| Accession number;02A0274868 |
| Title;Antibacterial and bactericidal activity of EGCg on Streptococcus pneumoniae. |
| Author;ITO ISAMU(Showadai I Saikingaku) OKUBO SACHIE(Showadai I Saikingaku) FUKUCHI KUNIHIKO(Showadai Rinshobyori) HARA YUKIHIKO(Tokyofudotekuno) SHIMAMURA TADAKATSU(Showadai I Saikingaku) |
Journal Title;Japanese Journal of Chemotherapy
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Journal Code:F0608A
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ISSN:1340-7007
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VOL.50;NO.2;PAGE.118-125(2002)
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| Figure&Table&Reference;FIG.5, TBL.2, REF.31 |
| Pub. Country;Japan |
| Language;Japanese |
| Abstract;The antibacterial activity of (-)epigallocatechin gallate(EGCg), purified from green tea was studied using 9 reference strains and 49 clinical isolated strains of Streptococcus pneumoniae. The MIC90 of EGCg against S. pneumoniae was 250.MU.g/mL. The concentrati of EGCg having antibacterial activity is equal to a daily consumable concentration of tea. The time-killing assay showed that a concentration of 500.MU.g/mL of EGCg showed marked killing activity against 1*104mL of bacteria(initial bacterial count) within 5 hours. However, 250 or 125.MU.g/mL of EGCg killed only moderate numbers of bacteria and remaining bacteria spread again later. To these remaining bacteria, EGCg at concentrations below the MIC was added 6 hours later. In these cases, remaining viable bacteria were killed using only half the MIC of EGCg. We studied the bactericidal effects of EGCg combined with benzylpenicillin(PCG) using 11 strains of penicillin-resistant S. pneumoniae(PRSP). Combing PCG with 1/4 the MIC of EGCg the concentration of PCG(0.06.MU.g/mL) that kills penicillin-sensitive strains now also killed highly penicillin-resistant strains. Analysis of penicillin-resistant genes in PRSP by polymerase chain reaction(PCR) showed 8 penicillin binding protein(PBP) 2B class B strains but no PBP 2B class A strain, indicating that the combined antibacterial effect of penicillin and EGCg on PRSP was obtained regardless of the resistance acquisition mechanism. (author abst.) |
