ELISA and modified toxin-binding inhibition test for quality control of the clostridial vaccine processes

Abstract

This study aimed to assess and standardize the ELISA and modified ToBI test in vitro methods in order to verify the potency of epsilon toxicoid in comparison with the in vivo TCP method. The following epsilon toxoids were used: NIBSC standard from batches 375/07, 532/08, 551/08, 373/07 and 378/07. These were evaluated using a TCP test, ELISA and ToBI tests. The results indicate that the correlation ratio between the dilutions of standard NIBSC toxicoid and absorbance values of 89.44% obtained with the ELISA method support the use of the curve to evaluate epsilon toxoids. However, it was observed that the absorbance values were similar for all toxoids, thus presenting no significant difference between higher and lower concentration toxoids. For the ToBI test, the correlation ratio of 96.76, obtained in the curve pattern, demonstrates the effectiveness of the curve to be used in the epsilon toxoid evaluation. The correlation ratio between the titration degrees of toxoids obtained through TCP and ToBI tests was higher than 90%. It is concluded that the type of ELISA test used does present discriminative power for toxoids with different concentrations, which does not support the use of this technique for such a purpose. The ToBI test can be used as a screening method for it is sensitive and effective to detect epsilon toxicoid produced by C. perfringens type D.

Pathologic findings on ruminant enteric clostridial diseases reveal specificities and differences among iota and iota-like toxins

“…In South American and European countries, diagnoses of enteric diseases are performed by analyzing clinical signs, characterization of macroscopic and microscopic lesions, detection of the C. perfringens toxins type present in the intestinal contents of infected animals by ELISA and PCR, isolation of the etiological agent in bacteriological cultures, demonstration of toxins in clinical samples and in supernatant fluid from pure cultures, or by Seroneutralization of the intestinal filtrate combined with specific antitoxins (Sobrinho et al, 2010;Sobrinho et al, 2014;Santana et al, 2018;Ghoneim and Hamza, 2017). PCR is a basic molecular technique that can be employed to detect C. perfringens strains by in vitro Multiplex PCR tests, in which the corresponding toxin genes are detected.…”

Total combining power: Technique for the evaluation of the quality control process of clostridiosis vaccines

“…Owing to the economic impact caused by enterotoxemia, it is important to develop methods and techniques that successfully prevent such diseases. Quantitative kits allow for the detection and quantification of these toxins or the testing of the potency of the clostridial vaccine (Sobrinho et al, 2011(Sobrinho et al, , 2014. Some tests, including the toxin binding inhibition (ToBI) test and enzyme linked immunosorbent assay (ELISA), aim to evaluate the quality of veterinary vaccines in order to replace or minimize the use of laboratory animals (Sobrinho et al, 2010).…”