头孢硫脒与6种抗菌药物对革兰氏阳性球菌的联合药敏研究

Study on the antibacterial activity of cefathiamidine combined with six antimicrobial agents against Gram-positive cocci

评价头孢硫脒分别与万古霉素、奈替米星、阿米卡星、环丙沙星、左氧氟沙星和加替沙星等 6种抗菌药物联合用药 ,对于临床分离的革兰氏阳性球菌 ,包括金黄色葡萄球菌 (Staphylococcusaureus ,SA )、表皮葡萄球菌 (Staphylococcusepidermidis ,SE)和粪肠球菌 (Enterococcusfaecalis ,EF)的体外联合抗菌效应。采用棋盘法设计 ,微量肉汤稀释法测定。测定不同浓度组合的六组抗菌药物对 90株临床分离的革兰氏阳性球菌的最低抑菌浓度 ,并计算FIC指数判定联合效应。FIC≤ 0 5为协同作用 ,0 5 <FIC≤ 1为相加作用 ,1<FIC≤ 2为无关作用 ,FIC >2为拮抗作用。头孢硫脒与万古霉素、奈替米星、阿米卡星、环丙沙星、左氧氟沙星、加替沙星联合应用后 ,其MIC50 显著降低。FIC指数分布 :FIC≤ 0 5占 60 %～ 90 % ;0 5 <FIC≤ 1占 10 %～3 3 3 % ;1<FIC≤ 2占 0～ 13 3 % ;FIC >2为 0。结果表明 6种抗菌药物与头孢硫脒联合用药后 ,对革兰氏阳性球菌基本表现为协同作用和相加作用 ,并以协同作用为主 ,无关作用较少 ,无拮抗作用。

To evaluate the antibiotic effects of cefathiamidine combined with vancomycin, netilmicin, amikacin, ciprofloxacin, levofloxacin or gatifloxacin respectively against 90 strains of Grams positive cocci. The protocol was designed by checkerboard method and the MICs of cefathiamidine alone and combined with other 6 antibiotics against the 90 strains of Gram positive cocci (30 strains of Staphylococcus aureus , 30 strains of Staphylococcus epidermidis , 30 strains of Enterococcus faecalis ) were determined by broth dilution method; the FIC index was calculated according to MIC results. The MIC 50 of cefathiamidine was reduced significantly when combined with vancomycin, netilmicin, amikacin, ciprofloxacin, levofloxacin or gatifloxacin. The percentage of the FIC index less than 0.5, from 0.5 to 1, from 1 to 2, more than 2 was 60%～90%, 10%～13.3%, 0, respectively. Results suggested that synergy and additivity of cefathiamidine combined with vancomycin, netilmicin, amikacin, ciprofloxacin, levofloxacin or gatifloxacin respectively against 90 strains of Gram positive cocci were primary in action, and there were little autonomy and no antagonism.