肺感方及其联合头孢噻肟对肺炎克雷伯菌生物被膜的体外干预作用

Effects of Feiganfang and its combination with cefotaxime on in vitro interventionto biofilm of Klebsiella pneumoniae

目的探讨肺感方单用及联合头孢噻肟对肺炎克雷伯菌(KP)生物被膜的体外抑制作用。方法二倍稀释法测定肺感方及头孢噻肟对KP标准菌株的最低抑菌浓度(MIC)。制备KP菌悬液及灭菌载体,将灭菌载体放入含有菌悬液的无菌24孔板内37℃恒温培养以建立体外生物被膜模型。实验分为模型组(灭菌生理盐水)、1/4 MIC肺感方组、1/4 MIC头孢噻肟组、1/4 MIC头孢噻肟+1/4 MIC肺感方组。每组均在建模时、建模第3天和第7天加入相应干预药物,在建模第3天和第7天银染法鉴定生物被膜,并采用连续稀释法行活菌计数。结果受试菌株建模3 d时可形成生物被膜,7 d时可形成较稳定生物被膜。在建模第3天及第7天,1/4 MIC头孢噻肟组、1/4 MIC肺感方组、1/4 MIC头孢噻肟+1/4 MIC肺感方组的生物被膜菌丝粘连及细菌团块形成依次减少;建模第7天,模型组、1/4 MIC肺感方组、1/4 MIC头孢噻肟组、1/4 MIC肺感方+1/4 MIC头孢噻肟组生物被膜活菌数依次减少(P<0.05)。结论 1/4 MIC肺感方可抑制肺炎克雷伯菌生物被膜形成,并可破坏已形成生物被膜,联合1/4 MIC头孢噻肟时作用更为显著,两药具有协同杀菌作用。

Objective To investigate the in vitro inhibitory effects of Feiganfang and and its combination with cefotaxime on biofilm of Klebsiella pneumoniae （KP）. Methods Minimum inhibitory concentrations （MIC） of Feiganfang and cefotaxime for bacterial strain of KP were determined using double dilution method. Bacterial suspension of KP and sterile carrier were prepared. The sterilization carrier was put into sterile 24-hole plate containing bacterial suspension for constant temperature incubation at 37℃ ,thus establishing the biofllm model in vitro. The experiment was grouped into model group（ sterile normal saline）, Feiganfang with 1/4MIC group, cefotaxime with 1/4MIC group,or Feiganfang 1/4MIC ＋ cefotaximel/4MIC group. In each group, corresponding intervention drugs were added at the time when modeling was finished, the 3rd day, and the 7th after modeling, identification of biofilm was conducted using silver staining method, and the viable count was measured using serial dilution at the 3ra day and the 7th after modeling. Results Biofilm and stable biofilm formed from the bacterial strains 3 days and 7 days after modeling,respectively. At the 3^rd day and the 7^th day after modeling,mycelium adhesion and bacterial mass formation of biofilm decreased in the order of Feiganfang with 1/4MIC group, cefotaxime with 1/4MIC group, and Feiganfang 1/4MIC ＋ cefotaximel/4MIC group. At the 7^th day after modeling, the viable count of biofilm decreased in the order of Feiganfang with 1/4MIC group,cefotaxime with 1/4MIC group, and Feiganfang 1/4MIC ＋ cefotaximel/4MIC group （all P 〈 0.05）. Conclusion Feiganfang with 1/4MIC can inhibit the formation of biofilm in KP,and destroy the formed biofilm,and its combination with cefotaxime of 1/4MIC was more effective, signaling a synergistic antibacterial effect.