Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism

Abstract

Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism.

Integration of Complete Plasmids Containing Bont Genes into Chromosomes of Clostridium parabotulinum, Clostridium sporogenes, and Clostridium argentinense

“…Currently, 24 C. sporogenes strains have been identified in the National Center for Biotechnology Information (NCBI) database that carry bont/B genes [ 20 , 23 , 24 , 25 ]. Seven of these strains contain bont/B1 gene clusters, 10 contain bont/B2 gene clusters, and five contain bont/B6 gene clusters.…”

Clostridia in Insect Processed Animal Proteins—Is an Epidemiological Problem Possible?

“…such as C. sporogenes could impact the biological safety for animals and humans. Strains of C. botulinum Group I (and, to a lesser extent, C. sporogenes) are a major cause of the three most frequent types of botulism in humans (foodborne, infant, and wound botulism) and are also responsible for botulism in animals [64,65]. C. sporogenes was also considered as the causative agent of secondary bacteraemia in immunocompetent patients [54].…”

Botulinum Toxin: From Poison to Possible Treatment for Spasticity in Spinal Cord Injury

“…All are related to the entry into the organism of toxins of C. botulinum and less frequently of C. barati, C. butyrricum, C. argentinense, and C. sporogenes. The route of entry and spread is usually enteral, although the toxicity is neurological [ 2 , 5 , 6 ].…”