噬菌体RZⅢ-3的生物学特性分析及对鸡大肠杆菌的疗效

摘要

为了解决目前严重的抗生素耐药性,寻找抗生素的替代品,作者探究了大肠杆菌噬菌体RZⅢ-3的基本生物学特性及其对致病性大肠杆菌1019的治疗效果.大肠杆菌噬菌体RZⅢ-3的生物学特性分析显示其效价可达到109 pfu·mL-1,透射电镜结果显示该噬菌体属于有尾目T4噬菌体.热稳定性较好,在60℃保温1h后噬菌体效价仍可达到107pfu·mL-1以上.对pH值的适应范围较宽,在pH4～10内仍能保持较高的裂解活性;该噬菌体的最适pH在7.0左右.最佳感染复数(MOI)为0.1,感染宿主菌的潜伏期20 min,爆发期70 min.大肠杆菌噬菌体RZⅢ-3对大肠杆菌1019有较强的裂解能力,可使SPF鸡肠道内大肠杆菌1019的数量降低96.5％.该大肠杆菌噬菌体RZⅢ-3在治疗特定的大肠杆菌感染中具有较大的应用潜能.%To solve the antibiotic resistance and find substitution of antibiotics,this study explored the basic biological characteristics of Escherichia coli phage RZⅢ-3 and its therapeutic effect on SPF chicken colibacillosis.The biological characteristics of Escherichia coli phage RZⅢ-3 showed that the titer was 109 pfu · mL-1,high stability to heat,the bacteriophage titer can reach more than 107 pfu · mL-1 after incubation at 60 ℃C for 1 h.It had a wide adaptive range of pH,and maintained a high cleavage activity at pH 4-10.The optimum pH of the phage was about 7.0,its optimal multiplicity of infection (MOI) was 0.1,and the incubation period of infected host bacteria was about 20 min.The results of transmission electron microscopy showed that the phage belonged to the T4 phage.Escherichia coli phage RZⅢ-3 on Escherichia coli 1019 had a strong ability to crack,The number of Escherichia coli 1019 in SPF chickens can be reduced by 96.5％.This indicated that the Escherichia coli phage RZⅢ-3 has a greater potential for the treatment of specific Escherichia coli infection.