The β-lactam-resistance modifier (−)-epicatechin gallate alters the architecture of the cell wall of Staphylococcus aureus
| Autor: | Peter W. Taylor, Kerstin Ehlert, Yukihiko Hara, Paul D. Stapleton, Saroj Shah |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Staphylococcus aureus
Teichoic acid Penicillin binding proteins Lysostaphin Peptidoglycan Biology Microbiology Molecular biology Catechin beta-Lactam Resistance Article Cell aggregation Cell wall chemistry.chemical_compound Epicatechin gallate Biochemistry chemistry Cell Wall Penicillin-Binding Proteins Lipoteichoic acid |
| Zdroj: | Microbiology. 153:2093-2103 |
| ISSN: | 1465-2080 1350-0872 |
| DOI: | 10.1099/mic.0.2007/007807-0 |
| Popis: | (-)-Epicatechin gallate (ECg), a component of green tea, sensitizes meticillin-resistant Staphylococcus aureus (MRSA) to beta-lactam antibiotics, promotes staphylococcal cell aggregation and increases cell-wall thickness. The potentiation of beta-lactam activity against MRSA by ECg was not due to decreased bacterial penicillin-binding protein (PBP) 2a expression or ECg binding to peptidoglycan. A 5-10 % reduction in peptidoglycan cross-linking was observed. Reduced cross-linking was insufficient to compromise the integrity of the cell wall and no evidence of PBP2a activity was detected in the muropeptide composition of ECg-grown cells. ECg increased the quantity of autolysins associated with the cell wall, even though the cells were less susceptible to Triton X-100-induced autolysis than cells grown in the absence of ECg. ECg promoted increased lysostaphin resistance that was not due to alteration of the pentaglycine cross-bridge configuration or inhibition of lysostaphin activity. Rather, decreased lysostaphin susceptibility was associated with structural changes to wall teichoic acid (WTA), an acid-labile component of peptidoglycan. ECg also promoted lipoteichoic acid (LTA) release from the cytoplasmic membrane. It is proposed that ECg reduces beta-lactam resistance in MRSA either by binding to PBPs at sites distinct from the penicillin-binding site or by intercalation into the cytoplasmic membrane, displacing LTA from the phospholipid palisade. Thus, ECg-mediated alterations to the physical nature of the bilayer will elicit structural changes to WTA that result in modulation of the cell-surface properties necessary to maintain the beta-lactam-resistant phenotype. |
| Databáze: | OpenAIRE |
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