Impact of Enterobius vermicularis infection and mebendazole treatment on intestinal microbiota and host immune response.

BACKGROUND: Previous studies on the association of enterobiasis and chronic inflammatory diseases have revealed contradictory results. The interaction of Enterobius vermicularis infection in particular with gut microbiota and induced immune responses has never been thoroughly examined. METHODOLOGY/FINDINGS: In order to answer the question of whether exposure to pinworm and mebendazole can shift the intestinal microbial composition and immune responses, we recruited 109 (30 pinworm-negative, 79 pinworm-infected) first and fourth grade primary school children in Taichung, Taiwan, for a gut microbiome study and an intestinal cytokine and SIgA analysis. In the pinworm-infected individuals, fecal samples were collected again at 2 weeks after administration of 100 mg mebendazole. Gut microbiota diversity increased after Enterobius infection, and it peaked after administration of mebendazole. At the phylum level, pinworm infection and mebendazole deworming were associated with a decreased relative abundance of Fusobacteria and an increased proportion of Actinobacteria. At the genus level, the relative abundance of the probiotic Bifidobacterium increased after enterobiasis and mebendazole treatment. The intestinal SIgA level was found to be lower in the pinworm-infected group, and was elevated in half of the mebendazole-treated group. A higher proportion of pre-treatment Salmonella spp. was associated with a non-increase in SIgA after mebendazole deworming treatment. CONCLUSIONS/SIGNIFICANCE: Childhood exposure to pinworm plus mebendazole is associated with increased bacterial diversity, an increased abundance of Actinobacteria including the probiotic Bifidobacterium, and a decreased proportion of Fusobacteria. The gut SIgA level was lower in the pinworm-infected group, and was increased in half of the individuals after mebendazole deworming treatment.

Immune responses in children infected with the pinworm Enterobius vermicularis in central Greece.

Previous studies have suggested an immunomodulatory and even protective role for Enterobius vermicularis, the least pathogenic human intestinal helminth. Here, in a study using haematological and serological parameters, we tested a total of 215 children from central Greece, with a mean age of 8.39, of whom 105 (48.84%) were infected with E. vermicularis and 110 (51.16%) were matched healthy controls. In particular, we analysed eosinophil counts (EO), serum eosinophil cationic protein (ECP), total and specific serum immunoglobulin E (IgE) and the ECP/EO ratio. The atopic status and the potential occurrence of clinically expressed allergic diseases were both taken into account. Eosinophils, ECP and IgE were found to be higher in infected than in uninfected children, indicating a type-2 immune response activation during infection. Atopic infected children exhibited higher IgE levels compared to non-atopic ones. EO and ECP were found to be lower in atopic children who had a history of allergic disease than in those with no such history. The type-2 oriented immune response elicited against E. vermicularis could contribute to a balanced activation of the immune system in the examined children. Interestingly, although the atopic children showed a stronger activation, they did not exhibit any symptoms and, moreover, there seemed to be some indication of immunosuppression in those children with a positive history of allergic disease.

At homeostasis filarial infections have expanded adaptive T regulatory but not classical Th2 cells.

Despite the well-documented immune suppression associated with human helminth infections, studies characterizing the immune response at the single-cell level are scanty. We used multiparameter flow cytometry to characterize the type of effector (Th1, Th2, and Th17) and regulatory (natural T regulatory cells [nTregs] and adaptive Treg cells [aTreg/type 1 regulatory cells (Tr1s)]) CD4(+) and CD8(+) T cells in filaria-infected (Fil(+)) and -uninfected (Fil(-)) individuals at homeostasis (in the absence of stimulation). Frequencies of CD4(+) lymphocytes spontaneously producing IL-4, IL-10, and IL-17A were significantly higher in Fil(+), as were those of IL-10(+)/IL-4(+) double-producing CD4(+) cells. Interestingly, frequencies of Th17 and aTreg/Tr1s but not classical Th1 or Th2 cells were significantly increased in Fil(+) compared to Fil(-) individuals. Although the frequency of nTreg was increased in Fil(+), IL-10 was overwhelmingly produced by CD4(+)CD25(-) cells. Moreover, the concentration of IL-10 produced spontaneously in vitro strongly correlated with the integrated geometric mean fluorescence intensity of IL-10-producing aTreg/Tr1s in Fil(+). Together, these data show that at steady state, IL-10-producing aTreg/Tr1 as well as nTreg and effector Th17 CD4(+) cells are expanded in vivo in human filarial infections. Moreover, we have established baseline ex vivo frequencies of effector and Tregs at homeostasis at a population level.

