Expressions and significances of LIF and RANTES in mouse model of bloodstream infection with single pathogen / 临床检验杂志

ABSTRACT

Objective To investigate the expressions of leukaemia inhibitory factor (LIF) and regulated upon activation,normal T cell expressed and secreted factor (RANTES) in mice with bloodstream infection by 4 different single pathogen and provide research basis for the early diagnosis of bacteriogenous bloodstream infection.Methods CD-1 (ICR,Institute of Cancer Research) mouse models of bloodstream infection with the standard strains of Staphylococcus aureus (S.aureus),Enterococcus faecalis (E.faecalis),Escherichia coli (E.coli) and Klebsiella pneumonia(K,pneumoniae) were established.The serum samples were collected at the 0.5,1,3,6,12,24 and 48 hours after infection and the concentrations of LIF and RANTES in mouse serum of experimental groups and control were detected by Luminex liquid chip system.Results The median lethal dose (LD50) of S.aureus,E.faecalis,E.coli and K.pneumoniae were 8.1 × 108/mL,9.6 × 108/mL,8.1 × 108/mL and 1.1 × 109/mL,respectively.The concentration of serum LIF was significantly increased in 1 hour after infection.The peak concentrations of LIF in the four groups were (51.6±5.0),(73.2±20.8),(7.3 ±0.9)and (6.1 ± 1.2) pg/mL respectively,and the differences were statistically significant compared with the control group (P ＜ 0.01).The concentrations of RANTES in E.faecalis group,E.coli group and K.pneumoniae group were increased after infection for 1 hour and increased significantly after infection for 3 hours.The increased concentrations of RANTES in E.coli group and K.pneumoniae group were more than those in S.aureus group and E.faecalis group.The peak concentrations of RANTES in S.aureus group,E.faecalis group,E.coli group and K.pneumoniae group were (1 929.0-± 25.2),(1 218.1 ± 227.4),(55.7 ± 10.0) and (179.2 ± 9.2)pg/mL,and the differences were statistically significant compared with the control group (P ＜ 0.01).Conclusion The concentrations of LIF and RANTES increased obviously in 1 h after the bacteria entered bloodstream.After 2 days of infections,the levels of LIF and RANTES in E.coli group and K.pneumoniae group were significantly higher than those in S.aureus group and the E.faecalis group.Combined detections of LIF and RANTES may be of certain values to differentiate the infections caused by the pathogens between gram positive and gram negative bacteria.