The detection of a deletion in the type B neurotoxin gene of Clostridium botulinum A(B) strains by a two-step PCR.
Differences between the type B neurotoxin gene sequence of Clostridium botulinum type A(B) and Cl. botulinum type B, including a six nucleotide deletion, were recently proposed as a cause of the lack of expression of this gene in the type A toxigenic strains. A polymerase chain reaction (PCR) based on two sets of primers was designed to investigate the absence of the 6-nucleotide sequence in the apparently unexpressed type B toxin gene of 42 strains of Cl. botulinum type A(B). Thirty-five strains were shown to exhibit a deletion in their type B toxin gene; two strains did not have the deletion and actually produced small amounts of type B toxin when tested by the mouse bioassay. This two-step PCR might be useful for the rapid determination of the presence of the six nucleotide deletion and consequently, whether the type B toxin is likely to be produced.
Food Department, Istituto Superiore di Sanità, Rome, Italy.
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Franciosa
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Hatheway
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Aureli
D000818:Animals; D001904:Botulinum Antitoxin; D001905:Botulinum Toxins / Q000235:genetics* / Q000633:toxicity; D019274:Botulinum Toxins, Type A; D003014:Clostridium botulinum / Q000235:genetics*; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis; D005798:Genes, Bacterial / Q000235:genetics; D051379:Mice; D009500:Neutralization Tests; D016133:Polymerase Chain Reaction / Q000379:methods*; D017384:Sequence Deletion / Q000235:genetics*; D013045:Species Specificity
D001904:Botulinum Antitoxin; D017931:DNA Primers; D004269:DNA, Bacterial; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A