RESUMEN

Intestinal protists in the gut microbiome are increasingly studied, but their basic epidemiology is not well understood. We explored the prevalence, genetic diversity, and potential zoonotic transmission of two protists colonizing the large intestine - Blastocystis sp. and Dientamoeba fragilis - in 37 species of non-human primates (NHPs) and their caregivers in six zoos in the Czech Republic. We analyzed 179 fecal samples (159 from NHPs, 20 from humans) by qPCR. Blastocystis sp. was detected in 54.7% (98/179) of samples, in 24 NHP species and in 57.2% of NHP samples (prevalence ranged between 36 and 80%), and in 35% of human samples (prevalence ranged between 0 and 67%). Using next generation amplicon sequencing, nine Blastocystis subtypes (ST1-ST5, ST7, ST8, and two novel subtypes) were identified. The two new Blastocystis subtypes (named ST47 and ST48) were described using Nanopore sequencing to produce full-length reference sequences of the small subunit ribosomal RNA gene. Some subtypes were shared between NHPs and their caregivers, suggesting potential zoonotic transmission. Mixed subtype colonization was frequently observed, with 52% of sequenced samples containing two or more subtypes. Dientamoeba was found only in NHPs with a prevalence of 6%. This study emphasizes the critical role of molecular diagnostics in epidemiological and transmission studies of these protists and calls for further research to better understand their impact on public health.

RESUMEN

PURPOSE: Dientamoeba fragilis (D. fragilis) is a common intestinal protozoan with a global distribution. In the present study, we aimed to determine genetic diversity of D. fragilis isolates with multilocus sequence typing (MLST) in the southwest of Turkey and analyse the clinical findings. MATERIALS AND METHODS: The study included faecal samples from 200 individuals in Aydin, Turkey. The positivity of D. fragilis was determined with 18 S rRNA gene-based PCR assay. Six nested-PCR reactions were set to amplify partial D. fragilis housekeeping genes in the positive samples. The sequences were aligned with the references from GenBank to detect nucleotide polymorphisms and haplotypes. Additionally, the clinical findings and demographic characteristics of patients were statistically analysed between D. fragilis-infected and non-infected cases. RESULTS: The positivity of D. fragilis was 16% (32 out of 200 cases) with 18 S rRNA based-PCR, and all were classified as "genotype 1". The analysis of six MLST loci revealed different haplotypes only at one locus; the remaining five loci exhibited no polymorphisms. The haplotypes in the present study were identical to at least one previously reported reference, except the locus "large subunit of RNA polymerase II" locus. There were no significant differences in any of the clinical findings or demographic characteristics between the infected and non-infected groups. CONCLUSIONS: Our study revealed a low genetic diversity of D. fragilis isolates from Turkey, like other countries including Italy, Denmark, the UK, Australia, and Brazil. The high degree of sequence similarity in housekeeping genes indicated the clonal distribution of D. fragilis.

Asunto(s)

Dientamoeba , Dientamebiasis , Variación Genética , Tipificación de Secuencias Multilocus , Dientamoeba/genética , Dientamoeba/aislamiento & purificación , Dientamoeba/clasificación , Turquía/epidemiología , Humanos , Dientamebiasis/parasitología , Dientamebiasis/epidemiología , Masculino , Femenino , Adolescente , Niño , Adulto , Adulto Joven , ARN Ribosómico 18S/genética , Heces/parasitología , Persona de Mediana Edad , Preescolar , Haplotipos , Genotipo , ADN Protozoario/genética , Reacción en Cadena de la Polimerasa , Anciano , Filogenia , Lactante

RESUMEN

Dientamoeba fragilis is a ubiquitous intestinal parasite with detection in the stools that has become increasingly frequent following the advent of PCR as a routine screening tool. However, the pathogenicity of this parasite is still much debated. In order to assess the potentially pathogenic nature of this protozoan, a retrospective case-control study was carried out between January and December 2020 on patients from Toulouse University Hospital, with the aim of evaluating the potential clinical effects and changes in laboratory parameters linked to the presence and load of D. fragilis in stools. After matching age, sex and mode of care (consultation or hospitalisation), no significant difference was observed in the frequency of clinical signs between the 36 patients who tested positive for Dientamoeba fragilis PCR in their stools and the 72 control patients who were PCR negative for this protozoan. The presence of D. fragilis in the faeces was not associated with changes in laboratory parameters. Furthermore, a high digestive load of D. fragilis had no identifiable impact on clinical and laboratory parameters. Only the concomitant presence of Blastocystis sp. in stools was significantly more frequent in the D. fragilis group (uni- and multivariate analysis). Finally, this study showed no significant difference in clinical or laboratory signs between patients carrying Dientamoeba fragilis and the control group, regardless of the intestinal parasite load, suggesting that D. fragilis could be considered a commensal of the digestive tract.

