阪崎克罗诺杆菌ESA_01393基因缺失及对表型的影响

Effect of Deletion and Phenotype of ESA_01393 Gene in Cronobacter sakazakii

阪崎克罗诺杆菌(Cronobacter sakazakii)是一种食源性致病菌,可导致新生儿、老年人和免疫功能低下的人感染,并且感染率和死亡率较高.阪崎克罗诺杆菌广泛存在于环境和食物中,对人类的危害较大,引起了广泛关注.然而,关于阪崎克罗诺杆菌运动性、生物膜形成和耐干燥性的具体分子机制尚不清楚.在阪崎克罗诺杆菌ATCCBAA-894中,ESA_01393基因是假设蛋白.与NCBI中大肠杆菌yebG基因(DNA损伤诱导蛋白)的蛋白序列比对结果显示,阪崎克罗诺杆菌ESA_01393蛋白序列与其相似度为68%.为了探索ESA_01393基因的功能,通过同源重组的方法构建ΔESA_01393突变菌株并进行基因回补,得到cpESA_01393回补株.通过比较阪崎克罗诺杆菌ATCCBAA-894野生型(WT)、ΔESA_01393和cpESA_01393的各方面特性,发现ESA_01393基因对阪崎克罗诺杆菌的生长、运动性和生物膜形成没有明显影响,但是参与了该菌耐干燥和DNA损伤修复过程.其作用机制可能与yebG基因类似,但仍有待进一步研究确定.本研究为进一步阐明阪崎克罗诺杆菌ESA_01393基因的功能提供了参考.

Cronobacter sakazakii,a food-borne pathogen,can infect neonates,elderly and immunocompromised populations with a high infection and mortality rate. C. sakazakii is widely found in the environment and food,causing great harm,and aroused widespread concern. However,the specific molecular mechanism remains unclear regarding the motility,biofilm formation,and desiccation tolerance in C. sakazakii. ESA_01393 gene is a hypothesized protein in C. sakazakii ATCC BAA-894. Compared with the protein sequence of yebG gene(DNA damage-inducing protein)of Escherichia coli in NCBI,the identity of ESA_01393 gene in C. sakazakii was 68%. In order to explore the faction of the ESA_01393 gene,in this study,the ESA_01393 mutant strain(ΔESA_01393) was constructed using the homologous recombination method,and the cpESA_01393 complementary strain was obtained. By comparing the characteristics of C. sakazakii ATCC BAA-894wild-type(WT),ΔESA_01393 and cpESA_01393,it was found that ESA_01393 gene had no significant effect on the growth,motility,and biofilm formation of C. sakazakii,but was involved in the process of desiccation resistance and DNA damage repair. This study suggests that the mechanism of ESA_01393 gene maybe similar to that of yebG,but remains to be determined by further research. Therefore,this study has laid a foundation for further elucidation of the function of ESA_01393 gene of C. sakazakii.