Microsporidiosis en pacientes pediátricos con leucemia o linfoma

espanolLos microsporidios son microorganismos intracelulares obligados caracterizados por producir esporas con pared de quitina y presentar un filamento polar mediante el cual vierten su esporoplasma a la celula huesped. En pacientes inmunocomprometidos Enterocytozoon bieneusi y Encephalitozoon intestinalis producen diarrea y diseminacion sistemica. En Mexico no hay informacion de microsporidios en ninos con cancer. Objetivo. El proposito de este estudio piloto fue identificar las especies de microsporidios en pacientes pediatricos con leucemia o linfoma. Material y metodos. Se obtuvieron muestras fecales de 13 pacientes, se procesaron para detectar microsporidios mediante tinciones de Ziehl-Neelsen y calcofluor, se obtuvo DNA para amplificar secuencias especificas del rRNA para identificar E. bieneusi, E. intestinalis, E cuniculi y E hellem mediante la reaccion en cadena de la DNA polimerasa (PCR), tambien se realizaron coproparasitoscopicos y coprocultivos. Resultados. Basados en caracteres morfologicos 7/13 muestras fueron positivas a microsporidios y con la PCR se determino la especie en 6/10. Se identifico E. bieneusi en tres pacientes con leucemia y uno con linfoma; E. intestinalis se encontro en dos ninos con leucemia. La mayoria de estos pacientes se encontraban en alto riesgo y en fase de reinduccion, consolidacion o con multiples quimioterapias. Todos los pacientes con microsporidios no tuvieron diarrea en el momento del muestreo; sin embargo, en dos ninos con diarrea se encontro Cyclospora cayetanensis. Tambien se obtuvieron muestras de las madres de cinco pacientes, en las tinciones todas mostraron esporas de microsporidios y por PCR se identifico la especie en tres de ellas. Conclusion. Las muestras de heces de pacientes con leucemia o linfoma contenian microsporidios, por esta razon, es necesario implementar estudios enfocados en la busqueda extraintestinal de estos microorganismos y analizar su impacto en la evolucion de pacientes con cancer. EnglishMicrosporidia are intracellular micro-organisms, characterized by mature spores with chitin walls and by one extrusive polar tube through which they pour their sporoplasm to the host cells. In immunocompromised patients, Enterocytozoon bieneusi and Encephalitozoon intestinalis produce diarrhea and systemic dissemination. In Mexico there is not information about microsporidia in children with cancer. Objective. The aim of this pilot study was to investigate the presence of microsporidia species in pediatric patients with leukemia or lymphoma. Material and methods. We obtained fecal samples from thirteen patients. The samples were processed to detect microsporidia by both modified Ziehl-Neelsen and clacofluor white stains, DNA was isolated to amplify rRNA specific sequences, to identify E. bieneusi, E. intestinalis, E. cuniculi and E. hellem by DNA polymerase chain reaction (PCR). Other parasites and pathogenic bacteria were also tested. Results. Based on morphologic traits 7/13 samples were found positives to microsporidia and 6/10 by PCR. Was identified E. bieneusi in three patients with leukemia and one with lymphoma, another two children with leukemia were infected with E. intestinalis. Almost all children were high-risk patients and in phase of re-induction, consolidation or with many chemotherapy treatments. All the patients with microspiridia did not present diarrhea at the moment of the sampling; however, in two children with diarrhea it was found Cyclospora cayetanensis. Also we obtained feces from five patients� mothers and microsporidia spores were identified by stain in all of them and by PCR it was diagnosed the species in three of them. Conclusion. It was demonstrated that the feces of patients with leukemia or lymphoma had microsporidia, therefore is necessary to know the prevalence of these microorganisms and to analyze their impact in evolution of cancer patients.