Infection and Drug Resistance (Sep 2019)
Evaluation of essential oil obtained from Mentha×piperita L. against multidrug-resistant strains
Abstract
Delia Muntean,1 Monica Licker,1 Ersilia Alexa,2 Iuliana Popescu,2 Calin Jianu,3 Valentina Buda,4 Cristina Adriana Dehelean,5 Roxana Ghiulai,6 Florin Horhat,1 Delia Horhat,7 Corina Danciu8 1Department of Microbiology, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, Romania; 2Department of Food Control, Faculty of Food Processing Technology, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, Timisoara 300645, Romania; 3Department of Food Tehnologies, Faculty of Food Engineering, Banat’s University of Agricultural Sciences and Veterinary Medicine “King Michael I of Romania”, Timişoara 300645, Romania; 4Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, Romania; 5Department of Toxicology, Faculty of Pharmacy, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, Romania; 6Department of Pharmaceutical Chemistry, Faculty of Pharmacy, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, Romania; 7Department of ENT, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, Romania; 8Department of Pharmacognosy, “Victor Babes” University of Medicine and Pharmacy, Timisoara 300041, RomaniaCorrespondence: Valentina Buda; Delia Horhat“Victor Babes” University of Medicine and Pharmacy, 2nd EftimieMurgu Square, Timisoara 300041, RomaniaTel +40 25 649 4804Fax +40 25 649 4804Email [email protected]; [email protected]: Bacterial multidrug resistance currently poses an increasingly serious threat, with important clinical consequences regarding treatment options. In 2017, the WHO released a global list of resistant bacteria, identifying multidrug-resistant (MDR) Gram-negative bacteria such as carbapenem-resistant Enterobacteriaceae, Pseudomonas aeruginosa or Acinetobacter baumannii, extended-spectrum cephalosporin-resistant Enterobacteriaceae as critical priorities for developing new strategies of treatment.Purpose: The novelty presented in this study refers to the evaluation of the volatile oil obtained from the leaves of Mentha×piperita L., on MDR strains from hospitalized patients.Material and methods: The essential oil was extracted by steam distillation and tested on six reference bacterial strains and also on the MDR strains collected from patients of the “Pius Brînzeu” Emergency Clinical County Hospital Timișoara. The in vitro antibacterial activity was evaluated by agar disk diffusion method and microdilution method.Results: Testing the antibacterial activity of peppermint oil on both reference strains and isolated MDR strains from hospitalized patients demonstrated its bactericidal effect. Minimum inhibitory concentration (MIC) was lower (20 mg/mL) for Staphylococcus aureus, Escherichia coli and Proteus mirabilis and higher (40 mg/mL) for Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii strains. Minimum bactericidal concentration (MBC) was equal to MIC, with the exception of Pseudomonas aeruginosa strains, where MBC was the double of MIC.Conclusion: The present study highlights the bactericidal activity of Mentha×piperita L. essential oil on all tested MDR or extensively drug-resistant Gram-positive and Gram-negative strains of Staphylococcus aureus, Escherichia coli, Klebsiellapneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Acinetobacter baumannii. This oil may be a therapeutic option in the near future for many infectious diseases produced by MDR bacteria.Keywords: bacterial multidrug resistance, peppermint, essential oil, bactericidal effect
