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 Maize and Grass Silage Feeding to Dairy Cows Combined with Different Concentrate Feed Proportions with a Special Focus on Mycotoxins, Shiga Toxin (stx)-Forming Escherichia coli and Clostridium botulinum Neurotoxin (BoNT) Genes: Implications for Animal Health and Food Safety

Dairy ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 91-125
Author(s):  
Sven Dänicke ◽  
Julia Krenz ◽  
Christian Seyboldt ◽  
Heinrich Neubauer ◽  
Jana Frahm ◽  
...  
Keyword(s):  
Food Safety ◽  
Dairy Cows ◽  
Shiga Toxin ◽  
Clostridium Botulinum ◽  
Dry Matter ◽  
Botulinum Neurotoxin ◽  
Fusarium Toxins ◽  
E Coli ◽  
Ph Values ◽  
Grass Silage

A feeding experiment was carried out with late-lactating cows over 12 weeks to evaluate the feeding value of a basic diet with maize and grass silage (MS, GS) when combined with varying portions of concentrate in the ration (20% and 60% on a dry matter basis) and to test the effects on health and performance, the transfer of important Fusarium toxins to blood and milk, the total and Shiga toxin (stx)-forming E. coli counts, and the presence of Clostridium botulinum neurotoxin (BoNT) genes in rectal fecal samples. MS was contaminated by a broader spectrum of fungal and other metabolites compared to GS. MS contained higher concentrations of the important Fusarium toxins deoxynivalenol (DON) and zearalenone (ZEN). Blood and milk levels of DON and ZEN residues generally reflected the differences in exposure at a low level. Feeding of MS with 60% concentrate feed induced subacute ruminal acidosis (SARA) associated with a marked drop in dry matter intake, fat corrected milk yield and a fat to protein ratio in milk of lower than 1. The SARA-associated higher ruminal LPS concentration did not affect the circulating concentrations of haptoglobin as an indicator of systemic inflammation. Lower rumen pH values in both MS-fed groups were associated with lower pH values, higher absolute E. coli counts and increased proportions of stx-positive E. coli in rectal feces. BoNT genes A, B, C, D, E and F remained undetectable in any of the fecal samples suggesting that feedstuffs were virtually free of the corresponding C. botulinum strains. In conclusion, maize feedstuff (silage, grains, starch-containing byproducts)-dominated rations for dairy cows should be avoided to reduce adverse effects on health and food safety.

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 Rapid Affinity Immunochromatography Column-Based Tests for Sensitive Detection of Clostridium botulinum Neurotoxins and Escherichia coli O157

2010 ◽  
Vol 76 (13) ◽  
pp. 4143-4150 ◽  
Author(s):  
Jason Brunt ◽  
Martin D. Webb ◽  
Michael W. Peck
Keyword(s):  
Escherichia Coli ◽  
Detection Limit ◽  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Grape Juice ◽  
Sensitive Detection ◽  
Animal Testing ◽  
E Coli ◽  
Specialized Equipment ◽  
Peach Juice

ABSTRACT Existing methods for detection of food-borne pathogens and their toxins are frequently time-consuming, require specialized equipment, and involve lengthy culture procedures and/or animal testing and are thus unsuitable for a rapid response to an emergency public health situation. A series of simple and rapid affinity immunochromatography column (AICC) assays were developed to detect Clostridium botulinum neurotoxin types A, B, E, and F and Escherichia coli O157 in food matrices. Specifically, for milk, grape juice with peach juice, and bottled water, the detection limit for the botulinum neurotoxin type A complex was 0.5 ng. Use of this method with a 10-ml sample would therefore result in a detection limit of 50 pg ml−l. Thus, this assay is approximately 2 orders of magnitude more sensitive than a comparable lateral-flow assay. For botulinum neurotoxin complex types B, E, and F, the minimum detection limit was 5 ng to 50 ng. Sensitive detection of E. coli O157 was achieved, and the detection limit was 500 cells. The AICC test was also shown to be specific, rapid, and user friendly. This test takes only 15 to 30 min to complete without any specialized equipment and thus is suitable for use in the field. It has the potential to replace existing methods for presumptive detection of botulinum neurotoxin types A, B, E, and F and E. coli O157 in contaminated matrices without a requirement for preenrichment.

