Lavender essential oil induces oxidative stress which modifies teh bacterial membrane permeability of carbapenase producing Klebsiella pnuemoniae

• Main Authors: Yang, Shun Kai, Yusoff, Khatijah, Thomas, Warren, Akseer, Riaz, Sultan Alhosani, Maryam, Abushelaibi, Aisha, Lim, Swee Hua Erin, Lai, Kok Song
• Format: Article
• Language: English
• Published: Nature Publishing Group 2020
• Online Access: http://psasir.upm.edu.my/id/eprint/89556/1/ABSTRACT.pdf; http://psasir.upm.edu.my/id/eprint/89556/; https://www.nature.com/articles/s41598-019-55601-0

Misuse of antibiotics in the clinical and agricultural sectors has caused the emergence of multidrugresistant (MDR) Klebsiella pneumoniae which contributes a threat to human health. In this study, we assessed the feasibility of lavender essential oil (LVO) as an antimicrobial agent in combinatory therapy with meropenem in suppressing the growth of carbapenemase-producing K. pneumoniae (KPC-KP). Synergistic interactions between LVO and meropenem were detected, which signifcantly reduce the inhibitory concentration of both LVO and meropenem by 15 and 4-fold respectively. Comparative proteomic profling identifed a disruption in the bacterial membrane via oxidative stress that was indicated by loss of membrane and cytoplasmic proteins and the upregulation of oxidative regulators. As a proof of concept, zeta potential measurements showed a change in cell surface charge while outer membrane permeability measurement indicated an increase in membrane permeability following exposure to LVO. This was indicative of a disrupted outer membrane. Ethidium bromide infux/efux assays demonstrated no signifcant efux pump inhibition by LVO, and scanning electron microscopy revealed irregularities on the cell surface after exposure to LVO. Oxidative stress was also detected with increased level of ROS and lipid peroxidation in LVO-treated cells. In conclusion, our data suggest that LVO induced oxidative stress in K. pneumoniae which oxidizes the outer membrane, enabling the infux of generated ROS, LVO and meropenem into the bacterial cells, causing damage to the cells and eventually death.