean prevalence of 5.3% (16/300) was estimated for Blastocystis infection among examined animals, with 6% and 4.7% for cattle and sheep, respectively. Among the people who had close and non-close animal contact, 16.7% (5/30) and 3.3% (1/30) were infected with Blastocystis, respectively (p < 0.05). All 22 positive samples were successfully sequenced at the SSU rRNA locus. Accordingly, Blastocystis isolates infecting domestic animals in Ilam belonged to the four STs (ST1-ST3, and ST10). Of the 16 animal isolates, nine sequences (four ST10, three ST3, and two ST1) were related to cattle, and seven sequences (three ST10, two ST3, and two ST2) were isolated from sheep. Among the six human isolates, ST3 was the most predominant ST, followed by STs 1, 2, 6, and 7 (one case each). Of note, ST1-ST3 were isolated in various farms both from animals and their breeders, which indicates the possible circulation of these STs between animal and human populations., (© 2024 International Society of Protistologists.)

Blastocystis sp. is a protozoan parasite that infects the intestines of humans and animals, causing chronic diseases such as skin rashes, abdominal pain, and irritable bowel syndrome. A survey was conducted to determine the prevalence and genetic diversity of Blastocystis sp. infection in cattle, in Hebei Province, China. 2746 cattle fecal samples were collected from 11 cities in Hebei Province and analyzed using polymerase chain reaction targeting the Blastocystis sp. barcoding gene. MEGA, PhyloSuite, and PopART were used to analyze the subtype, sequence signature, pairwise genetic distance, and genetic diversity indices. The results showed that the Blastocystis sp. detection rate was 12.60% (346/2746). The infection rate in different herds was affected by region, age, breeding mode, and variety; that is, the infection rates in areas of southern Hebei, cattle under one year old, intensive raising, and dairy cattle were higher than the infection rates in northern Hebei, cattle over one year old, scatter feeding, and beef cattle. Seven Blastocystis subtypes were identified, namely, ST1, ST2, ST5, ST10, ST14, ST21, and ST26; ST10 was the dominant subtype, and ST14 was the second most common subtype. A total of 374 polymorphic and conserved sites were obtained, including 273 invariable (monomorphic) sites and 101 variable (polymorphic) sites, accounting for 27.01% of all nucleotides. The nucleotide diversity index (Pi) was 0.07749, and the haplotype (gene) diversity index (Hd) was 0.946. This study provides the first comprehensive information on the epidemiological situation of Blastocystis sp. infection in cattle from Hebei Province, China, and revealed rich genetic diversity of Blastocystis sp., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Blastocystis is a protist that is distributed in the gut tract of humans and animals. However, the reports about Blastocystis infection in Tibetan antelope are scarce. We collected 173 Tibetan antelope feces samples from Xinjiang, Qinghai and Xizang, and amplified the SSU rRNA gene of 600 bp region of Blastocystis in our research. Fifty-one samples in total were positive for Blastocystis, with all subtypes being ST31. The lowest prevalence of Blastocystis was observed in Xizang (2/20, 9.1%), followed by Qinghai (18/92, 16.4%), Xinjiang (31/61, 33.7%). The highest prevalence of Blastocystis in Tibetan antelope was detected during the summer was (19/30, 38.8%). This is the first research work regarding the Blastocystis subtypes ST31 in Tibetan antelope. Our research provides information for future researches on the distribution of this Blastocystis subtype and the control of Blastocystis infection., Competing Interests: Declaration of competing interest The authors confirm that they have no known financial or interpersonal conflicts that would have appeared to have an impact on the research presented in this study., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Blastocystis sp. is a zoonotic protozoan parasite, and there is limited information about its molecular prevalence and subtypes (STs) distribution in camels globally, especially in Iran., Objectives: This study aimed to examine the prevalence, STs distribution, and zoonotic potential of Blastocystis sp. in one-humped and two-humped camels in Ardabil province, northwestern Iran., Methods: A PCR-sequencing tool using the SSU rRNA gene was employed to examine the occurrence and genetic variation of Blastocystis sp. in 150 faecal samples from Bactrian (Camelus bactrianus, 50 samples) and Dromedary (Camelus dromedarius, 100 samples) camels in Ardabil province., Results: The overall prevalence of Blastocystis sp. in camels was determined to be 12% (18/150) through microscopy and PCR analyses. Phylogenetically, this study identified three distinct zoonotic STs: ST7, ST10, and ST14. ST10 was the most prevalent, comprising 50% (9/18) of the isolated STs from camels. ST14 closely followed with 38.9% (7/18), while ST7 made up 11.1% (2/18) of the total STs. In brief, ST10, ST14, and ST7 represented 50% (7/14), 35.7% (5/14), and 14.3% (2/14) of the Blastocystis-positive cases in one-humped camels, respectively. Further, each of the ST10 and ST14 accounted for 50% (2/4) of the Blastocystis-positive samples in two-humped camels. An analysis of the available data reveals that out of the 37-44 identified Blastocystis STs, 15 (ST1-ST7, ST10, ST14, ST15, ST21, ST24, ST25, ST26, and ST30) have been reported in camels. The predominant STs observed are ST10 and ST14. Furthermore, among the 15 zoonotic STs (ST1-ST10, ST12-ST14, ST16, and ST23) of Blastocystis reported thus far, nine zoonotic STs (ST1-ST7, ST10, and ST14) have been found in camels., Conclusions: These findings indicate that camels serve as a proper reservoir for a diverse array of Blastocystis STs and thereby can play a significant role in the transmission of this protozoan infection to humans, animals, and water reservoirs., (© 2024 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

Dientamoeba fragilis and Blastocystis sp. are single-celled protozoan parasites of humans and animals. Although they are found in the intestines of healthy hosts, the pathogenicity of them is still unclear. To date, there is no report on D. fragilis and only two studies (without subtyping) on the occurrence of Blastocystis sp. in Musca domestica. In this study, fly samples were collected from livestock farms and their surroundings in the Kirsehir province (Central Anatolia Region) of Türkiye from May to August 2023. A total of 150 microscopically identified M. domestica samples were analyzed for the detection of D. fragilis and Blastocystis sp. molecularly. The overall prevalence of Blastocystis sp. and D. fragilis in M. domestica was determined to be 3.3% (5/150) and 8.0% (12/150), respectively. The SSU rRNA gene sequences of the isolates indicated genotype 1 of D. fragilis. Eleven isolates were identical and represented a single isolate (KAU-Dfrag1). BLAST analysis of KAU-Dfrag1 indicated identity with the isolates reported from humans, cattle, sheep, and budgerigars. The other isolate (KAU-Dfrag2) was polymorphic at two nucleotides from KAU-Dfrag1 and three