RNAⅢ抑制肽与抗生素协同抑制葡萄球菌感染的体外实验研究

Synergistic effects of RNAⅢ inhibitory peptide(RIP) and antibiotics on Staphylococcus aureus infections

目的探究RNAⅢ抑制肽(RIP)与抗生素协同抑制葡萄球菌感染的效果。方法选择临床常用的左氧氟沙星、青霉素、头孢唑啉、万古霉素、替考拉宁5种抗生素及RIP分别作用于金黄色葡萄球菌ATCC29213、ATCC25923和表皮葡萄球菌ATCC35984,对比不同抑制药对3种葡萄球菌的最低抑菌浓度(minimum inhibitory concentratin,MIC)值,并进一步分析RIP与左氧氟沙星协同抑制表皮葡萄球菌ATCC35984的作用。结果 RIP对3种葡萄球菌的MIC值均>128μg/ml,左氧氟沙星、青霉素、头孢唑啉、万古霉素和替考拉宁对金黄色葡萄球菌ATCC29213、ATCC25923的MIC值均在敏感范围内,而青霉素、头孢唑啉对表皮葡萄球菌ATCC35984的MIC则超出正常范围;与RIP联用能够有效提高左氧氟沙星的细菌灭杀效果,5、10μg/ml浓度下的RIP与2倍MIC的左氧氟沙星联合应用时可以完全清除表皮葡萄球菌ATCC35984生物被膜内细菌。结论 RIP对金黄色葡萄球菌和表皮葡萄球菌均无直接灭杀作用,无法取代抗生素,但联合应用RIP能够有效提高左氧氟沙星对葡萄球菌的灭杀效果。

Objective To investigate the efficacy of RNAIE inhibitory peptide （RIP） combined with antibiotics in the control of staphylococcal infections. Methods Five types of clinically commonly-used antibiotics, including penicillin, cefazolin, levofloxacin, vancomycin and teicoplanin,and RIP were respectively used against Staphylococcus aureus ATCC29213, ATCC25923 and Staphylococcus epidermidis ATCC35984. The MIC values of different inhibitors against three strains of Staphylococcus aureus were compared. The synergistic inhibition of Staphylococcus epidermidis ATCC35984 by RIP and levofloxacin was further analyzed. Results The MIC value of RIP against the three strains o f Staphylococcus aureus exceeded 128 pig/ml. The MIC values of levofloxacin, ampicillin, cefazolin and vancomycin and teicoplanin against Staphylococcus aureus ATCC29213 and ATCC25923 were within the sensitive range, while that of penicillin and cefazolin against Staphylococcus epidermidis ATCC35984 MIC exceeded the normal range. The combination with RIP could effectively improve the bactericidal effect of levofloxacin. RIP at the concentrations of 5, 10 jag/ml, when used in combination with levofloxacin at twice the MIC, could completely remove the biofilm bacteria of ATCC35984. Conclusion RIP has no direct effect on Staphylococcus aureus or Staphylococcus epidermidis, so it cannot take the place of antibiotics, but the combined use of RIP can effectively improve the effect of levofloxacin on Staphylococcus aureus.