scholarly journals Sequence Diversity of Genes Encoding Botulinum Neurotoxin Type F

2010 ◽  
Vol 76 (14) ◽  
pp. 4805-4812 ◽  
Author(s):  
Brian H. Raphael ◽  
Mallory J. Choudoir ◽  
Carolina Lúquez ◽  
Rafael Fernández ◽  
Susan E. Maslanka
Keyword(s):  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Nucleotide Diversity ◽  
Sequence Variation ◽  
Nucleotide Sequences ◽  
Gene Encoding ◽  
Group I ◽  
Genes Encoding ◽  
Outbreak Investigations ◽  
Result Analysis

ABSTRACT Botulism due to type F botulinum neurotoxin (BoNT/F) is rare (<1% of cases), and only a limited number of clostridial strains producing this toxin type have been isolated. As a result, analysis of the diversity of genes encoding BoNT/F has been challenging. In this study, the entire bont/F nucleotide sequences were determined from 33 type F botulinum toxin-producing clostridial strains isolated from environmental sources and botulism outbreak investigations. We examined proteolytic and nonproteolytic Clostridium botulinum type F strains, bivalent strains, including Bf and Af, and Clostridium baratii type F strains. Phylogenetic analysis revealed that the bont/F genes examined formed 7 subtypes (F1 to F7) and that the nucleotide sequence identities of these subtypes differed by up to 25%. The genes from proteolytic (group I) C. botulinum strains formed subtypes F1 through F5, while the genes from nonproteolytic (group II) C. botulinum strains formed subtype F6. Subtype F7 was composed exclusively of bont/F genes from C. baratii strains. The region of the bont/F5 gene encoding the neurotoxin light chain was found to be highly divergent compared to the other subtypes. Although the bont/F5 nucleotide sequences were found to be identical in strains harboring this gene, the gene located directly upstream (ntnh/F) demonstrated sequence variation among representative strains of this subtype. These results demonstrate that extensive nucleotide diversity exists among genes encoding type F neurotoxins from strains with different phylogenetic backgrounds and from various geographical sources.

scholarly journals Cloning, Nucleotide Sequence, and Expression of the Gene Encoding the Bacteriocin Boticin B from Clostridium botulinum Strain 213B

2000 ◽  
Vol 66 (12) ◽  
pp. 5480-5483 ◽  
Author(s):  
Sean S. Dineen ◽  
Marite Bradshaw ◽  
Eric A. Johnson
Keyword(s):  
Amino Acids ◽  
Nucleotide Sequence ◽  
Clostridium Botulinum ◽  
Shuttle Vector ◽  
Open Reading Frame ◽  
Gene Encoding ◽  
Reading Frame ◽  
Heat Stable ◽  
Group I

ABSTRACT Boticin B is a heat-stable bacteriocin produced byClostridium botulinum strain 213B that has inhibitory activity against various strains of C. botulinum and related clostridia. The gene encoding the bacteriocin was localized to a 3.0-kb HindIII fragment of an 18.8-kb plasmid, cloned, and sequenced. DNA sequencing revealed the boticin B structural gene,btcB, to be an open reading frame encoding 50 amino acids. A C. botulinum strain 62A transconjugant containing theHindIII fragment inserted into a clostridial shuttle vector expressed boticin B, although at much lower levels than those observed in C. botulinum 213B. To our knowledge, this is the first demonstration and characterization of a bacteriocin from toxigenic group I C. botulinum.

scholarly journals Evaluation of a Recombinant Hc of Clostridium botulinum Neurotoxin Serotype F as an Effective Subunit Vaccine

2008 ◽  
Vol 15 (12) ◽  
pp. 1819-1823 ◽  
Author(s):  
Yun-Zhou Yu ◽  
Na Li ◽  
Rui-Lin Wang ◽  
Heng-Qi Zhu ◽  
Shuang Wang ◽  
...  
Keyword(s):  
Clostridium Botulinum ◽  
Subunit Vaccine ◽  
Botulinum Neurotoxin ◽  
Protective Efficacy ◽  
Intraperitoneal Administration ◽  
Neutralization Assay ◽  
Gene Encoding ◽  
E Coli ◽  
Protective Antibodies ◽  
New Gene

