ABSTRACT
BACKGROUND: The soil-transmitted helminth (STH), Trichuris trichiura colonises the human large intestine where it may modify inflammatory responses, an effect possibly mediated through alterations in the intestinal microbiota. We hypothesised that patent T. trichiura infections would be associated with altered faecal microbiota and that anthelmintic treatment would induce a microbiota resembling more closely that observed in uninfected individuals. MATERIALS AND METHODS: School children in Ecuador were screened for STH infections and allocated to 3 groups: uninfected, T. trichiura only, and mixed infections with T. trichiura and Ascaris lumbricoides. A sample of uninfected children and those with T. trichiura infections only were given anthelmintic treatment. Bacterial community profiles in faecal samples were studied by 454 pyrosequencing of 16 S rRNA genes. RESULTS: Microbiota analyses of faeces were done for 97 children: 30 were uninfected, 17 were infected with T. trichiura, and 50 with T. trichiura and A. lumbricoides. Post-treatment samples were analyzed for 14 children initially infected with T. trichiura alone and for 21 uninfected children. Treatment resulted in 100% cure of STH infections. Comparisons of the microbiota at different taxonomic levels showed no statistically significant differences in composition between uninfected children and those with T. trichiura infections. We observed a decreased proportional abundance of a few bacterial genera from the Clostridia class of Firmicutes and a reduced bacterial diversity among children with mixed infections compared to the other two groups, indicating a possible specific effect of A. lumbricoides infection. Anthelmintic treatment of children with T. trichiura did not alter faecal microbiota composition. DISCUSSION: Our data indicate that patent human infections with T. trichiura may have no effect on faecal microbiota but that A. lumbricoides colonisation might be associated with a disturbed microbiota. Our results also catalogue the microbiota of rural Ecuadorians and indicate differences with individuals from more urban industrialised societies.
Subject(s)
Feces/microbiology , Microbiota , Trichuriasis/microbiology , Trichuris , Adolescent , Animals , Anthelmintics/pharmacology , Anthelmintics/therapeutic use , Bacteria/classification , Bacteria/drug effects , Bacteria/genetics , Child , Cluster Analysis , Ecuador/epidemiology , Female , Humans , Intestines/drug effects , Intestines/microbiology , Intestines/parasitology , Male , Microbiota/drug effects , RNA, Helminth , RNA, Ribosomal, 16S , Trichuriasis/drug therapy , Trichuriasis/epidemiology , Trichuriasis/parasitology , Trichuris/geneticsABSTRACT
El objetivo de este trabajo fue estudiar la relación entre la carga por garrapatas y la tasa de inoculación para Babesia bovis, B. bigemina y A. marginale en granjas lecheras de la región tropical de los llanos orientales de Santa Cruz, Bolivia. En estas fincas, el ganado es periódicamente bañado con acaricidas contra la garrapata Boophilus microplus, la única especie de importancia en la región. Se seleccionaron 51 terneros pertenecientes a cuatro granjas lecheras. Se visitaron estos animales mensualmente desde la edad de 2-3 meses hasta 7-8 meses. Se contaron las garrapatas hembras estándar de medio cuerpo de cada animal y se extrajeron muestras de suero, a las que se realizó pruebas de ELISA indirecta para detección de anticuerpos contra B. bovis, B. bigemina y A. marginale. Estos datos sirvieron para calcular tasas de inoculación para cada uno de los hemoparásitos. Se encontró una correlación lineal significativa entre los números de garrapatas transformados logarítmicamente y la tasa de inoculación para B. bovis, pero no para B. bigemina ni A. marginale. De las ecuaciones de regresión se calculó un número de garrapatas mínimo necesario para obtener estabilidad endémica. Se analizaron los resultados y se dieron recomendaciones prácticas.