Biofilm formation by pathogenic bacteria as well as their resilience to antibiotic treatments are a major health problem. Here, we sequenced and analyzed the genome of the clinical methicillin-resistant Staphylococcus aureus S1 (MRSA-S1) strain and established its sensitivity to the combination of methicillin and the leaderless two peptides enterocin DD14 (EntDD14). Such sensitivity was assessed in vitro based on the MIC/FIC values as well as on killing curves experiments. Moreover, combination of EntDD14 and methicillin was able to reduce the biofilm formation of Staphylococcus aureus S1 of about ∼30 %. Interestingly, genes thought to be involved in the virulence of MRSA-S1, like nuc and pvl which code, respectively, for nuclease and Panton-Valentine leucocidin, were shown to be downregulated following treatment with EntDD14 and methicillin. Similar effects were registered for other genes such as cflA, cflB and icaB, coding for bacterial ligands clumping factors A, B and intercellular adhesion factor respectively. All these data, suggest that combinations of bacteriocins and antibiotics are useful as a backup for treatment of bacterial infections.

由病原菌形成的生物膜以及它们对抗生素治疗的抵抗力是一个主要的健康问题。在这里，我们对临床耐甲氧西林金黄色葡萄球菌S1 (MRSA-S1) 菌株的基因组进行了测序和分析，并确定了其对甲氧西林和无前导两种肽肠菌素 DD14 (EntDD14) 组合的敏感性。基于 MIC/FIC 值以及杀伤曲线实验在体外评估了这种敏感性。此外，EntDD14 和甲氧西林的组合能够将金黄色葡萄球菌S1的生物膜形成减少约 30%。有趣的是，被认为与 MRSA-S1 毒力有关的基因，如nuc和pvl分别为核酸酶和 Panton-Valentine leucocidin 的代码在用 EntDD14 和甲氧西林处理后显示出下调。其他基因如cflA、cflB和icaB也有类似的影响，分别编码细菌配体结块因子 A、B 和细胞间粘附因子。所有这些数据表明，细菌素和抗生素的组合可用作治疗细菌感染的备用药物。