In this study, the tetracycline resistance of Enterococcus faecalis strains isolated from food was determined and molecular analyses of the resistance background were performed by determining the frequency of selected tetracycline resistance genes. In addition, the effect of high-pressure stress (400 and 500 MPa) on the expression of selected genes encoding tetracycline resistance was determined, as well as changes in the frequency of transfer of these genes in isolates showing sensitivity to tetracyclines. In our study, we observed an increase in the expression of genes encoding tetracyclines, especially the tet(L) gene, mainly under 400 MPa pressure. The study confirmed the possibility of transferring genes encoding tetracyclines such as tet(M), tet(L), tet(K), tet(W) and tet(O) by horizontal gene transfer in both control strains and exposed to high-pressure. Exposure of the strains to 400 MPa pressure had a greater effect on the possibility of gene transfer and expression than the application of a higher-pressure. To our knowledge, this study for the first time determined the effect of high-pressure stress on the expression of selected genes encoding tetracycline resistance, as well as the possibility and changes in the frequency of transfer of these genes in Enterococcus faecalis isolates showing sensitivity to tetracyclines and possessing silent genes. Due to the observed possibility of increased expression of some of the genes encoding tetracycline resistance and the possibility of their spread by horizontal gene transfer to other microorganisms in the food environment, under the influence of high-pressure processing in strains phenotypically susceptible to this antibiotic, it becomes necessary to monitor this ability in isolates derived from foods.

在本研究中，确定了从食品中分离的粪肠球菌菌株的四环素耐药性，并通过确定选定的四环素耐药基因的频率来进行耐药背景的分子分析。此外，还确定了高压应激（400 和 500 MPa）对编码四环素抗性的选定基因表达的影响，以及对四环素敏感的分离株中这些基因转移频率的变化。在我们的研究中，我们观察到编码四环素的基因，尤其是tet （L）基因的表达增加，主要是在400 MPa压力下。该研究证实了在暴露于高压的两个对照菌株中通过水平基因转移来转移编码四环素如tet (M)、tet (L)、tet (K)、tet (W)和tet (O)的基因的可能性。与施加更高的压力相比，将菌株暴露于 400 MPa 压力对基因转移和表达的可能性有更大的影响。据我们所知，这项研究首次确定了高压应激对编码四环素抗性的选定基因表达的影响，以及这些基因在粪肠球菌分离株中转移的可能性和频率的变化，这些基因对四环素耐药性表现出敏感性四环素类药物并拥有沉默基因。由于观察到一些编码四环素抗性的基因表达增加的可能性，以及在对这种抗生素表型敏感的菌株的高压加工的影响下，它们通过水平基因转移传播到食品环境中的其他微生物的可能性，有必要监测源自食品的分离物的这种能力。