Comparison of Clostridium botulinum genomes shows the absence of cold shock protein coding genes in type E neurotoxin producing strains

To collect specific information about the genetic mechanisms that Clostridium botulinum strains utilise when adapting to changing environments, 16 C. botulinum genomes were analysed with comparative genome sequence analysis. Particular attention was paid to low temperature adaptation and the presence of cold shock protein coding genes in these genomes was evaluated. Surprisingly, unlike any other studied strains, the type E neurotoxin-producing strains lacked these extremely conserved genes. This finding suggests unique mechanisms for the cold tolerance of these strains and offers a new perspective into the investigations concerning this subject. The sizes of the pangenome and core genome of a certain bacterial species are considered to reflect the versatility of the species. While the pangenome of C. botulinum was very large, the core genome appeared strikingly small, both findings highlighting the great diversity of C. botulinum strains.