Detection of circulating antigens in serum samples of mice experimentally infected with Trichinella spiralis by a sandwich ELISA based on IgY

Abstract

SummaryIn the present study, a sandwich ELISA based on IgY (egg yolk immunoglobulin) was developed for detection of circulating antigens (CAg) in sere of mice experimentally infected with Trichinella spiralis. The IgY-sandwich ELISA assay involved the use of chicken antibody IgY against excretory-secretory (ES) antigens of Trichinella spiralis muscle larvae as a capture antibody and mouse polyclonal antibody IgG to ES antigens as a detecting antibody. This method was able to detect as little as 3 ng/ml of ES antigens added to normal mouse serum. A group of sixteen mice was orally inoculated with 500 T. spiralis muscle larvae per animal. The serum samples from the infected mice were taken during 1 -35 days post-infection (dpi). The CAg was detectable as early as 8 dpi in the sera of infected mice. The level of CAg increased dramatically during 13 -15 dpi and reached a peak at 22 dpi and remained a plateau for 3 days, then declined gradually. Another peak of CAg occurred at 31 dpi. The anti-Trichinella antibodies was first detected in 14.3 % of the infected mice at 2 weeks post-infection (wpi), and reached a peak positive rate of 100 % at 5 wpi. Moreover, the infected mice were treated with abendazole at 5 wpi and the serum CAg levels increased significantly during 2 -6 days posttreatment (dpt) and then declined rapidly during 8 -14 dpt. By 42 dpt, the CAg levels decreased to the undetected level, but the detection rate of antibodies was still 100 %. The IgY-sandwich ELISA appears to be a sensitive for detection of antigenemia of T. spiralis and valuable to judge the efficacy of chemotherapy in trichinellosis.

Real-time PCR versus traditional and Nano-based ELISA in early detection of murine trichinellosis

“…Also, Wang et al (2012) found that T. spiralis circulating antigen was detected as early as 3 dpi in the serum of mice infected with 500 T. spiralis muscle larvae, and its level increased gradually and reached two peaks with detection rate of 40% and 100% at 13 and 24 dpi, respectively. Furthermore, Jing et al (2014) reported that T. spiralis circulating antigen was detectable as early as 8 dpi then increased radically during 13-15 dpi, peaking at 22 dpi in serum of mice infected with 500 larvae. The best cutoff of quantitative PCR in prediction of severe infection was ≥ 2.5841 with area under curve of 0.9, sensitivity of 80%, specificity of 81.5%, positive predictive value of 78.3%, negative predictive value of 83%, and overall accuracy of 80.8% (P < 0.001).…”

“…Also, Wang et al (2012) found that T. spiralis circulating antigen was detected as early as 3 dpi in the serum of mice infected with 500 T. spiralis muscle larvae, and its level increased gradually and reached two peaks with detection rate of 40% and 100% at 13 and 24 dpi, respectively. Furthermore, Jing et al (2014) reported that T. spiralis circulating antigen was detectable as early as 8 dpi then increased radically during 13–15 dpi, peaking at 22 dpi in serum of mice infected with 500 larvae.…”