Methicillin-resistant Staphylococcus aureus (MRSA) is a prevalent nosocomial pathogen, causing a wide range of diseases. The increased frequency of MRSA isolates in hospitals and the emergence of vancomycin resistance have sparked the search for new control strategies. This study aimed to characterize sixty-seven MRSA isolates collected from both infected patients and asymptomatic carriers in a Spanish hospital. RAPD-PCR allowed the identification of six genetic patterns. We also investigated the presence of genes involved in producing adhesins, toxins and the capsule; the biofilm; and antimicrobial resistance. A notable percentage of the isolates carried virulence genes and showed medium-high ability to form biofilms. Next, we assessed the strains’ susceptibility to two phages (phiIPLA-C1C and phiIPLA-RODI) and one endolysin (LysRODI). All strains were resistant to phiIPLA-C1C, and most (70.2%) were susceptible to phiIPLA-RODI. Regarding LysRODI, all strains displayed susceptibility, although to varying degrees. There was a correlation between endolysin susceptibility and the random amplification of polymorphic DNA (RAPD) profile or the presence of some virulence genes (fnbA, eta, etb, PVL and czr), but that was not observed with biofilm-forming ability, strain origin or phage sensitivity. Taken together, these findings can help to explain the factors influencing endolysin effectiveness, which will contribute to the development of efficient therapies targeting MRSA infections.

中文翻译：

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西班牙北部临床MRSA分离株的表征及其对噬菌体衍生抗微生物剂敏感性的评估。

耐甲氧西林金黄色葡萄球菌（MRSA）是一种流行的医院病原体，引起多种疾病。医院中MRSA分离株的频率增加，并且出现了万古霉素耐药性，这促使人们寻求新的控制策略。这项研究旨在表征在西班牙医院从感染患者和无症状携带者中收集的67种MRSA分离株。RAPD-PCR可以鉴定六个遗传模式。我们还研究了与产生粘附素，毒素和胶囊有关的基因的存在。生物膜；和抗菌素耐药性。显着百分比的分离株带有毒力基因，并显示出中等高的形成生物膜的能力。接下来，我们评估了菌株对两种噬菌体（phiIPLA-C1C和phiIPLA-RODI）和一种内溶素（LysRODI）的敏感性。所有菌株均对phiIPLA-C1C具有抗性，大部分（70.2％）对phiIPLA-RODI敏感。关于LysRODI，所有菌株均表现出敏感性，尽管程度不同。溶血素的易感性与多态性DNA（RAPD）图谱的随机扩增或某些毒力基因的存在之间存在相关性（fnbA，eta，etb，PVL和czr），但未观察到生物膜形成能力，菌株起源或噬菌体敏感性。综上所述，这些发现可以帮助解释影响细胞内溶素有效性的因素，这将有助于开发针对MRSA感染的有效疗法。