Molecular subtyping of Clostridium botulinum by pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis (PFGE) has been extensively used to estimate the genetic diversity of Clostridium botulinum. In addition, PFGE is the standard method for investigating foodborne outbreaks associated with various enteric pathogens, including C. botulinum. PFGE can be used to exclude a suspected but not confirmed food source when the patterns of the food and clinical isolates are different. Indistinguishable PFGE patterns may also be useful for linking isolates between patients or to a food source, but results must be interpreted within an epidemiological context to ensure isolates are truly related. Here, we describe a standardized laboratory protocol for molecular subtyping of C. botulinum by PFGE.