人工合成抗菌肽对口腔感染的防御作用的研究

目的体外观察不同浓度人工合成的抗菌肽（AMPs）对口腔常见感染白色念珠菌、大肠杆菌及金黄色葡萄球菌的抑制或杀灭作用。方法人工合成具有抗菌活性的七肽，并分离口腔常见感染白色念珠菌、大肠杆菌及金黄色葡萄球菌菌株。将人工合成的抗菌肽溶解于PBS溶液及无菌唾液中，通过试管法测定OD值（透光度）评价抗菌肽在不同时间、不同浓度对大肠杆菌的抑制作用；将抗菌肽制备成50-300μg／片不同浓度的药敏纸片，通过药敏纸片定量法（K-B法），观察抑菌环直径，评价不同浓度抗菌肽对白色念珠菌及金黄色葡萄球菌的抑制作用。结果当大肠杆菌1×10^5cfu／ml时，加入150μmol／L或200μmol／L抗菌肽作用30min后，细菌计数为0，而对照组浓度为6700-9200cfu／ml；抗菌肽药敏纸片在100μg/片时，对金黄色葡萄球菌及白色念珠菌的抑菌环直径分别为（13．7±1．1）mm和（11．4±0．7）mm，当抗菌肽纸片浓度在300μg／片时，其对金黄色葡萄球菌及白色念珠菌的抑菌环直径分别为（16．5±1．3）mm和（17．±1．1）mm。溶解在PBS溶液及无菌唾液中的抗菌肽抑菌活性差异无统计学意义。结论人工合成的抗菌肽体外可有效的抑制口腔常见白色念珠菌、大肠杆菌及金黄色葡萄球菌的感染，并且可在口腔唾液环境中稳定发挥抑菌活性。

The artificial antimicrobial peptides having potential application to preventing oral infection

Objective To observe the antibacterial activity of artificial antimicrobial peptides (AMPs) to Blastomyces albicans, E. coli and Staphylococcus aureus in oral infection in vitro. Methods The AMPs were dissolved into PBS or sterilized saliva, then the inhibi-tion of different concentration AMPs to E. coil was evaluated by tube testing. The inhibition effect of different concentration of AMPs to Staph-ylococcus aureus and Blastomyces albicans were evaluated by antibiotic-susceptive test paper. Results When the concentration of AMPs added to broth of E. coli is from 150μmol/L to 300μmol/L , the bacterium count is 0 while the number in control is 6700 ～ 9200cfu/ml. At 100μg/tablet AMPs, the diameter of inhibitor zones of Staphylococcus aureus and Blastomyces albicans are 13mm and 11 mm. At 300μg/ tablet, the diameter are 16 mm and 17mm. AMPs dissolved in PBS and saliva have similar antimicrobial activity. Gonclusions The AMPs is effective to prevent Blastomyces albicans, E. coli and Staphylococcus aurcus in oral infection in vitro.