The regulatory function of Blastocystis spp. on the immune inflammatory response in the gut microbiome

Occurrence and genotypic identification of Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis in dairy cattle in Heilongjiang Province, China

Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis are three common zoonotic intestinal parasites, and cattle are important hosts of these three intestinal protozoa. In this study, 1632 fecal samples were collected from dairy farms in Heilongjiang Province, China, and screened for Blastocystis sp., E. bieneusi, and G. duodenalis using polymerase chain reaction. Of these, 149 (9.13%) were positive for three zoonotic pathogens, including 104 (6.40%), 22 (1.35%), and 23 (1.41%) for Blastocystis sp., E. bieneusi, and G. duodenalis, respectively. Based on partial SSU rRNA gene sequencing analysis, 104 positive samples of Blastocystis sp. were found, and a total of nine known subtypes were identified, including ST10 (61), ST3 (18), ST14 (6), ST26 (7), ST24 (3), ST25 (2), ST1 (2), ST5 (2), and ST21 (1). Among these, three subtypes (ST1, ST3, and ST5) were recognized as zoonotic subtypes, and two subtypes (ST10 and ST14) were specific to animals. All 23 Giardia duodenalis-positive samples belonged to assemblage E (n = 23) based on sequenced beta-giardin (bg) and triosephosphate isomerase (tpi) genes. Three known genotypes of E. bieneusi, namely J (n = 9), I (n = 6), and BEB4 (n = 7), were identified by sequence analysis of the internal transcriptional spacer region gene. Our study provides basic data for prevention and control in Heilongjiang Province; however, further research is required to better understand the prevalence and public health significance of these pathogens in the Heilongjiang region.

The influence of plant extracts on viability of ST3 and ST7 subtypes of Blastocystis sp

Blastocystis sp. is one of the most frequently detected protozoa during stool specimen examination. In the last decade, the studies about the pathogenic potential of Blastocystis sp. have intensified. Additionally, treatment approaches against this parasite are still disputable. The study aimed to investigate the in vitro activity of the substances of natural origin against two subtypes (ST) of Blastocystis sp.-ST3 and ST7. Garlic and turmeric extracts exhibited the highest inhibitory effect in relation to the ST3 viability. While horseradish and turmeric were found to be the most effective extracts to the ST7 viability. The study showed that ginger, garlic, horseradish, and turmeric extracts have potent antimicrobial activity against Blastocystis ST3 and ST7, with the half-maximal inhibitory concentration (IC50) ranging from 3.8 to 4.8 µg/ml and from 3.3 to 72.0 µg/ml, respectively, and thus may be useful in the prevention and control of Blastocystis infections. Additionally, this research confirmed that Blastocystis ST7 is more resistant to the selected plant extracts treatment than Blastocystis ST3 which in consequence may bring some difficulties in its eradication.

The involvement of cytokine gene polymorphism in determining the vulnerability to Blastocystis and Helicobacter pylori co-infection in the Egyptian population

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.

Molecular detection and characterization of Blastocystis in herbivore livestock species in Portugal

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.

Blastocystis genetic diversity in animal and human samples from different departments of Colombia using complete sequencing of the 18S rRNA gene (SSU rRNA) by Oxford Nanopore Technologies (ONT)

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.

Prevalence and Genetic Characterization of Blastocystis in Sheep and Pigs in Shanxi Province, North China: From a Public Health Perspective

Blastocystis is a common zoonotic intestinal protozoan and causes a series of gastrointestinal symptoms in humans and animals via the fecal-oral route, causing economic losses and posing public health problems. At present, the prevalence and genetic structure of Blastocystis in sheep and pigs in Shanxi province remains unknown. Thus, the present study collected 492 sheep fecal samples and 362 pig fecal samples from three representative counties in northern, central and southern Shanxi province for the detection of Blastocystis based on its SSU rRNA gene. The results showed that the overall prevalence of Blastocystis in the examined sheep and pigs were 16.26% and 14.09%, respectively. Sequences analyses showed that four known subtypes (ST5, ST10, ST14 and ST30) in sheep and two subtypes (ST1 and ST5) in pigs were detected in this study, with ST5 being the predominate subtype among the study areas. Phylogenetic analysis showed that the same subtypes were clustered into the same branch. This study reveals that sheep and pigs in Shanxi province are hosts for multiple Blastocystis subtypes, including the zoonotic subtypes (ST1 and ST5), posing a risk to public health. Baseline epidemiological data are provided that help in improving our understanding of the role of zoonotic subtypes in Blastocystis transmission.

Faecal Viral Excretion and Gastrointestinal Co-Infection Do Not Explain Digestive Presentation in COVID-19 Patients

The physiopathological mechanisms responsible for digestive symptoms in COVID-19 patients are still unclear. The aim of this study was to determine the influence of faecal viral shedding on digestive symptoms and propose differential diagnoses in order to understand the gastrointestinal clinical spectrum in acute cases of COVID-19. All patients managed between March and May 2020, from whom stool samples were collected for microbiological investigations, were included. Microbiological analysis consisted of syndromic PCR screening and microscopic parasitological examination supplemented with microsporidia and multiplex protozoa PCR. SARS-CoV-2 infection was diagnosed via viral detection in respiratory and frozen stool samples, completed via serological test when necessary. Epidemiological, clinical, radiological, and biological data and clinical courses were compared according to COVID-19 status and faecal SARS-CoV-2 shedding and enteric co-infection status. The sample included 50 COVID+ and 67 COVID- patients. Faecal viral shedding was detected in 50% of stool samples and was associated with a higher viral load in the upper respiratory tract. Detected enteric pathogens were not different between subjects with different COVID-19 statuses or faecal SARS-CoV-2 shedding and had no impact on the clinical course for COVID-19 patients. The connection between SARS-CoV-2 shedding and enteric pathogen co-infection involvement in gastrointestinal presentation and clinical course is still unclear, suggesting other processes are involved in digestive disorders in COVID-19 patients.

First identification of Blastocystis sp. subtypes in Rex rabbits in China

Blastocystis sp. is a common protist that colonizes the intestinal tract in both humans and animals worldwide. A total of 666 fecal samples of Rex rabbits were collected from 12 farms in three administrative regions in Henan, China. Blastocystis sp. was screened and subtyped by PCR amplification of the small subunit ribosomal DNA. The results indicated that 31 (4.7%, 31/666) rabbits were positive for Blastocystis sp. across three farms (25.0%, 3/12). The infection rate of Blastocystis sp. in Rex rabbits was highest in Jiyuan at 9.1% (30/331), followed by Luoyang (0.5%, 1/191), with no positive infections found in Zhengzhou. The Blastocystis sp. infection rate in adults (10.2%, 14/287) was higher than that in young rabbits (4.5%, 17/379) (χ² = 0.0027, P > 0.50). Four Blastocystis sp. subtypes (ST1, ST3, ST4, and ST17) were identified in rabbits in the present study. Among them, the subtypes ST1 (n = 15) and ST3 (n = 14) were dominant, followed by ST4 (n = 1) and ST17 (n = 1). Blastocystis sp. ST1 was the dominant subtype in adult rabbits, and ST3 was the dominant subtype in young rabbits. This study enriches the data on the prevalence and subtype distributions of Blastocystis sp. in rabbits. More studies are needed among humans, domestic animals, and wild animals to obtain a better understanding of their role in the spread of Blastocystis sp.