关键词: 格拉瑟菌血清5型, cpxAR基因缺失株, 生长, 生物膜, 抗性, 毒力

Abstract: To investigate the pathogenic mechanism of the cpxAR two‑component gene in Glaesserella parasuis and screen for the deletion‑attenuated strain of Glaesserella parasuis serotype 5，the cpxAR double gene deletion strain（ΔcpxAR） of Glaesserella parasuis serotype 5 clinical isolate（GPS5） was constructed，and the growth characteristics，biofilm formation ability，environmental stress resistance and pathogenicity to guinea pigs were systematically analyzed.The results showed that after cpxAR gene deletion，there was no significant difference in colony morphology and growth rate between ΔcpxAR and its parent strain GPS5，but the biofilm formation ability was significantly weakened，the resistance to osmotic pressure，heat shock，oxidative stress and alkalinity was significantly reduced，and the virulence to guinea pigs was also significantly reduced. In conclusion，the cpxAR gene has no obvious regulatory effect on the growth of GPS5，but it has an important regulatory effect on its biofilm formation，environmental stress resistance and virulence.It lays a foundation for further exploration of the biological functions of the cpxAR two‑component system in Glaesserella parasuis and screening of attenuated strains of Glaesserella parasuis serotype 5.

Key words: Glaesserella parasuis serotype 5, cpxAR gene deletion strain, Growth, Biofilm, Resistance, Virulence