Prevalence and subtyping of Blastocystis sp. in ruminants in Southwestern, Iran.

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.

Molecular investigation of Blastocystis in children and calves in Bangladesh.

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.

Molecular detection, subtyping of Blastocystis sp. in migratory birds from nature reserves in northeastern China.

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.

Molecular prevalence and subtype characteristics of Blastocystis among school children in Hainan, the tropical island province of China.

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.

Unveiling Blastocystis epidemiology in Morocco: subtype diversity among clinical patients with and without gastrointestinal manifestations in the Meknes region.

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.

Blastocystis colonization and associations with population parameters in Thai adults.

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.

Accelerating the paradigm shift in Blastocystis research.

Blastocystis, once targeted as a harmful intestinal parasite, is now seen as potentially beneficial. Piperni et al. link its presence to improved gut health, higher microbial diversity, and favorable cardiometabolic outcomes, which suggests that Blastocystis might indicate a healthy diet and gut, possibly serving as a symbiont rather than a pathogen.

Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China.

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.

Prevalence of Blastocystis in Patients Referred to Bushehr Medical Centers and Its Relationship with Urticaria.

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.

Towards minimizing second-generation mis-identification of Blastocystis.

At least 1-2% of DNA sequences annotated as Blastocystis in GenBank represent organisms other than Blastocystis or sequence artefacts. As well as being biologically incorrect, such practice can lead to overestimates of genetic diversity, underestimated host specificity, and incorrect classification of samples tested for Blastocystis using DNA-based methods.

Genetic diversity and host specificity of Blastocystis in reptiles, Eastern Thailand.

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.

Chronic urticaria associated with Blastocystis hominis infection.

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.

Molecular screening for enteric parasites and subtyping of Blastocystis sp. in haemodialysis patients in Slovakia.

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 Kosice, 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.

Molecular investigation of Blastocystis sp. infections in wild rodents from the Inner Mongolian Autonomous Region and Liaoning province, China: High prevalence and dominance of ST4.

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.

Title: Enquête moléculaire sur les infections à Blastocystis chez des rongeurs sauvages de la région autonome de Mongolie intérieure et de la province du Liaoning, Chine : forte prévalence et dominance du sous-type ST4. Abstract: Les rongeurs sauvages sont des vecteurs clés de divers agents pathogènes humains, dont Blastocystis spp. Notre étude visait à évaluer la prévalence et les caractéristiques génétiques de Blastocystis chez les rongeurs sauvages de la région autonome de Mongolie intérieure et de la province chinoise du Liaoning. De novembre 2023 à février 2024, 486 rongeurs ont été capturés dans ces régions. Des matières fécales fraîches ont été collectées dans les intestins de chaque rongeur pour l'isolement de l'ADN et l'amplification par PCR du gène du cytochrome b des vertébrés (cytb) afin d'identifier les espèces de rongeurs. Par la suite, l'analyse PCR et le séquençage de la petite sous-unité partielle du gène de l'ARN ribosomal (ARNr) ont été utilisés pour détecter les Blastocystis dans tous les échantillons fécaux. Sur le total des échantillons, 27.4% (133/486) présentaient un résultat positif à Blastocystis. Les résultats ont révélé la présence de quatre espèces de rongeurs infectées par Blastocystis, 32.3% (63/195) chez Rattus norvegicus, 15.1% (16/106) chez Mus musculus, 20.2% (18/89) chez Apodemus agrarius et 37.5% (36/96) chez Cricetulus barabensis. L'analyse de séquence a confirmé l'existence de cinq sous-types de Blastocystis : ST1 (n = 4), ST2 (n = 2), ST4 (n = 125, le sous-type dominant), ST10 (n = 1) et un nouveau ST (n = 1). Les sous-types zoonotiques identifiés (ST1, ST2, ST4 et ST10) mettent en évidence le rôle possible joué par les rongeurs sauvages dans la transmission de Blastocystis à l'Homme, augmentant ainsi les risques d'infection humaine. Parallèlement, la découverte de nouvelles séquences fournit également de nouvelles informations sur la diversité génétique de ce parasite.

