Synergistic Activity of the Antibiotic Meropenem in Combination with Edible Mushroom Extracts against Multidrug Resistant Bacteria

Aims: The objective of this study was to evaluate the antibacterial potency of meropenem in synergism with five edible mushroom extracts against multidrug resistant clinical isolates. Methodology: Minimum Inhibitory Concentration (MIC) values of meropenem in combination with each of the extract of mushrooms Pleurotus ostreatus, Pleurotus florida, Pleurotus eous, Pleurotus sajorcaju, Calocybe indica was determined separately against multidrug resistant bacterial strains. Among the applied microbial strains four were extended spectrum beta lactamase (ESBL) producing Escherichia coli, one each of ESBL producing Klebsiella pneumoniae and Acinetobacter baumannii. The synergistic antibacterial activity was assessed and compared based on Fractional Inhibitory Concentration (FIC) index. Results: The extracts of the P. eous and P. ostreatus showed excellent synergistic activity, against all the strains of ESBL producing E. coli as well as ESBL producing Klebsiella pneumoniae, whereas the extract of mushroom P. florida and C. indica showed synergistic effect against some of the ESBL producing microorganisms. This study indicated edible mushrooms extracts can potentiate the action of standard antibiotic meropenem against multidrug resistant bacteria. Conclusion: Synergistic effect of conventional antibiotic meropenem with edible mushroom extracts against multidrug resistant microorganisms will help in fighting against multidrug resistant bugs in future.