Potencial probiótico de Enterococcus faecium isolados de queijo

Abstract

The purpose of this work was to identify, assess and compare some Enterococcus faecium potential probiotic micro-organisms isolated from artisanal cheese in Londrina. First, identified by molecular techniques already isolated strains of Enterococcus. The rest of the tests were made only with isolates of Enterococcus faecium. There was then a antibiogram forward to erythromycin 15 mg, 30 mg tetracycline and vancomycin 30 mg, checking the resistance or sensitivity of each isolate against these antibiotics. It was then performed simulation tests in vitro gastro-intestinal tract and compared with the commercial Lactobacillus acidophilus strain. To simulate the conditions in the mouth was performed to test for resistance to lysozyme, thus verifying its viability. Have to simulate conditions in the stomach was performed tolerance test in acid medium in cultivation. We evaluated the survival conditions simulating the small intestine, determining the viability of these micro-organisms against the pancreatin at pH 8.0. In the study of auto-aggregation, either isolated from E. faecium and a strain of commercial L.acidophilus were separately placed and the optical density verified of 540 nm. The results showed that the 98 Enterococcus, isolated from cheese, was 54.0% E. faecium, 39.8% E. faecalis and 6.2% Enterococcus spp. Regarding antimicrobial susceptibility were slightly resistant to the antibiotics tested, and 24.5% were resistant to erythromycin and 1.9% to tetracycline and vancomycin. Already in lysozyme resistance test after 120 min showed 15 isolates that had no significant difference at 5% when compared to L. acidophilus and 7 isolates were more resistant than the same. In result against acid stress after 3 h, 3 isolates showed no significant difference at 5% when compared with L. acidophilus and 2 isolates had greater resistance than Lactobacillus. Regarding testing survival to the small intestine, compared to commercial strain of L. acidophilus, presented with survival rates without significant difference, 21 isolates of E. faecium, and still can highlight the isolates 7 isolates, which found a higher survival rate than the control. 32 of the 53 isolates tested showed the ability to auto-aggregation, or 60%.