头孢呋辛/他唑巴坦对β内酰胺酶稳定性及抑酶增效作用

Stability of cefuroxime/tazobactam to β-lactamases and ability of tazobactam in preventing hydrolysis

目的观察在头孢呋辛(第2代头孢类抗生素)中加入不同配比他唑巴坦后,对β内酰胺酶的稳定性及抑酶保护作用。方法以超声破碎细菌,得粗制β内酰胺酶,紫外分光光度法测定抗菌药物浓度,计算酶对底物水解率,并以头孢呋辛水解率为100%,计算不同配比头孢呋辛/他唑巴坦的相对水解率和抑酶保护率。结果头孢呋辛中加入他唑巴坦后,β内酰胺酶对其水解率较单用头孢呋辛下降;对大多数菌株,相对水解率<30%,抑酶保护率>70%,3种配比与单用头孢呋辛比较有非常显著性差异(P<0.01)。结论他唑巴坦有很好的抑酶作用,提高了头孢呋辛对革兰阴性杆菌所产β内酰胺酶的稳定性。

Objective To investigate stability of cefuroxime combind with various ratio （ 1： 1, 2： 1, 4：1 ） tazobactam to β - lactamases and ability of tazobactam in preventing hydrolysis. Methods Rates of hy - drolysis were determined by spectrophotometric method. The amount of hydrolysis rates of cefuroxime alone were defined as 100% and calculate relative hydrolysis and prevention rates of the other compounds. Results In the presence of tazobactam, hydrolysis rates of cefuroxime by β- lactamases were significantly reduced. Relative hydrolysis rates of combinations by majority enzyme were less than 30% and prevention rates were more than 70% , showed significant deviation （ P 〈 0.01 ） compared with those of drug alone. Conclusion Tazobactam enhanced the stability of cefuroxime to β -lactamases extracts from gramnegative bacilli and showed ability of protection by inhibiting bacterial β - lactamases.