Influência dos íons metálicos no perfil aos antimicrobianos e na formação de biofilmes em cepas de Escherichia coli Uropatogênica(UPEC), Escherichia colienteroagregativa(EAEC) e Escherichia coli K-12

Abstract

Metallic ions, iron and copper are essential for all cells, as they fulfill cellular functions essential for life maintenance, acting as enzymatic cofactors, elements of the cellular membrane structure of DNA and enzymes. However, in high concentrations iron and copper ions may lead to the formation of reactive oxygen species (ROS), acting mainly on membrane lipid peroxidation and blocking the action of enzymes that are fundamental for cellular metabolism. ERO production is one of the mechanisms by which metals can interfere with the survival and virulence of bacterial species. Studies have shown that metal ions can interfere in the formation of biofilms and cause changes in the bacterial resistance profile to different classes of antimicrobials. The use of metals as antimicrobial agents is a practice used since antiquity. However, few studies address the influence of these metal ions on biofilm formation and resistance profile. In the present study we used iron and copper ions at concentrations of 100μM and 200μM (for both ions) to evaluate the biofilm production response in enteroaggregating Escherichia coli (EAEC), uropathogenic Escherichia coli (UPEC) and Escherichia coli K-12 ( wild and mutant deficient in DNA repair enzymes) against these metal ions. For this, we used the qualitative and semiquantitative biofilm formation tests, the biofilm viability test and the toxicity test. In the quantitative biofilm formation test, for EAEC 042 there was a significant reduction of the biofilm in the presence of iron and copper in the concentrations of 100 μM and 200 μM, respectively. For EAEC I49/3 there was an increase in biofilm production in the presence of iron in the concentration of 200μM and in the concentrations of 100μM and 200μM of copper. In the UPEC group there was an expressive increase of biofilm for the 7104 strain in the concentration of 100 μM and 200 μM of copper. The 666 strain had a biofilm increase in the concentrations of 200μM iron ion and 100μM and 200μM copper. Among the strains of E. coli K-12, biofilm increase was observed for wild strain AB1157 at concentrations of 100μM and 200μM of copper. In the qualitative test, wild-type strain E. coli K-12 (AB1157) presented filament when treated with 100 μM of copper and the mutant BW9091 at the concentration of 100 μM of iron. In the viability test 100% of strain BW 528 (double mutant nfo- and nth-) died when treated with copper. In the antibiotic resistance test the strain of UPEC 7104 showed a change in the profile of sensitive to resistant when treated with ciprofloxacin iron and copper ions. The strain 9260 showed a change in the resistance profile for sensitive when treated with cefuroxime, cefoxitin, cefotaxime, ceftazidime and ciprofloxacin. However, when treated with trimethoprim and trimethoprim / sulfamethoxazole, it presented a change in the profile of sensitive to resistant metal ions. The results obtained up to the present moment showed that the metal ions interfere with the biofilm production in pathogenic bacteria, modulating the virulence of these microorganisms. Copper and iron ions present as a possible microbial control strategy, since they modulate the profile of antimicrobial resistance in these microorganisms studied. Copper and iron ions represents a possible microbial control strategy, since they modulate the profile of antimicrobial resistance in these E. coli studied.