食源性希拉肠球菌R17基因组中前噬菌体的结构特征及其与宿主菌的相互影响

目的了解生鲜猪肉中分离的希拉肠球菌R17基因组中前噬菌体的结构特征及其和宿主菌的相互影响。方法利用PHAST软件预测希拉肠球菌R17基因组中前噬菌体基因的分布及其编码基因特征,分析前噬菌体中含有的毒力基因、耐药基因和环境抗性基因。结果在希拉肠球菌R17染色体上有3个前噬菌体,其中Prophage-1和Prophage-2是不完整的前噬菌体,Prophage-3是完整的前噬菌体。染色体上的噬菌体携带了多个细菌功能编码基因,包括与核苷酸转运和代谢功能相关的基因。希拉肠球菌R17质粒上有一个不完整的、携带了红霉素和杆菌肽耐药基因的前噬菌体Prophage-p,推测前噬菌体介导的基因水平转移使希拉肠球菌R17对红霉素和杆菌肽产生了耐药性。结论希拉肠球菌基因组中的前噬菌体具有多样性。前噬菌体在肠球菌向耐药菌进化过程中发挥了重要作用,应重视监控噬菌体介导的耐药性和致病性在食品中的扩散。

The structure characteristics of prophages of foodborne Enterococcus hirae R17 and their interaction relationships with host bacterium

Objective This study was to understand the structure characteristics of prophages in the genome of Enterococcus hirae R17, and also to analyze their interaction relationships with the host bacterium. Methods The gene distribution and gene encoding characteristics of prophages in the genome of Enterococcus hirae R17 were identified using the PHAST software. The virulence gene, antimicrobial resistance genes, and environmental resistance genes in the prophages were also analyzed. Results Three prophages were found on the chromosome of Enterococcus hirae,including two incomplete prophage elements (Prophage-1 and Prophage-2) and one complete prophage(Prophage-3). Some function genes of bacteria were found in the sequence of three prophages, including nucleotide transportation and metabolism related genes. One incomplete prophage carrying erythromycin- and bacitracin-resistance genes was identified in the plasmid, which suggested that prophage induced gene horizontal transfer caused erythromycin- and bacitracin-resistance of Enterococcus hirae R17. Conclusion This study laid a solid foundation for the diversity analysis of prophages of Enterococcus hirae. Prophages played an important role in promotion of antimicrobial resistance of enterococci. Scientists should pay more attention to the spread of antimicrobial resistance and pathogenicity induced by prophages.