噬菌体EC-p9和SM-p2内溶酶及穿孔素的特性及联合抑菌作用

Characteristics and combined bacteriostasis of endolysin and holin in phage EC-p9 and SM-p2

噬菌体的内溶酶(endolysin)和穿孔素(holin)是新型的抑菌剂,具有很大的潜力和发展空间。该文以大肠杆菌O157∶H7噬菌体EC-p9和沙门氏菌噬菌体SM-p2的内溶酶和穿孔素(Lys 9、Lys 2、Hol 9、Hol 2)为对象,通过平板菌落计数法研究了Lys 9、Lys 2、Hol 9、Hol 2的裂解活性;评估Lys 9、Lys 2、Hol 9、Hol 2对温度和pH的稳定性;研究了细菌是否会对这4种重组蛋白产生抗性;还研究了内溶酶、穿孔素及其混合物对细菌的联合抑菌作用。结果表明,Lys 9、Lys 2、Hol 9和Hol 2的最高裂解活性分别为61.348%、81.120%、74.251%和83.356%,具有很强的杀菌能力;Lys 9、Lys 2、Hol 9和Hol 2对温度和pH有较高的稳定性;12代内细菌不会对Lys 9、Lys 2、Hol 9和Hol 2产生抗性。此外,内溶酶和穿孔素在抑制病原菌上表现出协同作用。该实验结果为噬菌体内溶酶和穿孔素联合抑菌作用提供了理论依据。

The endolysin and holin of phage are new bacteriostatic agents with great potential and prospect.Lysis activity and bacteria resistance for Lys 9,Lys 2,Hol 9 and Hol 2 were studied.The stability of Lys 9,Lys 2,Hol 9 and Hol 2 to temperature and pH were evaluated by plate count using endolysin and holin of Escherichia coli O157:H7 phage EC-P9 and Salmonella phage SM-P2.The combined antibacterial effect of endolysin,holin and their mixtures was also determined.The results showed that Lys 9,Lys 2,Hol 9 and Hol 2 had strong bactericidal ability and the highest lysing activity of bacteria were 61.348%,81.120%,74.251%and 83.356%,respectively.Lys 9,Lys 2,Hol 9 and Hol 2 had excellent stability in a wide range of temperature and pH.The bacteria did not develop resistance to Lys 9,Lys 2,Hol 9 and Hol 2 within 12 generations.In addition,endolysin and holin showed synergistic effect on the inhibition of bacteria.The experimental results provide a theoretical basis for the combined antibacterial effect of endolysin and holin in phage.