Analysis of serum peptides in Candida albicans bloodstream infection based on MALDI-TOF MS / 解放军医学杂志

ABSTRACT

Objective To analyze the fingerprints of serum peptides in bloodstream infection induced by Candida albicans (C.albicans),with matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS),and establish the corresponding diagnostic model Methods To establish ICR mice model of C.albicans bloodstream infection,and collect the serum samples which were purified by weak cation exchange beads.The serum peptide finger printing was recognized by MALDITOF MS,and BioExplorer software was used for analysis between infection group and normal control group.Furthermore,the peptide fingerprints were analyzed between C.albicans infection group,Escherichia coli (E.coli) infection group and Staphylococcus aureus (S.aureus) infection group.Results Comparison between C.albicans infection group and normal control group,there were 135 polypeptide peaks,of which 5 polypeptides up-regulated,6 down-regulated and 7 up-regulated first and down-regulated afterwards.The diagnostic model was established by combination of 6 peaks (i.e.m/z 1610.9,1742.3,2666.4,2778.0,3345.1 and 4528.8),which possessed an accurate rate of 80.0％ in diagnosis of C.albicans infection.It was found by comprehensive comparison between C.albicans,E.coli and S.aureus infection groups that there were 5 polypeptides expressed collectively,i.e.m/z1513.8,2910.8,3538.1,3884.9 and 5007.3.Conclusions MALDI-TOF MS can be used to distinguish the C.albicans infection and normal polypeptide peaks.The collective polypeptides expressed in the infection groups can be further used to diagnose the infection.Establishment of corresponding diagnostic models may be helpful for early diagnosis of fungal bloodstream infection and provide a basis for reasonable clinical medication.