[Detection of Clostridium novyi type B alpha toxin using cell culture systems]

The aim of our study was to investigate if a cell culture assay can replace the toxin neutralisation test in mice for the potency testing of alpha toxoid containing clostridial vaccines for veterinary use. The basis for the development of our cell culture assay was the detection of the cytotoxic/cytopathic action of alpha toxin on cells in culture. Nine permanent cell lines were examined for their reaction to the alpha toxin. The action of the toxin was determined after three days by microscopic examination and MTT assay. The alpha toxin exhibited the strongest effect on the ESH-L cells. We were able to show that the cytopathic effect was neutralised by the international standard for gas gangrene antitoxin (C.novyi) but never by heterologous antisera. Our results showed that the ESH-L cell line was a suitable indicator for the detection of the cytotoxic effect of alpha toxin.