Epidemiological and clinical characteristics of Dientamoeba fragilis infection / Características clínicoepidemiológicas de las infecciones por Dientamoeba fragilis

INTRODUCTION: The characteristics of D. fragilis infection are described, with special focus on the clinical and epidemiological aspects. MATERIALS AND METHODS: A retrospective and descriptive study was performed, including all the patients with Dientamoeba fragilis infection who attended a specialized unit between January 2012 and December 2017. PCR was used to diagnose D. fragilis. Patients were treated with metronidazole or paromomycin and reviewed at four and eight weeks post-treatment. Cure was defined as the negativization of all parasitological tests, in absence of symptoms. RESULTS: 163 patients were diagnosed. The most frequent symptoms were abdominal pain (36.2%), chronic diarrhoea (12.3%), anal itching (10.4%), abdominal discomfort (9.2%), skin disease (8%), acute diarrhoea (4.3%) and vomiting (4.3%). Fifty patients were asymptomatic. Forty-two patients had eosinophilia in blood. Thirty-eight cases (23.3%) had a coinfection by Enterobius vermicularis. One hundred and seven patients received treatment, sixty-one of them with metronidazole and the rest with paromomycin. Ninety-nine patients (91%) were cured. The rate of cure was 100% in the paromomycin group versus 86.8% in the metronidazole group (p = 0.005; OR: 1.173 [1.057-1.302]). The absence of cure was associated with E. vermicularis coinfection (p = 0.014; OR: 6.167 [1.432-26.563] and with longer duration of the symptoms (175 [± 159SD]) versus 84 [± 88SD] days, p = 0.014) but multivariable analysis did not confirm these associations. CONCLUSION: Dientamoeba fragilis is an important and underestimated cause of gastrointestinal disease in both the autochthonous and immigrant or traveller population. More studies are needed to clarify its optimal treatment and the role played by E. vermicularis in its transmission and maintenance

INTRODUCCIÓN: Se describen las características clínicas y epidemiológicas de la infección por Dientamoeba fragilis. MATERIAL Y MÉTODOS: Se realizó un estudio retrospectivo y descriptivo de los pacientes diagnosticados de infección por D. fragilis en una unidad especializada entre 2012-2017. El diagnóstico de D. fragilis se realizó mediante PCR. Los pacientes fueron tratados con metronidazol o paromomicina y revisados a las 4 y 8 semanas tras tratamiento. Se consideró a los pacientes curados tras negativización microbiológica en ausencia de síntomas. RESULTADOS: Se analizaron 163 pacientes. Los síntomas más frecuentes fueron: dolor abdominal (36,2%), diarrea crónica (12,3%), prurito anal (10,4%), malestar abdominal (9,2%), síntomas cutáneos (8%), diarrea aguda y vómitos (4,3%, respectivamente). Cincuenta pacientes estaban asintomáticos. Cuarenta y dos pacientes presentaron eosinofilia. En 38 pacientes se observó coinfección por Enterobius vermicularis. Ciento siete pacientes recibieron tratamiento, 61 con metronidazol y el resto con paromomicina, con una curación del 91%. La tasa de curación fue del 100% en los pacientes tratados con paromomicina y del 86,8% en el grupo del metronidazol (p = 0,005; OR: 1,173 [1,057-1,302]). La no curación se asoció a la coinfección por E. vermicularis (p = 0,014; OR: 6,167 [1,432-26,563]) y con la mayor duración de los síntomas (175 [± 159 DE] versus 84 [± 88 DE] días; p = 0,014), pero el análisis multivariable no confirmó dichas asociaciones. CONCLUSIÓN: D. fragilis es causa importante y subestimada de enfermedad gastrointestinal tanto en poblaciones autóctonas como inmigrantes o viajeros. Se necesitan más estudios para aclarar su tratamiento óptimo y el papel desempeñado por E. vermicularis en su tratamiento

Ectosymbiotic bacterial microbiota densely colonize the surface of thelastomatid nematodes in the gut of the wood-feeding cockroach Panesthia angustipennis.

Cockroaches generally harbor thelastomatid nematodes (pinworms) in their gut. In this study, we discovered that the surfaces of two undescribed thelastomatid species in the hindgut of the wood-feeding cockroach Panesthia angustipennis were consistently and densely colonized by bacteria. Epifluorescence microscopy using 4',6-diamidino-2-phenylindole and transmission electron microscopy revealed that several distinct morphotypes of bacteria covered almost the entire body surface of the nematodes in single or multiple layers. Sequencing analysis of 16S rRNA amplicons of either entire nematodes or sections of nematode body surfaces indicated that the associated bacterial microbiota consisted of several dominant phylotypes belonging to either Dysgonomonadaceae (Bacteroidales termite cluster V), Rikennellaceae or Ruminococcaceae. These phylotypes formed clades with sequences previously obtained from cockroach and/or termite guts. Comparisons of the bacterial community structure of the entire cockroach hindgut microbiota vs the nematode-associated microbiota suggested that these dominant bacterial phylotypes preferentially colonized the nematode surface. The two nematode species shared most of the dominant bacterial phylotypes, but the bacterial community structures differed significantly. Colonization by five predominant phylotypes was confirmed by fluorescence in situ hybridization analysis using phylotype-specific probes. Our study provides fundamental information on this previously unknown ectosymbiosis between gut bacteria and thelastomatid pinworms.

