摘要
      多药耐药（MDR）细菌和耐药基因沿着食物链和环境的传播已经成为一种全球性但无声的流行病。为了应对这一挑战，最重要的是制定有效的策略来减少这些制剂的潜在污染。在本研究中，从山羊和羊肉屠宰场的整个肉类生产链的不同表面分离的30株肠球菌、葡萄球菌和假单胞菌被鉴定为携带多种抗生素抗性基因（ARGs）的耐多药细菌。测试了天然精油成分“EOCs”（香芹酚“CA”、“肉桂醛”CIN、“丁香酚”EU、“香叶醇”GE、“柠檬烯”LI和百里酚“TH”）、HLE消毒液（3-6%H2O2；水中2.2-4.4%乳酸和12.5-25mM EDTA）和EDTA对这些MDR细菌的抗菌效果。结果表明，最小抑菌浓度（MIC）是化合物和菌株的依赖性。此外，在1/2 MIC下评估了这些抗菌剂的协同作用。在这里，我们的研究显示了关于亚抑制浓度下的抑制作用的特别有希望的结果，这通过72小时内细菌生长动力学的分析得到了证实。此外，EOCs的抑制作用，研究了HLE消毒溶液和EDTA或它们的组合在开发和建立耐多药细菌生物膜中的作用，根据测试菌株的形态结构和EOCs的酚类特征获得了不同的结果。重要的是，考虑到对生物膜形成的有效抑制，EOCs与HLE或EDTA的组合显示出特别积极的结果。此外，EU和HLE/EDTA、TH、CA、GE、LI或CIN+EDTA/HLE的协同组合导致几个菌株的已建立生物膜的对数减少（1-6 log10 CFU），这取决于所使用的物种和组合，其中假单胞菌菌株最易感。鉴于这些结果，我们提出了基于亚抑制浓度EOCs和HLE或EDTA的组合的新型抗菌制剂，作为目前使用的方法的一种非常有前途的替代方案。值得注意的是，这一新策略显示出巨大的潜力，可以有效减少MDR细菌和ARGs在食物链和环境中的出现和传播，从而支持临床和工业领域耐药性和发病机制的减少，同时保留抗生素的治疗作用。
Abstract
The spread of multidrug resistant (MDR) bacteria and resistance genes along the food chain and the environment has become a global, but silent pandemic. To face this challenge, it is of outmost importance to develop efficient strategies to reduce potential contamination by these agents. In the present study, 30 strains of Enterococcus sp., Staphylococcus sp. and Pseudomonas sp. isolated from various surfaces throughout the meat production chain in a goat and lamb slaughterhouse were characterized as MDR bacteria harboring several antibiotic resistance genes (ARGs). The antimicrobial efficacy of natural essential oil components “EOCs” (carvacrol “CA,” cinnamaldehyde “CIN,” eugenol “EU,” geraniol “GE,” limonene “LI” and thymol “TH”), HLE disinfectant solution (3–6% H2O2; 2.2–4.4% lactic acid and 12.5–25 mM EDTA in water) and EDTA was tested against these MDR bacteria. Results showed that Minimum Inhibitory Concentrations (MIC) were compound and strain dependent. In addition, the synergistic effect of these antimicrobials was evaluated at 1/2 MIC. Here our study showed particularly promising results regarding the inhibitory effect at sub-inhibitory concentrations, which were confirmed by the analysis of bacterial growth dynamics over 72 h. Furthermore, the inhibitory effect of EOCs, HLE disinfectant solution and EDTA or their combinations was studied in developing and established biofilms of MDR bacteria obtaining variable results depending on the morphological structure of the tested strain and the phenolic character of the EOCs. Importantly, the combination of EOCs with HLE or EDTA showed particularly positive results given the effective inhibition of biofilm formation. Moreover, the synergistic combinations of EU and HLE/EDTA, TH, CA, GE, LI or CIN + EDTA/HLE caused log reductions in established biofilms of several strains (1–6 log10 CFU) depending on the species and the combination used, with Pseudomonas sp. strains being the most susceptible. Given these results, we propose novel antimicrobial formulations based on the combination of sub-inhibitory concentrations of EOCs and HLE or EDTA as a highly promising alternative to currently used approaches. This novel strategy notably shows great potential to efficiently decrease the emergence and spread of MDR bacteria and ARGs in the food chain and the environment, thus supporting the decrease of resistomes and pathogenesis in clinical and industrial areas while preserving the antibiotic therapeutic action.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9589356/