Exploring the diagnostic utility of recombinant low molecular weight cystic fluid proteins, Ag2 and Ag2V1, for serosurveillance of porcine cysticercosis

Abstract

Porcine cysticercosis caused by the metacestode stage of Taenia solium is an economically challenging disease having public health importance. Being one of the neglected tropical diseases, surveillance of porcine cysticercosis is essentially warranted in endemic countries to detect the transmission foci of infection to humans. Keeping this as background, in the present study, the genes encoding for two cystic fluid antigens (Ag2 and Ag2V1) of metacestode of T.solium were amplified, ligated into cloning vector, transformed into E.coli Top 10 cells and sequenced. After analysis and confirmation of nucleotide sequence of Ag2 and Ag2V1 genes, the purified and restriction enzyme digested PCR products were cloned. The confirmed positive clones were induced for expression of recombinant proteins and the proteins were purified by Ni-NTA affinity chromatography. The hyperimmune sera raised against native antigens of metacestode of T.solium were employed to characterize the purified recombinant proteins by Western blotting. After confirming the recombinant proteins, indirect enzyme linked immuno sorbent assays (iELISA) using recombinant Ag2 and Ag2V1 antigens were standardized. The iELISA employing recombinant Ag2 and Ag2V1 antigens revealed sensitivity of 98.1 % and 93.4 % and specificity of 91.2 % and 97.5 %, respectively. The weighted Cohen's kappa was calculated as 0.89 (95 % CI 0.804 to 0.975) for Ag2 and 0.857 (95 % CI 0.755 to 0.959) for Ag2V1. The assays developed in the present study can be employed for the surveillance of porcine cysticercosis to help in clean pork production. However, further studies involving larger sample sizes, particularly from scavenging pigs, are warranted to validate these findings.