Viability of the nematophagous fungus Pochonia chlamydosporia after passage through the gastrointestinal tract of horses.

The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) embedded in sodium alginate pellets after passage through the gastrointestinal tract of horses was assessed in vitro against Oxyuris equi eggs. Twelve previously dewormed crossbred mares, average weight of 362.5kg (+/-21) were used in the experiment. Each animal of the treated group received an oral dose (100g) of sodium alginate pellets containing P. chlamydosporia mycelial mass. The control group received pellets without fungus. Faecal samples from fungus-treated and control groups were collected at intervals of 8, 12, 24, 36, 48 and 72h after pellet administration and placed in Petri dishes containing 2% water-agar. One thousand eggs of O. equi were plated in Petri dishes of both treated and control groups, with six replicates, and incubated in oven, 25 degrees C, in the dark, for 30 days. At the end of the experiment, one hundred eggs were removed from each Petri dish and classified according to the following parameters: type 1, physiological and biochemical effect without morphological damage to eggshell, with hyphae adhered to the shell; type 2, lytic effect with morphological change in the eggshell and embryo without hyphal penetration, and type 3, lytic effect with morphological change in the eggshell and embryo, with hyphal penetration and internal egg colonization. Chlamydospore production was observed in Petri dishes of the treated group. The isolate VC4 remained viable after passing through the gastrointestinal tract of horses and maintained the ovicidal activity against O. equi eggs when compared with the control group (p<0.01) after each collection interval: 29.1% (8h), 28.2% (12h), 31.1% (24h), 27.4% (36h), 30.9% (48h) and 28.4% (72h). The results suggest that P. chlamydosporia could be used as an effective biological control agent of O. equi eggs in natural conditions.

Fitoterapia de la enterobiosis en escolares del Distrito de Ate-Vitarte. Lima-Perú, 1992 / Entherobiosis phytotherapy in students of Ate-Vitarte. Lima-Perú 1992

Se ha trabajado con una muestra poblacional de 190 niños que estudian en el Centro Educativo no estatal (CENE) "Walt Witman" de la Cooperativa 27 de abril, del distrito de Ate-Vitarte Lima. De los 190 niños estudiados, 105 resultaron positivos a enterobius vermicularis, mediante la técnica de Graham modificada. El objetivo principal es el demostrar la eficacia del tratamiento dosificando almendra de la pepa del zapallo (cucurbita maxima) y de las pepas de la papaya (carica papaya). Comprobando primero "in vitro" frente a ascaris soom, para luego determinar las dosis ideales, para ser administradas a los niños en mención, registrándose que el tratamiento con pepas de papaya es más eficaz y mejor tolerado. Estos productos son de bajo costo y no han producido efectos colaterales o secundarios.

Enterobiasis en alumnos del centro poblado Menor Herbay Alto, Cañete, Julio 1987 / Enterobiasis in school children of \"Centro Poblado Menor Herbay Alto, Cañete\", July 1987

Se ha realizado una encuesta parasitológica para buscar Enterovius vermicularis en una población escolar del "Centro Poblado Hervay Alto, Cañete". Se encuestó a 368 niños entre los 3 y 11 años de edad; se aplicó la prueba de Graham, encontrándose 255 (68.3 por ciento) positivos. En 50 por ciento de los casos positivos y a sus familiares se les dió tratamiento con resultado exitoso. Se trata de explicar la alta prevalencia de la enterobiasis en población escolar de la zona por la deficiencia del saneamiento ambiental, la precaria calidad de la vivienda, el hacinamiento, así como la baja condición socio-económica de la población. Se plantea que estos serían aspectos importantes en la prevención y control de este parasitismo

[On the epidemiology of Dientamoeba fragilis Jepps and Dobell 1918. 4th communication: evidence of Dientamoeba fragilis in Enterobius eggs using isoelectric point determination]. / Zur Epidemiologie von Dientamoeba fragilis Jepps et Dobell, 1918. 4. Nachweis von Dientamoeba fragilis in enterobius Eiern mit Hilfe von IEP-bestimmungen

By means of the method of determining the isoelectric point, the same conditions of absorption and stain intensity as in Dientamoeba cultivation forms were determined in cells found in Enterobius vermicularis eggs of Dientamoeba fragilis carried. By that way, identity of both stages, as well as function of pinworms as Dientamoeba fragilis vectors were confirmed.