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Title: Aucune preuve de la pathogénicité de Dientamoeba fragilis détecté dans les selles : une étude cas-témoins. Abstract: Dientamoeba fragilis est un parasite digestif ubiquitaire dont la détection dans les selles est devenue de plus en plus fréquente avec l'avènement de la PCR comme outil de détection de routine. Cependant, la pathogénicité de ce parasite est encore très discutée. Afin d'évaluer le caractère potentiellement pathogène de ce protozoaire, une étude rétrospective cas-témoins a été réalisée entre janvier et décembre 2020 sur des patients du CHU de Toulouse, dans le but d'évaluer les effets cliniques et biologiques potentiels associés à la présence et à la charge de D. fragilis dans les selles. Après appariement sur l'âge, le sexe et le mode de prise en charge (consultation ou hospitalisation), aucune différence significative n'a été observée dans la fréquence des signes cliniques entre les 36 patients testés positifs pour la PCR de Dientamoeba fragilis dans les selles et les 72 patients témoins avec une PCR négative pour ce protozoaire. La présence de D. fragilis dans les selles n'était pas associée à des modifications des paramètres biologiques. De plus, une charge digestive élevée de D. fragilis n'avait pas d'impact identifiable sur les paramètres cliniques et biologiques. Seule la présence concomitante de Blastocystis sp. dans les selles était significativement plus fréquente dans le groupe D. fragilis (analyse uni- et multivariée). En conclusion, cette étude n'a pas montré de différence significative concernant les signes cliniques ou biologiques entre les patients porteurs de Dientamoeba fragilis et le groupe témoin, quelle que soit la charge parasitaire digestive, indiquant que D. fragilis pourrait être considéré comme un commensal du tube digestif.

Asunto(s)

Dientamoeba , Dientamebiasis , Heces , Reacción en Cadena de la Polimerasa , Humanos , Heces/parasitología , Dientamoeba/aislamiento & purificación , Dientamoeba/genética , Femenino , Masculino , Dientamebiasis/parasitología , Dientamebiasis/epidemiología , Dientamebiasis/diagnóstico , Estudios de Casos y Controles , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Anciano , Blastocystis/aislamiento & purificación , Blastocystis/genética , Adulto Joven , ADN Protozoario/análisis , ADN Protozoario/aislamiento & purificación

RESUMEN

The protozoan parasite Dientamoeba fragilis is a frequently isolated stool organism and postulated cause of gastrointestinal symptoms. Peripheral blood eosinophilia has been described. This is the first study amongst the Australasian adult population to assess the relationship between organism detection and eosinophilia. A case-control study took place over 7 years at a single Sydney laboratory site, evaluating patients with D. fragilis identified on stool using real-time PCR with a recent full blood count, to control groups with Giardia spp. and sequential negatives with neither organism. A nested study compared those with microscopic evidence of D. fragilis as a marker of disease burden, to molecular diagnosis alone. Sixty-four D. fragilis, 30 Giardia spp., and 94 sequential controls were enrolled. Only 60.1% of samples were preserved in sodium acetate-acetic acid formalin (SAF) fixative, indication mostly not documented. The major co-organism detected amongst all participants was Blastocystis sp., particularly in the D. fragilis cohort (37.2%). The most common pathogen amongst sequential controls was Campylobacter spp. (7.4%). Patients with D. fragilis were more likely (12.5%) to have a clinically significant eosinophilia (>0.5×109/L) compared to those with Giardia spp. (3.3%) or sequential controls (4.3%) (p=0.03). A significant difference was also noted in the overall median eosinophil count of those with D. fragilis versus all controls (0.2 vs 0.1×109/L, p=0.01); however, this was within the reference interval (where up to >0.5×109/L is accepted in healthy individuals within a typical population). No eosinophil difference was found between those with molecular versus additional microscopic detection of D. fragilis (0.1 vs 0.1×109/L). These results support an association between the identification of clinically significant peripheral blood eosinophilia and D. fragilis presence, which may impact the diagnostic approach to the patient with unexplained eosinophilia. Further prospective trials may help assess any significance further and the implication of co-carriage with other enteric organisms. The importance of clinical indication and need for appropriate fixative media in diagnostic parasitology are also highlighted.

