Hu Yiyi, Jiang Jianping, Wang Dongliang, Guo Qinglan, Wang Minggui
Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.
Key Laboratory of Clinical Pharmacology of Antibiotics, National Health Commission of People's Republic of China, Shanghai, China.
Front Microbiol. 2023 Mar 8;14:1125531. doi: 10.3389/fmicb.2023.1125531. eCollection 2023.
The CRISPR-Cas system in can prevent the entry of -IncF plasmids. However, some clinical isolates bear the KPC-2 plasmids despite carrying the CRISPR-Cas system. The purpose of this study was to characterize the molecular features of these isolates. A total of 697 clinical isolates were collected from 11 hospitals in China, and tested for the presence of CRISPR-Cas systems using polymerase chain reaction. Overall, 164 (23.5%) of 697 isolates had type I-E (15.9%) or type I-E (7.7%) CRISPR-Cas systems. The most prevalent sequence type among isolates carrying type I-E CRISPR was ST23 (45.9%), followed by ST15 (18.9%). Isolates with CRISPR-Cas system were more susceptible to ten antimicrobials tested, including carbapenems, compared with the CRISPR-negative isolates. However, there were still 21 CRISPR-Cas-carrying isolates that showed resistance to carbapenems, and these isolates were subjected to whole-genome sequencing. Thirteen of these 21 isolates carried -bearing plasmids, of which nine had a new plasmid type, IncFII, and two had IncFII(PHN7A8) plasmids. In addition, 12 of these 13 isolates belonged to ST15, while only eight (5.6%, 8/143) isolates belonged to ST15 in carbapenem-susceptible carrying CRISPR-Cas systems. In conclusion, we found that -bearing IncFII plasmids could co-exist with the type I-E CRISPR-Cas systems in ST15 .
肠道菌中的CRISPR-Cas系统可阻止F- IncF质粒的进入。然而，一些临床分离株尽管携带CRISPR-Cas系统，却带有KPC-2质粒。本研究的目的是对这些分离株的分子特征进行表征。从中国11家医院共收集了697株临床分离株，并用聚合酶链反应检测CRISPR-Cas系统的存在情况。总体而言，697株分离株中有164株（23.5%）具有I-E型（15.9%）或I-E型（7.7%）CRISPR-Cas系统。携带I-E型CRISPR的分离株中最常见的序列类型是ST23（45.9%），其次是ST15（18.9%）。与CRISPR阴性分离株相比，具有CRISPR-Cas系统的分离株对包括碳青霉烯类在内的十种受试抗菌药物更敏感。然而，仍有21株携带CRISPR-Cas的分离株对碳青霉烯类耐药，对这些分离株进行了全基因组测序。这21株分离株中有13株携带F质粒，其中9株有新的质粒类型IncFII，2株有IncFII(PHN7A8)质粒。此外，这13株分离株中有12株属于ST15，而在携带CRISPR-Cas系统的对碳青霉烯类敏感的大肠埃希菌中，只有8株（5.6%，8/143）属于ST15。总之，我们发现携带F的IncFII质粒可与ST15大肠埃希菌中的I-E型CRISPR-Cas系统共存。
