o:6323 MICROENCAPSULATED ESSENTIAL OILS FROM TWO LAMIACEAE SPECIES FOR COMBAT AGAINST MULTI-RESISTANT ACINETOBACTER BAUMANNII en Antimicrobial resistance (AMR) threatens to increase its mortality rate to 10 million deaths per year by 2050, and Acinetobacter baumannii stands out with its insensitivity to almost all available therapeutic options. Potential solutions may be explored among naturally derived products, where essential oils (EOs) stand out with a broad spectrum of antimicrobial activity, complex chemical composition, and non-specific mechanisms of action postponing AMR development. Thus, we aimed to develop stable and effective microencapsulated systems of essential oils (EOs) derived from two species from Lamiaceae family, Origanum heracleoticum L. (oregano) and Thymus vulgaris L. (thyme). Microencapsulated complexes of oregano and thyme EOs (OEOC and TEOC) were prepared with hydroxypropyl-β-cyclodextrin as a carrier, and freeze-dried. The microdilution broth assay revealed higher antimicrobial activity of the OEOC sample compared to TEOC against 64 A. baumannii isolates recovered from COVID-19 patients admitted to intensive care units. Sub-inhibitory concentrations of microencapsulated EOs significantly decreased the biofilm formation of four A. baumannii isolates, representatives of a group of isolates based on the genetic pattern (Isolates 1, 2, 39, and 54). Contrary to antimicrobial potential, TEOC displayed slightly better antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Acinetobacter baumannii, oregano essential oil, thyme essential oil 1552100 978-86-7078-178-8 2024-12-04T08:30:15.938Z 44 no 46 Snežana Kuzmanović Nedeljković Institute for Medicinal Plant Research ''Dr. Josif Pančić'' Belgrade 0000-0003-4989-8758 46 Nada Ćujić Nikolić Institute for Medicinal Plants Research "Dr Josif Pančić" Belgrade 0000-0002-6736-3637 46 Tatjana Stević Institute for Medicinal Plants Research "Dr Josif Pančić" Belgrade 0000-0003-3399-7751 46 Dubravka Bigović Institute for Medicinal Plant Research ''Dr. Josif Pančić'' Belgrade 0000-0003-1999-2743 46 Katarina Šavikin Institute for Medicinal Plant Research ''Dr. Josif Pančić'' Belgrade 0000-0002-2086-9593 46 Brankica Filipić Faculty of Pharmacy, University of Belgrade application/pdf 1001942 https://unilib.phaidrabg.rs/o:6323 no yes 1 70 92000004 71A10 BOOK OF ABSTRACTS 179 179 XIII Congress of microbiologists of Serbia - Mikromed regio5 2024