Asunto(s)

Dientamoeba , Dientamebiasis , Eosinofilia , Heces , Humanos , Dientamoeba/aislamiento & purificación , Heces/parasitología , Heces/microbiología , Masculino , Adulto , Dientamebiasis/diagnóstico , Dientamebiasis/parasitología , Femenino , Persona de Mediana Edad , Eosinofilia/parasitología , Eosinofilia/diagnóstico , Eosinofilia/patología , Estudios de Casos y Controles , Anciano , Adulto Joven , Reacción en Cadena en Tiempo Real de la Polimerasa , Anciano de 80 o más Años

RESUMEN

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.

Asunto(s)

Infecciones por Blastocystis , Blastocystis , Moscas Domésticas , Muscidae , Humanos , Animales , Ovinos , Bovinos , Porcinos , Dientamoeba , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/veterinaria , Infecciones por Blastocystis/parasitología , Genotipo , Heces/parasitología , Prevalencia , Nucleótidos

RESUMEN

Blastocystis sp. and Dientamoeba fragilis are intestinal protists, which are common worldwide, but the pathogenic role of these organisms in gastrointestinal diseases is still controversial. This study aimed to investigate the frequency of Blastocystis sp. and D. fragilis in stool samples from adult patients with celiac disease (CD) by using conventional and molecular methods. A total of 75 patients with CD and 75 healthy individuals were included in this study. Fresh stool specimens collected from each individual were analyzed by conventional and molecular methods. The overall prevalence of Blastocystis sp. and D. fragilis was 41.3% (31/75) and 24% (18/75) in patients with CD, and 46.7% (35/75) and 13.3% (10/75) in healthy controls, respectively. There was no statistically significant difference in the prevalence of Blastocystis sp. and D. fragilis between CD patients and healthy individuals. Blastocystis sp. subtypes were identified in 20 CD and 16 control patients and the overall subtype distribution was observed as ST1 13.9%, ST2 30.6%, and ST3 55.6%. The prevalence of Blastocystis sp. and D. fragilis in adults with CD is similar to the prevalence of protozoa in healthy adults. In this study, the most prevalent Blastocystis subtype was ST3 and the most frequent allele was a34 in both CD patients and healthy individuals. No significant difference was found between the two groups in terms of the detection rates of Blastocystis sp. and D. fragilis, and it is thought that both protists may be colonisers of the intestinal microbiome.

Asunto(s)

Infecciones por Blastocystis , Blastocystis , Enfermedad Celíaca , Dientamoeba , Dientamebiasis , Heces , Humanos , Blastocystis/aislamiento & purificación , Blastocystis/genética , Dientamoeba/aislamiento & purificación , Dientamoeba/genética , Enfermedad Celíaca/parasitología , Enfermedad Celíaca/epidemiología , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Infecciones por Blastocystis/diagnóstico , Adulto , Dientamebiasis/epidemiología , Dientamebiasis/parasitología , Dientamebiasis/diagnóstico , Masculino , Femenino , Heces/parasitología , Persona de Mediana Edad , Prevalencia , Adulto Joven , Adolescente , Anciano

RESUMEN

Little is known about the life cycle and mode of transmission of Dientamoeba fragilis. Recently it was suggested that fecal­oral transmission of cysts may play a role in the transmission of D. fragilis. In order to establish an infection, D. fragilis 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 D. fragilis are vulnerable to highly acidic conditions. We also investigated further the ultrastructure of D. fragilis 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 D. fragilis.

Asunto(s)

Quistes , Dientamebiasis , Animales , Ratas , Ratones , Dientamebiasis/parasitología , Dientamoeba , Estadios del Ciclo de Vida , Trofozoítos , Retículo Endoplásmico , Heces/parasitología

