关键词: 水貂, 绿脓杆菌, 分离鉴定, 致病性

Abstract: To clarify the pathogenicity of Pseudomonas aeruginosa in mink,bacteria isolation was performed from 43 lung tissue samples which were collected from mink with hemorrhagic pneumonia from Zhucheng, Wendeng and Linyi in 2013. The isolates were identified by morphological observation, physicochemical tests, drug susceptibility tests and 16S rDNA sequencing. The 5 isolates were all Pseudomonas aeruginosa, named F1, F5, F6, F8 and F10, and the isolating rate was only 11.6%. The nucleotide homology of the 5 strains was 98. 9 % -99. 7 % by 16S rDNA sequence homology analysis. Phylogenetic analysis showed that F5、F6、F8、F10 and F1 were clustered in the same branch. F1 was selected as a representative strain for challenge tests on mice and mink, respectively and animal models of pathogenicity of P. aeruginosa to mice and mink were established. Pathogenicity tests showed that the LD50 for mice was 1.6 ×106 CFU/mL and the bacterial content in the lung was higher than in other organs, which indicated that strain F1 had a stronger pathogenicity in mice. The LD50 for minks was 3.2 ×107 CFU/mL and the mink which were inoculated with bacteria solution with 3.2 ×108 CFU/mL were all dead within 20 -44 h,however,the minks in other artificial infection groups only showed transient depression andAnepithymia. It suggests that P. aeruginosa has a certain degree of pathogenicity in mink.

Key words: Isolation and identification, Mink, Pathogenicity, Pseudomonas aeruginosa