Distribution and relevance of Dientamoeba fragilis and Blastocystis species in gastroenteritis: results from a case-control study

Boer, Maria Dullaert de; Schuurs, Theo A.; Vermeer, Marloes; Ruijs, G. J. H. M.; Zanden, Adri G. M. van der; Weel, Jan; Coppenraet, L.E.S. Bruijnesteijn van

doi:10.1007/s10096-019-03710-z

Cited by 27 publications

(31 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Blastocystis sp. and Dientamoeba fragilis are cosmopolitan intestinal protists commonly reported in people with and without symptoms [ 6 – 9 ]. Gastrointestinal symptoms, such as diarrhea, abdominal pain, and irritable bowel syndrome, have been associated with their infections/colonizations [ 10 – 12 ].…”

Section: Introductionmentioning

confidence: 99%

Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods

et al. 2021

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

confidence: 99%

Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Other species such as the stramenopile Blastocystis sp. and the trichomonad Dientamoeba fragilis have a less-defined pathogenic potential [6,7]. In contrast with the relative abundance of data existing in endemic areas, a comparatively much lower amount of information is currently available on the epidemiology of diarrhoea-causing protistan pathogens in medium-Parasitologia 2021, 1 84 to high-income countries.…”

Section: Introductionmentioning

confidence: 99%

Molecular Detection and Genotyping of Enteric Protists in Asymptomatic Schoolchildren and Their Legal Guardians in Madrid, Spain

et al. 2021

View full text Add to dashboard Cite

Asymptomatic carriage of diarrhoea-causing enteric protist parasites in the general population is poorly understood, particularly in medium- to high-income countries. This molecular epidemiological survey investigates the presence, molecular diversity, and household transmission of Giardia duodenalis, Cryptosporidium spp., Blastocystis sp., and Enterocystozoon bieneusi in schoolchildren aged 2–13 years (n = 74) and their legal guardians (n = 6) in Madrid, Spain. Enteroparasite detection and genotyping was conducted in stool samples by molecular (PCR and Sanger sequencing) methods. Potential associations linked to infections were investigated through epidemiological questionnaires. Giardia duodenalis was the most prevalent enteric parasite found (14%, 95% CI: 7.1–23), followed by Blastocystis sp. (10%, 95% CI: 6.2–22) and Cryptosporidium spp. (3.8%, 95% CI: 0.78–11). None of the participants tested positive for E. bieneusi. Sequence analyses revealed the presence of G. duodenalis assemblage B, sub-assemblage BIV in a single child. The three Cryptosporidium isolates obtained were assigned to C. hominis, two of them belonging to the gp60 subtype IbA10G2. Four Blastocystis subtypes were identified including ST2 (38%, 3/8), ST3 (25%, 2/8), ST4 (25%, 2/8), and ST8 (12%, 1/8). All G. duodenalis and Cryptosporidium isolates were detected in children only. Blastocystis ST3 and ST4 were circulating in members of the same household. Blastocystis carriage rates increased with the age of the participants. Presence of diarrhoea-causing enteric protists was common in apparently healthy children.

show abstract

“…A case control study reported that GI symptoms were more common in cases without D. fragilis or Blastocystis. In addition, they reported that both D. fragilis and Blastocystis frequency was higher in healthy controls than in cases with symptoms (35). However, some reported a correlation with age of cases and Blastocystis infection in particular age groups (19).…”

Section: Discussionmentioning

confidence: 98%

The high co-existence rate of Blastocystis and Dientamoeba fragilis in human faecal samples and the analysis of demographic and clinical findings

Malatyalı

Yıldız

Tileklioğlu

et al. 2021

Journal of Health Sciences and Medicine

View full text Add to dashboard Cite

Aim: Blastocystis and Dientamoeba fragilis (D. fragilis) are among the most common protozoon species in human faecal samples. The cross-sectional studies have reported the frequencies in a variety of populations. However, we have very limited information about the co-existence rate of those protozoans. The study aimed to compare D. fragilis frequency in Blastocystis positive and negative faecal samples in order to determine the co-existence rate. The secondary objective was to analyse demographic characteristics and gastrointestinal (GI) symptoms in relation to both infections. Material and Method: In the present study, we defined a study group that included 100 Blastocystis positive faecal samples and a control group that included 100 Blastocystis negative samples. The frequency of D. fragilis in samples was determined with a PCR assay specific to the small-subunit ribosomal RNA (SS rRNA) gene. A positive control of D. fragilis was used and the samples with amplification of the expected size (863 bp) were considered as positive. In addition to the statistical comparison of frequencies, the descriptive and clinical findings of cases were analysed retrospectively with Pearson chi-square or ANOVA tests. Results: The frequency of D. fragilis was 21% in Blastocystis positive group and it was 10% in Blastocystis negative group. There was statistically significant difference in terms of D. fragilis positivity between the groups (p <0.05). Age, gender and GI symptoms did not reveal a significant difference between the following groups: only Blastocystis infected (n=77), only D. fragilis infected (n=11), infected with both protozoans (n=34) and non-infected individuals (n=89) (p >0.05). Conclusion:Our study highlighted the high co-existence of D. fragilis and Blastocystis in human faecal samples. A possible explanation for this finding may be the faecal-oral transmission of these protozoans. In addition, analysis of clinical findings was supported common asymptomatic colonisation of Blastocystis and D. fragilis.

show abstract

Distribution and relevance of Dientamoeba fragilis and Blastocystis species in gastroenteritis: results from a case-control study

Cited by 27 publications

References 32 publications

Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods

Investigation of neglected protists Blastocystis sp. and Dientamoeba fragilis in immunocompetent and immunodeficient diarrheal patients using both conventional and molecular methods

Molecular Detection and Genotyping of Enteric Protists in Asymptomatic Schoolchildren and Their Legal Guardians in Madrid, Spain

The high co-existence rate of Blastocystis and Dientamoeba fragilis in human faecal samples and the analysis of demographic and clinical findings

Contact Info

Product

Resources

About