nucleotides from known genotypes from GenBank and represented a variant of genotype 1. The Blastocystis sp. isolates were found to be identical and represent a single genotype (KAU-Blast1). BLAST analysis revealed that the KAU-Blast1 genotype belonged to the potentially zoonotic subtype 5 (ST5) and exhibited the highest genetic identity (ranging from 99.4 to 99.6%) with pigs, cattle, and sheep from different countries. Our study provides the first data on the molecular prevalence, epidemiology, and genotypic characterization of D. fragilis and Blastocystis sp. in M. domestica., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Blastocystis is a ubiquitous intestinal protist in humans and animals worldwide. The traditional livestock free-roaming raising system in rural communities increases the risk of infection with contact with a wider range of pathogens transmitted via the faecal-oral route associated with that wildlife-livestock-human interface. However, no studies have been conducted to determine the occurrence and subtype distribution of Blastocystis in livestock in Portugal. Here, we collected 180 faecal samples from herbivore livestock (cattle, goats, horses, and sheep) in different regions of the country to investigate Blastocystis prevalence and subtype diversity using PCR and next-generation amplicon sequencing. Blastocystis was present in 40.6% (73/180; 95% CI: 33.31-48.11) of the samples (goats, 81.0%; sheep, 60.9%; cattle, 32.2%). None of the horse samples were Blastocystis-positive. Eighteen subtypes were detected (ST1-ST3, ST5-ST7, ST10, ST13, ST14, ST21, ST23-ST26, ST30, ST42-ST44). Mixed infections were detected in 97.3% of the Blastocystis-positive samples. Potentially zoonotic subtypes were identified in 75.0%, 96.4%, and 100% of the Blastocystis-positive specimens collected from cattle, sheep, and goats, respectively. These results demonstrate that cattle, sheep, and goats harbour a high diversity of Blastocystis subtypes in the study regions. Importantly, our data provide novel molecular evidence strongly suggesting that some Blastocystis STs/ST subgroups may have differential host specificity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aims: The present study aimed to identify any potential association between IL-1β and TNF-α gene polymorphism and the risk of Blastocystis infection as well as co-infection of Blastocystis with Helicobacter pylori (H.pylori)., Methodology: A total of 314 stool samples were collected and examined microscopically for the detection of parasitic infection. DNA was extracted from all samples and utilized to identify Blastocystis molecularly. Positive samples were used for H. pylori detection by rapid tests and PCR. Moreover, we investigate polymorphism in the TNF-α gene at position -1031T/C, -308 G/A, and IL-1β at position +3954C/T using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay., Results: Out of the 314 stool samples, Blastocystis was detected in 93 (29.6 %); among them, 54 (58.1 %) had a mixed infection of Blastocystis with H. pylori. The TT genotype of the IL-1β gene at position +3954 was significantly higher in Blasocystis-infected patients than in uninfected patients (17.2% vs. 6.3 %, P = 0.02), which might be considered a risk factor (OR = 3.2; CI =1.21-8.52). The TNF-α at position -1031 TT genotype was significantly higher in Blastocystis-infected patients than uninfected patients (44.1% vs. 10.8 %, P< 0.0001). The T allele (OR= 2.67; CI=1.51-4.72, P = 0.0008) might be considered a risk factor. The TNF- α at position -308 AA genotype is higher in Blasocystis infected than uninfected (17.2% vs 7.2 %, P = 0.03). TNF-α -308 AA (OR = 2.72; CI = 1.08-6.89) and A allele (OR= 1.46; CI= 0.797-2.66) might be considered risk factors. The TNF- α at position -308 G/A showed that the GG is the most frequent genotype in Blastocystis with H. pylori-positive patients with a significant association (P = 0.004), as well as the G allele (P = 0.02). The G allele (OR=1.924; CI= 1.071-3.454) might be considered a risk factor for co-infection of Blastocystis and H. pylori., Conclusion: SNPs (-1031 T/C and -308 G/A) of the TNF-α and (+3954 C/T) of the IL-1β may be a useful marker in the assessment of the risk of Blastocystis infection, and TNF-α at position -308 G/A) may be a predictor for co-infection of Blastocystis with H. pylori., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Blastocystis spp. are the most common intestinal protozoan parasites detected in human stool samples. While identified long before today, its pathogenicity remains controversial. It is generally asymptomatic but in symptomatic cases, many gastrointestinal symptoms, especially diarrhea, have been associated with Blastocystis infection. In recent years, the relationship between the symptoms observed in cases and Blastocystis subtypes (ST) has been reported. The aim of this study was to detect Blastocystis in diarrheal cases admitted to the Aydın Adnan Menderes University Faculty of Medicine, Department of Parasitology Laboratory, to determine subtypes and allele diversity and to investigate its relationship with clinical symptoms. For this purpose, diarrheal stool samples of 200 cases were included in the study and their demographic characteristics (age, gender, residence) and clinical findings (abdominal pain, dyspepsia, nausea-vomiting, weakness, weight loss, anal itching, rash, urticaria) were recorded. Blastocystis was detected by direct microscope method (DM) and by molecular analyses which were performed with polymerase chain reaction (PCR). Subtype diversity was determined based on DNA sequence analysis by PCR targeting the Blastocystis ribosomal ribonucleic acid small subunit (SSU rRNA) gene. In addition, alleles related to Blastocystis subtypes were determined and statistically compared between all data and clinical findings. In the current study, Blastocystis was detected in 31 (15.5%) samples by DM and in 35 (17.5%) samples by PCR specific to the Blastocystis SSU rRNA gene among 200 diarrheal stool samples. No statistical difference was detected between Blastocystis and demographic characteristics. Dyspepsia and nausea-vomiting symptoms differed significantly in cases with Blastocystis compared to negative ones (p= 0.0025, p= 0.0498). Blastocystis subtype was detected in 33 samples by SSU rRNA sequence analysis, and the subtype distribution was ST1 (n= 10, 30.3%), ST2 (n= 4, 12.1%) and ST3 (n= 19, 57.6%). In the statistical evaluation between clinical findings and Blastocystis subtypes, a relationship was found between dyspepsia and Blastocystis ST3 (p= 0.0039). The allele diversity of Blastocystis subtypes was determined as allele 4 (10/10) in all ST1, allele 11 (2/4) and 12 (2/4) in ST2, allele 34 (14/19), 36 (4/19), and 38 (1/19) in ST3. In conclusion, our study provides important data on the molecular epidemiological characteristics of the Blastocystis by determining positivity, subtypes and alleles in diarrheal cases. Therefore, within the scope of the one health approach, comprehensive molecular epidemiological studies are required to determine the presence and genotypes of Blastocystis in human, animal and environmental samples.

