Temperature dependency of Clostridium botulinum C and D toxin production from anaerobically enriched bovine gastrointestinal samples.

AIMS: To determine whether Clostridium botulinum neurotoxin (BoNT) production in anaerobic culture was affected by temperature and could influence the sandwich ELISA (sELISA) detection of group III toxins in pre-enriched gastrointestinal (GI) contents from clinically suspect cattle botulism cases.

METHODS AND

RESULTS

Bovine post-mortem GI samples taken from 124 and 96 animals with suspect and nonsuspect botulism, respectively, were pre-enriched anaerobically at 30 and 37°C prior to testing by sELISA. After enrichment at 37°C, BoNT was demonstrated in all clinically suspect bovine botulism cases that had been identified by the mouse bioassay, and enrichment by both temperatures enabled BoNT detection in a number of mouse bioassay-negative suspect cases.

CONCLUSIONS

Culture temperature does influence the production of group III BoNT, and incubation at both 30 and 37°C is required for optimum detection.

SIGNIFICANCE AND IMPACT OF THE STUDY: The in vitro assay defined in this study has the potential of improving the confirmation rate of clinically suspect cattle botulism cases whilst reducing the use of the costly and ethically sensitive mouse bioassay, the current diagnostic gold standard for BoNT testing.