Background
The Elek and guinea pig lethality test have been used to determine whether a Corynebacterium is pathogenic or non-pathogenic. The guinea pig test is accurate but obviously undesirable while the Elek test is complicated, difficult to perform and not always accurate.
Most non-toxigenic species of Corynebacteria possess the enzyme pyrazinamidase which catalyses the hydrolysis of pyrazinamide into ammonia and pyrazinoic acid, this hydrolysis can be detected by the addition of 20% (w/v) Ammonium ferrous sulphate to the test material.
Toxigenic species are not able to hydrolyse the pyrazinamide
Material Safety Data Sheet (En)
