Selection of primers for specific detection of Clostridium botulinum typesB and E neurotoxin genes using PCR method

Improved oligonucleotide primers were designed to flank 370- and 307-bp fra gments of the bont genes encoding botulinum neurotoxins types B and E, resp ectively. Primer specificity was confirmed for reference strains of Clostri dium botulinum types B and E for strains representing bacterial species com mon in food, and for the DNA mixtures of C. botulinum types B and E in the presence of background DNA isolated from cold smoked salmon and ham. The de tection limit of template DNAs of C. botulinum types B and E from the DNA m ixtures increased from 1 to 0.1 ng by raising annealing temperature from 50 degreesC to 62 degreesC. (C) 2001 Elsevier Science B.V. All rights reserve d.