ABSTRACT
Objective To find out the valuable early diagnostic antigen of Schistosoma japonicum. Methods The sera of rabbits were collected at different time after the rabbits were infected with cercariae of Schitosoma japonicum. The fractions of the soluble cercaria antigen (SCA), soluble adult worm antigen (AWA) and soluble egg antigen (SEA) were separated by SDS-PAGE and recognized by Western blotting with rabbits' sera of different time of post-infection. Results In Western blotting, the bands of 94, 48, 41, 40 kDa and 38 kDa of SCA appeared the earliest and were recognized by the rabbits sera of 2-week post-infection, the bands of 71 kDa and 23 kDa of SCA reacted with the rabbits sera of 3-week post-infection strongly. The bands of 71 kDa and 58 kDa of AWA appeared the earliest and were recognized by rabbits sera of 3-week post-infection. The bands of SEA reacted earliestly to the rabbits sera of 4-week post-infection were 270, 151, 73, 69, 50 kDa and 24 kDa. Conclusion The fraction antigens of 94, 71, 48, 41, 40, 38 kDa and 23 kDa of SCA, the fraction antigens of 71 kDa and 58 kDa of AWA and the fraction antigens of 270, 151, 73, 69, 50 kDa and 24 kDa of SEA could be recognized by sera of acute infected rabbits and might have potential early immuno-diagnosis value for schistosomiasis.
ABSTRACT
Objective To evaluate the effect of DDIA on detecting cattle schistosomiasis. Methods The sera of schistosomiasis cattle, negative control cattle and fascioliasis cattle were detected with DDIA and compared with COPT. Results The sensitivity, specificity and across reaction of DDIA using 10 ?l of sample sera were 95.7%, 96.0% and 20.0% respectively and COPT were 72.9%, 100.0% and 0 respectively. Conclusions DDIA has high sensitivity and specificity for detecting cattle schistosomiasis with 10 ?l of sample serum, and the sensitivity is higher than that of COPT.
ABSTRACT
Objective To evaluate the stability of dipstick dye immunoassay (DDIA) kit forschisitosomiasis diagnosis. Methods By means of detection of the sera from infected people withSchistosoma japonicum and healthy people, the stability of the DDIA kit, which stored at 37℃,room temperature or 4 ℃ respectively, was evaluated depending on the detective results ofsensitivity, specificity, detectable minimum and coefficient variation ( CV). Results Thesensitivity, specificity, detectable minimum and coefficient variation of the DDIA kit were invariableafter the kits stored at 37 ℃ for 180 days, and at room temperature or 4 ℃ for 360 days.Conclusion The DDIA kit is stable while it stores at 37℃ for 180 days, and at room temperatureor 4℃ for 360 days at least.
ABSTRACT
Objective To develop a fast, simple immunodiagnosis assay for early diagnosis of schistosomiasis. Methods The soluble cercariae antigen(SCA) labeled colloidal dye was used as the detecting antigen for schistosomiasis. A dipstick dye immunoassay(SCA-DDIA) for early diagnosis of schistosomiasis was established. The antibodies in sera of infected rabbits in early stage of infection by SCA-DDIA were detected and compared with SEA-DDIA. The sera from people with acute and chronic schistosomiasis and other parasitic diseases and from healthy people were tested by SCA-DDIA and SEA-DDIA. Results In infected rabbits during early stage of infection, the average time of antibody detected by SCA-DDIA was 22 d , at day 30 post-infection all experimental rabbits were positive with SCA-DDIA, the detected time was earlier than that with SEA-DDIA. The sensitivity of SCA-DDIA for acute, chronic schistosomiasis japonica were 100.0% and 93.3% respectively. The specificity for healthy persons was 99.0%. The cross reaction rates with paragonimiasis westermani, clonorchiasis sinensis and fasciolopsiasis buski were 26.3%, 0 and 0 respectively. The results were similar to that by SEA-DDIA. Conclusion The SCA-DDIA is more useful for early diagnosis of schistosomiasis.
ABSTRACT
Objective To establish rSAG1-IgM-ELISA with purified rSAG1 fusion protein for immunodiagnosis of toxoplasmosis. Methods The rSAG1 fusion protein was purified by Ni 2+ column. The ELISA plate was coated with different concentrations of rSAG1, reacted with pooled positive and negtive human sera. Goat anti-human IgM conjugated to horseradish peroxidase was used as the second antibody. The appropriate detecting condition of the rSAG1-IgM-ELISA assay was determined by orthogonal experiment. The reproducibility, sensitivity and specificity of the assay were assessed. Thirty-five IgM-positive and 57 IgM-negative human sera detected by the imported IgM-ELISA kit were detected with the rSAG1-IgM-ELISA. Results The purity of rSAG1 was above 90%. The appropriate detecting condition was that the coated rSAG1 was 2 5 ?g/ml, the human serum was in 1∶100 dilution, and the second antibody was in 1∶4000 dilution. The coefficient of variation (CV) value of IgM-positive and IgM-negative pooled sera were 13 8% and 7 7% respectively. The inhibition rate of the assay was 62 0% The positive correspondence rate and negative correspondence rate were 82 9% (29/35) and 91 2% (52/57) respectively,the total correspondence rate was 88 0%, compared with the imported IgM-ELISA kit. Conclusions The rSAG1-IgM-ELISA has high sensitivity and specificity, and good correspondence rate with the imported IgM-ELISA kit. It indicates that rSAG1-IgM-ELISA has potential value for early diagnosis of toxoplasmosis.