淀粉样欧文氏菌,肠杆菌科的革兰氏阴性菌,是火灾疫病的病原体,一种毁灭性的植物病害,影响到玫瑰科内的多种宿主物种,对商业苹果和梨生产构成全球主要威胁。在当前可用的有限数量的控制选项中,在开花期预防性应用抗生素似乎是最有效的。病原体细胞通过花的花腺和其他自然开口进入植物,比如伤口,并且能够在植物内快速运动并建立全身性感染。已经表征了淀粉芽孢杆菌的许多毒力决定因素,包括III型分泌系统(T3SS),胞外多糖(EPS)淀粉,生物膜的形成,和运动性。为了成功建立感染,E.amylovora使用复杂的调节网络来感知相关的环境信号,并协调涉及两个成分信号转导系统的早期和晚期毒力因子的表达,双-(3'-5')-环二-GMP(c-di-GMP)和群体感应。LPS生物合成基因簇是在葡萄的Rubus和Spiraeoideaae感染基因型之间观察到的相对较少的遗传差异之一。其他差异因素,例如与HrpT3SS(编码T3SS装置的hrp基因)相关的整合共轭元件的存在和组成,最近有描述。在本次审查中,我们介绍了毒力因子研究的最新发现,重点关注它们在细菌发病机理中的作用,并指出其他值得未来研究来表征它们的毒力因子。
Erwinia amylovora, a Gram negative bacteria of the Enterobacteriaceae family, is the causal agent of fire blight, a devastating plant disease affecting a wide range of host species within Rosaceae and a major global threat to commercial apple and pear production. Among the limited number of control options currently available, prophylactic application of antibiotics during the bloom period appears the most effective. Pathogen cells enter plants through the nectarthodes of flowers and other natural openings, such as wounds, and are capable of rapid movement within plants and the establishment of systemic infections. Many virulence determinants of E. amylovora have been characterized, including the Type III secretion system (T3SS), the exopolysaccharide (EPS) amylovoran, biofilm formation, and motility. To successfully establish an infection, E. amylovora uses a complex regulatory network to sense the relevant environmental signals and coordinate the expression of early and late stage virulence factors involving two component signal transduction systems, bis-(3\'-5\')-cyclic di-GMP (c-di-GMP) and quorum sensing. The LPS biosynthetic gene cluster is one of the relatively few genetic differences observed between Rubus- and Spiraeoideae-infecting genotypes of E. amylovora. Other differential factors, such as the presence and composition of an integrative conjugative element associated with the Hrp T3SS (hrp genes encoding the T3SS apparatus), have been recently described. In the present
review, we present the recent findings on virulence factors research, focusing on their role in bacterial pathogenesis and indicating other virulence factors that deserve future research to characterize them.