RESUMEN

OBJECTIVES: The aim of this study was to assess the clinical significance of Dientamoeba fragilis (DF) and Blastocystis species (Bs) in human stool. METHODS: Observational study of patients ≥18 years, who were tested by stool multiplex PCR for bacteria and parasites between April 2019 and March 2022. Although DF and Bs are part of the PCR kit, these results are not routinely reported to the patient or the ordering physician. The main outcomes were the incidence of symptoms during 14 days before the referral to stool PCR test, and the incidence of several clinical outcomes during 60 days after the PCR test (symptoms, referrals to further evaluation, prescription of symptomatic, or antibiotic treatment). RESULTS: A total of 27 918 patients were tested by stool PCR during the 3 study years. A total of 6215 (22.3%) and 5337 (19.2%) were positive for DF and Bs, respectively. The incidence of symptoms before the test was similar in those positive for Bs or DF and those with all-negative PCR (adjusted OR and 95% CI of 0.87 [0.80-0.95] and 0.82 [0.76-0.88] for Bs and DF, respectively), whereas significantly higher (2.47 [2.23-2.73]) in those positive for the other multiplex PCR assay components. During the 60 days after the test, the prevalence of any of the outcomes was similar in those positive for Bs or DF and those with negative PCR (adjusted OR and 95% CI of 0.92 [0.83-1.02] and 0.89 [0.81-0.97] for symptoms, 0.84 [0.75-0.94] and 0.93 [0.85-1.01] for referrals, 0.88 [0.75-1.03] and 0.82 [0.71-0.94] for symptomatic treatment, and 0.88 [0.75-1.02] and 0.86 [0.75-0.98] for antibiotic treatment in the Bs and DF positive individuals, respectively). The PCR cycle threshold was not associated with any of the outcomes. DISCUSSION: Positive stool PCR for DF or Bs was not associated with any of the measured clinical outcomes.

Asunto(s)

Blastocystis , Humanos , Blastocystis/genética , Dientamoeba/genética , Relevancia Clínica , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Heces/parasitología , Antibacterianos

RESUMEN

Indigenous people live in remote areas of Colombia. Multiple infections with bacteria, protozoa and/or helminths are common, as well as colonization in various forms. This study focused on the question of whether and to what extent various pathogens interact with each other. Therefore, a mathematical approach was retrospectively applied to PCR-based data of 244 stool samples, collected in two datasets. A stable cluster solution of the pathogens assessed was determined, and a unique configuration between Blastocystis hominis/Campylobacter spp./Giardia lamblia forming cluster 1 and Dientaemoeba fragilis was verified. A pathogen density-dependent interplay appeared between the B. hominis/Campylobacter spp./G. lamblia cluster, D. fragilis and Ascaris lumbricoides. The applied mathematical approach demonstrated that co-infections with parasites of questionable pathological relevance such as B. hominis and D. fragilis can be of diagnostic relevance due to their ability to promote or repress other pathogens. With the increasing availability of highly sensitive multiplexed molecular diagnostic approaches even in resource-limited settings, where multiple colonization of infection events with enteric pathogens in parallel are common, the importance of interpreting whole pathogen patterns rather than just individual pathogen detection may become more and more relevant.

RESUMEN

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.

Asunto(s)

Blastocystis , Enfermedad Celíaca , Lacticaseibacillus paracasei , Probióticos , Humanos , Niño , Lacticaseibacillus , Autoinmunidad , Estudios Retrospectivos , Heces/parasitología , Blastocystis/genética , Bacterias , Probióticos/uso terapéutico , Probióticos/farmacología , Método Doble Ciego , ADN Ribosómico

RESUMEN

To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea patients and 50 healthy individuals were collected and evaluated using direct microscopy and molecular methods to screen for bacteria, protozoa, and viruses. The prevalence of Blastocystis was 24.6% in total and more frequent in the healthy group (30.0%). The commonly detected STs (subtypes) were ST3 (40.0%) and ST2 (34.2%). The distribution of Blastocystis STs in the healthy and diarrheal groups did not show any difference in sex and age, but ST3 was detected more frequently in patients aged from 40 to 59 years (p < 0.05). Alleles 4 (8/12) and 2 (4/12) were present in ST1; 9 (3/5) and 12 (2/5) in ST2; 34 (9/14), 36 (3/14), and 38 (2/14) in ST3; and only allele 42 (2/2) in ST4. D. fragilis was present in 8.4% of the population. However, there was no statistically significant difference between the healthy and diarrheic groups (12.0% and 6.5%, respectively), neither with respect to age nor sex. Co-infection was 58.3% and was more frequent in healthy individuals (33.3%) than in diarrhea patients (25.0%). Blastocystis ST3 was the most common subtype detected, with D. fragilis at 33.3%. Salmonella, Shigella, or helminth eggs were not observed in all groups, but Entamoeba histolytica, Giardia intestinalis, Cryptosporidium, Rotavirus, Adenovirus, and Clostridium difficile toxin were found only in diarrhea patients. These findings support the hypothesis that Blastocystis and D. fragilis may be part of the healthy human gut microbiome.