ABSTRACT A new gene encoding the Hc domain of Clostridium botulinum neurotoxin serotype F (FHc) was designed and completely synthesized with oligonucleotides. A soluble recombinant Hc of C. botulinum neurotoxin serotype F was highly expressed in Escherichia coli with this synthetic FHc gene. Subsequently, the purified FHc was used to vaccinate mice and evaluate their survival against challenge with active botulinum neurotoxin serotype F (BoNT/F). After the administration of FHc protein mixed with Freund adjuvant via the subcutaneous route, a strong protective immune response was elicited in the vaccinated mice. Mice that were given two or three vaccinations with a dosage of 1 or 10 μg of FHc were completely protected against an intraperitoneal administration of 20,000 50% lethal doses (LD50) of BoNT/F. The BoNT/F neutralization assay showed that the sera from these vaccinated mice contained high titers of protective antibodies. Furthermore, mice were vaccinated once, twice, or three times at four different dosages of FHc using Alhydrogel (Sigma) adjuvant via the intramuscular route and subsequently challenged with 20,000 LD50 of neurotoxin serotype F. A dose response was observed in both the antibody titer and the protective efficacy with increasing dosage of FHc and number of vaccinations. Mice that received one injection of 5 μg or two injections of ≥0.04 μg of FHc were completely protected. These findings suggest that the recombinant FHc expressed in E. coli is efficacious in protecting mice against challenge with BoNT/F and that the recombinant FHc subunit vaccine may be useful in humans.

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

Toxins ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 586
Author(s):  
Jason Brunt ◽  
Arnoud H. M. van Vliet ◽  
Andrew T. Carter ◽  
Sandra C. Stringer ◽  
Corinne Amar ◽  
...  
Keyword(s):  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Geographic Origin ◽  
Comparative Genomic ◽  
Snp Analysis ◽  
Clostridium Sporogenes ◽  
Wound Botulism ◽  
Group I ◽  
Genomic Study ◽  
The Impact

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.

The complete genome sequence ofClostridium botulinumF str. 230613, insertion sites, and recombination of BoNT gene clusters

Genome ◽  
2011 ◽  
Vol 54 (7) ◽  
pp. 546-554 ◽  
Author(s):  
Ren-Mao Tian ◽  
Tao Li ◽  
Xiao-Jun Hou ◽  
Qin Wang ◽  
Kun Cai ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Recombination Event ◽  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Gene Clusters ◽  
Pectin Lyase ◽  
Group I ◽  
A Cell ◽  
Insertion Sites ◽  
Lyase Domain

The genomic DNA of Clostridium botulinum F str. 230613 includes a chromosome (3 993 083 bp, 3502 coding sequences (CDs)) and a plasmid (17 531 bp, 25 CDs). The arrangement of the botulinum neurotoxin serotype F (BoNT/F) gene cluster, a 15-kb (or longer) fragment including the bont gene and other relevant genes, and its different insertion sites in C. botulinum A2 and C. botulinum F were formulated. Mobile elements and virulence factors were analysed. We also found a cell adhesion and pectin lyase domain–containing protein, which may function in attaching to the host and as a pectin lyase. The nine BoNT gene clusters of group I C. botulinum strains were located at three sites in the chromosome of C. botulinum F str. 230613. This study showed the inserting inclination of BoNT/A1 tend to have gene clusters inserted at site 3, BoNT/F at site 2, and BoNT/A2 at site 1. Additionally, we found the recombination event between the BoNT gene clusters of sites 2 and 3, a mechanism that contributed to the diversity of the BoNT gene cluster arrangement.

scholarly journals Intratracheal inoculation of AHc vaccine induces protection against aerosolized botulinum neurotoxin A challenge in mice

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Changjiao Gan ◽  
Wenbo Luo ◽  
Yunzhou Yu ◽  
Zhouguang Jiao ◽  
Sha Li ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Clostridium Botulinum ◽  
Freeze Drying ◽  
Botulinum Neurotoxin ◽  
Secretory Iga ◽  
Immune Protection ◽  
Dry Powder ◽  
Botulinum Neurotoxin A ◽  
Spray Freeze Drying

AbstractBotulinum neurotoxin (BoNT), produced by Clostridium botulinum, is generally known to be the most poisonous of all biological toxins. In this study, we evaluate the protection conferred by intratracheal (i.t.) inoculation immunization with recombinant Hc subunit (AHc) vaccines against aerosolized BoNT/A intoxication. Three AHc vaccine formulations, i.e., conventional liquid, dry powder produced by spray freeze drying, and AHc dry powder reconstituted in water are prepared, and mice are immunized via i.t. inoculation or subcutaneous (s.c.) injection. Compared with s.c.-AHc-immunized mice, i.t.-AHc-immunized mice exhibit a slightly stronger protection against a challenge with 30,000× LD50 aerosolized BoNT/A. Of note, only i.t.-AHc induces a significantly higher level of toxin-neutralizing mucosal secretory IgA (SIgA) production in the bronchoalveolar lavage of mice. In conclusion, our study demonstrates that the immune protection conferred by the three formulations of AHc is comparable, while i.t. immunization of AHc is superior to s.c. immunization against aerosolized BoNT/A intoxication.

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