Abstract：
The SCCmec typing is crucial for investigating methicillin-resistant S. aureus, relying primarily on the combination of ccr and mec gene complexes. To date, 19 ccr genes and 10 ccr gene complexes have been identified, forming 15 SCCmec types. With the vast release of bacterial genome sequences, mining the database for novel ccr gene complexes and SCC/SCCmec elements could enhance MRSA epidemiological studies. In this study, we identified 12 novel ccr genes (6 ccrA, 3 ccrB and 3 ccrC) through mining of the NCBI database, which forming 12 novel ccr gene complexes and 10 novel SCC elements. Overexpression of five groups of novel Ccr recombinases (CcrA9B3, CcrA10B1, CcrC3, CcrC4, and CcrC5) in a mutant MRSA strain lacking the ccr gene and extrachromosomal circular intermediate (ciSCC) production significantly promoted ciSCC production, demonstrating their biological activity. This discovery provides an opportunity to advance MRSA epidemiological research and develop database-based bacterial typing methods.
摘要：
SCCmec分型对于研究耐甲氧西林金黄色葡萄球菌至关重要，主要依靠ccr和mec基因复合物的结合。迄今为止,已鉴定出19个ccr基因和10个ccr基因复合物，形成15种SCCmec类型。随着细菌基因组序列的大量释放，挖掘新的ccr基因复合物和SCC/SCCmec元件的数据库可以增强MRSA流行病学研究。在这项研究中,我们鉴定了12个新的ccr基因(6个ccrA，3ccrB和3ccrC)通过挖掘NCBI数据库，形成12个新的ccr基因复合物和10个新的SCC元件。五组新型Ccr重组酶（CcrA9B3，CcrA10B1，CcrC3，CcrC4和CcrC5）在缺乏ccr基因和染色体外环状中间体（cisc）产生的突变MRSA菌株中的过表达显着促进了cisc的产生，展示他们的生物活性。这一发现为推进MRSA流行病学研究和开发基于数据库的细菌分型方法提供了机会。
