沈阳农业大学学报2025，Vol.56Issue(5)：62-70,9.DOI:10.3969/j.issn.1000-1700.2025.05.007
奶牛乳腺炎源性乳酸乳球菌表型和致病性研究
Phenotype and Pathogenicity of Mastitis-derived Lactococcus lactis in Dairy Cows
摘要
Abstract
[Objective]Lactococcus lactis is a potential causative agent of mastitis in dairy cows.This study was carried out to understand the bacterial characteristics and pathogenic role of Lactococcus lactis and select effective drugs for treatment.[Methods]In this experiment,the Lactococcus lactis was isolated and identified and genotyped from milk samples of cows suffering from mastitis using traditional bacterial isolation and purification techniques and PCR,and its morphology was detected by scanning electron microscopy and antibiotic susceptibility of the isolates was examined.Based on the typing results,strong virulent strains were screened,and injected into the mammary glands of BALB/c pregnant rats,to detect the changes in the degree of mammary tissue damage at different modeling times and the expression of ASC,p65 and phosphorylated p65 in mammary tissues at 48h.To evaluate the therapeutic effect of antibiotics on mice with lactococcus lactis-induced mastitis,the mammary glands were modeled in the same way and treated with marbofloxacin to assess the therapeutic effect of the drugs.[Results]The results showed that the eight isolated strains of Lactococcus lactis could be categorized into three subtypes,among which the LL-1 subtype was the most virulent strain,which induced mastitis with a significant increase in the expression of p65,phosphorylated p65 and ASC in the tissues.In addition,all subtypes were sensitive to marbofloxacin and vancomycin and the therapeutic effect of high-dose marbofloxacin was obvious.[Conclusion]Marbofloxacin is an effective drug for treating bovine mastitis caused by Lactococcus lactis.The present study lays the foundation for improving the therapeutic effect of lactococcosis originating from clinical mastitis in dairy cows,and also provides reference for the scientific prevention and control of mastitis in dairy cows in the future.关键词
乳酸乳球菌/奶牛乳腺炎/炎性因子/分离鉴定Key words
Lactococcus lactis/cow mastitis/inflammatory factors/isolation and characterization分类
农业科技引用本文复制引用
董婧,金圣奇,刘正伟,王月强,潘婷婷,于立溶,王天成,李林..奶牛乳腺炎源性乳酸乳球菌表型和致病性研究[J].沈阳农业大学学报,2025,56(5):62-70,9.基金项目
中央引导地方科技发展专项项目(2023JH6/10010006 9) （2023JH6/10010006 9）
辽宁省创新能力提升联合基金项目(2021-NLTS-11-05) （2021-NLTS-11-05）
