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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 -
New Microbes and New Infections Sep 2023(), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling....
BACKGROUND
(), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling. Currently, many studies of treatment options only have small sample sizes and report results that are partly contradictory.
METHODS
Investigating data retrieved from Helsinki University Hospital and Helsinki City patient records, we searched for the most effective antiprotozoal in treating infections. To study microbiological clearance of , we collected laboratory results of control samples from patients given one of four commonly used antiprotozoals: doxycycline, metronidazole, paromomycin, or secnidazole. For patients symptomatic prior to antiprotozoal treatment, we also retrieved data on clinical outcomes. Furthermore, we explored factors associated with faecal clearance and clinical cure.
RESULTS
A total of 369 patients (median age 38) and 492 treatment episodes were included. Paromomycin (n = 297) proved effective (clearance rate 83%), showing strong association with faecal clearance (aOR 18.08 [7.24-45.16], p < 0.001). For metronidazole the rate was 42% (n = 84), for secnidazole 37% (n = 79), and doxycycline 22% (n = 32). In pairwise comparisons, paromomycin outdid the three other regimens (p < 0.001, test). Faecal clearance was associated with clinical cure (aOR 5.85 [3.02-11.32], p < 0.001).
CONCLUSIONS
Faecal clearance, strongly associated with clinical cure, is most effectively achieved with a course of paromomycin, followed by metronidazole, secnidazole and doxycycline. Our findings will be useful in devising treatment guidelines for adults with symptomatic infection.
PubMed: 37786407
DOI: 10.1016/j.nmni.2023.101179 -
Tropical Parasitology 2022() diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2%...
INTRODUCTION
() diagnosis is an intestinal protozoan parasite globally found in rural and urban areas and is attracting a growing interest. Its prevalence in stool varies from 0.2% to more than 19% depending upon the population studied.
MATERIALS AND METHODS
This study was based on the examination of 100 stool samples of randomly referred cases in a rural area in Motobus district, Kafr El-Sheikh governorate, Egypt. Our aim was to investigate the presence of in stool of the examined individuals using conventional polymerase chain reaction (PCR) compared to wet mount and trichrome stain with confirmation of infection by transmission electron microscopy.
RESULTS
was detected in 13/100 of the stool samples examined using wet mount smears, while trichrome stain detected 17/100. Conventional PCR diagnosed 41 cases of in the studied group. A very good agreement was found between wet mount and trichrome stain for diagnosing , while there was fair agreement between conventional PCR and both microscopy methods. Transmission electron microscope was performed on pooled positive samples that revealed the internal structures of trophozoite with its characteristic nucleus.
CONCLUSIONS
PCR technique was superior to microscopy for the detection of . Trichrome stain remains vital for microscopic diagnosis.
PubMed: 36643979
DOI: 10.4103/tp.tp_93_21 -
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 -
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 -
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 -
PLoS Neglected Tropical Diseases Oct 2021The clinical significance of Blastocystis sp. and Dientamoeba fragilis in patients with gastrointestinal symptoms is a controversial issue. Since the pathogenicity of...
Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods.
INTRODUCTION
The clinical significance of Blastocystis sp. and Dientamoeba fragilis in patients with gastrointestinal symptoms is a controversial issue. Since the pathogenicity of these protists has not been fully elucidated, testing for these organisms is not routinely pursued by most laboratories and clinicians. Thus, the prevalence of these organisms and the subtypes of Blastocystis sp. in human patients in Turkey are not well characterized. This study aimed to determine the prevalence of Blastocystis sp. and D. fragilis in the diarrheic stool samples of immunodeficient and immunocompetent patients using conventional and molecular methods and to identify Blastocystis sp. subtypes using next generation sequencing.
MATERIAL AND METHODS
Individual stool specimens were collected from 245 immunodeficient and 193 immunocompetent diarrheic patients between March 2017 and December 2019 at the Gazi University Training and Research Hospital in Ankara, Turkey. Samples were screened for Blastocystis sp. and D. fragilis by conventional and molecular methods. Molecular detection of both protists was achieved by separate qPCRs targeting a partial fragment of the SSU rRNA gene. Next generation sequencing was used to identify Blastocystis sp. subtypes.
RESULTS
The prevalence of Blastocystis sp. and D. fragilis was 16.7% and 11.9%, respectively as measured by qPCR. The prevalence of Blastocystis sp. and D. fragilis was lower in immunodeficient patients (12.7% and 10.6%, respectively) compared to immunocompetent patients (21.8% and 13.5%, respectively). Five Blastocystis sp. subtypes were identified and the following subtype distribution was observed: ST3 54.4% (n = 37), ST2 16.2% (n = 11), ST1 4.4% (n = 3), ST6 2.9% (n = 2), ST4 1.5% (n = 1), ST2/ST3 11.8% (n = 8) and ST1/ST3 8.8% (n = 6). There was no statistically significant difference in the distribution of Blastocystis sp. subtypes between immunocompetent and immunodeficient patients.
CONCLUSION AND RECOMMENDATION
Our findings demonstrated that Blastocystis sp. and D. fragilis are commonly present in immunocompetent and immunodeficient patients with diarrhea. This study is the first to use next generation sequencing to address the presence of Blastocystis sp. mixed subtypes and intra-subtype variability in clinical samples in Turkey.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Blastocystis; Diarrhea; Dientamoeba; Feces; Female; High-Throughput Nucleotide Sequencing; Humans; Immunocompetence; Male; Middle Aged; Primary Immunodeficiency Diseases; Turkey; Young Adult
PubMed: 34613993
DOI: 10.1371/journal.pntd.0009779 -
The Korean Journal of Parasitology Apr 2020In most developing countries, Dientamoeba fragilis infection is an obscure protozoan infection. We aimed to determine a frequency and clinical importance of D. fragilis...
In most developing countries, Dientamoeba fragilis infection is an obscure protozoan infection. We aimed to determine a frequency and clinical importance of D. fragilis infection in Taif, Saudi Arabia. A 1-year case control study included patients with gastrointestinal (cases, n=114) or non-gastrointestinal symptoms (controls, n=90). The fecal samples were examined with the classical parasitological methods for intestinal protozoa, and by real time PCR for D. fragilis. The infection by D. fragilis was detected in 5.8% by PCR and in 4.4% patients by microscopy. The infection was identified more in control group (n=9) than in cases (n=3); a sole infection in 11 patients and mixed with Giardia in 1 patient. The other enteric parasites detected were Blastocystis sp. (8.3%), Giardia sp. (5.3%), Cryptosporidium sp. (2.9%), Entamoeba histolytica (1.4%), Entamoeba coli (0.9%) and Hymenolepis nana (0.4%). Our results tend to reinforce the need to increase awareness of D. fragilis infection in Saudi Arabia.
Topics: Asymptomatic Diseases; Case-Control Studies; Dientamoeba; Dientamoebiasis; Digestive System Diseases; Humans; Polymerase Chain Reaction; Saudi Arabia
PubMed: 32418381
DOI: 10.3347/kjp.2020.58.2.129 -
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