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., (© 2023 International Society of Protistologists.)

A total of 500 fecal samples were collected from Equus animals in six different cities (Ardabil, Namin, Nir, Meshginshahr, Germi, and Khalkhal) of Ardabil Province, northwestern Iran, with 200 samples from horses, 200 from donkeys, and 100 from mules. Of the horse samples, 100 were from racing horses under special monitoring and care, while the remaining 100 were from non-racing horses, including those used for herding or in rural areas. All fecal samples were examined for the presence of Blastocystis sp. using PCR amplification of the SSU rRNA gene's barcode region after DNA extraction. The molecular prevalence of Blastocystis infection in Equus animals was 7.6% (38/500). Blastocystis was more common in horses [11.5% (23/200)] than in donkeys [5.5% (11/200)] and mules [4% (4/100)] (P > 0.05). Compared to racing horses [3% (3/100)], non-racing/rural horses [20% (20/100)] exhibited a substantially higher prevalence of Blastocystis (P < 0.05). The prevalence of Blastocystis in diarrheal samples and younger animals was remarkably higher than in formed samples and older animals, respectively (P < 0.05). No significant difference in Blastocystis infection prevalence was found between the genders of examined animals (P > 0.05). In Equus animals, 38 Blastocystis isolates included eight STs: ST10 [31.6% (12/38)], ST1 [21.1% (8/38)], ST2 [15.8% (6/38)], ST3 [10.5% (4/38)], ST4 [7.9% (3/38)], ST7 [5.2% (2/38)], ST14 [5.2% (2/38)], and ST6 [2.6% (1/38)]. These results suggest that Equus animals act as a proper reservoir for numerous Blastocystis STs, consequently playing a crucial part in the spread of this protozoan infection to humans, animals, and water reservoirs., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: 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., Methods: 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., Results: 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., Conclusion:  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., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Purpose: The presence of Blastocystis sp. is commonly observed in humans and different animals, displaying a wide range of genetic variations with the discovery of multiple subtypes (STs). However, the prevalence and distribution of these STs in edible marine fish and marine mammals remain uncertain. This study marks the first survey conducted in Iran and the second global molecular investigation to examine the occurrence and STs distribution of Blastocystis in various species of edible marine fish., Methods: This study screened 200 fresh intestinal contents from 10 well-known fish species (Narrow-barred mackerel, Indo-pacific king mackerel, Tigertooth croaker, Silver pomfret, Black pomfret, Longtail tuna, John's snapper, Blackspotted croaker, Four-finger threadfin, and Javelin grunter) in southern Iran, caught in the Persian Gulf. All collected samples were evaluated by microscopy and SSU-PCR methods., Results: Based on both microscopy and PCR, the overall prevalence of Blastocystis sp. in evaluated fish species was 2% (4/200). In brief, Blastocystis sp. was reported from Narrow-barred mackerel [10% (2/20)], Silver pomfret [5% (1/20)], and Tigertooth croaker [5% (1/20)]. Interestingly, among infected fish species three zoonotic STs (ST1, ST2, and ST7) were identified. ST2 was the most predominant ST [50% (2/4)], followed by ST1 and ST7, one sample each [5% (1/20)]., Conclusion: Overall, the prevalence and STs distribution of Blastocystis in edible marine fish along with the possibility of its zoonotic transmission are still open to question and require extensive and more detailed studies., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Blastocystis hominis (B. hominis) is a protozoan parasite that has a worldwide distribution. Some studies have suggested a link between B. hominis and the development of irritable bowel syndrome (IBS). The objective of this study was to determine the prevalence of B. hominis in patients with IBS compared to healthy individuals., Material and Methods: A total of 65 stool samples from patients with IBS and 65 samples from healthy individuals in northern Iran were examined. The samples were tested using various methods including direct smear, formalin ether sedimentation and culture to detect the presence of B. hominis. Additionally, polymerase chain reaction (PCR) was performed on all culture-positive isolates to confirm the results and identify the genotype., Results: B. hominis was detected in 15.38% of IBS patients and 9.2% of the healthy group. The culture in RPMI1640 was found to be better than the formalin ether and direct smear methods. Positive samples were confirmed using the molecular method. No significant difference was observed in the order of B. hominis infection between the two groups., Conclusions: The results of our study indicate that no significant difference was observed in the order of B. hominis infection between IBS patients and healthy groups. Therefore, further study is necessary to determine the potential pathogenic effects of this parasite and its role in causing IBS., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The Blastocystis subtype ST10 has been recognized to contain a great deal of diversity at the sequence level, potentially indicating the presence of multiple new STs within the clade. However, the data needed to validate these new STs were not available. To help resolve this diversity, full-length small subunit (SSU) rRNA gene reference sequences were generated using Oxford Nanopore MinION long-read sequencing from 21 samples representing multiple domestic and wild hosts and geographic regions and covering the sequence diversity previously described using fragments of the SSU rRNA gene. Phylogenetic and pairwise distance analyses were used to compare full-length sequences of the SSU rRNA gene generated in this study with all other valid STs of Blastocystis. We present data supporting the division of ST10/ST23 cluster into five subtypes, ST10, ST23, and three new subtypes with the proposed ST designations of ST42, ST43, and ST44. As the host range of Blastocystis continues to expand with new subtypes and new hosts being frequently identified, the reference sequences provided in this study will assist in accurate sequence classification and help to clarify the epidemiology of this common intestinal microeukaryote., (© 2023 International Society of Protistologists. