Abstract Thermochemolysis-GC-MS was used to characterize Methicillin resistant Staphylococcus aureus (MRSA) and a predatory actinobacteria isolated from Moroccan marine water through their membrane fatty acids released as methyl esters (FAMEs). FAMEs from MRSA were dominated by branched iso and anteiso C15, straight C18 and C20 whereas the predatory actinobacteria was dominated by branched C14, iso and anteiso C15, and straight C16. The iso to anteiso C15 ratio was 0.44 for MRSA and 0.9 for the actinomycete. A co-culture of actinomycetes and bacteria was conducted during 15 days. An increase in the iso to anteiso ratio, a decrease in C18 and C20 FAMEs and an increase in branched C14 and C16 FAMEs demonstrated the predation of MRSA by the actinomycete. The total amount of FAMEs which was significantly higher in the studied actinobacteria (83 mg/g) compared to MRSA (17 mg/g) increased during the co-culture demonstrating the predation. Principal Component (PCA) and Hierarchical Cluster Analysis (HCA) were used to correlate fatty acids (FA) distributions with the strains. HCA allowed to discriminate between MRSA and the actinobacteria. With PCA, long chained (>C18) FAMEs correlated with MRSA whereas short branched-chained FAMEs correlated with the actinobacteria and T15. Consequently, a clear distinction in the chemotaxonomy of MRSA and actinobacteria was established by PCA. Additionally, PCA highlighted the predation of MRSA by the actinobacteria through dissimilarity between MRSA and T15 and similarity between actinobacteria and T15.

中文翻译：

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热化学分解-GC-MS 作为化学分类和捕食性监测捕食性放线菌对抗多药耐药细菌的工具

摘要 热化学分解-GC-MS 用于表征耐甲氧西林金黄色葡萄球菌 (MRSA) 和通过其以甲酯 (FAME) 形式释放的膜脂肪酸从摩洛哥海水中分离的掠食性放线菌。MRSA 的 FAME 以支链 iso 和 anteiso C15、直 C18 和 C20 为主，而掠食性放线菌以支链 C14、iso 和 anteiso C15 以及直 C16 为主。对于 MRSA，iso 与 antiiso C15 之比为 0.44，放线菌为 0.9。在 15 天内进行放线菌和细菌的共培养。iso 与 anteiso 比率的增加、C18 和 C20 FAME 的减少以及分支 C14 和 C16 FAME 的增加证明了放线菌对 MRSA 的捕食。与 MRSA (17 mg/g) 相比，在研究的放线菌中显着更高的 FAME 总量 (83 mg/g) 在共培养期间增加，证明了捕食。使用主成分 (PCA) 和分层聚类分析 (HCA) 将脂肪酸 (FA) 分布与菌株相关联。HCA 允许区分 MRSA 和放线菌。对于 PCA，长链 (>C18) FAME 与 MRSA 相关，而短支链 FAME 与放线菌和 T15 相关。因此，PCA 明确区分了 MRSA 和放线菌的化学分类。此外，PCA 通过 MRSA 和 T15 之间的不同以及放线菌和 T15 之间的相似性，突出了放线​​菌对 MRSA 的捕食。