目的建立大肠杆菌生物膜(BF)体外模型,研究不同浓度新疆黑蜂胶对大肠杆菌体外培养BF形成及清除的影响。方法采用微孔板改良法复制大肠杆菌体外BF模型,采用试管二倍稀释法测定新疆黑蜂胶的最低抑菌浓度(MIC),并检测黑蜂胶不同浓度对大肠杆菌BF形成的影响,同时通过检测新疆黑蜂胶对成熟BF中活菌数的影响,评价其对成熟BF的清除作用。结果新疆黑蜂胶醇提物对大肠杆菌的MIC为12.50 g/L,当浓度为6.25 g/L时新疆黑蜂胶就可在早期干扰细菌BF的形成,作用呈剂量依赖性;当浓度达到50.00 g/L时,其抑制BF的作用与庆大霉素相比差异无统计学意义(P〉0.05)。在对成熟BF的清除作用中的研究中,当黑蜂胶浓度达12.50 g/L时,能有效清除成熟BF,而当浓度达到50.00 g/L时,其清除成熟BF的作用与庆大霉素相比差异无统计学意义(P〉0.05)。结论新疆黑蜂胶醇提物在体外具有抑制大肠杆菌BF形成的作用,且能通过破坏已形成的BF起到抗菌作用,为临床辅助治疗耐药性感染,提供实验依据。
Objective To establish the Escherichia coli biofilm(BF) and investigate the effect of different concentration of Xinjiang black propolis extract on the formation of BF. Methods The Escherichia coli BF was induced in vitro by MPP improved method. Minimal inhibitory concentrations(MICs) were measured by doubling dilution. Escherichia coli were treated with different diluted Xinjiang black propolis extract and the formation and growth of Escherichia coli on BF were tested by determination of viable bacterial counts,and the scavenging effect of mature BF was evaluated. Results The MIC of Escherichia coli was 12.50 g/L of Xinjiang black propolis extract. 6.25 g/L of black propolis extract could inhibit the formation of BF,and the effect was dose dependent. When the concentration was 50.00 g/L,the inhibitory effect of the BF was no statistically significant difference compared with Gentamicin(P 0.05). In the study of the clear role in mature BF,when the black propolis concentration was 12.50 g/L,it could effectively remove mature BF,and when the concentration was 50.00 g/L,its effect in removal of mature BF,there was no significant difference compared with Gentamicin(P 0.05). Conclusion Xinjiang black propolis extract can effevtively inhibit the BF′s formation of Escherichia coli in vitro. It can also destroy the mature BF,and can provide experimental basis for clinical auxiliary treatment of resistance to infection.