Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
Department of Laboratory Medicine, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.
Int J Antimicrob Agents. 2020 Aug;56(2):106050. doi: 10.1016/j.ijantimicag.2020.106050. Epub 2020 Jun 13.
Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) have disseminated worldwide and are a major threat to public health. The multidrug-resistant (MDR)-phenotype of KPC-KP are commonly associated with the presence of high molecular weight bla plasmids. Restriction-modification (R-M) systems provide bacteria with innate defense against plasmids or other infectious gene elements. As bla plasmids are favored by such MDR K. pneumoniae, it was of interest to examine the co-distribution of R-M and acquired bla plasmids in KPC-KP. A total of 459 clinical K. pneumoniae isolates in China and 217 global whole-genome sequences in GenBank were collected to determine the prevalence of type I R-M systems. The type I R-M systems were scarce in the KPC-positive group and high-risk Klebsiella pneumoniae clonal group 258 (CG258). The polymorphisms of type I R-M observed in K. pneumoniae revealed the ubiquity of their recognition sequences in DNA; therefore, the type I R-M systems could attack most invading DNA elements, such as bla genes. Overall, this work indicated the type I R-M systems may impact the acquisition of bla genes in K. pneumoniae.
产碳青霉烯酶肺炎克雷伯菌（KPC）的肺炎克雷伯菌（KPC-KP）已在全球传播，对公共卫生构成重大威胁。KPC-KP 的多药耐药（MDR）表型通常与存在高分子量 bla 质粒有关。限制修饰（R-M）系统为细菌提供了对质粒或其他感染基因元件的固有防御。由于 bla 质粒受到这种 MDR 肺炎克雷伯菌的青睐，因此研究 R-M 和获得的 bla 质粒在 KPC-KP 中的共同分布很有意思。本研究共收集了中国 459 株临床肺炎克雷伯菌分离株和 GenBank 中 217 株全球全基因组序列，以确定 I 型 R-M 系统的流行率。I 型 R-M 系统在 KPC 阳性组和高风险肺炎克雷伯菌克隆组 258（CG258）中很少见。肺炎克雷伯菌中观察到的 I 型 R-M 系统的多态性表明其识别序列在 DNA 中的普遍性；因此，I 型 R-M 系统可以攻击大多数入侵的 DNA 元素，如 bla 基因。总的来说，这项工作表明 I 型 R-M 系统可能影响肺炎克雷伯菌中 bla 基因的获得。
