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Parasitology Mar 2024Little is known about the life cycle and mode of transmission of . Recently it was suggested that fecal–oral transmission of cysts may play a role in the transmission...
Little is known about the life cycle and mode of transmission of . Recently it was suggested that fecal–oral transmission of cysts may play a role in the transmission of . In order to establish an infection, is required to remain viable when exposed to the pH of the stomach. In this study, we investigated the ability of cultured trophozoites to withstand the extremes of pH. We provide evidence that trophozoites of are vulnerable to highly acidic conditions. We also investigated further the ultrastructure of cysts obtained from mice and rats by transmission electron microscopy. These studies of cysts showed a clear cyst wall surrounding an encysted parasite. The cyst wall was double layered with an outer fibrillar layer and an inner layer enclosing the parasite. Hydrogenosomes, endoplasmic reticulum and nuclei were present in the cysts. Pelta-axostyle structures, costa and axonemes were identifiable and internal flagellar axonemes were present. This study therefore provides additional novel details and knowledge of the ultrastructure of the cyst stage of .
Topics: Animals; Rats; Mice; Dientamoebiasis; Dientamoeba; Life Cycle Stages; Trophozoites; Endoplasmic Reticulum; Feces; Cysts
PubMed: 38250789
DOI: 10.1017/S0031182024000076 -
Dientamoeba fragilis associated with microbiome diversity changes in acute gastroenteritis patients.Parasitology International Dec 2023This study examined the correlation between intestinal protozoans and the bacterial microbiome in faecal samples collected from 463 patients in New Zealand who were...
This study examined the correlation between intestinal protozoans and the bacterial microbiome in faecal samples collected from 463 patients in New Zealand who were diagnosed with gastroenteritis. In comparison to traditional microscopic diagnosis methods, Multiplexed-tandem PCR proved to be more effective in detecting intestinal parasites. Among the identified protozoans, Blastocystis sp. and Dientamoeba fragilis were the most prevalent. Notably, D. fragilis was significantly associated with an increase in the alpha-diversity of host prokaryotic microbes. Although the exact role of Blastocystis sp. and D. fragilis as the primary cause of gastroenteritis remains debatable, our data indicates a substantial correlation between these protozoans and the prokaryote microbiome of their hosts, particularly when compared to other protists or patients with gastroenteritis but no detectable parasitic cause. These findings underscore the significance of comprehending the contributions of intestinal protozoans, specifically D. fragilis, to the development of gastroenteritis and their potential implications for disease management.
Topics: Animals; Humans; Dientamoeba; Intestinal Diseases, Parasitic; Blastocystis; Gastroenteritis; Parasites; Feces
PubMed: 37482266
DOI: 10.1016/j.parint.2023.102788 -
Parasites & Vectors Nov 2023Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus paracasei 8700:2 positively affect the fecal bacteriome in children with celiac disease autoimmunity after 6... (Randomized Controlled Trial)
Randomized Controlled Trial
Effects of Lactiplantibacillus plantarum and Lacticaseibacillus paracasei supplementation on the single-cell fecal parasitome in children with celiac disease autoimmunity: a randomized, double-blind placebo-controlled clinical trial.
BACKGROUND
Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus paracasei 8700:2 positively affect the fecal bacteriome in children with celiac disease autoimmunity after 6 months of supplementation. The aim of the present investigation was to study the effects of Lactiplantibacillus plantarum HEAL9 and Lacticaseibacillus paracasei 8700:2 on the single-cell parasitome, with a primary focus on Blastocystis.
METHODS
Stool samples were collected from 78 Swedish children with celiac disease autoimmunity participating in a randomized, double-blind, placebo-controlled clinical trial to either receive a mixture of supplementation with L. plantarum HEAL9 and L. paracasei 8700:2 (n = 38) or placebo (n = 40). A total of 227 stool samples collected at baseline and after 3 and 6 months of intervention, respectively, were retrospectively analyzed for Blastocystis by quantitative real-time PCR and subtyped by massively parallel amplicon sequencing. Other single-cell parasites were detected by untargeted 18S rDNA amplicon sequencing and verified by real-time PCR. The relation between the parasites and the bacteriome community was characterized by using 16S rDNA profiling of the V3-V4 region.
