Optimization of In-House Indirect-ELISA & EITB Assays Employing Cysticercus cellulosae Antigens for Serological Detection and PCR Assays for Molecular Detection of Porcine Cysticercosis

Abstract

Background: Porcine cysticercosis, caused by metacestodes of Taenia solium is an important neglected zoonosis. We evaluated the presence of anti-cysticercal antibodies and T. solium specific DNA in pig sera and blood samples respectively collected from Maharashtra, India.
 Methods: A total of three antigens (Scolex Antigen (SA), Membrane Body Antigen (MBA) and Excretory-Secretory Antigen (ESA)) were prepared from metacestodes of T. solium and employed in an in-house developed indirect-IgG ELISA for serological screening of 1000 porcine sera samples at Department of Veterinary Public Health, Nagpur Veterinary College, Maharashtra, India. The ELISA positive sera samples were subjected to EITB Assay for detection of immunodominant peptides. An effort has been made for molecular detection of porcine cysticercosis by PCR assay targeting large subunit rRNA gene of T. solium from blood samples of the corresponding ELISA-positive pigs.
 Results: The overall seroprevalence of porcine cysticercosis employing SA, MBA and ESA was 12.6%, 8.7% and 12.5% respectively. The lower and medium molecular weight peptides were the most frequently recognised in EITB assay. The numbers of bands recognised in EITB assay were observed to be proportionate with the corresponding ELISA O.D. values. An amplification product of 286 bp was observed in 22.98% (20/87), 30.35% (30/99) and 17.14% (12/70) of the sero-positive samples against SA, ESA and MBA respectively.
 Conclusion: EITB still remains the gold standard serodiagnosis test for cysticercosis. The inclusion of a greater number of positive samples and purification of antigens may improve the diagnostic efficacy of the tests.