{"title":"赋予头孢他啶-阿维巴坦耐药性的两种新型 KPC 变体在体内的复杂进化轨迹。","authors":"","doi":"10.1016/j.ijantimicag.2024.107265","DOIUrl":null,"url":null,"abstract":"<div><p>More and more ceftazidime-avibactam-resistant KPC-producing <em>Klebsiella pneumoniae</em> have been reported with its widespread use, and the detection rate of KPC variants has increased dramatically. However, the evolutionary mechanism and fitness effects during KPC mutation remained unknown. Here, we report the complex in vivo evolutionary trajectories of two novel KPC variants, KPC-155 (L169P/GT242A) and KPC-185 (D179Y/GT242A), from <em>K. pneumoniae</em> in the same patient. The novel variants were shown to confer ceftazidime-avibactam resistance but restore carbapenem susceptibility based on the results of plasmid transformation assays, cloning experiments, and enzyme kinetic measurements. In vitro, competition experiments highlighted the adaptive advantage conferred by strains carrying these KPC variants, which could lead to the rapid spread of these ceftazidime-avibactam-resistant strains. The growth curve indicated that <em>bla</em><sub>KPC-185</sub> had better growth conditions at lower avibactam concentration compared to <em>bla</em><sub>KPC-155</sub>, which was consistent with ceftazidime-avibactam use in vivo. In addition, replicative transposition of the IS<em>26</em>-flanked translocatable unit (IS<em>26</em>-IS<em>Kpn6</em>-<em>bla</em><sub>KPC</sub>-IS<em>Kpn27</em>-IS<em>26</em>) also contributes to the <em>bla</em><sub>KPC</sub> amplification and formation of two copies (<em>bla</em><sub>KPC-2</sub> and <em>bla</em><sub>KPC-185</sub>), conferring both carbapenem and ceftazidime-avibactam resistance. However, strains with double copies showed reduced competitive advantage and configuration stability. The comparative plasmid analysis of IS<em>26</em> group (IS<em>26</em>-<em>bla</em><sub>KPC</sub>-IS<em>26</em>) and Tn1721 group (Tn<em>1721</em>-<em>bla</em><sub>KPC</sub>-IS<em>26</em>) revealed that IS<em>26</em>-insertion could influence the distribution of resistance genes and ability of self-conjugation. The dynamic changes in <em>bla</em><sub>KPC</sub> configuration highlight the need for consistent monitoring including antimicrobial susceptibility testing and determination of <em>bla</em><sub>KPC</sub> subtypes – during clinical treatment, especially when ceftazidime-avibactam is administered.</p></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Complex evolutionary trajectories in vivo of two novel KPC variants conferring ceftazidime-avibactam resistance\",\"authors\":\"\",\"doi\":\"10.1016/j.ijantimicag.2024.107265\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>More and more ceftazidime-avibactam-resistant KPC-producing <em>Klebsiella pneumoniae</em> have been reported with its widespread use, and the detection rate of KPC variants has increased dramatically. However, the evolutionary mechanism and fitness effects during KPC mutation remained unknown. Here, we report the complex in vivo evolutionary trajectories of two novel KPC variants, KPC-155 (L169P/GT242A) and KPC-185 (D179Y/GT242A), from <em>K. pneumoniae</em> in the same patient. The novel variants were shown to confer ceftazidime-avibactam resistance but restore carbapenem susceptibility based on the results of plasmid transformation assays, cloning experiments, and enzyme kinetic measurements. In vitro, competition experiments highlighted the adaptive advantage conferred by strains carrying these KPC variants, which could lead to the rapid spread of these ceftazidime-avibactam-resistant strains. The growth curve indicated that <em>bla</em><sub>KPC-185</sub> had better growth conditions at lower avibactam concentration compared to <em>bla</em><sub>KPC-155</sub>, which was consistent with ceftazidime-avibactam use in vivo. In addition, replicative transposition of the IS<em>26</em>-flanked translocatable unit (IS<em>26</em>-IS<em>Kpn6</em>-<em>bla</em><sub>KPC</sub>-IS<em>Kpn27</em>-IS<em>26</em>) also contributes to the <em>bla</em><sub>KPC</sub> amplification and formation of two copies (<em>bla</em><sub>KPC-2</sub> and <em>bla</em><sub>KPC-185</sub>), conferring both carbapenem