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Blastocystis is an intestinal microeukaryote that has raised attention due to its wide distribution in animals and humans. The risk of zoonotic circulation primarily arises from close contact with infected animals. Therefore, the following study aimed to evaluate the diversity and frequency of Blastocystis subtypes in Colombian human and animal samples using complete sequencing of the 18S rRNA gene. For this purpose, 341 human stool samples and 277 animal fecal samples (from cattle, sheep, goat, pigs, cats, and dogs), were collected from different Colombian regions and analyzed using PCR-based detection and full-length 18S SSU rRNA gene Next-Generation Sequencing (NGS). Among the 618 samples from both hosts, humans and animals, the results revealed widespread Blastocystis frequency, with 48.09% (n = 164) in humans and 31.4% (n = 87) detection in animals. Dogs, cats, sheep, pigs, and wild animals tested positive, aligning with global prevalence patterns. Also, 29 human samples and 23 animal samples were sequenced using ONT technology from which 11 long-read unique sequences were generated and cluster with their compared reference sequences. The subtype distribution varied within hosts, detecting ST1 and ST3 in both human and animal samples. Subtypes ST5, ST10, ST14, ST15, ST21, ST24, ST25 and ST26 were limited to animals hosts, some of which are considered to have zoonotic potential. On the other hand, ST2 was found exclusively in human samples from Bolivar region. Mixed infections occurred in both animal and humans, 60.86% and 27.58% respectively. Moreover, to our knowledge, this is the first study in Colombia identifying ST15 in pigs and ST25 in sheep. The subtypes (STs) identified in this study indicate that certain animals may serve as reservoirs with the potential for zoonotic transmission. The identification of zoonotic subtypes highlights the use of Next Generation Sequencing as the depth and resolution of the sequences increases providing insights into STs of medical and veterinarian significance. It also reveals the coexistence of diverse subtypes among hosts. Further research is essential for understanding transmission dynamics, health implications, and detection strategies for Blastocystis occurrence in animals and humans, mainly associated to the role of animals as reservoirs and their close interaction with humans., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Wild rodents are key carriers of various human pathogens, including Blastocystis spp. Our study aimed to assess the prevalence and genetic characteristics of Blastocystis among wild rodents in the Inner Mongolian Autonomous Region and Liaoning Province of China. From November 2023 to February 2024, 486 rodents were captured in these regions. Fresh feces were collected from the intestines of each rodent for the isolation of DNA and PCR amplification of the vertebrate cytochrome b (cytb) gene to identify rodent species. Subsequently, PCR analysis and sequencing of the partial small subunit of the ribosomal RNA (rRNA) gene were utilized to detect Blastocystis in all fecal samples. Of the total samples, 27.4% (133/486) were found to be Blastocystis positive. The results revealed the presence of four species of rodents infected with Blastocystis, 32.3% (63/195) in Rattus norvegicus, 15.1% (16/106) in Mus musculus, 20.2% (18/89) in Apodemus agrarius, and 37.5% (36/96) in Cricetulus barabensis. Sequence analysis confirmed the existence of five Blastocystis subtypes: ST1 (n = 4), ST2 (n = 2), the ST4 (n = 125, the dominant subtype), ST10 (n = 1), and a novel ST (n = 1). The identified zoonotic subtypes (ST1, ST2, ST4, and ST10) highlight the possible role played by wild rodents in the transmission of Blastocystis to humans, thereby elevating the chances of human infection. Meanwhile, the discovery of novel sequences also provides new insights into the genetic diversity of this parasite., (© L. Liu et al., published by EDP Sciences, 2024.)

Objective: The aim of this study was to determine the prevalence of opportunistic parasites and Blastocystis spp. in patients with gastric cancer (CA) and to determine the significance of these parasite., Methods: The patient group and the control group were composed of 100 people each. The stool samples were examined under the microscope for intestinal parasites with the native-Lugol method. Then, samples were multiplied by formol-ethyl acetate method and stained with modified acid-fast method., Results: Intestinal parasite positivity was indicated in 14% of the gastric CA, and 2% of the healthy individuals (p=0.001). Blastocystis spp. (p=0.009) was identified in 11%, Cryptosporidium spp. was identified in 4%, G. intestinalis was identified in 2%, and C. cayetanensis was identified in 1% of the patient group. There were significant differences between the intestinal parasite positivity (p=0.012), abundant Blastocystis spp. positivity (p=0.041) and all Blastocystis spp. positivity (p=0.037) in patient and control groups. Most of the patients who were positive for parasites had diarrhea., Conclusion: Based findings, it was concluded that it would be beneficial to evaluate gastric CA patients, especially those with diarrhea, for intestinal parasites.

