合成抗菌肽对大肠杆菌的体外抑制作用

Inhibitive action of synthetic antimicrobial peptides on E.coli in vitro

目的 观察不同浓度抗菌肽在不同时间内对大肠杆菌体外抑制和杀灭作用。方法 将2种不同浓度的抗菌肽分别加到1×105 cfu.mL-1大肠杆菌菌液中,振荡培养0.5～6 h, 其中取5个时间段菌液,一部分培养后进行细菌计数,另一部分放入肉汤中继续培养,16h后测定不同时间段的A值。结果 在细菌浓度一定,加入抗菌肽200 mmol.L-1,作用时间为0.5,6 h时,A值分别为0.15,0.63。加入抗菌肽400 mmol.L-1,作用时间0.5～6 h时,A值为0.002～0.001,对照组A值为0.98。结论 抗菌肽杀菌效果与抗菌肽和细菌量有关,抗菌肽活性分子足够量才能杀死细菌,未受到抗菌肽作用的菌体能继续分裂繁殖。

Objective To observe the inhibitive action of antimicrobial peptides indifferent concentration to E.coli. Methods Put the two of antimicrobial peptides ofdifferent concentration to the Broth of E.coli(concentration, 1×105 cfu.mL-1), afterthe incubation about 0.5～6 h, mensuring the A value and judging the inhibition ofantimicrobial peptides in different concentration to E.coli. Results The A value is0.15 when the concentration of antimicrobial peptides is 200 mmol.L-1 for 0.5 h. Forthe time of 6 h, the A is 0.63. The A value is from 0.002 to 0.001 with the concentration400 mmol.L-1 within 0.5 ～6 h. while the control A value is 0.98. Conclusion Theantibacterial effect of antimicrobial peptides is relevant to the amount of antimicrobialpeptides and there must be enough active moleculers of antimicrobial peptides onevery bacterium individual that can kill the bacteriums. Otherwise, the bacteriumswill keep on growing.