AW: Green tea irrigation

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Thanks for this important info Asfy, not sure if I still want to try the green tea...--- asfy <asfyso@...> schrieb am Sa, 6.2.2010:Von: asfy <asfyso@...>Betreff: Green tea irrigationAn: samters Datum: Samstag, 6. Februar 2010, 18:21

Nils,If you want to irrigate with green tea, it might help against the polyps, but on the other hand I found this abstract you might want to be aware of. The green tea polyphenol EGCG increases staph resistance against some antibiotics.-----------Int J

Food Microbiol. 2010 Jan 20. [Epub ahead of print]Staphylococcal strains adapted to epigallocathechin gallate (EGCG) show reduced susceptibility to vancomycin, oxacillin and ampicillin, increased heat tolerance, and altered cell morphology.Bikels-Goshen

T, Landau

E, Saguy

S, Shapira

R.Institute of Biochemistry, Food Science and Nutrition, The H. Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot, 76100, Israel.Epigallocathechin gallate (EGCG) possesses many

beneficial properties, such as anticarcinogenicity , antiatherogenicity,

as well as antioxidant and antibacterial activities. However, the bacterial response to sublethal concentrations of EGCG has not been studied. Here we investigated whether short exposure of staphylococci strains to sublethal doses of EGCG can lead to adaptation and cross-resistance. Two-hour exposure of five strains to 20microg/ml of EGCG did not affect the growth rate but significantly elevated the resistance towards antibiotics targeting the bacterial cell wall. The magnitude of cross-resistance towards such antibiotics varied with the staphylococci strain, with Staphylococcus aureus Newman exhibiting the highest magnitude of cross-resistance, showing a 2, 4 and 8-fold increase in resistance towards vancomycin, oxacillin and ampicillin respectively. All EGCG-adapted strains were also more heat tolerant than

their control counterparts as derived from the Weibull model. Adaptation to EGCG led to a moderate increase in heat resistance of the adapted strains S. epidermis ATCC 12228, S. aureus Newman, and S. aureus

ATCC 29213, and an extremely pronounced increase for S. aureus ATCC 6538 and S. aureus RN4220. The shape of the survival curve also varied with the staphylococci strain. Transmission electron microscopy (TEM) analysis revealed suppressed separation of daughter cells in cultures exposed to EGCG, as evidenced by the pseudomulticellular appearance and by more than 2-fold increase in cell wall thickness. These observations raise concerns over the potential of EGCG utilization in therapy in that

it may contribute to the development and enhancement of microbial resistance mechanisms. Copyright © 2010 Elsevier B.V. All rights reserved.PMID: 20132996 [PubMed - as supplied by publisher]

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