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., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The prevalence of Blastocystis sp., its genetic diversity and the distribution of circulating subtypes (STs) were molecularly investigated in a cohort of autochthonous and immigrant patients with gastrointestinal symptoms hospitalized over the period February 2022-June 2023 at the Policlinico Ospedaliero-Universitario "Riuniti", Foggia, in Southern Italy. The population variables, including patient geographical origin, gender and age classes were reported. Out of the 927 investigated patients, 36 (3.9%) were positive for Blastocystis sp. A statistically significant association with African origin and age classes >18 years old was found. ST1 (allele 4), ST2 (alleles 9, 13), ST3 (alleles 34, 36) and ST4 (allele 92) were the subtypes detected with a different distribution between autochthonous and immigrant patients. Co-infections with enteric protozoa such as Giardia duodenalis and Dientamoeba fragilis, pathogenic bacteria as Clostridioides difficile, Campylobacter jejuni and Aeromonas sp. and viral infections such as Norovirus were found in 33% of cases. This is the first study of Blastocystis sp., its circulating subtypes and allele variability among patients with different geographical origin in an area of Southern Italy, in the Central Mediterranean, characterized by high immigrant pressure. These results provide baseline data to better investigate a potential interaction between Blastocystis sp. and other risk factors in patients with gastrointestinal symptoms., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest and that they have no actual or potential competing financial interests., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Blastocystis is a common enteric protist infecting humans, domestic animals, and wildlife worldwide. However, data on the prevalence and subtype diversity of Blastocystis in free-living wild birds in urban districts are rare. In this study, a total of 138 fresh fecal samples from free-living wild birds were collected from three universities and three communities in Xinxiang, China, to explore the infection rate, Blastocystis subtypes present and zoonotic potential of this protist. Blastocystis presence was determined with nested-PCR amplification based on the partial small ribosomal subunit (SSU rRNA) gene. Presence was detected from one community (Wupu) at an overall rate of 1.5% (2/136). Further DNA sequencing and phylogenetic analyses identified two ruminant-associated subtypes, ST10 (n = 1) and ST24 (n = 1), implying a cross-species transmission of Blastocystis from ruminants. This is the first report on the infection of ST10 and ST24 in free-living wild birds in an urban area in China. As potentially zoonotic subtypes, the occurrence of ST10 and ST24 suggests that these free-living birds could play a role in spreading Blastocystis to humans in Xinxiang., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Objective: To investigate the prevalence and subtype distribution of Blastocystis sp. in pigs in Anhui Province., Methods: 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., Results: 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%) (χ 2 = 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%) (χ 2 = 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., Conclusions: The prevalence of Blastocystis sp. is high in pigs in Anhui Province, with three zoonotic subtypes identified, including ST1, ST3, and ST5.

The gut microbiota comprises the collective genomes of microbial symbionts and is composed of bacteria, fungi, viruses, and protists within the gastrointestinal tract of a host. Although the literature associated with gut microbiota is increasing, studies on eukaryotes in the human gut are just beginning to surface. Blastocystis is one of the most common intestinal parasites of humans and animals and is estimated to colonise more than 1 billion people on a global scale. However, the understanding of the genetic characteristics of Blastocystis subtype (ST) at the genome level and its relationship with other members of the gut microbiota is still limited. In this study, by surveying the prevalence and genome characteristics of Blastocystis sp. ST3 in a Chinese population (prevalence % = 6.09%), the association of Blastocystis sp. ST3 with region and time and the structure of the resident gut bacterial population was clarified. We identified novel sequences (50 mitochondrial and 41 genome sequences) and determined their genetic diversity amongst strains within Blastocystis sp. ST3 (4.14 SNPs/kb). Furthermore, we found that colonisation of Blastocystis was strongly associated with increased bacterial richness and higher abundance of several anaerobes. Finally, we performed time series sampling on two Blastocystis-positive individuals and confirmed that Blastocystis could exist continually in the human gut microbiota and persist for a long time, even for 4 years., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Molecular characterisation of endobionts that are shared among human and non-human hosts can help shed light on the epidemiology and inform studies that aim to unravel the role of these organisms in health and disease. Two of the most common of shared endobionts include the single-celled intestinal protists Blastocystis and Entamoeba. Here, we present the first known data on genetic diversity and host specificity of these two genera in Greenland. Faecal DNA samples from 243 muskoxen and 44 sheep were submitted to metabarcoding of nuclear small subunit ribosomal DNA. Entamoeba- and Blastocystis-specific sequences were clustered, and consensus sequences were subjected to taxonomic query. Using MinION-based sequencing, near-complete nuclear small subunit ribosomal DNA sequences were obtained from four faecal samples. Of the 243 muskox samples, 180 (74%) and 19 (8%) were positive for Blastocystis and Entamoeba, respectively. Forty (91%) and six (14%) of the 44 sheep samples were positive for Blastocystis and Entamoeba, respectively. Blastocystis subtypes (ST) 10, 14, 21, 24-26, and a novel subtype (ST40) were identified. Colonisation by more than one subtype was common. ST40 was common in muskoxen but limited to Northeast Greenland. Entamoeba bovis and the E. bovis-associated ribosomal lineages (RL) 1 and 8 were found, and three conditional lineages (CL) 3, 4, and 10 were confirmed; CL10 was promoted to RL12. Several novel lineages were identified, all of which were linked to the E. bovis complex. In conclusion, Blastocystis was far more common than Entamoeba and found in approximately three of every four animals; both can be considered common colonisers of large herbivorous mammals in Greenland. Multiple subtypes/lineages of both genera were commonly observed, some of which were novel, but most of which are seen in many other parts of the world., (Copyright © 2023 Australian Society for Parasitology. All rights reserved.)

