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Screening of herbal extracts against multi‐drug resistant Acinetobacter baumannii
Author(s) -
Miyasaki Yoko,
Nichols W. Stephen,
Morgan Margie A.,
Kwan Jamie A.,
Van Benschoten M. M.,
Kittell Patricia Emmett,
Hardy W. David
Publication year - 2010
Publication title -
phytotherapy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 129
eISSN - 1099-1573
pISSN - 0951-418X
DOI - 10.1002/ptr.3113
Subject(s) - antimicrobial , acinetobacter baumannii , broth microdilution , antibacterial activity , traditional medicine , minimum inhibitory concentration , agar , antibiotics , microbiology and biotechnology , agar diffusion test , medicine , bacteria , antibiotic resistance , biology , pseudomonas aeruginosa , genetics
Antibiotic resistance is increasing resulting in a decreasing number of fully active antimicrobial agents available to treat infections with multi‐drug resistant (MDR) bacteria. Herbal medicines may offer alternative treatment options. A direct inoculation method simulating the standard disc diffusion assay was developed to determine in vitro antimicrobial activity of sixty herbal extracts against MDR‐ Acinetobacter baumannii ( A. baumannii ). Eighteen herbal extracts inhibited MDR‐ A. baumannii on agar plates, although the magnitude and quality of bacterial inhibition differed considerably among the antibacterial herbal extracts. Next, minimal inhibitory concentration (MIC) of these antibacterial herbal extracts was calculated using a broth microdilution assay. For most herbal extracts, the larger the zone of inhibition on agar plates, the lower the MIC. In general, hetero‐resistance on agar plates correlated with higher MIC. The skip well phenomenon was seen with two herbal extracts. In conclusion, 30% of the screened herbal extracts demonstrated in vitro antibacterial activity against MDR‐ A. baumannii using similar rigorous testing methods as those commonly employed for assessing antimicrobial activity of synthetic antibacterial agents. Characterization of a specific compound conferring this antibacterial activity of the herbal extracts may help to identify novel antimicrobial agents active against highly resistant bacteria. Copyright © 2010 John Wiley & Sons, Ltd.