RESULTS
Three different single-cell protists were identified, of which the highest prevalence was found for Dientamoeba fragilis (23.1%, 18/78 children), followed by Blastocystis (15.4%, 12/78) and Entamoeba spp. (2.6%, 2/78). The quantity of the protists was stable over time and not affected by probiotic intervention (P = 0.14 for Blastocystis, P = 0.10 for D. fragilis). The positivity of the protists was associated with increased bacteriome diversity (measured by multiple indices, P < 0.03). Bacterial composition was influenced by the presence of the protists: positivity of Blastocystis was inversely associated with Akkermansia (at the levels of the genus as well as its family, order, class and phylum); P < 0.002), Faecalibacterium (P = 0.003) and Romboutsia (P = 0.029); positivity of D. fragilis was inversely associated with families Enterobacteriaceae (P = 0.016) and Coriobacteriaceae (P = 0.022) and genera Flavonifractor (P < 0.001), Faecalibacterium (P = 0.009), Lachnoclostridium (P = 0.029), Ruminococcus (P < 0.001) and Granulicatella (P = 0.018).
CONCLUSIONS
The prevalence of single-cell protists is low in children with celiac disease autoimmunity. The colonization was stable regardless of the probiotic intervention and associated with increased diversity of the fecal bacteriome but inversely associated with some beneficial bacteria.
Topics: Humans; Child; Lacticaseibacillus; Lacticaseibacillus paracasei; Autoimmunity; Celiac Disease; Retrospective Studies; Feces; Blastocystis; Bacteria; Probiotics; Double-Blind Method; DNA, Ribosomal
PubMed: 37946274
DOI: 10.1186/s13071-023-06027-1 -
Parasitology Research Apr 2024Dientamoeba fragilis and Blastocystis sp. are single-celled protozoan parasites of humans and animals. Although they are found in the intestines of healthy hosts, the...
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.
Topics: Humans; Animals; Sheep; Cattle; Swine; Blastocystis; Dientamoeba; Houseflies; Blastocystis Infections; Muscidae; Genotype; Feces; Prevalence; Nucleotides
PubMed: 38622363
DOI: 10.1007/s00436-024-08202-4 -
European Journal of Gastroenterology &... Feb 2022
Topics: Blastocystis; Dientamoeba; Feces; Freezing; Humans; Irritable Bowel Syndrome
PubMed: 34845142
DOI: 10.1097/MEG.0000000000002327 -
PloS One 2022The increasing interest to perform and investigate the efficacy of fecal microbiota transplantation (FMT) has generated an urge for feasible donor screening. We report...
BACKGROUND
The increasing interest to perform and investigate the efficacy of fecal microbiota transplantation (FMT) has generated an urge for feasible donor screening. We report our experience with stool donor recruitment, screening, follow-up, and associated costs in the context of clinical FMT trials.
METHODS
Potential stool donors, aged between 18-65 years, underwent a stepwise screening process starting with an extensive questionnaire followed by feces and blood investigations. When eligible, donors were rescreened for MDROs and SARS-CoV-2 every 60-days, and full rescreening every 4-6 months. The costs to find and retain a stool donor were calculated.
RESULTS
From January 2018 to August 2021, 393 potential donors underwent prescreening, of which 202 (51.4%) did not proceed primarily due to loss to follow-up, medication use, or logistic reasons (e.g. COVID-19 measures). 191 potential donors filled in the questionnaire, of which 43 (22.5%) were excluded. The remaining 148 candidates underwent parasitology screening: 91 (61.5%) were excluded, mostly due to Dientamoeba fragilis and/or high amounts of Blastocystis spp. After additional feces investigations 18/57 (31.6%) potential donors were excluded (mainly for presence of Helicobacter Pylori and ESBL-producing organisms). One donor failed serum testing. Overall, 38 out of 393 (10%) potential donors were enrolled. The median participation time of active stool donors was 13 months. To recruit 38 stool donors, €64.112 was spent.
