College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China.
Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada.
J Infect Dis. 2024 Jul 25;230(1):231-238. doi: 10.1093/infdis/jiae044.
Staphylococcal cassette chromosome mec (SCCmec) typing is crucial for investigating methicillin-resistant Staphylococcus aureus (MRSA), 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 National Center for Biotechnology Information (NCBI) database, forming 12 novel ccr gene complexes and 10 novel SCC elements. Overexpression of 5 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.
葡萄球菌盒式染色体 mec（SCCmec）分型对于研究耐甲氧西林金黄色葡萄球菌（MRSA）至关重要，主要依赖于 ccr 和 mec 基因复合物的组合。迄今为止，已经鉴定出 19 个 ccr 基因和 10 个 ccr 基因复合物，形成了 15 种 SCCmec 型。随着细菌基因组序列的大量发布，从数据库中挖掘新型 ccr 基因复合物和 SCC/SCCmec 元件可以增强 MRSA 流行病学研究。在这项研究中，我们通过挖掘美国国立生物技术信息中心（NCBI）数据库，鉴定出了 12 个新型 ccr 基因（6 个 ccrA、3 个 ccrB 和 3 个 ccrC），形成了 12 个新型 ccr 基因复合物和 10 个新型 SCC 元件。在缺乏 ccr 基因和额外染色体环状中间体（ciSCC）产生的突变型 MRSA 菌株中过表达 5 组新型 Ccr 重组酶（CcrA9B3、CcrA10B1、CcrC3、CcrC4 和 CcrC5）显著促进了 ciSCC 的产生，证明了它们的生物学活性。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。
