Comparative Assessment of ELISA and MLD for Measurement of Epsilon Toxin in Enterotoxemia Vaccine Production Process

One of the most common veterinary biologicals is enterotoxemia vaccines that produced against Clostridium perfringens.Enterotoxemia diseases are mediated by toxins and epsilon is the most pathogenic toxin so killed vaccines comprise toxoided forms of these toxins. During vaccine manufacture toxin production is measured by Minimum Lethal Dose (MLD) tests that rely on animal testing in mice that measures the minimum concentration of toxins.The objective of the present study was to compare the performace of ELISA assay that quantify epsilon toxins and toxoids with MLD and correlation evaluation. Suitable in vitro assays would completely replace the use of animals in testing at these stages, furthermore ELISA test has the ability to detect toxin and toxoids while MLD detect the active toxins only.۲۰ supernatant sample of type D fermenter culture which contain active toxin used in this research for MLD test after activatin with trypsin serial dilutions was done and for each dilution, ۰.۵ ml was inoculated intravenously into each of two mice. for ELISA assay microtitration plates coated with proper dilutions of supernatant samples and standard toxins as positive control and other stages was performed and results interpreted. Pearson correlation coefficient and linear regression analysis used for the correlation between MLD and ELISA results.Correlation coefficient greater than zero indicates a positive relationship between two tests so precise replacements of ELISA by mouse tests in this stage would significantly reduce animal usage in vaccine production and is a suitable replacement for very painful, stressful and prone to high variability assay.

کلیدواژه ها:

Clostridium perfringens ، Epsilon toxi ، MLD ، ELISA