Atuação de nanocomposto a base de sálvia no controle da motilidade plasmidial em biofilmes de Escherichia coli e Salmonella Heidelberg

Abstract

Bacterial biofilms represent a serious problem for the food industry, including the facilitation of gene exchange processes between bacteria, determining the acquisition of virulence and adaptation factors, with emphasis on antimicrobial resistance. The conditions of the industrial environment intensify the process of formation of sessile bacterial structures and nanotechnology appears as an innovative proposal for its control. The objective was to evaluate the frequency of conjugation of mixed biofilms of Escherichia coli and Salmonella Heidelberg under conditions that mimic the industrial environment (presence of whey) and the effect of sage-based nanocompounds on this process. S. Heidelberg was used as a donor for the blaTEM gene and the E. coli J53 strain as a recipient, which were subjected to the overnight conjugation process. The frequency of conjugation of the blaTEM gene was performed using a phenotypic (selective medium count) in the presence and absence of whey and sage-based nanocomposite. Comparison between the control groups and those treated with sage nanocompound, in the presence and absence of whey, revealed that the conjugation frequency was 2.85 and 3.18 times lower in the presence of the nanocompound. The average counts (log CFU/mL) showed statistically significant differences between the transconjugants treated with the sage nanocomposite without the addition of whey (5.84±0.61) compared to the traditional control group (6.30±0 ,37). However, the counts in treatments with sage in the presence of whey (6.57±0.53), compared to the control also supplemented (6.59±0.47) showed no difference. The use of sage nanoparticles has shown promise in controlling gene exchange and mitigating blaTEM gene transfer in traditional mixed S. Heidelberg and E. coli biofilms. The presence of whey increased the frequency of gene exchanges, and in the presence of this co-product, the sage nanocomposite was not a mitigating agent for these events.