Background: Blastocystis hominis (Bh) is zoonotic parasitic pathogen with a high prevalent globally, causing opportunistic infections and diarrhea disease. Human immunodeficiency virus (HIV) infection disrupts the immune system by depleting CD4 + T lymphocyte (CD4 + T) cell counts, thereby increasing Bh infection risk among persons living with HIV (PLWH). However, the precise association between Bh infection risk and HIV-related biological markers and treatment processes remains poorly understood. Hence, the purpose of the study was to explore the association between Bh infection risk and CD4 + T cell counts, HIV viral load (VL), and duration of interruption in antiviral therapy among PLWH., Methods: A large-scale multi-center cross-sectional study was conducted in China from June 2020 to December 2022. The genetic presence of Bh in fecal samples was detected by real-time fluorescence quantitative polymerase chain reaction, the CD4 + T cell counts in venous blood was measured using flowcytometry, and the HIV VL in serum was quantified using fluorescence-based instruments. Restricted cubic spline (RCS) was applied to assess the non-linear association between Bh infection risk and CD4 + T cell counts, HIV VL, and duration of interruption in highly active antiretroviral therapy (HARRT)., Results: A total of 1245 PLWH were enrolled in the study, the average age of PLWH was 43 years [interquartile range (IQR): 33, 52], with 452 (36.3%) being female, 50.4% (n = 628) had no immunosuppression (CD4 + T cell counts > 500 cells/μl), and 78.1% (n = 972) achieved full virological suppression (HIV VL < 50 copies/ml). Approximately 10.5% (n = 131) of PLWH had interruption. The prevalence of Bh was found to be 4.9% [95% confidence interval (CI): 3.8-6.4%] among PLWH. Significant nonlinear associations were observed between the Bh infection risk and CD4 + T cell counts (P for nonlinearity  < 0.001, L-shaped), HIV VL (P for nonlinearity  < 0.001, inverted U-shaped), and duration of interruption in HARRT (P for nonlinearity  < 0.001, inverted U-shaped)., Conclusions: The study revealed that VL was a better predictor of Bh infection than CD4 + T cell counts. It is crucial to consider the simultaneous surveillance of HIV VL and CD4 + T cell counts in PLWH in the regions with high level of socioeconomic development. The integrated approach can offer more comprehensive and accurate understanding in the aspects of Bh infection and other opportunistic infections, the efficacy of therapeutic drugs, and the assessment of preventive and control strategies., (© 2023. National Institute of Parasitic Diseases.)

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Blastocystis sp., is an intestinal protist with a broad host range and a high prevalence in human populations worldwide, even in developed Western countries. The publication of conflicting evidence has divided the scientific community about the pathogenic role of this parasite. Even though, genetic studies on Blastocystis sp. revealed associations between genotypes and different pathogenic profiles. Conventionally, the detection of this parasite is based on microscopic or PCR methods, which offer meager or null performance in detecting mixed infections. In this work, we applied a metataxonomic NGS approach targeting the V4 region of the eukaryotic SSU-rRNA gene and classical phylogenetic methods. This approach allowed us to detect Blastocystis sp. in stool samples from infected children living in an urban setting in the city of Medellin attending the same daycare center. Phylogenetic analysis identified the subtypes present in the children as ST1, ST2, and ST3. Besides, mixed infections of subtypes ST1 + ST3 were spotted in 16% of the analyzed stool samples., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Blastocystis is a unicellular, anaerobic protist inhabiting the intestinal tract of diverse animal hosts, including human. Information regarding Blastocystis in small ruminants, namely goats and sheep, is limited globally; thus, this study was carried out to investigate the distribution and determinants of Blastocystis in ruminant livestock animals from Penang, Malaysia. Fecal samples from 127 cattle, 149 goats, and 100 sheep were examined for Blastocystis by in vitro cultivation using modified Jones' medium, while DNA barcoding was used for subtyping. Overall, 23.1% (87/376) of animals screened were positive for Blastocystis sp. The prevalence of infection was significantly higher in goats than in cattle and sheep, while the female gender, semi-intensive farming system, and the Northeast Penang Island district were identified as potential risk factors for Blastocystis infection. Blastocystis sp. ST5, ST14, and ST25 were identified in cattle; ST5, ST10, ST13, and ST14 in goats; and ST4, ST5, ST14, and ST15 in sheep. ST5 and ST14 were found to be the most abundant and widespread subtypes in the study area. To the best of our knowledge, this is the first report of ST4 from sheep and ST13 from goats, thus serving as an update to the host range of Blastocystis sp. ST4 and ST13. The isolation of ST4 and ST5 in this study suggests that ruminant livestock animals could serve as reservoirs of human infection., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Blastocystis is one of the important zoonotic parasites which can infect humans and various animals worldwide and has become a growing global public health concern. The study aims to obtain the data of Blastocystis infection and the information of the genetic characteristic., Methods: In the present study, 489 fecal samples were collected from diarrhea outpatients in Ningbo, Zhejiang province, and were examined the presence of Blastocystis by polymerase chain reaction combined with sequencing., Results: A total of 10 samples (2.04%, 10/489) were positive for Blastocystis with no significant difference among sex and age groups, respectively. Eight samples were successfully sequenced, and five zoonotic ST3 and three zoonotic ST1 with two new sequences were identified., Conclusions: We first demonstrated the occurrence of Blastocystis infection in diarrhea outpatients in Ningbo, with two zoonotic subtypes (ST1 and ST3) and two new sequences being characterized. Meanwhile, mixed infection of Blastocystis and E. bieneusi was found which indicates the importance of investigation of multiple parasites. Finally, more extensive studies will be needed to better understand the transmission of Blastocystis at human-animal-environment interface and provide evidence for the development of one health strategies for the prevention and control of such diseases., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Blastocystis sp. is a common eukaryotic microorganism that colonizes the intestinal tract of several animals, including humans, although its role as a pathogen is still unclear. In the present study, we report the prevalence and risk