New Haplotypes of Blastocystis sp. Identified in Faeces from Various Animal Groups in Algeria.

PURPOSE: Blastocystis sp. is a single-celled, anaerobic, parasitic protozoan commonly found in the intestinal tract of animals and humans globally. Genetic analysis has revealed significant diversity within its species, leading to the identification of at least 40 subtypes (ST1-ST40). This study aimed to identify and differentiate Blastocystis in faeces samples from various animal hosts in Algeria. METHODS: A total of 403 fecal samples, collected from both domestic and zoo animals, were subjected to PCR amplification and sequencing of Blastocystis-specific small subunit ribosomal RNA (SSU-RNA) gene. RESULTS: The overall prevalence of Blastocystis in animals was found to be 38.9%. Through comprehensive phylogenetic and phylogeographic analyses, we identified four distinct subtypes (ST1 in both domestic and zoo animals, and ST3, ST4, and ST5 exclusively in zoo animals), encompassing nine different haplotypes, including five that appear original to Algeria. CONCLUSION: This study represents the first epidemiological molecular investigation of Blastocystis sp. in animals in Algeria.

Blastocystis hominis -associated Acute Appendicular Peritonitis in a 9-Year-old Boy: A Case Report and a Comprehensive Review of the Literature.

Although Blastocystis sp. has been classically considered a commensal parasite with limited pathogenicity, recent studies suggest that its pathogenic potential is high. We report the case of a 9-year-old Spanish male who presented with peritonitis secondary to acute appendicitis with abundant intra-abdominal turbid-free fluid. A standard appendectomy was performed, and a sample of the fluid was taken for microbiological culture. Multimicrobial flora was isolated in peritoneal fluid culture. The antibiotic resistance study showed that all the microorganisms were sensitive to meropenem. On the 5th postoperative day, a control blood test showed relative eosinophilia and a persistently elevated C-reactive protein. A stool parasitological study showed abundant cysts morphologically compatible with Blastocystis hominis . The hematoxylin & eosin and Giemsa study identified abundant parasitic cysts in the appendix. The patient evolved favorably and is currently asymptomatic and under follow-up. Regarding acute appendicitis, there is only one report in the literature of peritonitis of appendiceal origin associated with Blastocystis sp. In conclusion, although infrequent, parasitosis should be considered as a potential etiological agent of acute appendicitis, even in nonendemic areas. Relative eosinophilia or persistently elevated acute phase reactants despite adequate antibiotic coverage should help to establish diagnostic suspicion.

Recombinase polymerase amplification - lateral flow dipstick for rapid and visual detection of Blastocystis spp.

Blastocystis spp. is a ubiquitous protozoon in the intestinal tract of human and many animals. Microscopic examination is the main method of clinical diagnosis for Blastocystis spp., which is prone to false negative. A simple and rapid diagnosis of Blastocystis spp. infection is an important step to prevent and control blastocystosis. Here, a recombinase polymerase amplification-lateral flow dipstick (RPA-LFD) assay was developed for rapid visual detection of Blastocystis spp. DNA amplification could be performed within 18 min at 37°C. The minimum DNA detection limit was 1 pg/µL, and there was no cross-reactivity with 12 other non-target pathogens, which was consistent with the sensitivity of conventional PCR (cPCR). Furthermore, 56 fecal samples from the Third Affiliated Hospital of Xinxiang Medical University were tested using RPA and cPCR methods respectively, and the results were completely consistent. The results show that RPA-LFD method has high accuracy and visual results, which provides a new choice for the differential diagnosis and rapid field detection of Blastocystis spp.

Microscopic and molecular prevalence and associated risk factors with Toxocara and Blastocystis infection in dogs and cats in Mitidja, Algeria.

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.

Molecular detection and genotyping of Dientamoeba fragilis and Blastocystis sp. in housefly Musca domestica (Diptera: Muscidae): first report for Dientamoeba fragilis.

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.

First molecular subtyping and zoonotic significance of Blastocystis sp. in Dromedary (C. dromedarius) and Bactrian (C. bactrianus) camels in Iran: A molecular epidemiology and review of available literature.

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.