scholarly journals E. coli Enterotoxin LtB Enhances Vaccine-Induced Anti-H. pylori Protection by Promoting Leukocyte Migration into Gastric Mucus via Inflammatory Lesions

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 982
Author(s):  
Xiaoyan Peng ◽  
Rongguang Zhang ◽  
Chen Wang ◽  
Feiyan Yu ◽  
Mingyang Yu ◽  
...  
Keyword(s):  
Cellular Immunity ◽  
Protective Efficacy ◽  
Gastric Injury ◽  
Oral Vaccines ◽  
Gastric Mucus ◽  
E Coli ◽  
Non Invasive ◽  
Considerable Impact ◽  
H Pylori

Current studies indicate that the anti-H. pylori protective efficacy of oral vaccines to a large extent depends on using mucosal adjuvants like E. coli heat-lable enterotoxin B unit (LtB). However, the mechanism by which Th17/Th1-driven cellular immunity kills H. pylori and the role of LtB remains unclear. Here, two L. lactis strains, expressing H. pylori NapA and LtB, respectively, were orally administrated to mice. As observed, the administration of LtB significantly enhanced the fecal SIgA level and decreased gastric H. pylori colonization, but also markedly aggravated gastric inflammatory injury. Both NapA group and NapA+LtB group had elevated splenocyte production of IL-8, IL-10, IL-12, IL-17, IL-23 and INF-γ. Notably, gastric leukocytes’ migration or leakage into the mucus was observed more frequently in NapA+LtB group than in NapA group. This report is the first that discusses how LtB enhances vaccine-induced anti-H. pylori efficacy by aggravating gastric injury and leukocytes’ movement into the mucus layer. Significantly, it brings up a novel explanation for the mechanism underlying mucosal cellular immunity destroying the non-invasive pathogens. More importantly, the findings suggest the necessity to further evaluate LtB’s potential hazards to humans before extending its applications. Thus, this report can provide considerable impact on the fields of mucosal immunology and vaccinology.

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.

scholarly journals Analysis of Neurotoxin Cluster Genes in Clostridium botulinum Strains Producing Botulinum Neurotoxin Serotype A Subtypes

2008 ◽  
Vol 74 (9) ◽  
pp. 2778-2786 ◽  
Author(s):  
Mark J. Jacobson ◽  
Guangyun Lin ◽  
Brian Raphael ◽  
Joanne Andreadis ◽  
Eric A. Johnson
Keyword(s):  
Amino Acid ◽  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Amino Acid Sequences ◽  
Gene Sequences ◽  
Amino Acid Levels ◽  
Cluster Type ◽  
Botulinum Neurotoxin Serotype A ◽  
Cluster Gene ◽  
Degree Of Similarity

ABSTRACT Neurotoxin cluster gene sequences and arrangements were elucidated for strains of Clostridium botulinum encoding botulinum neurotoxin (BoNT) subtypes A3, A4, and a unique A1-producing strain (HA− Orfx+ A1). These sequences were compared to the known neurotoxin cluster sequences of C. botulinum strains that produce BoNT/A1 and BoNT/A2 and possess either a hemagglutinin (HA) or an Orfx cluster, respectively. The A3 and HA− Orfx+ A1 strains demonstrated a neurotoxin cluster arrangement similar to that found in A2. The A4 strain analyzed possessed two sets of neurotoxin clusters that were similar to what has been found in the A(B) strains: an HA cluster associated with the BoNT/B gene and an Orfx cluster associated with the BoNT/A4 gene. The nucleotide and amino acid sequences of the neurotoxin cluster-specific genes were determined for each neurotoxin cluster and compared among strains. Additionally, the ntnh gene of each strain was compared on both the nucleotide and amino acid levels. The degree of similarity of the sequences of the ntnh genes and corresponding amino acid sequences correlated with the neurotoxin cluster type to which the ntnh gene was assigned.

Domain Organization in Clostridium botulinum Neurotoxin Type E Is Unique: Its Implication in Faster Translocation

2009 ◽  
Vol 386 (1) ◽  
pp. 233-245 ◽  
Author(s):  
Desigan Kumaran ◽  
Subramaniam Eswaramoorthy ◽  
William Furey ◽  
Jorge Navaza ◽  
Martin Sax ◽  
...  
Keyword(s):  
Clostridium Botulinum ◽  
Botulinum Neurotoxin ◽  
Domain Organization
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