Diagnosis of Yersinia pseudotuberculosis Infection by Enzyme-Linked Immunosorbent Assay

Paik, InKi; Kim, MeAe; Cho, Chong Rae

Abstract

BACKGROUND: Diagnostic rate of Yersinia pseudotuberculosis infection by stool culture is low and slide agglutination (SA) method in serum has diagnostic problem due to high false positive rate and cross reaction with other febrile diseases. Therefore we tried to develop first stage whole cell Enzyme-linked immunosorbent assay (ELISA) test against Y. pseudotuberculosis antigen using Korean strains of Y. pseudotuberculosis.
METHODS
Korean strains of Y. pseudotuberculosis (serotype:4b and 15) were cultured and cell wall was destroyed by sonifier and used as antigen. Microplate wells were coated with antigen and sera of three group (patient group, control group and adult group) were added and incubated at 37degreesC. Peroxidase conjugated rabbit antihuman IgG and goat antihuman IgM were added and substrate (3,3',5,5'-tetramethylbenzidine) adding was followed. Optical density was measured by spectrophotometer at 450 nm.
RESULTS
Patient group (n=22) who has more than 1:80 titer in SA method showed 27.3% positivity in IgG antibody and 63.6% positivity in IgM antibody in noncompetitive sandwich method of ELISA test. Adult group (n=50) showed 26.0% positivity in IgG antibody. Positivity rate of antibody in ELISA test was not correlated with agglutination titer in SA method but both antibodies were positive in 3 cases which have agglutination titer above 1:1280.
CONCLUSIONS
Whole cell ELISA test was tried by Y. pseudotuberculosis antigens using serotypes which were isolated in Korea. Positivity rate of both IgG and IgM antibodies by ELISA test was not correlated with agglutination titer of SA method.