CONCLUSION
Recruitment of stool donors for FMT is challenging. In our Dutch cohort, failed eligibility of potential donors was often caused by the presence of the protozoa Dientamoeba fragilis and Blastocystis spp.. The exclusion of potential donors that carry these protozoa, especially Blastocystis spp., is questionable and deserves reconsideration. High-quality donor screening is associated with substantial costs.
Topics: Humans; Adolescent; Young Adult; Adult; Middle Aged; Aged; Fecal Microbiota Transplantation; Donor Selection; SARS-CoV-2; COVID-19; Feces; Clostridium Infections
PubMed: 36264933
DOI: 10.1371/journal.pone.0276323 -
The Pediatric Infectious Disease Journal Apr 2021Dientamoeba fragilis in children has been associated with gastrointestinal symptoms, like abdominal pain and diarrhea. The mechanism underlying these symptoms in...
BACKGROUND
Dientamoeba fragilis in children has been associated with gastrointestinal symptoms, like abdominal pain and diarrhea. The mechanism underlying these symptoms in children with D. fragilis remains unclear. We hypothesized that concomitant microbial alterations, which have been described in other parasitic infections, may be associated with gastrointestinal symptoms in D. fragilis.
METHODS
In this case-control study performed in 2 centers, 19 children referred to a pediatrician because of gastrointestinal symptoms and with a positive fecal PCR for D. fragilis were included as cases. We included 19 healthy children as controls and matched for age and gender, selected from an existing cohort of 63 children. A PCR for D. fragilis was performed on fecal samples of the 19 controls to assess D. fragilis carriership in this asymptomatic group. Microbiota was analyzed with the IS-pro technique, and the intestinal microbiota composition and diversity were compared between the 2 groups.
RESULTS
Microbiota of children with D. fragilis and gastrointestinal symptoms did not significantly differ in terms of composition and diversity compared with controls, both on phylum and species level. In the asymptomatic controls, a positive fecal PCR for D. fragilis was found in 16 of 19 (84.2%).
CONCLUSION
Intestinal microbiota does not seem to play a key role in the presence of clinical symptoms in children with D. fragilis. The pathogenicity of D. fragilis and pathophysiologic pathways underlying the development of gastrointestinal symptoms remains yet to be clarified.
Topics: Abdominal Pain; Case-Control Studies; Child; Child, Preschool; Cohort Studies; Diarrhea; Dientamoeba; Dientamoebiasis; Feces; Gastrointestinal Diseases; Gastrointestinal Microbiome; Genetic Variation; Humans
PubMed: 33181781
DOI: 10.1097/INF.0000000000002975 -
International Journal of Molecular... Dec 2022is a cosmopolitan intestinal protist colonizing the human gut with varying prevalence depending on the cohort studied and the diagnostic methods used. Its role in human...
is a cosmopolitan intestinal protist colonizing the human gut with varying prevalence depending on the cohort studied and the diagnostic methods used. Its role in human health remains unclear mainly due to the very sporadic number of cross-sectional studies in gut-healthy populations. The main objective of this study was to expand knowledge of the epidemiology of in gut-healthy humans and their animals. A total of 296 stool samples from humans and 135 samples from 18 animal species were analyzed. Using qPCR, a prevalence of 24% was found in humans in contrast to conventional PCR (7%). In humans, several factors were found to influence the prevalence of . A more frequent occurrence of was associated with living in a village, traveling outside Europe and contact with farm animals. In addition, co-infection with spp. was observed in nearly half of the colonized humans. In animals, was detected in 13% of samples from eight species using qPCR. Our molecular phylogenies demonstrate a more frequent occurrence of Genotype 1 in gut-healthy humans and also revealed a likely a new protist species/lineage in rabbits related to and other related organisms.
