<i>Clostridium botulinum</i> Strain Af84 Contains Three Neurotoxin Gene Clusters: <i>Bont/A2</i>, <i>bont/F4</i> and <i>bont/F5</i>

<div><p>Sanger and shotgun sequencing of <i>Clostridium botulinum</i> strain Af84 type Af and its botulinum neurotoxin gene (<i>bont</i>) clusters identified the presence of three <i>bont</i> gene clusters rather than the expected two. The three toxin gene clusters consisted of <i>bont</i> subtypes A2, F4 and F5. The <i>bont/A2</i> and <i>bont/F4</i> gene clusters were located within the chromosome (the latter in a novel location), while the <i>bont/F5</i> toxin gene cluster was located within a large 246 kb plasmid. These findings are the first identification of a <i>C. botulinum</i> strain that contains three botulinum neurotoxin gene clusters.</p>