Wisconsin Alumni Research Foundation

Kristin M Marshall

Eric Arthur Johnson

Marite Bradshaw

Sabine Pellett

A mutant strain of the bacteriumhaving an inactivated botulinal neurotoxin gene is disclosed. The mutant strain contains an artificially created and inserted modified intron vector between nucleotides 580 and 581 of the sense strand of the gene. The mutant strain can be used in microbiological challenge testing of foods and food processing methods.

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The present invention provides novelconjugatively transmissible plasmids and methods of use thereof. Specifically, described herein are novel, conjugatively transmissible clostridial plasmids which are capable of being transferred among and between clostridial species. The novel plasmids of the present invention therefore permits the delivery of heterologous clostridial genes into a clostridial host, such as, and the expression of genes of interest in that host, including clostridial toxins and the nontoxigenic components of the toxin complex, toxin fragments, or antigenic portions thereof, in a way both that ensures abundant expression and facilitates purification. Furthermore, toxins with altered structures, chimeric, hybrid toxins, and other toxin derivatives valuable in medicine could be synthesized in this system.

Conjugative plasmids and methods of use thereof

The present invention provides a novel isolated plasmid, wherein the plasmid is a native plasmid found in uniquetype A strains and encode either BoNT/A3 or BoNT/A4 and BoNT/B. The present invention also provides a method of obtaining a plasmid-encoded botulinum neurotoxin and botulinum neurotoxin complex comprising the step of isolating a plasmid encoding the cntA/A or cntA/B neurotoxin gene and genes encoding protein components of the toxin complex from atype A strain. The inventors performed comparative analyses of representative BoNT/A subtype strains by pulsed-field gel electrophoresis (PFGE) and Southern hybridizations with probes specific for the BoNT/A and B genes, cntA/A and cntA/B. Unexpectedly, the inventors determined that the genes encoding BoNT/A3 in the A3 strain, and BoNT/A4 and BoNT/B in the A4 strain, are on plasmids.

The present invention provides a novel isolated plasmid, wherein the plasmid is a native plasmid found in uniquetype A strains and encode either BoNT/A3 or BoNT/A4 and BoNT/B. The present invention also provides a method of obtaining a plasmid-encodedneurotoxin andneurotoxin complex comprising the step of isolating a plasmid encoding the cntA/A or cntA/B neurotoxin gene and genes encoding protein components of the toxin complex from atype A strain. The inventors performed comparative analyzes of representative BoNT/A subtype strains by pulsed-field gel electrophoresis (PFGE) and Southern hybridizations with probes specific for the BoNT/A and B genes, cntA/A and cntA/B. Unexpectedly, the inventors determined that the genes encoding BoNT/A3 in the A3 strain, and BoNT/A4 and BoNT/B in the A4 strain, are on plasmids.

Growing community of inventors

South Beloit, IL, United States of America

Kristin M Marshall