Antibacterial activity of Syzygium aromaticum (clove) against uropathogens producing ESBL, MBL, and AmpC beta-lactamase: Are we close to getting a new antibacterial agent?

INTRODUCTION: The present study was done to access the antibacterial activity of clove (Syzygium aromaticum) against extended-spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL), and AmpC beta-lactamase-producing gram-negative bacteria causing urinary tract infection. METHODS: A total of 221 gram-negative uropathogens were isolated and screened for beta-lactamase (ESBL, MBL, and AmpC) production and further tested against ethanolic extract of clove (S. aromaticum) for its antibacterial activity. RESULTS: Clove was effective against all gram-negative isolates but the best antibacterial activity was shown against Proteus species with 19 mm zone of inhibition, 0.39 mg/ml minimum inhibitory concentration (MIC) and 0.19 mg/ml minimum bactericidal concentration (MBC). CONCLUSIONS: Clove extract showed different antibacterial potential against all gram-negative uropathogens. Clove activity for particular strain was found to be similar between isolates producing beta-lactamase and non beta-lactamase.