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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 -
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 -
Journal of Infection in Developing... Jan 2018Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to...
INTRODUCTION
Dientamoeba fragilis, an intestinal trichomonad, occurs in humans with and without gastrointestinal symptoms. Its presence was investigated in individuals referred to Milad Hospital, Tehran.
METHODOLOGY
In a cross-sectional study, three time-separated fecal samples were collected from 200 participants from March through June 2011. Specimens were examined using traditional techniques for detecting D. fragilis and other gastrointestinal parasites: direct smear, culture, formalin-ether concentration, and iron-hematoxylin staining. The presence of D. fragilis was determined using PCR assays targeting 5.8S rRNA or small subunit ribosomal RNA.
RESULTS
Dientamoeba fragilis, Blastocystis sp., Giardia lamblia, Entamoeba coli, and Iodamoeba butschlii were detected by one or more traditional and molecular methods, with an overall prevalence of 56.5%. Dientamoeba was not detected by direct smear or formalin-ether concentration but was identified in 1% and 5% of cases by culture and iron-hematoxylin staining, respectively. PCR amplification of SSU rRNA and 5.8S rRNA genes diagnosed D. fragilis in 6% and 13.5%, respectively. Prevalence of D. fragilis was unrelated to participant gender, age, or gastrointestinal symptoms.
CONCLUSIONS
This is the first report of molecular assays to screen for D. fragilis in Iran. The frequent finding of D. fragilis via fecal analysis indicated the need to include this parasite in routine stool examination in diagnostic laboratories. As the length of amplification target correlates to the sensitivity of PCR, this assay targeting the D. fragilis 5.8S rRNA gene seems optimal for parasite detection and is recommended in combination with conventional microscopy for diagnosing intestinal parasites.
PubMed: 31628834
DOI: 10.3855/jidc.9643 -
The American Journal of Tropical... Nov 2018is an intestinal protozoan, usually considered nonpathogenic. However, in the last years, there has been an attempt to clarify its possible pathogenic role. We aim to... (Observational Study)
Observational Study
is an intestinal protozoan, usually considered nonpathogenic. However, in the last years, there has been an attempt to clarify its possible pathogenic role. We aim to evaluate the clinical and epidemiological characteristics of -infected patients. Adults with detection in feces who attended the Vall d'Hebron University Hospital (Barcelona, Spain) were evaluated retrospectively from April 2009 to March 2014. We classified the patients in asymptomatic, symptomatic without other causes except infection of , and symptomatic with another cause. Among symptomatic patients, treatment response was evaluated. One hundred eight patients were included. Sixty-three percent of the patients were immigrants, 29.6% were autochthonous, and 7.4% were travelers. Forty-nine (45.3%) patients presented symptoms, and eosinophilia was observed in 26 (24.1%) patients. Overall, 59 (54.7%) patients were asymptomatic, 15 (13.8%) presented symptoms which were attributable to other causes, and 34 (31.5%) patients presented symptoms with no other causes. In this last group, 29 patients received specific treatment and 65.5% of them presented a complete resolution of the symptoms. The group of symptomatic patients with no other cause had more proportion of women, more proportion of autochthonous people, and were older compared with the group of asymptomatic patients. infection should be considered as pathogenic when other causes are ruled out.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Asymptomatic Infections; Dientamoeba; Dientamoebiasis; Eosinophilia; Feces; Female; Humans; Male; Middle Aged; Retrospective Studies; Risk Factors; Spain; Tertiary Care Centers; Young Adult
PubMed: 30328410
DOI: 10.4269/ajtmh.18-0433 -
Journal of Clinical Microbiology May 2019is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the... (Comparative Study)
Comparative Study
is a gastrointestinal trichomonad parasite whose pathogenicity is yet to be determined. The difficulty involved in microscopically diagnosing in feces led to the development of real-time PCR methodologies for the detection of in stool samples. Prevalence studies in Europe show much higher levels of infection where a laboratory-developed real-time assay is the predominant assay for the detection of than in regions that use the EasyScreen assay for detection of gastrointestinal pathogens. The aim of this study was to compare a commercially available assay (Genetic Signatures EasyScreen assay) to a widely used laboratory-developed real-time PCR method. Two hundred fifty fecal samples were screened using the laboratory-developed real-time assay on four real-time PCR platforms producing a number of discrepant results. Limit-of-detection studies were undertaken to attempt to resolve sensitivity for each platform tested. The presence or absence of DNA in discrepant samples was shown using PCR amplicon next-generation sequencing. Eukaryotic 18S diversity profiling was conducted on discrepant samples to identify the presence or absence of additional protozoan species in samples that may be responsible for cross-reactivity seen in these samples. The results revealed the potential for multiple false-positive results when using the laboratory-developed real-time assay across multiple real-time platforms using manufacturer default settings. This report provides recommendations to resolve these issues where possible and suggestions for future prevalence studies, and it emphasizes the EasyScreen assay as the molecular method of choice as well as the need for standardization of detection assays across all nations screening for .
Topics: Cross-Sectional Studies; DNA, Protozoan; Dientamoeba; Dientamoebiasis; Europe; False Positive Reactions; Feces; High-Throughput Nucleotide Sequencing; Humans; Reagent Kits, Diagnostic; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 30814263
DOI: 10.1128/JCM.01466-18 -
The American Journal of Tropical... Feb 2012Dientamoeba fragilis is a commonly occurring pathogenic protozoan often detected at higher rates in stool samples than Giardia intestinalis. However, little is known...
Dientamoeba fragilis is a commonly occurring pathogenic protozoan often detected at higher rates in stool samples than Giardia intestinalis. However, little is known about its life cycle and mode of transmission. A total of 210 environmental and household samples were examined for the presence of D. fragilis by culture and polymerase chain reaction. Of 100 environmental samples, D. fragilis was detected only in untreated sewage. In the household samples D. fragilis was detected in 30% of household contacts tested and was not detected in any domestic pets. This study provides evidence that environmental transmission of D. fragilis is unlikely and that pets played no role in transmission of the disease in this study. Direct transmission from infected persons is the most likely mode of transmission for D. fragilis. The study also highlights the need for household contacts to be screened, given the propensity of close contacts to become infected with the organism.
Topics: Animals; DNA, Protozoan; Dientamoeba; Dientamoebiasis; Disease Reservoirs; Environment; Family Characteristics; Feces; Giardia lamblia; Host-Parasite Interactions; Humans; Life Cycle Stages; Pets; Polymerase Chain Reaction
PubMed: 22302854
DOI: 10.4269/ajtmh.2012.11-0526 -
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 -
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 -
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