factors associated with Blastocystis infection in scholars from a rural community in Mexico. A cross-sectional observational study was carried out on schoolchildren aged 3 to 15 years old; fecal samples were analyzed by culture, Faust technique, and molecular analysis. In addition, a structured questionnaire was applied to identify possible risk factors. Of the 177 samples obtained, Blastocystis sp. was the microorganism that presented the highest frequency (n=78, 44%), and included the following subtypes (STs): ST1 (n=43, 56.5%), ST2 (n=18, 23.6%), and ST3 (n=15, 19.7%); Blastocystis STs were not identified in two cases. No associating factors were found between Blastocystis infection or among STs vs. symptoms. During bivariate analysis, no statistically significant risk factors were found, except for the variable of "eating sweets, snacks, and handmade food on the way home" (p=0.04). Therefore, it is plausible to conclude that schoolchildren become infected with Blastocystis sp. mainly outside their homes, perhaps by eating contaminated handmade food on their way to or from school; however, this variable should be evaluated in detail in future studies., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Blastocystis is a common intestinal protist with a global distribution in humans and many other animals. Yet, the status of Blastocystis as a pathogen, the risk factors associated with its transmission, and its zoonotic potential remain ill-defined. Here, we explored subtype (ST) diversity and potential risk factors for Blastocystis infection in 98 children from Apulo, Colombia. Samples were screened for Blastocystis via PCR, and ST identification was performed through next-generation amplicon sequencing (NGS). Associations between the presence of Blastocystis and individual STs and sociodemographic variables were assessed via logistic regression analyses. Seventy-one samples (72.4%) were Blastocystis-positive, and NGS revealed the presence of five STs (ST1-ST5). ST1, ST2, and ST3 were common and observed in nearly equal proportions (~ 40%), while samples with ST4 (1.4%) and ST5 (5.6%) were comparatively rare. The presence of mixed STs in the same sample was also common (28.2%). Comparisons among children within the same household identified that shared ST profiles were common, but diversity within family units was also observed. Logistic regression analyses returned significant associations between the presence of Blastocystis, individual subtypes, or mixed subtypes for several variables. Intriguingly, the presence of animals was one of the most common significant associations. Taken together, these data represent an important step forward in understanding both the potential routes and risk factors that may influence Blastocystis transmission and will be useful in shaping future studies which seek to clarify the relationships between STs, pathogenicity, and zoonotic transmission., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Blastocystis is a common microeukaryotic intestinal parasite in humans and other animal hosts globally. However, no large-scale longitudinal study has ever been conducted for Blastocystis. To understand patterns of infection prevalence and subtype diversity and their relationship with host age, we have conducted the most comprehensive longitudinal study of Blastocystis infection ever performed. Dairy calves from a herd located in Maryland, USA, were followed from birth through 24 months of age, and 990 individual fecal samples from 30 calves were collected over the study period, representing three age groups (pre-weaned, post-weaned, and heifer). All samples were screened for Blastocystis via PCR, and subtype determination was performed using next-generation amplicon sequencing. Associations between age group and infection status were assessed using logistic regression analyses. Blastocystis infection prevalence increased with time, significant associations were observed between age groups and infection risk, and a cumulative prevalence of 100% was observed among the study population during the 24-month period. Thirteen previously reported subtypes (ST1-6, ST10, ST14, ST21, ST23-26) and one potentially novel subtype were observed. Diversity within ST10 supports the need for division of the subtype into new subtype designations. Associations between subtype and age group were explored, and relationships between subtypes and infection chronicity are described. While subtype diversity increased with age in the study population, distinct patterns of individual subtype prevalence and chronicity were observed, supporting the importance of subtype discrimination in studies of host infection and disease. The data from this study represent a significant advance in our understanding of Blastocystis infection dynamics within a single host population over time and can be used to inform future studies of Blastocystis epidemiology in both humans and other animal hosts., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Intestinal parasitic infections are a global health problem that causes morbidity and mortality, especially in children living in rural areas. In this study, stool samples of pediatric patients with gastrointestinal complaints were examined by conventional and molecular methods to determine the prevalence of intestinal parasites. A total of 100 pediatric patients with gastrointestinal complaints and 50 healthy children were included in the study. Stool samples were collected from each child and examined by direct microscopic examination (native-Lugol method), formol-ethyl acetate concentration technique, Kinyoun's acid-fast staining, and Wheatley trichrome staining methods. Real-time PCR was used for the detection of Blastocystis spp. and D. fragilis in the stool samples. Sanger sequencing was used to identify Blastocystis spp. subtypes. One or more intestinal parasites were found in 12% (n = 100) of the patient group and 1% (n = 50) of the control group using conventional techniques. By using real-time PCR, Blastocystis spp. was discovered in 14% (14/100) of the patient group and 8% (4/50) of the control group. There was no significant difference in the frequency of Blastocystis spp. between the two groups. The most prevalent Blastocystis subtype was ST1 and the most frequent allele was a2 among the samples successfully amplified and sequenced. D. fragilis was detected in 17% (17/100) of the patient group and 8% (4/50) of the control group by real-time PCR. The prevalence of D. fragilis was not significantly different between the patient and control groups, as well. Blastocystis spp. and D. fragilis were found in high prevalence in pediatric patients with gastrointestinal complaints in this study. Although the role of these protists as a pathogen in humans is still controversial, it is supposed to the presence of the parasites are associated with gastrointestinal disorders such