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Trends in Parasitology Jul 2014Trichomonads are common parasites of many vertebrate and invertebrate species, with four species classically recognized as human parasites: Dientamoeba fragilis,... (Review)
Review
Trichomonads are common parasites of many vertebrate and invertebrate species, with four species classically recognized as human parasites: Dientamoeba fragilis, Pentatrichomonas hominis, Trichomonas vaginalis, and Trichomonas tenax. The latter two species are considered human-specific; by contrast, D. fragilis and P. hominis have been isolated from domestic and farm mammals, demonstrating a wide host range and potential zoonotic origin. Several new studies have highlighted the zoonotic dimension of trichomonads. First, species typically known to infect birds and domestic mammals have been identified in human clinical samples. Second, several phylogenetic analyses have identified animal-derived trichomonads as close sister taxa of the two human-specific species. It is our opinion, therefore, that these observations prompt further investigation into the importance of zoonotic trichomonads for human health.
Topics: Animals; Bird Diseases; Birds; Humans; Phylogeny; Trichomonas Infections; Trichomonas vaginalis; Zoonoses
PubMed: 24951156
DOI: 10.1016/j.pt.2014.05.005 -
Clinical Microbiology Reviews Jul 2016Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its... (Review)
Review
Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome.
Topics: Animals; Dientamoeba; Dientamoebiasis; Disease Models, Animal; Humans; Intestines; Life Cycle Stages; Phylogeny
PubMed: 27170141
DOI: 10.1128/CMR.00076-15 -
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 -
Journal of Clinical Microbiology Sep 2016Dientamoeba fragilis is a single-celled protozoan, closely related to the trichomonads. Reported worldwide as causing human gastrointestinal symptoms, D. fragilis is... (Review)
Review
Dientamoeba fragilis is a single-celled protozoan, closely related to the trichomonads. Reported worldwide as causing human gastrointestinal symptoms, D. fragilis is very common and is second only to Blastocystis spp. Dientamoebiasis equals or exceeds the incidence of giardiasis. This minireview includes diagnostic options, clinical relevance, therapy, an animal model, the confirmed cyst stage, and sequencing data. The development of a rodent model, fulfilling Koch's postulates, and the confirmation of a cyst stage have clarified transmission routes, including fecal-oral transmission. The prevalence of D. fragilis varies between 0% to over 82%; results depend on the geographic location, group studied, and diagnostic methods used.
Topics: Animals; Antiprotozoal Agents; Dientamoeba; Dientamoebiasis; Disease Models, Animal; Humans; Incidence; Intestinal Diseases, Parasitic; Neglected Diseases; Prevalence
PubMed: 27053676
DOI: 10.1128/JCM.00400-16 -
Virus Evolution 2022Metagenomic techniques have facilitated the discovery of thousands of viruses, yet because samples are often highly biodiverse, fundamental data on the specific cellular...
Metagenomic techniques have facilitated the discovery of thousands of viruses, yet because samples are often highly biodiverse, fundamental data on the specific cellular hosts are usually missing. Numerous gastrointestinal viruses linked to human or animal diseases are affected by this, preventing research into their medical or veterinary importance. Here, we developed a computational workflow for the prediction of viral hosts from complex metagenomic datasets. We applied it to seven lineages of gastrointestinal cressdnaviruses using 1,124 metagenomic datasets, predicting hosts of four lineages. The , strongly associated to human gum disease (periodontitis), were predicted to infect , an oral pathogen itself involved in periodontitis. The , originally linked to fatal equine disease, were predicted to infect a variety of parabasalid protists, including in humans. Two viral lineages observed in human diarrhoeal disease (CRESSV1 and CRESSV19, i.e. pecoviruses and hudisaviruses) were predicted to infect spp. and respectively, protists responsible for millions of annual human infections. Our prediction approach is adaptable to any virus lineage and requires neither training datasets nor host genome assemblies. Two host predictions (for the and CRESSV1 lineages) could be independently confirmed as virus-host relationships using endogenous viral elements identified inside host genomes, while a further prediction (for the ) was strongly supported as a virus-host relationship using a case-control screening experiment of human oral plaques.
PubMed: 36325032
DOI: 10.1093/ve/veac087 -
Revista Do Instituto de Medicina... 2021In order to provide additional data on the prevalence and genetic diversity of Dientamoeba fragilis in human populations, we conducted a study in children from...
In order to provide additional data on the prevalence and genetic diversity of Dientamoeba fragilis in human populations, we conducted a study in children from low-income communities in Sao Paulo State, Brazil. Fecal samples from daycare center attendees up to 6 years old (n=156) and staff members (n=18) were submitted to PCR and sequencing of D. fragilis as well as to microscopic examination for the presence of other intestinal parasites. All children assessed were asymptomatic and 10.3% (16/156) were positive for D. fragilis. No worker was found to be positive. An association between Dientamoeba and coinfection with other intestinal parasites was observed. Concerning the genetic diversity, 14 and only two isolates were genotype 1 and genotype 2, respectively. Our findings outline interesting aspects: (1) asymptomatic children as carriers of Dientamoeba in communities in which environmental conditions ensure parasite transmission and, (2) association between Dientamoeba infection in young children and coinfection with other enteric parasites, reinforcing its transmission via the fecal-oral route.
