司帕沙星和妥舒沙星的体内外抗菌作用研究

目的观察国产司帕沙星、妥舒沙星及其它四种氟喹诺酮类抗菌药对成都地区780株临床分离菌的体外抗菌活性，并比较司帕沙星、妥舒沙星和环丙沙星对金葡球菌、大肠埃希菌和铜绿假单胞菌感染小鼠的体内抗菌活性。方法用琼脂稀释法测定国产司帕沙星和妥舒沙星的MIC50和MIC90，并与其它四种氟喹诺酮类抗菌药进行了比较。本文还测定了抗菌药对金葡球菌、大肠埃希菌和铜绿假单胞菌感染小鼠治疗的ED50结果体外试验表明司帕沙星和妥舒沙星能有效抑制或杀灭革兰阳性、革兰阴性菌及厌氧菌，显示了广谱抗菌活性。司帕沙星和妥舒沙星对革兰阳性菌的抗菌活性是环丙沙星的2～8倍，氧氟沙星和氟罗沙星的4～16倍，是诺氟沙星的16～32倍。司帕沙星对MRSA的抗菌活性与妥舒沙星相似，但优于环丙沙星、氧氟沙星、氟罗沙星和诺氟沙星。司帕沙星对大多数革兰阴性菌的抗菌活性与环丙沙星和妥舒沙星相似，是氧氟沙星、氟罗沙星和诺氟沙星的2～8倍。两药对厌氧菌的抗菌活性也较环丙沙星强。口服或皮下注射司帕沙星对金葡球菌和大肠埃希菌所致小鼠全身性感染的保护作用优于环丙沙星和妥舒沙星。同一给药途径下司帕沙星对铜绿假单胞菌所致小鼠全身性感染的保护作用与妥舒沙星和环丙沙星相似。三种受试药对金葡球菌和大肠埃希菌所致小鼠全身性感染的保护作用优于铜绿假单胞菌所致感染。结论司帕沙星和妥舒沙星对革兰阳性菌和厌氧菌的体外抗菌活性优于环丙沙星和其它药物，对大多数革兰阴性菌的抗菌活性与环丙沙星相似，但优于其它受试药。司帕沙星对金葡球菌和大肠埃希菌所致小鼠全身性感染的体内保护作用优于环丙沙星和妥舒沙星。同一给药途径下司帕沙星对铜绿假单胞菌所致小鼠全身性感染的保护作用与妥舒沙星和环丙沙星相似。

Study on the in vitro and in vivo antibacterial activities of sparfloxacin and tosufloxacin

Objective To investigate the in vitro and in vivo antibacterial activities of domestic sparfloxacin (SPFX), tosufloxacin (TFLX). Methods The minimal inhibitory concentrations (MIC50 and MIC90) of SPFX and TFLX against 780 clinical isolates were detected by agar dilution method and compared with those of four other fluoroquinolones. ED50 were also measured in mice systemically infected with S. aureus, P. aeruginosa and E. coli. Results Results showed that both domestic SPFX and TFLX were broad-spectrum antibacterial agents since they inhibited or killed Gram-positive, Gram-negative and anaerobic clinical isolates effectively. The antibacterial activities of SPFX and TFLX against Gram-positive microorganisms were about 2～8 fold stronger than that of ciprofloxacin (CPFX), 4～16 fold stronger than that of flerofloxacin (FLRX) and ofloxacin (OFLX), and 16～32 fold more potent than that of norfloxacin (NFLX). SPFX had a similar activity against methicillin- resistant S. aureus (MRSA) to TFLX, but better activities than those of CPFX, FLRX, OFLX and NFLX. The antibacterial activity of SPFX against the majority of the Gram-negative clinical isolates was similar to those of TFLX and CPFX, and was about 2～8 fold more potent than those of OFLX, FLRX and NFLX. SPFX and TFLX also showed better activity against anaerobic isolates than that of CPFX.The protective effects of SPFX in systemic infections of mice caused by S. aureus, E. coli are better than those of TFLX and CPFX when administered orally or subcutaneously. In systemically infected mice causded by P. aeruginosa, the protective effect of SPFX was similar to TFLX and CPFX when administered with the same route. SPFX, TFLX and CPFX showed better protective effect on S. aureus and E. coli infected mice than that of P. aeruginosa. Conclusion Domestic SPFX and TFLX showed more potent in vitro activities against Gram-positive and anaerobic isolates than those of CPFX and other fluoroquinolones. Against majority of the Gram-negative isolates, their activities were similar to those of CPFX, but better than other tested fluoroquinolones. The protective effects of SPFX on S. aureus and E. coli infected mice were superior to those of TFLX and CPFX. When administered with the same route, the protective effect of SPFX on systemic infection mice caused by P. aeruginosa was similar to TFLX and CPFX.