关键词: 兔, 支气管败血波氏杆菌, 百日咳杆菌黏附素, 基因缺失, 生物学特性, 免疫原性

Abstract: We constructed pertactin (PRN) deletion mutant strain of rabbit Bordetella bronchiseptica (Bb) to study the function of pathogenesis of Bb, and to provide a theoretical basis for researching live attenuated vaccine against Bb. The 550 bp fragment of PRN1（upstream of PRN）and 440 bp fragment of the PRN2（downstream of PRN）were amplified by PCR respectively. The two fragments together with Gentamycin (GM) gene were linked and inserted into suicide vector, and the recombinant suicide vector was named as pMEG375PRN1GMPRN2. The recombinant suicide vector was transformed into host strain SM10. The transformed SM10 was mated with recipient strain Bb on the solid phase membrane, and the recombinant suicide vector was transformed into the recipient bacteria. According to homologous recombination and the principle of resistance screening, mutant strain was generated and was named as Bb△PRN. We compared Bb△PRN with wild type（WT）strain on genetic stability, growth characteristics, hemolytic activity, cell adhesion properties, immunogenicity. The results showed that the mutant strain stabilized genetically and grew slower than the wild type. There was no significant difference between them on hemolytic activity and adhesion on Hep2 cells. Comparing with parent strain, the virulence of mutant stain was attenuated about two fold. The assay of immunogenicity showed that Bb△PRN could produce a strong immune capacity. All of results indicated that mutant strain had good immunogenicity, and it could provide a theoretical basis for researching live attenuated vaccine against Bb.

Key words: rabbit, Bordetella bronchiseptica, pertactin (PRN), gene deletion, biological characteristics, immunogenicity