Construction and biological characterization of an LLO-InlP deletion strain of Listeria monocytogenes
A Listeria monocytogenes LM681 △LLO-InlP gene deletion strain was constructed through the temperature sen-sitive(Ts)plasmid vector gene knockout method,and the OD600 nm values at different times were plotted to analyze the growth curves indicating the in vitro growth ability of three strains of bacteria:LM681,LM681 △ InlP,and LM681 △ InlP-△LLO.Cells were infected with each strain at an MOI value of 10.The adhesion and invasion ability were detected in human cho-rionic trophoblast cells(HTR-8/SV40)and human choriocarcinoma cells(JEG-3).At the animal level,the median lethal dose(LD50)in mice,and the bacterial loads in the brain,liver and spleen after infection were measured to explore the effects of the LLO and InlP genes on the biological characteristics of Listeria monocytogenes.The missing strain LM681 with a fragment size of 1 125 bp △ InlP,LM681 △ InlP-△ LLO(parent strain LM681 with 2 292 bp)was successfully obtained.The growth curve results indicated no significant difference in OD6oo values among bacteria.The deletion of LLO and InlP genes greatly decreased the virulence of LM in both animal infection and in vitro culture cell infection models.The InlP gene facilitates the LM681 strain's adherence to,and invasion of,trophoblast cells,thus laying a foundation for studying the role of InlP in the pathogenesis of Listeria monocytogenes.
国家科技期刊平台
NSTL
万方数据
维普
