Pal A, Tripathi A. 4-Chloromercuribenzoic acid enhances carbapenem sensitivity among pathogenic Gram negative bacteria by altering bla
VIM, adeB and ompC expression.
J Infect Public Health 2019;
13:806-814. [PMID:
31836318 DOI:
10.1016/j.jiph.2019.11.008]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/11/2019] [Accepted: 11/10/2019] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND
Rapid global dissemination of carbapenem resistant Gram negative bacteria (CRGNB) is supposed to be clinically most alarming. Since, p-chloromercuribenzoic acid (pCMB) is a well known metallo-beta-lactamase inhibitor; evaluation of its bactericidal and carbapenem resistance reversing potential would be important.
METHODS
In this study, bactericidal and meropenem resistance reversing potential of pCMB was investigated against CRGNB by MIC determination, checkerboard assay, time-kill assay and cellular viability assay. Effect of pCMB on cellular morphology was visualized by Scanning Electron Microscopy. Further, quantitative Real Time-PCR was performed to evaluate effects of pCMB on clinically relevant metallo-beta-lactamases, major efflux pumps and outer membrane proteins expression.
RESULTS
pCMB exhibited at least four fold reduced MIC value (2-256μg/ml) than that of meropenem against CRGNB. Moreover, pCMB exhibited synergism with meropenem against 86.06% of CRGNB. MIC of pCMB (16-32μg/ml) could kill upto 99.96% bacteria within 6-8h of dosing. pCMB exerted bactericidal activity by severely disrupting cell wall integrity. Reversal of carbapenemase property of CRGNB by pCMB might have developed through alteration of blaVIM, acrB, mexB and ompk36 expression.
CONCLUSIONS
Hence, the current study identified pCMB as a potential bactericidal agent which enhanced meropenem sensitivity by altering blaVIM, acrB, mexB and ompk36 expression.
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