大环内酯类抗生素对生物被膜菌产β-内酰胺酶的作用

目的 探讨不同浓度阿奇霉素、红霉素、罗红霉素对生物被膜肺炎克雷伯杆菌产β-内酰胺酶的影响.方法 应用改进的平板培养法建立肺炎克雷伯杆菌生物被膜模型,用扫描电镜观察鉴定.取肺炎克雷伯杆菌30株,经37 ℃ 24h孵育,比浊法配制0.5麦氏比浊标准(MCF)菌悬液,分为A组(生物被膜组)、B.组1最低抑菌浓度(MIC)阿奇霉素生物被膜组]、B2组(1/8 MIC阿奇霉素生物被膜组)、C,组(1 MIC红霉素生物被膜组)、C2组(1/8 MIC红霉素生物被膜组)、D1组(1 MIC罗红霉素生物被膜组)、D2组(1/8 MIC 罗红霉素生物被膜组)七组,每组200μ1.分别检测各组产β-内酰胺酶的活性.结果 A组、B1组、B2组、C1组、C2组、D1组、D2组β-内酰胺酶的活性分别为0.6534、0.3196、0,4260、0.5028、0.5108、0.6524、0.6470 U/mg,B1组、B2组、C1组、C2组β-内酰胺酶活性均明显低于A组,差异有统计学意义(P＜0.05);D1组、D2组β-内酰胺酶活性与A组比较差异无统计学意义(P＞0.05).B1组β-内酰胺酶活性明显低于B2组,差异有统计学意义(P＜0.05);C1组与C2组比较差异无统计学意义(P＞0.05).结论 高浓度的阿奇霉素对生物被膜有较强的破坏作用.

Abstract：

Objective To investigate the effect of azithromycin,erythromycin and roxithromyein at varying concentration on the β-lactamase produced in the biofilm of Klebsiella pneumoniae.Methods Models of Klebsiella pneumoniae were built up with the modified flat-board method and identified with the confocal scanning laser microscopy.Thirty Klebsiella pneumoniae were incubated at 37 ℃for 24 h,and allocated into 7 groups:biofilm (group A),by 1 MIC azithromycin (group B1),by 1/8 MIC azithromycin (group B2),by 1 MIC erythromycin (group C1),by 1/8 MIC erythromycin (group C2),by 1 MIC roxithromycin (group D1),and biofilm induced by 1/8 MIC roxithromycin (group D2),with 200 μ1 each.The β-lactamase activity in each group was quantitated.Results The β-lactamase activity in group A,group B1,group B2,group C1,group C2,group D1 and group D2 was 0.6534,0.3196,0.4260,0.5028,0.5108,0.6524 and 0.6470 U/mg respectively.The β-lactamase activity in group B1,group B2,group C1 and group C2 was lower than that in group A,and statistically significant difference was observed (P＜0.05).The B-lactamase activity in group D1 and group D2 was similar to that in group A,and no statistically significant differences was observed between them (P＞0.05).The β-lactamase activity in group B1 was lower than that in group B2,and statistically significant difference was observed (P <0.05).No statistically significant difference was observed between group C1 and group C2 (P＞0.05).Conclusion Azithromycin at higher concentration exerts better effects on biofilm formation than other macrolides.