Establishment and preliminary evaluation of a rapid detection method for germ tube-specific antigens of Candida albicans

Abstract

Objective To establish a double-antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) for the rapid detection of germ tube-specific antigens of Candida albicans,and to evaluate its specificity and sensitivity.Methods A DAS-ELISA was established with the monoclonal antibody McAb03.2C1-C2 as the primary antibody,and horseradish peroxidase (HRP) labeled McAb03.2C1-C2 as the secondary antibody.The established assay was used to detect germ tube-specific antigens of Candida albicans in sera from 5 patients with systemic Candida albicans infection and from 6 rabbit models at 12,24,48,72hours,on week 1,2 after infection with Candida albicans.Results A good liner relationship was observed between the absorbance value at 495 nm and antigen concentrations when the titer of McAb03.2C1-C2 was 1 ∶ 4000 and the concentration of coated antigen varied from 1.25 to 40 μg/ml.The specificity and sensitivity of the DAS-ELISA were 95％ and 92％ respectively in the detection of germ tube-specific antigens in the rabbit models.The results of detection with DAS-ELISA in serum specimens from the patients were consistent with those with the routine method.Conclusions A DAS-ELISA is primarily established for the rapid detection of germ tube-specific antigens of Candida albicans,and has shown a satisfactory sensitivity and specificity in the animal model experiment. Key words: Candida albicans; Antibodies, monoclonal; Enzyme-linked immunosorbent assay; Sensitivity and specificity