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- Sterner, Olov, et al.
(författare)
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Mutagens in larger fungi. I. Forty-eight species screened for mutagenic activity in the Salmonella/microsome assay
- 1982
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Ingår i: Mutation Research/Genetic Toxicology. - : Elsevier BV. - 0165-1218. ; 101:4, s. 269-281
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Tidskriftsartikel (refereegranskat)abstract
- Specimens of large fungi (mushrooms) were screened for mutagenic activity by the Salmonella/microsome assay, with strains TA98, TA2637 and TA100. Out of 48 species tested, 37 exhibited a significant but for the most part weak activity. The activity observed in the presence of S9 mix was typically between 0 and 50% of that without, and in no case was the activity increased in the presence of microsomal enzymes. Six metabolites reported to occur in some of the species included in this investigation were also tested. Significant mutagenic activity was found with isovelleral (5) from Lactarius sp., agaritine (3) from Agaricus bisporus and related sp. and β-nitraminoalanine (7) from Agaricus silvaticus. Isovelleral may be a major mutagen in some of the sharp-tasting and mutagenic Russulaceae sp. A. bisporus (cultivated specimen) was weakly mutagenic toward all three strains of S. typhimurium used, and agaritine was weakly active toward TA2637 alone. This implies that this fungus might contain other mutagenic material as well. β-Nitraminoalanine was not found in the particular collection of A. silvaticus tested here. The mutagenicity observed for the fungus in this work may therefore be due to other metabolites. Even though many species found to be mutagenic are used as food, it seems premature to make specific recommendations about eventual health risks. Further information is needed about the chemistry and toxicology of the active compounds as well as about the effects of various methods used in preparing mushrooms for food.
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- Svanborg Eden, C, et al.
(författare)
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Influence of adhesins on the interaction of Escherichia coli with human phagocytes
- 1984
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Ingår i: Infection and Immunity. - 1098-5522. ; 44:3, s. 672-680
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Tidskriftsartikel (refereegranskat)abstract
- The fitness between bacterial adhesins and target cell receptors, determining bacterial adherence to epithelial cells in urinary tract infections, was shown to influence also the interaction with human polymorphonuclear leukocytes (PMNL). Two sets of homogenic strains, constructed to express either, both, or none of the globotetraosylceramide-sensitive (GS) adhesins specific for globoseries glycolipid receptors or the mannose-sensitive (MS) adhesins inhibited by alpha-methyl mannoside were compared regarding charge, hydrophobicity, and binding to PMNL. The mutants of a hydrophilic pyelonephritis strain required MS adhesins for binding to and activation of the PMNL. Removal of the MS adhesins from the mutant carrying both MS and GS adhesins abolished chemiluminescence and binding. A pronounced chemiluminescence reaction was induced by the hydrophobic strain without GS or MS adhesins . Transformants of this strain expressing the MS adhesin bound to and activated the PMNL. Poor binding and activation were found with mutants and transformants carrying only the GS adhesins . The improved reactivity after coating of the PMNL with the appropriate receptor glycolipid supported the previously reported absence of globoseries glycolipids in those cells as the reason for the refractoriness to bacteria with GS adhesins . The mechanism of binding, which improves epithelial cell adhesion, may prevent binding to PMNL, thus improving the survival of Escherichia coli in the kidney.
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