BACKGROUND Staphylococcus aureus is a primary pathogen of orthopedic infections. By mediating antimicrobial resistance, S. aureus biofilm plays an important role in the recalcitrance of orthopedic infections, especially for the intractable osteomyelitis (OM). This study investigated the relationship between biofilm production and various genetic or phenotypic characteristics among orthopedic S. aureus strains. METHODS A total of 137 orthopedic S. aureus isolates were enrolled and divided into OM and non-OM groups. Biofilm production was evaluated using the crystal violet assay. Genetic and phenotypic characteristics including MRSA identification, MLST and spa typing, carriage of virulence genes, drug resistance, and patients' inflammatory responses indicators were characterized. The relationship between biofilm production and above-mentioned features was respectively analyzed among all isolates and compared between OM and non-OM isolates. RESULTS Biofilm production presented no significant difference between OM (including 9 MRSA isolates) and non-OM (including 21 MRSA isolates) strains. We found that ST88, t377 and ST630-MSSA-t377 strains produced very strong biofilms, while MLST types of ST15, ST25, ST398, ST5, ST59 and spa types of t002, t2325, t437 tended to produce weaker biofilms. Strains with the following profiles produced stronger biofilms: fib(+)-hlgv(+)-lukED(+)-sei(-)-sem(-)-seo(-) for all isolates, sei(-)-sem(-)-seo(-) for OM isolates, and cna (+)-fib (+)-hlgv (+)-lukED (+)-seb(-)-sed(-) for non-OM isolates. In addition, not any single drug resistance was found to be related to biofilm production. We also observed that, among OM patients, strains with stronger biofilms caused weaker inflammatory responses. CONCLUSION Some genetic or phenotypic characteristics of orthopedic strains were associated with biofilm production, and this association could be different among OM and non-OM strains. The results are of great significance for better understanding, evaluating and managing different kinds of biofilm-associated orthopedic infections, and provide potential targets for biofilm clearance.

中文翻译：

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调查生物膜的生产及其与OM（骨脊髓炎）和非OM骨科金黄色葡萄球菌的遗传和表型特征的关系。

背景技术金黄色葡萄球菌是骨科感染的主要病原体。通过介导抗菌素耐药性，金黄色葡萄球菌生物膜在骨科感染的顽固抵抗中起着重要作用，特别是对于顽固性骨髓炎（OM）。这项研究调查了生物膜金黄色葡萄球菌菌株之间生物膜生产与各种遗传或表型特征之间的关系。方法总共招募了137例矫形金黄色葡萄球菌分离株，分为OM组和非OM组。使用结晶紫测定法评估生物膜产量。遗传和表型特征包括MRSA鉴定，MLST和水疗分型，毒力基因携带，耐药性以及患者的炎症反应指标。在所有分离株中分别分析了生物膜产量与上述特征之间的关系，并比较了OM和非OM分离株。结果生物膜的产量在OM（包括9个MRSA分离株）和非OM（包括21个MRSA分离株）菌株之间没有显着差异。我们发现ST88，t377和ST630-MSSA-t377菌株产生非常强的生物膜，而MLST类型的ST15，ST25，ST398，ST5，ST59和spa类型的t002，t2325，t437倾向于产生较弱的生物膜。具有以下特征的菌株产生更强的生物膜：fib（+）-hlgv（+）-lukED（+）-sei（-）-sem（-）-seo（-）用于所有分离株，sei（-）-sem（-） ）-seo（-）用于OM分离株，cna（+）-fib（+）-hlgv（+）-lukED（+）-seb（-）-sed（-）用于非OM分离株。另外，没有发现任何单一的耐药性与生物膜的产生有关。我们还观察到，在OM患者中，具有更强生物膜的菌株导致较弱的炎症反应。结论骨科菌株的某些遗传或表型特征与生物膜的产生有关，这种关联在OM和非OM菌株之间可能有所不同。这些结果对于更好地了解，评估和管理与生物膜相关的各种骨科感染类型具有重要意义，并为生物膜清除提供了潜在的目标。