Research on the detection of IgG antibodies in saliva with Trichinella spiralis adult worm excretory-secretory antigen

Abstract

Objective To evaluate the feasibility of the detection of IgG antibodies in saliva with Trichinella spiralis adult worm excretory-secretory antigen (AWESA). Methods Animal model of Japanese big ears rabbits infected with T. spiralis was established, AWESA was prepared. Saliva and serum of the rabbits before and 1-6 weeks post infection and that of the control group were collected. Taking commercial kit detecting anti-T. spiralis IgG antibody as control, indirect enzyme-linked immunosorbent assay (ELISA) using AWESA was developed. Anti-T. spiralis IgG antibodies in saliva and serum of the rabbits before and 1-6 weeks post infection and that of the control group were detected with ELISA. A values of saliva and serum from the detection with AWESA and commercial kit were tested with linear regression analysis. The comparisons of positive rates from the detection with AWESA and commercial kit were determined by the chi-square test. Results The positive rates of saliva and serum from rabbits infected with T. spiralis before infection and 1-6 weeks postinfection obtained by AWESA were 0,5%, 20%, 40%, 60%, 85%, 90% and 0, 30%, 60%, 85%, 95%,100%, 100% ,respectively. There were significant linear correlations between A values of saliva and A values of serum every week, except for before and 1 week and 2 week post-infection ( P ＞ 0.05, P ＞ 0.05, P ＞ 0.05, P ＜0.05 ,P ＜0.05 ,P ＜0.05 ,P ＜0.05, respectively). The positive rates of saliva and serum from rabbits infected with T. spiralis before and 1-6 weeks post-infection obtained by commercial kit detecting anti-T. spiralis IgG antibody were 0, 15% ,20% ,40% ,55% ,75% ,90% and 0,35% ,60% ,95% ,95%, 100%, 100%, respectively.There were significant correlations between A values of saliva and A values of serum every week, except that of before infection, 1 week and 3 week post-infection ( P ＞ 0.05 、P ＞ 0.05 、P ＜ 0.05 、P ＞ 0.05 、P ＜ 0.05 、P ＜0.05 、P ＜ 0.05, respectively). Conclusion The positive rates of the detection of anti-T. spiralis IgG antibodies in saliva and serum by AWESA were of consistency with that by commercial kit. Key words: T. spiralis; Adult worm excretory-secretory antigen; Saliva; Serum; ELISA