as diarrhea, abdominal pain, nausea, and vomiting. More case-control studies are needed to understand the pathogenic or commensal role of these parasites on the intestinal microbiota, especially in both patients with gastrointestinal disorders and healthy individuals., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Blastocystis sp. is one of the most prevalent intestinal protozoa found in humans and many other animals. The present study aimed to examine the distribution and genetic diversity of Blastocystis sp. in stool samples from patients with gastrointestinal complaints in İzmir, Turkey., Methods: All stool samples of 439 patients with gastrointestinal complaints were examined by native-Lugol and trichrome staining. To investigate the presence of Blastocystis sp. in stool samples, DNA was isolated, and PCR was performed with the barcode region in the SSU rRNA gene. PCR positive samples were sequenced to identify subtypes and alleles of Blastocystis sp., Results: The prevalence of Blastocystis sp. was found to be 16.6% (73/439) in patients with gastrointestinal complaints in İzmir, Turkey. Three different Blastocystis sp. subtypes were identified. ST3 (28/55; 51.0%) was the most common subtype followed by ST2 (19/55; 34.5%) and ST1 (8/55; 14.5%). Itching and diarrhea were the most prominent clinical symptoms in Blastocystis sp. positive patients. When clinical symptoms and subtypes were compared, diarrhea was found in 62.5%, 47.4%, and 46.4% of patients with ST1, ST2, and ST3 subtypes, respectively. In addition, itching was found in 37.5%, 32.1%, and 21.1% of patients with ST1, ST3, and ST2, respectively. Six distinct alleles were identified by allele analysis of Blastocystis 18S rRNA gene: allele 4 for ST1, alleles 9, 11, and 12 for ST2, and alleles 34 and 36 for ST3. In this study, Blastocystis sp. was detected in 16 of 21 districts, including the central and rural districts of İzmir. Although ST1 was detected in central districts, it was not found in rural districts., Conclusion: This study provides comprehensive data on the prevalence and molecular epidemiology of the genetic diversity at the level of subtypes and alleles of Blastocystis sp. in different districts of İzmir province in Turkey. To the best of our knowledge, this is the first study which evaluates the distribution of subtypes and alleles of Blastocystis sp. according to PCR and SSU rRNA gene sequencing in patients with gastrointestinal complaints in different districts of İzmir province in Turkey., (© 2023. The Author(s) under exclusive licence to Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Blastocystis sp. is a common intestinal protist, reported from symptomatic and asymptomatic subjects. Blastocystis sp. has been reported from a broad spectrum of gastrointestinal disorders. Celiac disease (CD) is an autoimmune disorder of the small intestine, which leads to the lack of tolerance against gluten. Long-term following of gluten-free diet in CD patients decreases the gut microbiota restoration and probably decreases the chance of Blastocystis sp. colonization. The current study aimed to investigate the prevalence of Blastocystis sp. and its subtypes in CD patients in comparison to healthy subjects. Stool samples were collected from 238 participants including 92 confirmed CD patients and 146 healthy subjects. Upon DNA extraction, the presence of Blastocystis sp. was evaluated using amplification of discriminative regions of the small ribosomal RNA (ssu rRNA) gene. To characterize subtypes and alleles, amplified fragments were sequenced. Phylogenetic trees were constructed to visualize subtype correlation. Our findings showed that 21% (50) of samples including 16.3% (15/92) and 23.97% (35/146) were positive for Blastocystis sp. in CD patients and healthy controls, respectively. Except family relationship, other variables were not statistical correlated with the presence of Blastocystis sp.. Totally, 25 samples were successfully sequenced. Accordingly, ST1, ST2, and ST3 were characterized in 8 (32%), 9 (36%), and 8 (32%) of samples, respectively. Allele discrimination showed that all ST1 were allele 4; alleles 11, 9, and 12 were retrieved from ST2, and alleles 34, 36, and 38 were observed in ST3. The relationship between colonization of Blastocystis sp. and alteration in the gut microbiota composition is indeterminate, however, this hypothesis that following gluten-free diet in CD patients may affect the colonization of Blastocystis sp. via alteration in the gut microbiota composition could be interesting for further investigations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Intestinal helminths, including Soil-Transmitted Helminth (STH), and Gastrointestinal Protist (GP) infections are major contributors to the global burden of disease, particularly in low-income countries such Ecuador. Their epidemiology in these settings is largely unknown., Methodology: This prospective cross-sectional study investigates the carriage of intestinal helminths, including STH, and GP in asymptomatic schoolchildren (3-11 years) in the Chimborazo and Guayas provinces, Ecuador. Single stool samples (n = 372) and epidemiological questionnaires on demographics and potential risk factors were collected from participating schoolchildren. Conventional microscopy examination was used as screening method, and molecular (PCR and Sanger sequencing) assays were used to further investigate the epidemiology of some GP. A multivariate logistic regression analysis was used to evaluate the strength of the association of suspected risk factors with the presence of helminths and GP., Principal Findings: At least one intestinal parasite species was observed by microscopy in 63.2% (235/372) of the participating schoolchildren. Enterobius vermicularis (16.7%, 62/372; 95% CI: 13.0-20.9) and Blastocystis sp. (39.2%, 146/372; 95% CI: 34.2-44.2) were the most prevalent among helminths and GP, respectively. Assemblages A (50.0%), B (37.5%) and A+B (12.5%) were detected within Giardia duodenalis and ST3 (28.6%), ST1 and ST2 (26.2% each), and ST4 (14.3%) within Blastocystis sp. Three genotypes, two known (A: 66.7%; KB-1: 16.7%) and a novel (HhEcEb1, 16.7%) were identified within Enterocytozoon bieneusi. Municipality of origin, household overcrowding, and poor sanitation and personal hygiene habits were risk factors for childhood intestinal parasites colonization., Conclusions/significance: Despite massive government drug administration programs, STH and GP infection remain a public health concern in paediatric populations living in poor-resource settings. Molecular analytical methods are required to better understand the epidemiology of these intestinal parasites. This study provides novel information on the occurrence of Blastocystis sp. and E. bieneusi genetic variants circulating in Ecuadorian human populations., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)