Reversal of Ampicillin Resistance in MRSA via Inhibition of Penicillin-Binding Protein 2a by<i>Acalypha wilkesiana</i>

Santiago, Carolina; Pang, Ee Leen; Lim, Kuan‐Hon; Loh, Hwei‐San; Ting, Kang Nee

doi:10.1155/2014/965348

Cited by 20 publications

(16 citation statements)

References 30 publications

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“…Among them, tellimagrandin and corilagin have been reported to be active in combination with oxacillin and revert PBP2a-mediated rather than blactamase-mediated resistance. (Santiago et al 2014;Shiota et al 2004;Stapleton et al 2007). The presence of compounds of this type may thus explain the Cola gigantea and a part of Vitellaria paradoxa effects, which showed a synergistic effect with both oxacillin and ampicillin in the present study.…”

Section: Resultssupporting

confidence: 55%

Preliminary evidences of the direct and indirect antimicrobial activity of 12 plants used in traditional medicine in Africa

2015

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In a world of increasing resistance to current antibiotics, search of novel therapeutic options is urgently needed. The aim of this work was to screen plant crude extracts for direct or indirect (inhibition of resistance) antimicrobial activity. Four crude extracts from 12 plants traditionally used in Africa for the treatment of infections were obtained by successive extraction with hexane, dichloromethane, ethyl acetate, and methanol. All extracts were tested against Staphylococcus aureus MRSA ATCC33591 [resistant to b-lactams by production of b-lactamases and of a modified PBP target (PBP2a)]. Direct antimicrobial activity was tested by determination of Minimal Inhibitory Concentrations (MIC), and indirect activity, by determining interactions between antibiotics and extracts using checkerboard titration and calculation of Fractional Inhibitory Concentration Index (FICI; synergy: FICI B 0.5; additivity: FICI B 1). Combined antibiotics were ampicillin (sensitive to resistance mediated by b-lactamases and PBP2a) and oxacillin (sensitive to resistance mediated by PBP2a only). The dichloromethane extract of Vitellaria paradoxa leaves, the methanol extracts of Vitellaria paradoxa, Cola gigantea leaves and twigs, and of Tapinanthus bangwensis aerial parts showed direct antimicrobial activity (MIC 250-500 mg/L). The methanol extracts of Vitellaria paradoxa and Cola gigantea leaves and twigs showed additive or synergistic effects with oxacillin and ampicillin on MRSA ATCC33591 (FICI 0.28-1), suggesting a possible inhibition of PBP2a. The methanol extract of Tapinanthus bangwensis aerial parts and Anchomanes difformis roots improved the activity of ampicillin only (FICI 0.38-1), suggesting b-lactamase inhibition. Polyphenols and particularly tannins were shown to be responsible for these last effects, at least partially for Vitellaria paradoxa. These data need further research aiming at identifying the active compounds in these extracts.

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Section: Resultssupporting

confidence: 55%

Preliminary evidences of the direct and indirect antimicrobial activity of 12 plants used in traditional medicine in Africa

2015

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“…A clear protein band (76 kDa) was discovered in the MRSA cultures. The intensity of PBP2a expression in the MRSA cultures that were exposed to 0Á78 lg ml À1 ampicillin was higher than that of the control group MRSA, which is consistent with some other reports (Santiago et al 2014;Santiago et al 2015) that a low concentration of ampicillin can increase PBP2a expression in MRSA; however, the low concentration of vancomycin does not affect PBP2a expression in MRSA. The MRSA culture treated with 50 and 100 lg ml À1 S20b appeared to have attenuated PBP2a expression compared to that of the control group MRSA.…”

Section: Inhibition Of Pbp2a Expression In Mrsa By S20bsupporting

confidence: 91%

Pithecellobium clypeariaextract enriched in gallic acid and luteolin has antibacterial activity against MRSA and reduces resistance to erythromycin, ceftriaxone sodium and levofloxacin

Liu

Huang

Zhou

et al. 2020

J. Appl. Microbiol.

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Aims Antibiotic adjuvants can give a second life to the antibiotics to which bacteria are highly resistant. We evaluated the antimicrobial effects of extracts from Pithecellobium clypearia against methicillin‐resistant Staphylococcus aureus (MRSA) and also the potential for synergy with several antibiotics. Methods and Results For this study, four extracts from P. clypearia were tested on MRSA using the broth microdilution method for activity assessment. The ethyl acetate fraction (S20b) had the strongest antibacterial activity against MRSA among the fractions tested. In all, 14 compounds such as gallic acid and luteolin in S20b were analysed by UFLC‐Q‐TOF‐MS/MS. S20b combined with erythromycin showed synergy effects against MRSA and combined with ceftriaxone sodium and levofloxacin showed additive effects against MRSA. Electron microscopy showed that extract S20b damaged the MRSA cell wall and K+ efflux measurements indicated that extract S20b increased cell membrane permeability. Moreover, S20b suppression of PBP2a expression was assessed by Western blot. Furthermore, an in vivo study was used to investigate the therapeutic potential of S20b based on a mouse pneumonia model. Conclusions The in vitro study results have shown that S20b not only inhibits MRSA growth directly but also reduces the resistance of MRSA to the evaluated antibacterial agents. Based on the in vivo study, it can be concluded that S20b can treat pneumonia in the mouse model. Significance and Impact of the Study This study is the first research to demonstrate that S20b can inhibit MRSA growth and reduce drug resistance of clinical isolates to antibiotics. S20b has the potential to be used as a therapeutic agent against MRSA and treatment for MRSA pneumonia.

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“…The fraction also subjugated the MIC of ampicillin. It was proposed by the authors that corilagin could be the compound responsible for this synergistic action (Santiago et al, 2014). In another synergistic evaluation of tannic acid with antibiotics, the MICs of oxacillin and cefdinir decreased to <0.06 with 100 mg/L of tannic acid.…”

Section: Synergymentioning

confidence: 96%

Scope of Hydrolysable Tannins as Possible Antimicrobial Agent

2016

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Hydrolysable tannins (HTs) are secondary metabolites from plants, which are roughly classified into gallotannins and ellagitannins having gallic acid and ellagic acid residues respectively attached to the hydroxyl group of glucose by ester linkage. The presence of hexahydroxydiphenoyl and nonahydroxyterphenoyl moieties is considered to render antimicrobial property to HTs. HTs also show considerable synergy with antibiotics. Nevertheless, they have low pharmacokinetic property. The present review presents the scope of HTs as future antimicrobial agent. Copyright © 2016 John Wiley & Sons, Ltd.

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Reversal of Ampicillin Resistance in MRSA via Inhibition of Penicillin-Binding Protein 2a byAcalypha wilkesiana

Cited by 20 publications

References 30 publications

Preliminary evidences of the direct and indirect antimicrobial activity of 12 plants used in traditional medicine in Africa

Preliminary evidences of the direct and indirect antimicrobial activity of 12 plants used in traditional medicine in Africa

Pithecellobium clypeariaextract enriched in gallic acid and luteolin has antibacterial activity against MRSA and reduces resistance to erythromycin, ceftriaxone sodium and levofloxacin

Scope of Hydrolysable Tannins as Possible Antimicrobial Agent

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