为探究外膜蛋白A(outer membrane protein A,OmpA)对米尔伊丽莎白菌致病作用的影响,以蛙源米尔伊丽莎白菌FL160902为研究对象,通过同源重组法构建OmpA缺失株△ompA,比较缺失株和野生株的生长特性、生物膜形成能力、抗血清杀伤能力、对细胞的黏附能力以及对蛙的致病性差异.结果显示:△ompA的生长能力和抗血清杀伤能力与野生株无显著差异;但与野生株相比,△ompA的生物膜形成能力增加了66%,△ompA对bEnd.3细胞的黏附能力降低了61%;黑斑蛙感染试验显示,△ompA在黑斑蛙血液、脾和脑组织中的载菌量分别为(3.15×108±0.09×108)、(2.11×108±0.07×108)和(6.61×108±0.16×108)copies/g,均显著低于野生株,且△ompA对黑斑蛙的致死率为37%,显著低于野生株的致死率(75%).上述结果表明,ompA基因缺失不改变米尔伊丽莎白菌的抗血清杀伤能力,但增加了菌株的生物膜形成能力,减弱了菌株的黏附能力,从而降低了该菌对蛙的致病性.
Function of outer membrane protein A in pathogenicity of Elizabethkingia miricola from frog
To study the role of outer membrane protein A(OmpA)in the pathogenicity of Elizabeth-kingia miricola,the ompA gene mutant strain(△ompA)was constructed via homologous recombination using E.miricola FL160902 as the wild type strain.Subsequently,the growth characteristics,biofilm for-mation,serum survival ability,adhesion ability,bacterial colonization of the wild strain and △ompA,as well as their pathogenicity to frogs were analyzed.The results showed that there was no significant differ-ence in growth characteristics and survive ability in frog serum between △ompA and wild strain.However,compared with the wild strain,the biofilm formation capacity of △ompA increased by 66%,and the adhe-sion capacity of △ompA to bEnd.3 cells decreased by 61%.The results of animal experiment showed that the average bacterial load of △ompA in the blood,spleen and brain of infected frogs were(3.15×108±0.09×108),(2.11×108±0.07×108)and(6.61×108±0.16×108)copies/g,respectively,which were sig-nificantly lower than that of the wild strain infected frogs(P<0.05),and the lethality rate of frogs infected with △ompA was 37%,which was significantly lower than that of the wild strain(75%).The results indi-cated that ompA deletion did not change the antiserum killing ability of E.miricola,but increased the bio-film forming ability of E.miricola,reduced its adhesion ability and decreased its pathogenicity to frogs.
Elizabethkingia miricolagene deletionouter membrane protein Apathogenicity
NETL
NSTL
万方数据
维普
