试验分析了梨火疫病菌(Erwinia amylovora)Ea273基因组上新的T3SS(TypeⅢSecretion System,T3SS)致病岛特征并验证它们在Erwinia属的21个菌株基因组上是否存在。生物信息学分析发现,Ea273基因组不同位点上存在两个新的T3SS致病岛,称为PAI-2和PAI-3,大小分别为32.889kb和21.792kb。经PCR和Southern blot证明Ea273、Ea246、Ea262、Ea528以及Ea6445个菌株基因组存在PAI-2和PAI-3。PAI-3和PAI-2在基因结构和组成上相似,同源性超过70%,PAI-3包含PAI-2所有基因,两者和昆虫内生菌S.glossinidius编码的T3SS的SSR-1致病岛非常相似。 The characteristics of the T3SS pathogenicity island of Erwinia amylovora Ea273 genome were analyzed and the existence of 21 genomic sequences in Erwinia genus was tested. Bioinformatics analysis showed that there were two new T3SS pathogenic islands at different sites in Ea273 genome, named PAI-2 and PAI-3, with sizes of 32.889kb and 21.792kb, respectively. The results of PCR and Southern blot showed that PAI-2 and PAI-3 existed in the genomes of Ea273, Ea246, Ea262, Ea528 and Ea644. PAI-3 and PAI-2 are similar in gene structure and composition with over 70% homology. PAI-3 contains all PAI-2 genes, both SSR-1 of T3SS encoded by the insect endophyte S. gossinidius Sickle Island is very similar.