Botulism laboratory testing

The mouse bioassay is the standard diagnostic laboratory test for botulism (36). The procedure detects whether a type-specific antitoxin protects the mice against any bomlinum toxin that may be present in the clinical specimen. The bioassay, which takes 1-2 days to complete (range 6-96 h), can detect 0.03 ng of botulinum toxin. In addition to the bioassay, anaerobic cultures of clinical specimens can isolate the organism in 7-10 days (range 5-21) days, but a mouse bioassay is necessary to confirm that the culture isolates produced the toxin (36). 

Botulism is confirmed by laboratory tests which indicate the presence of the C. botulinus bacterium or toxin in the patient s blood serum, gastric contents, or stool, or in the case of wound botulism, in woimd specimens. 

A botulinum antitoxin is available and can be obtained from stores held in regional centres and the HPA Centre for Infections as well as Porton Down. The decision to use antitoxin therapy will usually be made by a senior infectious diseases clinician and should rely on clinical or historical features rather than laboratory test results. Surgical debridement and antibiotic therapy may be indicated for suspected wound botulism. Respiratory failure may require endotracheal intubation and mechanical ventilation with subsequent monitoring and treatment in a critical care environment. 

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