[Establishment of mouse model and preliminary screening of serum biomarkers for Candidemia].

Objective: To establish mouse models of Candidemia, and investigates statistically significant polypeptide peaks to provide auxiliary diagnosis of this disease. Methods: A total of 170 specific pathogen free adult male ICR mice with body mass of 27-30 g were completely randomly divided into Candida albicans infection group (n=80), Candida parapsilosis infection group (n=80) and the normal control group (n=10), and the two kinds of Candidemia mouse models were established via tail vein injection. The serum samples were analyzed by Matrix-assisted laser desorption-ionization time of flight mass spectrometry and relevant software, and the polypeptide peaks with significant differences were screened to establish diagnostic models. Results: A total of 65 differential polypeptide peaks were obtained compared with the Candida albicans infection group and the normal control group. Combined with m/z 1 100.4, 1 581.0, 3 808.0 as differential polypeptide peaks to established the diagnostic model, the sensitivity was 95.24%(40/42), the specificity was 90.63%(29/32), the accuracy rate was 93.24%(69/74), and the AUC value of the ROC curve was 0.972(95%CI: 0.941-1.000). A total of 73 differential polypeptide peaks were obtained compared with Candida parapsilosis infection group and the normal control group. Combined with m/z 1 433.2, 1 148.5, 4 093.5, 4 522.2, 8 140.9, 8 234.6 as differential polypeptide peaks to established the diagnostic model, the sensitivity was 95%(38/40), the specificity was 81.25%(26/32), the accuracy rate was 88.89%(64/72), and the AUC value of the ROC curve was 0.953(95%CI: 0.903-1.000). A total of 78 differential polypeptide peaks were obtained compared with Candida albicans infection group and Candida parapsilosis infection group. Combined with m/z 2 736.9, 8 091.5, 8 153.7 as differential polypeptide peaks to established the diagnostic model, the accuracy of distinguishing C. albicans infection from C. parapsilosis infection was 98.78%(81/82). Conclusions: Successfully screened the differential polypeptides and established the related diagnostic models. Which is helpful to find serum biomarkers for the auxiliary diagnosis of Candidemia, and provides a basis for the early diagnosis and the rational use of drugs.