Echinococcosis granulosus in stray dogs and Echino-IHAT in the hunters in Cairo, Egypt.

A total of fifty stray dogs of both sex and of different ages were examined for natural infection with Echinococcus granulosus after post-mortem. Three main intestinal helminthes were recovered. These were in descending order of abundance Dipylidium caninum, Toxocara canis and E. granulosus. The latter worm was demonstrated in eight of them (16%). The sera of three out of 21 dog-hunters (14.3%) showed positive Echino-IHAT. Two of the hunters suffered Enterobius vermicularis and one of them had Taenia saginata as well. But, the abdominal X-ray of the two hunters was more or less normal and did not show any hydatid cyst.

A survey of helminthic infections in the residents of rural areas near Ulaanbaatar, Mongolia.

A total of 738 samples was collected to survey the helminthic infections of residents in two rural areas near Ulaanbaatar, Mongolia for 2 weeks from July 23 to August 2, 1998. Among 391 scotch-taped slides of anal swabs of children and of young teenagers. Enterobius vermicularis eggs were detected in 138 cases (35.3%). With the fecal samples of 206 Kato-Katz thick smear slides from adults, the eggs of E. vermicularis were observed in 9 cases and Taenia sp. in one case, respectively. And by ELISA on 141 blood samples absorbed to blood sampling paper, 12 cases (8.5%) were found to be positive against the hydatid cyst antigen. Enterobiasis and hydatidosis are two major endemic diseases which are related closely to the life style of Mongolian.

Atopy and enteroparasites.

UNLABELLED: There are not many studies about the intestinal parasitosis (IP) and atopic asthma (AA) relationship, and these show discordant results, possibly due to different studies design and differences in population selection. On the basis of personal results obtained by an epidemiological inquiry designed to estimate the prevalence of enteroparasitoses in asthmatic children and vice vesa, the aim of this study was to compare the prevalence of IP in AA and in a control group (CG) by a cross sectional study using clinical and laboratorial parameters, applied to 63 children (47 with AA and 16 in CG) aged 6 to 11 years, 37 males and 26 females, Caucasians, with the same socioeconomical conditions, consecutively selected in our Hospital. The results showed: The IP in AA children was 21.3%; the IP in CG was 25%; in the group with AA and IP, 40% of them had symptomology of IP; in the CG with IP, 100% had symptoms. CONCLUSIONS: The IP prevalence in AA was not statistically different from the IP in CG (p > 0.05) More data are needed to clarify the significant differences between the symptomatology rates of IP in asthmatic and non asthmatics; the reduced number of patients with symptoms in AA may reflect modulation of IP in AA and/or different parasite load.

Induction of lymphoma in antigenically stimulated athymic mice.

Athymic mice infected with pinworms or carrying human tumor xenografts frequently develop a lymphoproliferative disorder which eventually leads to lymphoma. By immunofluorescent analysis of involved tissues, the lymphomas appear to be mixtures of null cells, B-cells, and T-cells. When each lymphoma is established in tissue culture, a predominant cell type grows out. We have now established lymphoma lines of null cells, B-cells, and T-cells. Lymphoma development is preceded by the secretion into the bloodstream of large amounts of murine leukemia virus M.W. 70,000 glycoprotein antigen; however, very little virus is produced. In vivo, the expression of viral envelope antigen appears within a few days after human tumor transplantation and precedes the development of lymphoma by about a month. Cells expressing viral antigens are first seen in the diffuse cortex of lymph nodes and the periarteriolar white sheath of the spleen, the tissue domains in which lymphomas also first appear.