Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as one of the serious pathogen that causes acquired infections worldwide. Its emerging need to discover novel, safe and potent anti-MRSA drugs. In this study, primary screening by anti-MRSA activity assay found one strain WA5-2-37 isolated from the intestinal tract of Periplaneta americana, exhibited great activity against MRSA ATCC 43300. The strain WA5-2-37 produced actinomycin X2 and collismycin A which showed strong inhibition of MRSA with minimum inhibitory concentration (MIC) values of 0.25 and 8 μg/mL. The structures of the pure compounds were elucidated by analysis of mass spectrometry (MS), 1H and 13C nuclear magnetic resonance (NMR). The strain WA5-2-37 was considered as Streptomyces globisporus on the basis of morphological characteristics, genotypic data, and phylogenetic analysis. This is the first reported naturally occurring strain of S. globisporus isolated from the intestinal tract of P. americana, whereas it has almost been found from plants, marine, and soil previously. Moreover, S. globisporus has not been reported to produce any anti-MRSA substances previously, such as actinomycin X2 and collismycin A. In conclusion, the insect-derived strain of S. globisporus WA5-2-37 was considered of great potential as a new strain of producing actinomycin X2, collismycin A or other anti-MRSA compounds.

中文翻译：

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由美国蟑螂（Periplaneta americana）的肠道链球菌WA5-2-37产生的放线菌素X2和Collismycin A的抗MRSA活性。

耐甲氧西林的金黄色葡萄球菌（MRSA）是导致全球范围内获得性感染的严重病原体之一。它迫切需要发现新颖，安全和有效的抗MRSA药物。在这项研究中，通过抗MRSA活性测定的初步筛选发现，一种从美洲围plane肠道分离的WA5-2-37菌株对MRSA ATCC 43300表现出强大的活性。WA5-2-37菌株产生了放线菌素X2和CollismycinA。在最小抑制浓度（MIC）值为0.25和8μg/ mL的情况下，对MRSA表现出强烈的抑制作用。通过质谱分析（MS），1H和13C核磁共振（NMR）阐明了纯化合物的结构。根据形态特征，基因型数据，菌株WA5-2-37被认为是双链链霉菌。和系统发育分析。这是首次报道的天然存在的从美国假单胞菌的肠道分离出的球孢链球菌菌株，而以前几乎是从植物，海洋和土壤中发现的。此外，以前尚未报道过球形双歧杆菌可产生任何抗MRSA物质，例如放线菌素X2和CollismycinA。总之，认为球形双歧杆菌WA5-2-37的昆虫来源菌株具有很大的潜力。新菌株产生放线菌素X2，Collismycin A或其他抗MRSA化合物。