Nanocontrole da transferência horizontal de gene de resistência a antibióticos em bactérias de importância em alimentos

Abstract

The uncontrolled use of antibiotics has been triggering the increasing appearance of superresistant bacteria, being, therefore, one of the biggest concerns worldwide. In addition, currently, there is low production of new antimicrobials in proportion to the high emergence of these superbugs. As antibiotics are also used in animal production, the appearance of superbugs in products of animal origin (POA) has been recurrent and difficult to eliminate in the production chain, and may therefore cause foodborne illnesses (DTAs) that are difficult to treat. An alternative that has been showing promising results is the use of essential oils combined with nanotechnology in order to mitigate the transfer of these resistant genes to other bacteria in the industrial environment of poultry, for example. Therefore, the main objective of this work was to evaluate the effect of a nanostructured lipid carrier of sage essential oil on the control of the bacterial conjugation process between wild strains of Salmonella Heidelberg (SH01) which is a donor of blaTEM genes in its planktonic form and Escherichia coli J53 AzR (resistant sodium azide) as a receptor. The evaluation was performed by determining the frequency of E. coli transconjugants via phenotypic and genotypic analysis, using antimicrobial resistance test and conventional PCR, respectively. Three different conjugation techniques were standardized and methodology 1, liquid medium with three hours of incubation, was chosen as the best one according to the highest frequency of conjugation and the significance in the count of transconjugants, mainly with chicken juice (CJ) (p=0.0013). In testing the nanocarrier, the FCR values were reduced from 2.2% to 0.028% in the traditional test and from 6.2 to 0.098% in the conjugation using CJ corresponding to a reduction of transconjugants of 79.6 times without CJ and 67, 6 times with CJ. Furthermore, all colonies of transconjugants chosen at random presented the blaTEM gene genotypically identified, confirming the effectiveness of the process. Thus, the nanocomposite demonstrated a promising effect as a reducer/inhibitor of bacterial conjugation applicable to the poultry industry.