Análise da microbiota em fase aguda da esquistossomose hepática e intestinal e a possível interação de espécies de Schistosoma e bactérias

Abstract

Schistosomiasis, caused by species of the trematode Schistosoma, is a neglected disease, very common in developing countries, and more than 200 million people need treatment. In the evolution of schistosomiasis there is a compromise in the morphological and functional structure of the gastrointestinal tract. Under these conditions, bacteria from the intestinal microbiota itself can reach the bloodstream, or associate with the adult worm and egg. Thus, in the present work, a literary review was carried out regarding the microbiota, geohelminth and schistosomiasis interaction. Experimentally, the composition of the BALB/c mice microbiota in the acute phase of mansonic and japanese schistosomiasis and the possible impacts of the infection on the intestine and liver were analyzed. There was a division of 5 groups of animals: CBr control from Brazil and SmBr infected with S. mansoni from Brazil; CJp control of Japan; SmJp infected with S. mansoni in Japan and SjJp infected with S. japonicum in Japan. Thus, the analysis of the intestinal microbiota was performed by obtaining the DNA from the feces of mice and subsequent metagenomic sequencing. Although the count of Colony Forming Units (CFU) in the feces of the infected (SmBr) was higher than in the control, this difference was not statistically significant (p = 0.3637), as well as in the SmJp and SjJp groups (p = 0.5564). The results of metagenomics for SmBr indicate an increase in the number of bacteria belonging to the phylum Bacteroidetes (56.6% to 77%) and a decrease in the phylum Firmicutes (37.5% to 13.9%) in the intestinal microbiota. The results of the quantitative PCR for the phylum Bacteroidetes confirmed the results obtained in the metagenomics, finding a greater quantity in the SmBr group, as well as a decrease in Firmicutes. The livers of the animals in the control and infected groups were also obtained to evaluate the composition of the microbiota, and only the infected animals had bacteria in the liver. Molecular analysis shows the presence of bacteria from the phylum Firmicutes, Bacteroidetes and Proteobacterias. Four species of bacteria were isolated from the liver of SmBr animals and their identification was performed using the MALDI TOF technique (Bordetella hinzii, Haemophilus haemolyticus, Lactococcus garvieae and Escherichia coli); SmJp (Staphylococcus nepalensis and Staphylococcus sciuri) and SjJp (Enterococcus galinarum, Staphylococcus sciuri and Paenibacillus). Tests to determine the sensitivity profile of bacteria to different antibiotics (Clindamycin, Doxycycline, Erythromycin, Gentamicin, Levofloxacin and Sulfamethoxazole + Trimethoprim) showed that all species studied showed sensitivity to Gentamycin. This antibiotic showed greater efficiency both by the analysis of Minimum Inhibitory Concentration and by the Minimum Microbicide Concentration. For Erythromycin, the bacteria B. hinzii, L. garvieae, S. nepalensis and S. sciuri showed sensitivity. As for Levofloxacino, H. haemolyticus, E. coli, L. garvieae, S. nepalensis and S. sciuri were sensitive. In histological sections, it was possible to observe exudative schistosomal granulomas in the liver; and in the intestine, egg retention of parasites in the mucous layer and increased cellularity were identified, which consisted of accumulation of mononuclear and polymorphonuclear cells. It was also possible to verify that some bacteria are able to adhere to the surface of adult worms (E. coli) and eggs (L. garvieae) of S. mansoni. The results obtained indicate a change in the intestinal microbiota with possible spread of bacteria to other organs, such as the liver, showing a possible bacterial translocatio