Carbapenem Resistance and Antibacterial Potential of the Libyan Endemic Plant Arbutus pavarii Against Metallo-β-Lactamase-Producing Gram-Negative Bacteria

Background Carbapenem-resistant Gram-negative bacteria (CR-GNB), especially metallo-β-lactamase (MBL) producers, are WHO-designated critical-priority pathogens. In Libya, systematic laboratory data are scarce, and no studies have assessed endemic medicinal plants as adjunctive options.

To determine the prevalence of carbapenem resistance and MBL production among clinical Gram-negative pathogens in Misurata, Libya, and to preliminarily evaluate the antibacterial activity and phytochemical composition of Arbutus pavarii extracts.

A cross-sectional study was conducted on 244 non-duplicate Gram-negative isolates from hospitalized patients. Carbapenem resistance was assessed by Kirby–Bauer disk diffusion, and MBL production confirmed by double-disk synergy and combined disk tests. Ethanolic and aqueous extracts from A. pavarii leaves, stems, and fruits were tested against resistant isolates using disc diffusion. Phytochemical profiles were analyzed by high-performance liquid chromatography (HPLC).

The predominant isolates were Acinetobacter baumannii (29.5%), Klebsiella pneumoniae (26.2%), and Pseudomonas aeruginosa (19.7%). Carbapenem resistance exceeded 60% in these pathogens, with MBL activity detected in 54.5% of resistant K. pneumoniae. Ethanolic extracts, particularly from leaves and stems, showed measurable inhibition zones (up to 9.3 ± 7.3 mm, p < 0.05), while aqueous extracts were less active. HPLC analysis revealed abundant catechin and quercetin correlating with antibacterial activity.

This first laboratory-based report from Libya highlights the high prevalence of CR-GNB and MBL production, while introducing A. pavarii as a promising endemic plant with adjunctive antibacterial potential. The findings provide essential baseline AMR data and support exploration of resource-sensitive alternatives in African healthcare settings. - Received: - Version Posted: