Analysis of biological characteristics and pathogenicity of caf1 deletion mutant strain of Yersina pestis
CHENG Peng-bo1, 2, LU Hao1, CAO Chao-yue1, JIANG Nan1, ZHANG Li-li1, ZHAO Yue-e1, LU Jian-chun1, ZHOU Dong-sheng1, HU Ling-fei1, YANG Wen-hui1
1. State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing 100071, China; 2. Anhui Mdeical University,Hefei 230032,China
Abstract：To explore the effect of the caf1 gene deletion on biological characteristics and pathogenicity of Y. pestis. A caf1 deletion strain of Y. pestis was constructed using CRISPR/Cas12a based gene editing method, and the deletion of caf1 was confirmed by PCR. The in-vitro biological characteristics (including morphology, growth rate, aggregation rate) and virulence of caf1 deletion mutant strain were determined and compared with those of wild type strain. PCR results showed that caf1 deletion mutant strain was successfully constructed. The morphology and growth rate of the mutant strain did not change significantly compared with those of the wild strain. Compared with the wild strain, the caf1 deletion mutant strain can gather and deposit from the liquid medium more quickly. LD50 analysis showed that the lethal dose of caf1 deletion mutant strain to mice infected via aerosol route reduced significantly. Furthermore, the virulence of caf1 deletion mutant strain to mice was significantly reduced compared with that of wild type strain infected via intratracheal inoculation, nasal drops, subcutaneous and tail vein injections routes. The deletion of caf1 gene enhances the aggregation rate of Y. pestis, but reduce the virulence of Y. pestis to mice.
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2020, Vol. 36 
