Viability of Strongyloides venezuelensis eggs and larvae in vermiculite containing the fungus Duddingtonia flagrans.

Strongyloidiasis is the most clinically important disease among the infections caused by geohelminths, seeing that this parasite can cause autoinfection. The use of nematophagous fungi like Duddingtonia flagrans, that have predation action on eggs and infecciososas forms of helminths, emerges as an alternative method for environmental control. For this reason, analyzing the viability of larvae and eggs of Strongyloides venezuelensis and the action of Duddingtonia flagrans AC001 in vermiculite, as well as the action of the nematophagous fungi in different growth stages, is important to elaborate and define the best culture conditions that favor the activity of the fungus. Two different growth conditions were applied: both eggs and AC001 fungi were added at the same time to the vermiculite (assay A) and the addition of eggs after the growth of the AC001 fungi in the vermiculite (assay B). To recover the L3 larvae, the Baermann-Moraes method was applied, followed by the counting of L3 dead and alive. At last, it was observed that the vermiculite enriched with organic material is an adequate culture medium not only for the growth of the S. venezuelensis but also for the growth of the D. flagrans fungus, being therefore, a satisfactory culture medium for tests of viability and predatory action of this fungus. It was also observed that the activity of the AC001 fungus is greater when it is growing concomitantly with the eggs, in other words, when it is in the adaptation phase.

Peripheral blood CD4+/CD25+ regulatory T cells in alcoholic patients with Strongyloides stercoralis infection.

An increased number of regulatory T (Treg) cells has been reported in patients with HTLV-1 and Strongyloides stercoralis co-infection, suggesting the contribution of these cells to worm survival. As Strongyloides infections have been found to be highly prevalent in chronic alcoholics, we investigated the effect of abusive ethanol ingestion on the induction of Treg cells in alcoholic patients with Strongyloides infection. Treg cells were assessed by flow cytometry in the peripheral blood of 12 healthy non-alcoholic (control) and 14 alcoholic patients (alcoholic) without Strongyloides infection and five non-alcoholics (controlSs) and five chronic alcoholics (alcoholSs) with Strongyloides infection. The results showed significantly higher frequencies of Treg cells in the alcoholic, controlSs and alcoholSs group patients than in the control group patients. However, the frequencies of Treg cells did not differ between the alcoholSs and controlSs groups. In conclusion, our results demonstrate that ethanol consumption induced an increase in the number of circulating Treg cells in chronic alcoholics in this study but was unable to potentiate the induction of these cells in alcoholics with Strongyloides infection.

Comparative study of cultivation of feces in vermiculite or charcoal to obtain larvae of Strongyloides venezuelensis.

INTRODUCTION: We compared feces culturing in charcoal or vermiculite to obtain Strongyloides venezuelensis larvae. METHODS: Feces (5 g) from infected rats was mixed with vermiculite (10 g) or coal (10 g) in plastic cups and incubated at 28°C for 48 h. Larvae were recovered using Baermann-Moraes method. RESULTS: Significantly higher number of positive larval cultures were recovered from vermiculite than from charcoal (15/17 and 4/17, respectively; p < 0.001; 990.6 ± 307.5 and 215 ± 78.1 larvae, p = 0.027). CONCLUSIONS: Vermiculite yields more larvae and provides cleaner pellets, improving larvae identification and facilitating their use for other purposes.

Parasitological stool sample exam by spontaneous sedimentation method using conical tubes: effectiveness, practice, and biosafety.

INTRODUCTION: Spontaneous sedimentation is an important procedure for stool examination. A modification of this technique using conical tubes was performed and evaluated. METHODS: Fifty fecal samples were processed in sedimentation glass and in polypropylene conical tubes. Another 50 samples were used for quantitative evaluation of protozoan cysts. RESULTS: Although no significant differences occurred in the frequency of protozoa and helminths detected, significant differences in protozoan cyst counts did occur. CONCLUSIONS: The use of tube predicts a shorter path in the sedimentation of the sample, increases concentration of parasites for microscopy analysis, minimizes the risks of contamination, reduces the odor, and optimizes the workspace.

Parasitological stool sample exam by spontaneous sedimentation method using conical tubes: effectiveness, practice, and biosafety / Exame parasitológico de fezes pelo método de sedimentação espontânea utilizando tubos cônicos: eficácia, praticidade e biossegurança

INTRODUCTION: Spontaneous sedimentation is an important procedure for stool examination. A modification of this technique using conical tubes was performed and evaluated. METHODS: Fifty fecal samples were processed in sedimentation glass and in polypropylene conical tubes. Another 50 samples were used for quantitative evaluation of protozoan cysts. RESULTS: Although no significant differences occurred in the frequency of protozoa and helminths detected, significant differences in protozoan cyst counts did occur. CONCLUSIONS: The use of tube predicts a shorter path in the sedimentation of the sample, increases concentration of parasites for microscopy analysis, minimizes the risks of contamination, reduces the odor, and optimizes the workspace.

INTRODUÇÃO: A sedimentação espontânea é um procedimento importante para o exame parasitológico de fezes. Uma modificação desta técnica utilizando tubos cônicos foi realizada e avaliada. MÉTODOS: Cinquenta amostras de fezes foram processadas em cálices de sedimentação de vidro e em tubos cônicos de polipropileno. Outras 50 amostras foram usadas para avaliação quantitativa de cistos de protozoários. RESULTADOS: Embora não tenham sido encontradas diferenças significativas na frequência de helmintos e protozoários identificados, houve diferença significativa na contagem de cistos de protozoários. CONCLUSÕES: O uso do tubo prevê um caminho mais curto na sedimentação da amostra, aumenta a concentração de parasitas para a análise microscópica, minimiza os riscos de contaminação, reduz o odor e otimiza o espaço de trabalho.