多杀性巴氏杆菌X73株与P1059株原生质体融合株的构建

Establishment of the Protoplast Fusion Cells of P。multo-cida X73 and P1059 Strains

将多杀性巴氏杆菌Ｘ７３株（ＰｍＲ、ＴｃＳ）与ｐ１０５９株（ＴｃＲ、ＰｍＳ）作为亲本，在脱氧核糖核酸酶（ＤＮａｓｅ）存在的条件下，以ＰＥＧ作为助融剂，进行原生质体融合，然后于高渗琼脂平板上再生细胞壁，再转种在含四环素（Ｔｃ）和多粘菌素Ｂ（Ｐｍ）的双抗培养基上检出融合株。获得的４个融合株，形态及染色特性、生化反应、毒力等均符合多杀性巴氏杆菌的特性；具有双抗药性和两亲本株的抗原组分，说明两种细菌细胞发生了融合和染色体重组。经多次传代证明融合株是稳定的。

With P, multocida X73(PmR , TcS) and P1059 (TcR ,PmS)as theparental strains, their protoplasts were prepared and protoplast fusion was induced withPEG in the presence of DNase, Fusion cells were selected on hypertonic medium supple-mented with Pm and Tc。 4 strains of Fusion cells have been obtained in the experiment。The results showed that all the fusion strains have kept the hereditary properties, suchas the morphology, staining, biochemical activities, virulence , antigenic structure, etc,of the parent strains of P.multocida。 The fusion strains were resistant to both polymyx-in and tetracycline。 It suggested that the protoplasts of P, multocida X73 and P1059strains have been fused and their chromosomes recombinated. The fusion strains werestable after a series of passages,