and ceftazidime-avibactam resistance. However, strains with double copies showed reduced competitive advantage and configuration stability. The comparative plasmid analysis of IS<em>26</em> group (IS<em>26</em>-<em>bla</em><sub>KPC</sub>-IS<em>26</em>) and Tn1721 group (Tn<em>1721</em>-<em>bla</em><sub>KPC</sub>-IS<em>26</em>) revealed that IS<em>26</em>-insertion could influence the distribution of resistance genes and ability of self-conjugation. The dynamic changes in <em>bla</em><sub>KPC</sub> configuration highlight the need for consistent monitoring including antimicrobial susceptibility testing and determination of <em>bla</em><sub>KPC</sub> subtypes – during clinical treatment, especially when ceftazidime-avibactam is administered.</p></div>\",\"PeriodicalId\":13818,\"journal\":{\"name\":\"International Journal of Antimicrobial Agents\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.9000,\"publicationDate\":\"2024-07-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Antimicrobial Agents\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0924857924001833\",\"RegionNum\":2,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"INFECTIOUS DISEASES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Antimicrobial Agents","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0924857924001833","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"INFECTIOUS DISEASES","Score":null,"Total":0}
Complex evolutionary trajectories in vivo of two novel KPC variants conferring ceftazidime-avibactam resistance
More and more ceftazidime-avibactam-resistant KPC-producing Klebsiella pneumoniae have been reported with its widespread use, and the detection rate of KPC variants has increased dramatically. However, the evolutionary mechanism and fitness effects during KPC mutation remained unknown. Here, we report the complex in vivo evolutionary trajectories of two novel KPC variants, KPC-155 (L169P/GT242A) and KPC-185 (D179Y/GT242A), from K. pneumoniae in the same patient. The novel variants were shown to confer ceftazidime-avibactam resistance but restore carbapenem susceptibility based on the results of plasmid transformation assays, cloning experiments, and enzyme kinetic measurements. In vitro, competition experiments highlighted the adaptive advantage conferred by strains carrying these KPC variants, which could lead to the rapid spread of these ceftazidime-avibactam-resistant strains. The growth curve indicated that blaKPC-185 had better growth conditions at lower avibactam concentration compared to blaKPC-155, which was consistent with ceftazidime-avibactam use in vivo. In addition, replicative transposition of the IS26-flanked translocatable unit (IS26-ISKpn6-blaKPC-ISKpn27-IS26) also contributes to the blaKPC amplification and formation of two copies (blaKPC-2 and blaKPC-185), conferring both carbapenem and ceftazidime-avibactam resistance. However, strains with double copies showed reduced competitive advantage and configuration stability. The comparative plasmid analysis of IS26 group (IS26-blaKPC-IS26) and Tn1721 group (Tn1721-blaKPC-IS26) revealed that IS26-insertion could influence the distribution of resistance genes and ability of self-conjugation. The dynamic changes in blaKPC configuration highlight the need for consistent monitoring including antimicrobial susceptibility testing and determination of blaKPC subtypes – during clinical treatment, especially when ceftazidime-avibactam is administered.
期刊介绍：
The International Journal of Antimicrobial Agents is a peer-reviewed publication offering comprehensive and current reference information on the physical, pharmacological, in vitro, and clinical properties of individual antimicrobial agents, covering antiviral, antiparasitic, antibacterial, and antifungal agents. The journal not only communicates new trends and developments through authoritative review articles but also addresses the critical issue of antimicrobial resistance, both in hospital and community settings. Published content includes solicited reviews by leading experts and high-quality original research papers in the specified fields.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