Topics: Animals; Humans; Rabbits; Cross-Sectional Studies; Dientamoebiasis; Feces; Dientamoeba; Prevalence
PubMed: 36499734
DOI: 10.3390/ijms232315407 -
Journal of Travel Medicine Feb 2023Blastocystis sp. is a worldwide-distributed protist colonizing the guts of humans and a great variety of animals. It is unclear whether it is just a commensal or an... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Blastocystis sp. is a worldwide-distributed protist colonizing the guts of humans and a great variety of animals. It is unclear whether it is just a commensal or an infectious parasite that prompts eradication.The main objective of this study was to evaluate the usefulness of metronidazole in patients with gastrointestinal symptoms harbouring only Blastocystis sp. In addition, we explored whether Blastocystis subtype or concomitant parasitic infection detected by polymerase chain reaction (PCR) may influence treatment outcome.
METHODS
We included adults with persistent gastrointestinal symptoms (>14 days) visiting a primary care physician and in whom stool microscopy revealed only Blastocystis sp. Eligible patients were randomized to receive 10 days of metronidazole or placebo, followed by a crossover if still symptomatic. The primary outcome was normal stool consistency. Secondary outcomes were the changes in other abdominal symptoms (bloating, flatulence, abdominal pain, number of daily bowel movements) and general wellbeing. After the clinical phase of the study, Blastocystis subtypes were determined by PCR sequencing and stool samples were tested for 11 other protozoa with an in-house PCR.
RESULTS
We screened 581 outpatients for inclusion, of which 50 met the eligibility criteria. There was no difference in the primary outcome, nor any of the secondary outcomes between the subjects treated with metronidazole and placebo.The most frequent Blastocystis subtypes were ST4 (11/36) and ST2 (10/36). The in-house PCR was positive for other protozoa in 25% (10/40) of the patients. We identified Dientamoeba fragilis in 5, Entamoeba dispar in 3 and Cyclospora cayetanensis in 2 patients. Stratified analysis according to Blastocystis subtype or the presence of other protozoa showed no significant difference in treatment outcome with metronidazole or placebo.
CONCLUSIONS
Among patients infected with Blastocystis sp., metronidazole, compared with placebo, was not better in improving gastrointestinal symptoms, irrespective of subtype or microscopically undetected coinfection with other protozoa.
Topics: Adult; Animals; Humans; Blastocystis; Blastocystis Infections; Metronidazole; Pilot Projects; Gastrointestinal Diseases; Feces
PubMed: 36440639
DOI: 10.1093/jtm/taac143 -
Tropical Medicine and Infectious Disease Sep 2021While the prevalence of intestinal parasitic infections (IPI) has been most commonly studied in African and Asian populations, less is known about the prevalence rates... (Review)
Review
While the prevalence of intestinal parasitic infections (IPI) has been most commonly studied in African and Asian populations, less is known about the prevalence rates of IPI in European children, as well as the potential risk factors that favor the spread of parasites. We aimed to review published evidence on the prevalence rates of IPI in children residing in Europe, and to quantitatively synthesize the results of published studies. We searched Medline from 1 January 2015 to 1 April 2021 to address the most recently published prevalence patterns of IPI in European children. Random-effects meta-analyses were performed by type of IPI infection, age group and sex, depending on data availability. Of the 967 potentially relevant articles, eight eligible cross-sectional studies were included in this analysis, yielding a sample of 3376 children (0-19 years). The overall prevalence rate was 5.9% for any IPI in children residing in European countries. was the most commonly detected parasite yielding a prevalence rate of 10.7%. Other parasites included and . Studies focusing on specific types of parasites showed prevalence rates ranging from 1.3% for to 68.3% for . Despite the scarce literature, the present review showed relatively low prevalence rates of IPI in Europe. Future studies accounting for proper diagnostic methods used for the detection of parasites and including information on potential sociodemographic factors, such as travelling history and history of immigration, are needed to guide clinicians about which children to test, as well as when and how to test children for IPI.
PubMed: 34564544
DOI: 10.3390/tropicalmed6030160