中国畜牧兽医2024，Vol.51Issue(5)：2027-2036,10.DOI:10.16431/j.cnki.1671-7236.2024.05.024
LIPI-3和LIPI-4共存对致病性单核细胞增生李斯特菌毒力的影响
Influence of Coexistence of LIPI-3 and LIPI-4 on Virulence of Pathogenic Listeria monocytogenes
摘要
Abstract
[Objective]This study was aimed to explore the impact of the coexistence of LIPI-3 and LIPI-4 on the virulence of Listeria monocytogenes(LM),reveal their potential regulatory effects on bacterial virulence,and lay a foundation for further research on the pathogenic mechanisms of LM.[Method]LM928(possessing LIPI-4 present)and LM873(possessing both LIPI-3 and LIPI-4)were used as research objects to monitor the adhesion and invasion of two strains by infecting HCMEC/D3 cells.The effect of two strains on the median lethal dose(LD50)of chicken embryos were evaluated by chicken embryo infection test.The hemolytic activity of two strains were determined using hemolysis test.The apoptosis of HCMEC/D3 cells was analyzed using flow cytometry to evaluate the ability of two strain to induce cell apoptosis.The transcriptional differences of virulence genes between two strains under BHI culture conditions and post-infection of HCMEC/D3 cells were compared using Real-time quantitative PCR.[Result]There was no significant difference of adhesion rates between LM928 and LM873 strains(P＞0.05).The invasion rate of LM928 strain was extremely significantly higher than that of LM873 strain(P＜0.01).The LD50 of LM873 strain was approximately 1 000 times that of LM928 strain.The hemolytic values of LM928 and LM873 strains were 24 and 23,respectively.The apoptosis rate induced by LM928 strain at 24 and 48 h post-infection were significantly or extremely significantly higher than that of LM873 strain(P＜0.05 or P＜0.01),while there was no significant difference of the apoptosis rate between LM873 strain and control group(P＞0.05).When cultured in BHI culture,compared with LM928 strain,the transcription levels of virulence genes mpl,inlB,inlC,inlP,actA,plcA,plcB and sigB in LM873 strain were significantly or extremely significantly upregulated(P＜0.05 or P＜0.01),and the transcription levels of hly,inlA and iap genes were extremely significantly or significantly downregulated(P＜0.01 or P＜0.05).After infecting HCMEC/D3 cells,compared with LM928 strain,the transcription levels of virulence genes inlP,actA,plcA,plcB and prfA in LM873 strain were significantly or extremely significantly upregulated(P＜0.05 or P＜0.01),and the transcription levels of hly,mpl,inlA,inlB,inlC and iap genes were extremely significantly downregulated(P＜0.01).[Conclusion]The coexistence of LIPI-3 and LIPI-4 reduced the virulence of LM,which holded significant implications for further research into the molecular mechanisms and complex interactions of LIPI-3 and LIPI-4 in bacterial virulence regulation.关键词
单核细胞增生李斯特菌(LM)/LIPI-3/LIPI-4/毒力/毒力基因Key words
Listeria monocytogenes(LM)/LIPI-3/LIPI-4/virulence/virulence gene分类
农业科技引用本文复制引用
钱瑞宣,殷中科,刘璐,王静,王正荣,蒋建军,李楠,康立超,马勋,刘彩霞,史唯地,寇丽君,任慧杰,祁亚涛..LIPI-3和LIPI-4共存对致病性单核细胞增生李斯特菌毒力的影响[J].中国畜牧兽医,2024,51(5):2027-2036,10.基金项目
国家自然科学基金(32160833、32160834、32260895) （32160833、32160834、32260895）
省部共建绵羊遗传改良与健康养殖国家重点实验室开放课题(MYSKLKF201905) （MYSKLKF201905）
江苏省人兽共患病学重点实验室(R1901) （R1901）
