rmlA 基因缺失影响禽致病性大肠杆菌的生物被膜形成

rmlA gene deletion affects biofilm formation by avian pathogenic Escherichia coli

摘要:

摘要:【目的】构建禽致病性大肠杆菌(Avian pathogenic Escherichia coli，APEC) rmlA基因缺失株，研究该缺失株的生物学特性。【方法】利用Red重组系统构建rmlA缺失株;比较野生株与缺失株在生长特性、运动性和生物被膜形成能力等方面的差异;运用Real-time PCR技术，比较野生株与rmlA缺失株对APEC部分毒力基因转录的影响。【结果】rmlA缺失株，不影响APEC的生长和运动特性，但生物被膜形成能力显著增强，且使luxS、irp2基因转录水平分别上调2倍、1.8 倍，iucD、fyuA则下调25倍。【结论】APEC的rmlA基因可以影响禽致病性大肠杆菌的生物被膜形成能力及部分毒力基因的转录水平;而对APEC的生长、运动特性没有影响。

Abstract:

Abstract:［Objective］To characterize rmlA gene inavian pathogenic Escherichia coli (APEC).［Methods］We constructed the rmlA mutant of APEC by the Red recombination system．Then we analyzed the differences of growth，movement and biofilm formation between mutant strain and wild strain．We compared the differences of virulence gene transcription between mutant strain and wild strain by real-time PCR.［Results］The rmlA mutant did not affect the growth and motility of APEC，but enhanced the biofilm formation significantly．In addition，the transcription level of some virulence genes in rmlA mutant showed that the luxS ，irp2 were raised 2 and 1.6 times respectively，but decreased the iucD and fyuA by 25 times compared to the wild strain． ［Conclusion］These data indicate that the rmlA gene could strengthen the ability of APEC biofilm formation，and affect the transcription level of some virulence genes，but not the growth and motility．