Topics: Brazil; Child; Child, Preschool; Dientamoeba; Dientamoebiasis; Feces; Humans; Intestinal Diseases, Parasitic; Prevalence
PubMed: 33978095
DOI: 10.1590/S1678-9946202163039 -
Pathogens (Basel, Switzerland) Jun 2023We aimed to assess the performance of the Novodiag Stool Parasites (NSP) assay in the diagnosis of the most common intestinal protozoan and microsporidia infections.
OBJECTIVES
We aimed to assess the performance of the Novodiag Stool Parasites (NSP) assay in the diagnosis of the most common intestinal protozoan and microsporidia infections.
METHODS
A panel of 167 selected stool samples was retrospectively analysed with the NSP assay and compared to routine microscopy and qPCR methods for the detection of pathogenic protozoa and microsporidia.
RESULTS
Whereas specificity was high for all protozoa and microsporidia, NSP sensitivity was strongly dependent on the comparative method used as reference. When compared to microscopic methods, NSP sensitivity was high (96.7 to 100%) for , and but was lower for (85.2%) and ≤50% for and . In comparison to conventional qPCR, the NSP assay demonstrated lower sensitivity characteristics dependent on parasite loads, reaching 60 to 70% for , , spp. and Sensitivity was 100% for , but none of the five samples containing spp. were detected.
CONCLUSIONS
The overall performance of the NSP assay in the diagnosis of gastrointestinal protozoa and microsporidia seems to be better than or equivalent to that observed with microscopic methods but inferior to that obtainable with classical targeted qPCR.
PubMed: 37513736
DOI: 10.3390/pathogens12070889 -
Archives of Disease in Childhood Jul 2019To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
OBJECTIVE
To study the association between colonisation and faecal calprotectin to see whether the parasite is a harmless commensal or a gut pathogen.
DESIGN
Cross-sectional study of previously collected stool samples.
SETTING AND PATIENTS
Two hundred stool samples originated from children aged 5-19 years with chronic abdominal pain and diarrhoea, who were seen in paediatric clinics in the Netherlands and Belgium and in whom somatic gastrointestinal disorders were excluded. Another 122 samples came from a healthy community-based reference population of the same age. All stool samples were analysed with real-time PCR for the detection of and with an ELISA for calprotectin-a biomarker of gastrointestinal inflammation.
MAIN OUTCOME MEASURES
Prevalence of colonisation and results of stool calprotectin testing.
RESULTS
was detected in 45% (95% CI 38% to 51%) of patients and in 71% (95% CI 63% to 79%) of healthy children. Median (IQR) concentrations of calprotectin in patients and healthy children with a positive PCR result were not different from those with a negative PCR result (40 (40-55) μg/g vs 40 (40-75) μg/g, respectively).
CONCLUSION
Since colonisation is most prevalent in healthy children and is not associated with an increase in faecal calprotectin concentration, our data do not support the inference that is a pathogenic parasite. Routinely testing for in children with chronic abdominal pain should therefore be discouraged.
Topics: Abdominal Pain; Adolescent; Belgium; Child; Child, Preschool; Cohort Studies; Cross-Sectional Studies; Dientamoeba; Dientamoebiasis; Feces; Female; Humans; Male; Netherlands; Prevalence; Prospective Studies; Real-Time Polymerase Chain Reaction; Retrospective Studies; Young Adult
PubMed: 30798256
DOI: 10.1136/archdischild-2018-316383 -
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 -
Biology Nov 2022The human gastrointestinal microbiota contains a diverse consortium of microbes, including bacteria, protozoa, viruses, and fungi. Through millennia of co-evolution, the... (Review)
Review
The human gastrointestinal microbiota contains a diverse consortium of microbes, including bacteria, protozoa, viruses, and fungi. Through millennia of co-evolution, the host-microbiota interactions have shaped the immune system to both tolerate and maintain the symbiotic relationship with commensal microbiota, while exerting protective responses against invading pathogens. Microbiome research is dominated by studies describing the impact of prokaryotic bacteria on gut immunity with a limited understanding of their relationship with other integral microbiota constituents. However, converging evidence shows that eukaryotic organisms, such as commensal protozoa, can play an important role in modulating intestinal immune responses as well as influencing the overall health of the host. The presence of several protozoa species has recently been shown to be a common occurrence in healthy populations worldwide, suggesting that many of these are commensals rather than invading pathogens. This review aims to discuss the most recent, conflicting findings regarding the role of intestinal protozoa in gut homeostasis, interactions between intestinal protozoa and the bacterial microbiota, as well as potential immunological consequences of protozoa colonization.
PubMed: 36552252
DOI: 10.3390/biology11121742