Asunto(s)

Infecciones por Blastocystis , Blastocystis , Criptosporidiosis , Cryptosporidium , Humanos , Adulto , Persona de Mediana Edad , Blastocystis/genética , Dientamoeba/genética , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Prevalencia , Proteína 1 Similar al Receptor de Interleucina-1 , Diarrea/epidemiología , Diarrea/parasitología , Heces/parasitología

RESUMEN

Background: Dientamoeba fragilis (DF), 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 DF infections. To study microbiological clearance of DF, 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 â€‹= â€‹297) proved effective (clearance rate 83%), showing strong association with faecal clearance (aOR 18.08 [7.24-45.16], p â€‹< â€‹0.001). For metronidazole the rate was 42% (n â€‹= â€‹84), for secnidazole 37% (n â€‹= â€‹79), and doxycycline 22% (n â€‹= â€‹32). In pairwise comparisons, paromomycin outdid the three other regimens (p â€‹< â€‹0.001, χ2 test). Faecal clearance was associated with clinical cure (aOR 5.85 [3.02-11.32], p â€‹< â€‹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 D. fragilis infection.

RESUMEN

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.

Asunto(s)

Blastocystis , Gastroenteritis , Parasitosis Intestinales , Parásitos , Animales , Humanos , Dientamoeba , Parasitosis Intestinales/parasitología , Blastocystis/genética , Gastroenteritis/parasitología , Heces/parasitología

RESUMEN

Intestinal parasitic infections are a global health problem that causes morbidity and mortality, especially in children living in rural areas. In this study, stool samples of pediatric patients with gastrointestinal complaints were examined by conventional and molecular methods to determine the prevalence of intestinal parasites. A total of 100 pediatric patients with gastrointestinal complaints and 50 healthy children were included in the study. Stool samples were collected from each child and examined by direct microscopic examination (native-Lugol method), formol-ethyl acetate concentration technique, Kinyoun's acid-fast staining, and Wheatley trichrome staining methods. Real-time PCR was used for the detection of Blastocystis spp. and D. fragilis in the stool samples. Sanger sequencing was used to identify Blastocystis spp. subtypes. One or more intestinal parasites were found in 12% (n = 100) of the patient group and 1% (n = 50) of the control group using conventional techniques. By using real-time PCR, Blastocystis spp. was discovered in 14% (14/100) of the patient group and 8% (4/50) of the control group. There was no significant difference in the frequency of Blastocystis spp. between the two groups. The most prevalent Blastocystis subtype was ST1 and the most frequent allele was a2 among the samples successfully amplified and sequenced. D. fragilis was detected in 17% (17/100) of the patient group and 8% (4/50) of the control group by real-time PCR. The prevalence of D. fragilis was not significantly different between the patient and control groups, as well. Blastocystis spp. and D. fragilis were found in high prevalence in pediatric patients with gastrointestinal complaints in this study. Although the role of these protists as a pathogen in humans is still controversial, it is supposed to the presence of the parasites are associated with gastrointestinal disorders such as diarrhea, abdominal pain, nausea, and vomiting. More case-control studies are needed to understand the pathogenic or commensal role of these parasites on the intestinal microbiota, especially in both patients with gastrointestinal disorders and healthy individuals.

Asunto(s)

Infecciones por Blastocystis , Blastocystis , Enfermedades Gastrointestinales , Parasitosis Intestinales , Parásitos , Animales , Humanos , Niño , Parásitos/genética , Infecciones por Blastocystis/epidemiología , Infecciones por Blastocystis/parasitología , Heces/parasitología , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Blastocystis/genética , Enfermedades Gastrointestinales/epidemiología , Prevalencia

RESUMEN

Dientamoeba fragilis 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 D. fragilis 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 D. fragilis. A more frequent occurrence of D. fragilis was associated with living in a village, traveling outside Europe and contact with farm animals. In addition, co-infection with Blastocystis spp. was observed in nearly half of the colonized humans. In animals, D. fragilis 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 D. fragilis and other related organisms.

