%0 Journal Article %A Stapleton, Paul D %A Shah, Saroj %A Ehlert, Kerstin %A Hara, Yukihiko %A Taylor, Peter W %T The β-lactam-resistance modifier (−)-epicatechin gallate alters the architecture of the cell wall of Staphylococcus aureus %D 2007 %J Microbiology, %V 153 %N 7 %P 2093-2103 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.2007/007807-0 %K PBP, penicillin-binding protein %K LTA, lipoteichoic acid %K EGCg, (−)-epigallocatechin gallate %K VISA, vancomycin-intermediate-resistant S. aureus %K MSSA, meticillin-susceptible S. aureus %K EC, (−)-epicatechin %K WTA, wall teichoic acid %K ECg, (−)-epicatechin gallate %K MRSA, meticillin-resistant Staphylococcus aureus %I Microbiology Society, %X (−)-Epicatechin gallate (ECg), a component of green tea, sensitizes meticillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics, promotes staphylococcal cell aggregation and increases cell-wall thickness. The potentiation of β-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 β-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 β-lactam-resistant phenotype. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.2007/007807-0