重组人血小板型磷脂酶A_2杀菌作用的研究

Bactericidal Effect of Recombinant Human Platelet Phospholipase A_2

目的 探讨利用基因工程制备重组人血小板型磷脂酶A2 (phospholipaseA2 ,PLA2 )对不同细菌在体外的杀菌作用 ,为临床用于治疗细菌感染提供依据。方法 将不同浓度的重组PLA2 或抗生素与不同的菌株在 37℃共同孵育 2h ,然后铺琼脂板 ,次日记录每一琼脂板上的菌落生成数 (CFU) ,计算出PLA2 作用后细菌生存率和杀灭 95 %细菌 (LD95)的PLA2 浓度。结果 重组人血小板型PLA2 对金黄色葡萄球菌、枯草芽胞杆菌、表皮葡萄球菌、粪肠球菌等革兰阳性 (G+)菌有较强杀菌作用 ,PLA2 的LD95的范围在 6～ 4 0 0ng/ml之间 ,对耐甲氧西林金黄色葡萄球菌(MRSA)也有较强的作用 ,LD95为 4 0 0ng/ml。结论 重组人血小板型PLA2 对革兰阳菌有较强的杀菌作用 。

OBJECTIVE To explore the bactericidal effect of recombinant human platelet phospholipase A 2 (PLA 2) on the different bacteria strain in vitro and provide important information for clinical application of the recombinant PLA 2 in the treatment of bacteria infection. METHODS Bacterial solution with different concentration of recombinant PLA 2 and antibiotic at 37℃for 2 hours in a water bath was incubated. The reaction solution was then diluted and agar plates were poured, and the bacteria in 37℃ for 18 20 hours were grown. The colony formed unit was counted and the bacteria survival rate and lethal dose of 95% (LD 95 ) were calculated. RESULTS The recombinant PLA 2 possessed relatively potent bactericidal activity on the Gram positive bacteria, such as Staphylococcus aureus, S. epidermidis, Bacillus subtilis and Enterococcus faecalis. The range of LD 95 of the PLA 2 to the bacteria was 6 400 ng/ml. CONCLUSIONS The recombinant human platelet PLA 2 possesses a strong bactericidal activity against Gram positive bacteria, and it has a great potential to be developed as a new anti bacterial drug.