No genotoxicity is detectable for Escherichia coli strain Nissle 1917 by standard in vitro and in vivo tests
| Autor: | Trudy M. Wassenaar, Birgit Klinkert, Michael Schimiczek, Rudolf von Bünau, Silke Dubbert |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0301 basic medicine
E. coli Nissle Biology medicine.disease_cause Ames test law.invention Microbiology 03 medical and health sciences Probiotic 0302 clinical medicine comet assay law In vivo medicine Escherichia coli Colony-forming unit genotoxicity In vitro Original Research Paper Comet assay 030104 developmental biology 030220 oncology & carcinogenesis colibactin probiotic Genotoxicity |
| Zdroj: | European Journal of Microbiology & Immunology |
| ISSN: | 2062-8633 |
| DOI: | 10.1556/1886.2019.00025 |
| Popis: | Probiotic Escherichia coli strain Nissle 1917 (EcN) has a long history of safe use. However, the recently discovered presence of a pks locus in its genome presumably producing colibactin has questioned its safety, as colibactin has been implicated in genotoxicity. Here, we assess the genotoxic potential of EcN. Metabolic products were tested in vitro by the Ames test, a mutagenicity assay developed to detect point mutation-inducing activity. Live EcN were tested by an adapted Ames test. Neither the standard nor the adapted Ames test resulted in increased numbers of revertant colonies, indicating that EcN metabolites or viable cells lacked mutagenic activity. The in vivo Mammalian Alkaline Comet Assay (the gold standard for detecting DNA-strand breaks) was used to determine potentially induced DNA-strand breaks in cells of the gastro-intestinal tract of rats orally administered with viable EcN. Bacteria were given at 109–1011 colony forming units (CFU) per animal by oral gavage on 2 consecutive days and daily for a period of 28 days to 5 rats per group. No significant differences compared to negative controls were found. These results demonstrate that EcN does not induce DNA-strand breaks and does not have any detectable genotoxic potential in the test animals. |
| Databáze: | OpenAIRE |
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