产单核细胞李斯特菌减毒候选菌株分子生物学特性研究

目的为了确定用于减毒的产单核细胞李斯特菌菌株,对初筛入选的血清型为1/2a菌株Lm1、Lm2、Lm3和Lm4的分子生物学特性进行了比较研究。方法利用PCR技术均成功地扩增出4株菌株的hly基因及actA和plcB基因片段。以LD50的测定试验作为菌株毒力指征,对4株菌株的毒力进行了测定。结果4株菌株均为强毒菌株,其中菌株Lm4的毒力最强,用BALB/c小鼠测得的LD50为1.47×104CFU。结论确定以Lm4作为候选菌株。

Molecular characterization of candidate strains of the Listeria monocytogenes to be attenuated

To screen the suitable candidate strains of the attenuated Listeria monocytogenes for the development of vaccine, a comparative study was made on the molecular characterization of serotypes of 1/2a strains Lm1, Lm2, Lm3 and Lm4.The hly , actA and plcB gene fragments of these strains were amplified with PCR. By using LD_ 50 as the virulent index for bacterial strains, the virulences of these 4 strains were compared. The experimental results demonstrated that all these strains appeared to be virulent, among which the toxicity of strain Lm4 was the strongest one with its LD_ 50 value of 1.47x l0~4 CFU per BALB/c mouse.It suggests that the strain Lm4 may be a good candidate strain to be attenuated for use in the development of Listertia monocytogenes vaccine.