Construction and Characterization of sao Gene Knock-out Mutant of Streptococcus suis Serotype 2 Chinese Highly Virulent Strain 05ZYH33

Abstract:

To construct the mutant strain Δsao, the recombinant gene knock-out vector was constructed consisting of Spcr cassette with the flanking homology regions of gene sao. The sao gene was replaced by Spcr cassette according to the principle of homologous recombination. PCR analysis, RT-PCR analysis and western blot were used to confirm that sao gene was replaced completely by the Spcr cassette. The results suggested that the mutant of 05ZYH33 sao gene was successfully constructed. Analysis of biological characteristics showed that there were no obvious distinctions in hemolytic activity, growth characteristics and virulence between the mutant and the wild type strain 05ZYH33. The construction of the mutant strain 05ZYH33Δsao laid the foundation for father research on the role of sao during infection.