Asunto(s)

Dientamebiasis , Animales , Humanos , Conejos , Estudios Transversales , Dientamebiasis/epidemiología , Dientamebiasis/diagnóstico , Heces , Dientamoeba/genética , Prevalencia

RESUMEN

The diagnosis of obesity comprises subjects with totally different phenotypes and metabolic profiles. Systemic inflammation and oxidative stress derived from the white adipose tissue are suggested as the link between this disease and the development of insulin resistance and metabolic comorbidities. The presence of unicellular eukaryotic parasites colonizing the human gut ecosystem is a common circumstance, and yet their influence on the inflammatory and redox status of the obese host has not been assessed. Herein, a set of inflammatory and redox biomarkers were assessed together with a parasitological analysis of 97 severely obese subjects. Information was also collected on insulin resistance and on the antioxidant composition of the diet. The global prevalence of intestinal unicellular parasites was 49.5%, with Blastocystis sp. the most prevalent protozoan found (42.3%). Colonized subjects displayed a higher total antioxidant capacity and a trend towards higher extracellular superoxide dismutase activity, regardless of their insulin resistance status, along with lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratios in plasma in the insulin-resistant subgroup. No changes in malondialdehyde levels, or in inflammatory cytokines in plasma, were found in regard to the colonization status. In conclusion, enteric eukaryotic unicellular parasites may play an important role in modulating the antioxidant defenses of an obese host, thus could have beneficial effects with respect to the development of systemic metabolic disorders.

RESUMEN

Objective: This study aimed to evaluate the distribution of intestinal parasites in refugee and native patients who applied to a territory hospital in Turkey. Methods: A total of 17911 patients who were admitted to our hospital between January 2018 and January 2019 were evaluated retrospectively in terms of intestinal parasites. The patients' stool samples were investigated for the existence of intestinal parasites by direct wet mount preparation, formalin ether concentration technique and cellophane tape method. The data obtained were compared between patient groups according to the examination method. Results: The overall prevalence of E. vermicularis in refugee children was found twice higher than that in native patients and the most common symptom was abdominal pain in these patients. Intestinal parasite detection rates were significantly higher in the stool concentration method than in the direct wet mount examination. Cutaneous complaints and protein energy malnutrition/growth retardation were the most common clinical conditions besides gastrointestinal symptoms in patients with intestinal parasitosis. Conclusion: In our study, the prevalence of Blastocystis sp. in refugees was found to be higher than in the normal population. Intestinal parasitic infections should be investigated with proper diagnostic methods especially in children with PEM/GR and cutaneous symptoms in addition to gastrointestinal problems.

Asunto(s)

Parasitosis Intestinales , Parásitos , Refugiados , Animales , Niño , Hospitales , Humanos , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Estudios Retrospectivos , Turquía/epidemiología

RESUMEN

Obesity is an epidemic causing a metabolic health crisis. Herein, the interactions between the gut prokaryotic and eukaryotic communities, metabolic comorbidities and diet were studied. Stool samples from 56 subjects, 47 with type III obesity and 9 with type II obesity and cardiovascular risk or metabolic disease, were assessed for the richness, diversity and ecology of the bacterial gut community through metagenomics, together with the study of the presence of common unicellular eukaryote parasites (Blastocystis sp., Dientamoeba fragilis and Giardia intestinalis) by qPCR. Clinical information regarding metabolic comorbidities and non-alcoholic hepatic fatty liver disease was gathered. To assess the quality of the patients' diet, each participant filled in three dietary questionnaires. The most prevalent parasite Blastocystis sp. (46.4%), together with D. fragilis (8.9%), was found to be associated with higher mean diversity indexes regarding non-colonized subjects; the opposite of that which was observed in those with G. intestinalis (16.1%). In terms of phyla relative abundance, with Blastocystis sp. and D. fragilis, very slight differences were observed; on the contrary, G. intestinalis was related to an increase in Bacteroidetes and Proteobacteria, and a decrease in Firmicutes and Actinobacteria, presenting the lowest Firmicutes/Bacteroidetes ratio. At genus level, Blastocystis sp. and/or D. fragilis was accompanied with an increase in Lactobacillus spp., and a decrease in Akkermansia spp., Bifidobacterium spp. and Escherichia spp., while G. intestinalis was associated with an increase in Bacteroides spp., and a decrease in Faecalibacterium spp., Prevotella spp. and Lactobacillus spp., and the highest Bacteroides spp./Prevotella spp. ratio. Participants with non-alcoholic hepatic fatty liver presented a higher Firmicutes/Bacteroidetes ratio, and those with type 2 diabetes displayed a significantly lower Faecalibacterium spp./Escherichia spp. ratio, due to an overrepresentation of the genus Escherichia spp. The presence of parasites was associated with variations in the richness, diversity and distribution of taxa in bacterial communities, confirming a gain in diversity associated with Blastocystis sp. and providing different functioning of the microbiota with a potential positive effect on comorbidities such as type 2 diabetes, insulin resistance and metabolic syndrome. Future basic and clinical studies should assess the beneficial or pathogenic effect of these eukaryotes on obese subjects and focus on deciphering whether they may imply a healthier metabolic profile.

Asunto(s)

Blastocystis , Diabetes Mellitus Tipo 2 , Obesidad Mórbida , Parásitos , Animales , Bacterias/genética , Heces/microbiología , Humanos

RESUMEN

Dientamoeba fragilis is a flagellated protozoan with amoeba-like morphology that inhabits the human gastrointestinal tract. It is endemic in a vast geography around the world, including developed countries. There are limited studies on non-human hosts of the parasite, and suitable hosts have not been clarified. The parasite has been detected in non-human primates, pigs, cats, dogs and rats. There is no study in the literature investigating and detecting the presence of this parasite in cattle. In this study, stool samples taken from 163 different cattle and calves from 11 different farms between March 2017 and May 2022 were examined for the detection of D. fragilis via PCR. Trichrome staining was performed on all PCR-positive samples. The isolates with the expected amplicon size were sequenced using the 18S ribosomal RNA region, and their genotypes were determined by BLAST analysis. Sequences were analysed with the most similar and reference sequences in the literature, forming a phylogenetic tree. We detected D. fragilis in 31 (19.01%) of the 163 stool samples. D. fragilis cysts/trophozoites were detected by trichrome staining method in six of 31 samples. All PCR products selected for molecular analysis from positive samples had the same nucleotide sequence. As a result of BLAST analysis, all sequences were determined to belong to D. fragilis genotype 1. This study determined for the first time that cattle are suitable hosts for D. fragilis. Furthermore, the parasite subtype we detected belongs to genotype 1, which is the most common type in humans, suggesting that the parasite may have a zoonotic character. Our result is important in terms of the epidemiology of the parasite, as the mode of transmission is controversial, and available data on its suitable hosts are limited.

Asunto(s)

Enfermedades de los Bovinos , Dientamebiasis , Enfermedades de los Perros , Enfermedades de los Roedores , Enfermedades de los Porcinos , Bovinos , Animales , Perros , Ratas , Porcinos , Dientamoeba/genética , Dientamebiasis/epidemiología , Dientamebiasis/diagnóstico , Dientamebiasis/parasitología , Dientamebiasis/veterinaria , Filogenia , Heces/parasitología , Reacción en Cadena de la Polimerasa/métodos , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de los Bovinos/epidemiología

RESUMEN

Objective: Parasitic infections emerge as a significant health problem, especially in underdeveloped and developing countries. Epidemiological data play an important role in taking effective measures against parasitic diseases. Methods: Clinical samples (stool, blood, bone marrow and tissue samples, etc.) that were sent to Hacettepe University Hospitals Parasitology Laboratory between 2014 and 2019 were analyzed retrospectively. Results: The positivity rates of the parasites detected in this study are as follows; Blastocystis sp. (71.6%), Dientamoeba fragilis (13.3%), Giardia lamblia (4.7%), Echinococcus spp. (1.9%), Enterobius vermicularis (1.8%) and Taenia spp. (0.3%). In this study, four of the patients were found to be positive for Leishmania spp. and two patients for Plasmodium falciparum and four patients for Plasmodium spp. E. histolytica/E. dispar cysts and/or trophozoites examined by Trichrome staining in our study were not detected within six years. Conclusion: According to this data and in the light of the results obtained from different regions of our country, it will be possible to properly direct the necessary strategies for the diagnosis, treatment of parasitic infections and the implementation of preventive measures.

Asunto(s)

Giardia lamblia , Parasitosis Intestinales , Animales , Dientamoeba , Docentes , Heces/parasitología , Humanos , Parasitosis Intestinales/diagnóstico , Parasitosis Intestinales/epidemiología , Parasitosis Intestinales/parasitología , Prevalencia , Estudios Retrospectivos