氨曲南联合头孢他啶/阿维巴坦对产金属β-内酰胺酶肠杆菌目细菌的体外协同作用初探

In vitro synergistic activity of aztreonam combined with ceftazidime/avibactam on metallo-β-lactamases-producing Enterobacteriaceae bacteria

目的探讨氨曲南(aztreonam,ATM)与头孢他啶/阿维巴坦(ceftazidime averbatan,CAZ/AVI)联合使用对产金属β-内酰胺酶(metallo-β-lactamases,MBLs)肠杆菌目细菌的体外协同作用。方法收集四川大学华西医院2019年11月—2020年4月临床分离的32株产MBLs且同时满足对ATM及CAZ/AVI耐药;采用PCR扩增技术进行基因型检测,采用微量肉汤稀释法测定ATM及CAZ/AVI的MIC及棋盘稀释法检测ATM联合CAZ/AVI对产MBLs的肠杆菌目细菌的协同作用。结果32株产MBLs的菌株中,产NDM-1型金属酶19株,产NDM-5型金属酶12株及产IMP型金属酶1株;ATM联合CAZ/AVI对其中26株产MBLs的菌株有体外协同作用,占比81.3%;未出现无关和拮抗作用。结论ATM联合CAZ/AVI对产NDM金属酶菌株体外有协同抗菌作用的可能性较高,因此有条件情况下,如果临床治疗需要最好做联合药敏试验以更好的指导临床用药。

Objective To investigate the in vitro synergistic activity of aztreonam(ATM)and ceftazidime/avibactam(CAZ/AVI)on metal-β-lactamases-producing(MBLs)Enterobacteriaceae bacteria.Methods 32 metallo-β-lactamases-producing strains were isolated from West China Hospital,Sichuan University from November 2019 to April 2020 which were resistant to aztreonam and ceftazidime/avibactam were collected,the genes were analyzed by polymerase chain reaction,the minimum inhibitory concentration of aztreonam and ceftazidime/avibactam were determined by using micro broth dilution method and the synergistic activity of ATM combined with CAZ/AVI on metallo-β-lactamases-producing.Enterobacteriaceae were determined by using checkerboard dilution.Results Among the 32 strains of MBLs-producing,19 strains coproducing NDM-1,12 strains coproducing NDM-5 and 1 IMP were identifed;ATM and CAZ/AVI has synergistic activity on the MBLs of 26 plants,which is 81.3%.There was no correlation and antagonism.Conclusion ATM combined with CAZ/AVI is more likely to have synergistic antibacterial effect on NDM metalloenzyme producing strains in vitro,therefore,clinical treatment needs to do combined drug sensitivity test to better guide clinical medication.