Centre of Biological Engineering (CEB), Laboratory of Research in Biofilms Rosário Oliveira (LIBRO), University of Minho, Braga, Portugal.
LABBELS - Associate Laboratory, Braga, Portugal.
Lett Appl Microbiol. 2022 May;74(5):787-795. doi: 10.1111/lam.13665. Epub 2022 Mar 8.
Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant opportunistic pathogen with a great ability to form biofilms. Herein, the antimicrobial potential of Thymbra capitata essential oil (EO) against MRSA biofilms was investigated. The determination of the minimum inhibitory concentration (MIC) and the minimum lethal concentration (MLC) of the T. capitata EO was first investigated on a group of clinical isolates from septicaemias, diabetic foot ulcers and osteomyelitis. Biofilms were incubated with the EO at the MLC and its anti-biofilm potential was investigated. A strong antimicrobial activity was observed, with MIC and MLC values between 0·32 and 0·64 mg l . However, the concentration of EO necessary for the eradication of planktonic cells was insufficient to significantly reduce the biofilm biomass of some isolates. Nevertheless, cell culturability and overall cellular metabolism was strongly reduced in all biofilms tested, only when the EO was tested. Contrary to the tested antibiotics, T. capitata EO showed a significant antimicrobial activity against MRSA biofilms, by reducing cellular metabolism and cellular culturability.
耐甲氧西林金黄色葡萄球菌（MRSA）是一种具有很强形成生物膜能力的多药耐药机会致病菌。本研究旨在探讨 Thymbra capitata 精油（EO）对 MRSA 生物膜的抗菌潜力。首先，在一组来自败血症、糖尿病足溃疡和骨髓炎的临床分离株上，研究了 T. capitata EO 的最小抑菌浓度（MIC）和最小致死浓度（MLC）。将生物膜与 MLC 的 EO 孵育，并研究其抗生物膜潜力。结果显示，EO 具有很强的抗菌活性，MIC 和 MLC 值在 0.32 至 0.64 mg l 之间。然而，对于一些分离株，消灭浮游细胞所需的 EO 浓度不足以显著减少生物膜生物量。然而，只有在测试 EO 时，所有测试的生物膜中的细胞可培养性和整体细胞代谢才会受到强烈抑制。与测试的抗生素不同，T. capitata EO 通过降低细胞代谢和细胞可培养性，对 MRSA 生物膜表现出显著的抗菌活性。
