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Tytuł:
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Temperature-Dependent Growth Characteristics of Bacillus thuringiensis in a Ratatouille Food Model.
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Autorzy:
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Heini N; Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 272, 8057 Zurich, Switzerland.
Stephan R; Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 272, 8057 Zurich, Switzerland.
Filter M; German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277 Berlin, Germany; and.
Plaza-Rodriguez C; German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277 Berlin, Germany; and.
Frentzel H; German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277 Berlin, Germany; and.
Ehling-Schulz M; Functional Microbiology, Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
Johler S; Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 272, 8057 Zurich, Switzerland.
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Źródło:
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Journal of food protection [J Food Prot] 2020 May 01; Vol. 83 (5), pp. 816-820.
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Typ publikacji:
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Journal Article
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Język:
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English
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Imprint Name(s):
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Publication: 2023- : [New York, NY] : Elsevier
Original Publication: Ames, Iowa, International Association of Milk, Food, and Environmental Sanitarians.
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MeSH Terms:
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Bacillus thuringiensis*/growth & development
Temperature*
Enterotoxins/*analysis
Vegetables/*microbiology
Bacillus cereus ; Food Microbiology
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Contributed Indexing:
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Keywords: Bacillus thuringiensis; Food matrix; Food safety; Insecticide; Multiplication
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Substance Nomenclature:
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0 (Enterotoxins)
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Entry Date(s):
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Date Created: 20200423 Date Completed: 20201105 Latest Revision: 20230227
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Update Code:
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20240105
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DOI:
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10.4315/0362-028X.JFP-19-358
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PMID:
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32318723
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Abstract: In contrast to Bacillus cereus, the role of Bacillus thuringiensis in foodborne illness has been controversially discussed. As B. thuringiensis-based biopesticides containing a mixture of crystal toxins and viable spores are widely used, a current European Food Safety Authority opinion underlines the need for additional data to enable risk assessment. However, it is currently poorly understood if B. thuringiensis is able to multiply in food, which is crucial to sound risk assessment. Therefore, the aim of this study was to investigate growth of selected B. thuringiensis strains from food and insecticides in a ratatouille food model. To this end, the growth parameters of three B. thuringiensis strains were determined: insecticide strain ABTS-351 (CH_119, B. thuringiensis serovar kurstaki), insecticide strain ABTS-1857 (CH_121, B. thuringiensis serovar aizawai), and CH_48 (wild-type B. thuringiensis isolated from rosemary), producing extremely high levels of enterotoxins. After an initial drop in colony counts, we observed a statistically significant growth for the tested B. thuringiensis strains between 6 and 24 h at 22, 30, and 37°C, conditions mimicking prolonged holding times. We were also able to show that the enterotoxin overproducer CH_48 can grow up to 108 CFU/g in the ratatouille matrix within 24 h at 37°C. The two midlevel enterotoxin formers ABTS-351 (CH_119) and ABTS-1857 (CH_121) isolated from biopesticides exhibited growth between 6 and 24 h, with one of the strains growing to 107 CFU/g. To our knowledge, this is the first study providing evidence of B. thuringiensis growth in a food model with intact competitive flora. Our findings suggest strain-specific variation and stress the complexity of assessing the risk related to B. thuringiensis in food, indicating that some strains can represent a risk to consumer health when vegetable-based foods are stored under conditions of prolonged temperature abuse.
(Copyright ©, International Association for Food Protection.)
