A influência da antibioticoterapia na tricuríase em fase crônica

Abstract

Geohelminthiasis are parasitic infections caused by nematodes and transmitted by direct or indirect contact of the host with soil contaminated with human feces. Human trichuriasis is developed by the species Trichuris trichiura. T.muris has been used as an experimental model and has proven to be a powerful tool for exploring infection establishment and maintenance processes. The effectiveness of drugs used against geohelminthiasis has diminished over time as they are widely distributed for preventive chemotherapy, so the threat of resistance is real and immediate. There is a need to study new forms of treatment for soil-borne diseases. This study aims to evaluate the impact of antibiotic therapy on the parasitic biology of Trichuris muris, and the effects of this drug on tissue changes caused by infection and its influence on the intestinal microbiota and the bacteria associated with the process of tissue invasion as a result of this parasitosis. Male mice (swiss webster) were infected with 150 T. muris eggs. After infection was established, the animals were treated with subcutaneous Piperacillin + Tazobactan (8mg / day) for eight days. Stool samples were collected for parasitological examination and after 45 days the animals were euthanized and necropsied. Different tissues were collected and processed for hematological / biochemical, immunological and histopathological techniques. Our results show that the treatment had no impact on the parasite's reproductive biology, fecal egg clearance and parasite load. As expected, the infected animals presented a significant thickening of the intestinal mucosa, submucosa and muscular layer, where we characterized a polymorphonuclear infiltrate, with few macrophages, in the intestinal mucosa and submucosa an intense polymorphonuclear and lymphoplasmic infiltrate. Antibiotic therapy promoted a significant reduction in epithelial submucosa thickening, reducing the inflammatory infiltrate, with few cells identified in this layer. In the immunological aspects we observed a decrease in IL-10 production in the infected animals serum treated and a reduction of IL-6 and an increase of TNF and INF- in the mesenteric lymph node and serum of this group. There was an increase in IL-6 in the caecum of infected animals compared to those treated. Regarding Th2 cytokines, our data suggest, even without significant difference, a reduction in IL-4 and IL-10 release in the serum of infected animals undergoing treatment. Invasive bacteria were identified only in the submucosa of untreated infected and control animals as well as the presence of enterobacteria was observed only in these two groups. We conclude that antibiotic therapy has no impact on nematode reproductive activity or parasite load, indicating that this drug has no action against the parasite. However, the treatment significantly reduced intestinal bacterial colonization and this resulted in the elimination of the bacterial invasion process in the epithelial submucosa, providing a significant reduction in the intestinal inflammatory infiltrate. We found that chronic trichuriasis develops a more serious infectious aspect due to the synergism that occurs between adult worm lesions and invasion of opportunistic bacteria.