title: Differentiation of the gene clusters encoding botulinum neurotoxin type A complexes in Clostridium botulinum type A, Ab, and A(B) strains.
abstract: We describe a strategy to identify the clusters of genes encoding components of the botulinum toxin type A (boNT/A) complexes in 57 strains of Clostridium botulinum types A, Ab, and A(B) isolated in Italy and in the United States from different sources. Specifically, we combined the results of PCR for detecting the ha33 and/or p47 genes with those of boNT/A PCR-restriction fragment length polymorphism analysis. Three different type A toxin gene clusters were revealed; type A1 was predominant among the strains from the United States, whereas type A2 predominated among the Italian strains, suggesting a geographic distinction between strains. By contrast, no relationship between the toxin gene clusters and the clinical or food source of strains was evident. In two C. botulinum type A isolates from the United States, we recognized a third type A toxin gene cluster (designated type A3) which was similar to that previously described only for C. botulinum type A(B) and Ab strains. Total genomic DNA from the strains was subjected to pulsed-filed gel electrophoresis and randomly amplified polymorphic DNA analyses, and the results were consistent with the boNT/A gene clusters obtained.
authors.affiliation: Centro Nazionale per la Qualità degli Alimenti e per i Rischi Alimentari, Reparto Pericoli Microbiologici Connessi agli Alimenti, Istituto Superiore della Sanità, Rome, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Franciosa
authors.forename: Francesca
authors.initials: F
authors.lastname: Floridi
authors.forename: Antonella
authors.initials: A
authors.lastname: Maugliani
authors.forename: Paolo
authors.initials: P
authors.lastname: Aureli
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001905:Botulinum Toxins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019274:Botulinum Toxins, Type A / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D003014:Clostridium botulinum / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D047013:Clostridium botulinum type A / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D047014:Clostridium botulinum type B / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D051379:Mice; D005810:Multigene Family; D009500:Neutralization Tests; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D001426:Bacterial Proteins; C096323:rimabotulinumtoxinB; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A