Antibacterial Mode of Action of Cinnamomum verum Bark Essential Oil, Alone and in Combination with Piperacillin, Against a Multi-Drug-Resistant Escherichia coli Strain.
This study aimed to investigate the mechanism of action of the cinnamon bark essential oil (CB), when used singly and also in combination with piperacillin, for its antimicrobial and synergistic activity against beta-lactamase TEM-1 plasmid-conferred Escherichia coli J53 R1. Viable count of this combination showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis on the stability of treated cultures for cell membrane permeability by CB when tested against sodium dodecyl sulfate revealed that the bacterial cell membrane was disrupted by the essential oils. Scanning electron microscopy observation and bacterial surface charge measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed reduction, indicating the possibility of the presence of quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%), and eugenol (6.57%) were the major components in the essential oil. From this study, CB has the potential to reverse E. coli J53 R1 resistance to piperacillin through two pathways; modification in the permeability of the outer membrane or bacterial QS inhibition.
School of Postgraduate Studies and Research, International Medical University, 57000 Kuala Lumpur, Malaysia.
Polly Soo Xi
PS
Yap
Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Thiba
T
Krishnan
Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Kok-Gan
KG
Chan
Department of Physiology, Perdana University-Royal College of Surgeons Ireland (PU-RCSI), 43400 Serdang, Selangor, Malaysia.
Swee Hua Erin
SH
Lim
D000900:Anti-Bacterial Agents / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002935:Cinnamomum zeylanicum / Q000737:chemistry*; D015169:Colony Count, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D004357:Drug Synergism; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D008401:Gas Chromatography-Mass Spectrometry; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D010878:Piperacillin / Q000494:pharmacology*; D024301:Plant Bark / Q000737:chemistry; D010957:Plasmids; D053038:Quorum Sensing / Q000187:drug effects; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism
D000900:Anti-Bacterial Agents; D009822:Oils, Volatile; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1; D010878:Piperacillin
Cinnamomum verum; antibacterial activity; chemical composition; essential oil; membrane permeability; quorum sensing