Antimicrobial resistance (AMR) is a critical One Health challenge affecting human, animal, and environmental health, driven by the spread of antimicrobial resistance genes (ARGs) across urban, suburban, and natural ecosystems. Effective AMR monitoring is vital for understanding its spread and mitigating impacts, with bioindicators like bees offering valuable environmental insights. This study evaluated the solitary bee Osmia bicornis L. as a bioindicator for environmental AMR in the Bologna area (Emilia-Romagna, Italy), across eight sites from urbanised to natural areas. A total of 96 female bees (12 per site) were sampled two weeks after emergence for microbiological and molecular analyses. Microbial cultures from the bee surface and gut yielded 94 bacterial isolates, assessed for AMR. DNA extracted from the recovered bacterial isolates was analysed by PCR for the detection of ARGs. The highest prevalence of antimicrobial resistance was observed for aztreonam, cefotaxime, colistin, and nalidixic acid, with several strains showing multidrug resistance. Resistance to cefoxitin, chloramphenicol, and gentamicin was linked to human-associated bacteria. In contrast, resistance to trimethoprim/sulfamethoxazole was more frequently detected in gut isolates than in bacteria recovered from the bee surface. Genes conferring resistance to colistin, β-lactams, and tetracyclines were the most prevalent. ARG occurrence was detected across all environments and reached its highest frequency in the agricultural site. Urban areas showed higher trimethoprim/sulfamethoxazole resistance, while colistin and beta-lactam resistance genes were widely distributed. These findings highlight O. bicornis as a reliable bioindicator for AMR surveillance, aligning with previous research on Apis mellifera. The study underscores the need to monitor ARG epidemiology, especially in suburban environments, to guide strategies addressing the global AMR emergence.
Cilia, G., Resci, I., Zavatta, L., De Septis, F.P., Turchi, B., Sgolastra, F. (2026). The potential role of mason bees (Osmia bicornis L. 1758) in biomonitoring antimicrobial-resistant environmental bacteria. URBAN ECOSYSTEMS, 29(5), 1-18 [10.1007/s11252-026-02099-w].
The potential role of mason bees (Osmia bicornis L. 1758) in biomonitoring antimicrobial-resistant environmental bacteria
Zavatta, Laura;de Septis, Felix Pinerolo;Sgolastra, Fabio
2026
Abstract
Antimicrobial resistance (AMR) is a critical One Health challenge affecting human, animal, and environmental health, driven by the spread of antimicrobial resistance genes (ARGs) across urban, suburban, and natural ecosystems. Effective AMR monitoring is vital for understanding its spread and mitigating impacts, with bioindicators like bees offering valuable environmental insights. This study evaluated the solitary bee Osmia bicornis L. as a bioindicator for environmental AMR in the Bologna area (Emilia-Romagna, Italy), across eight sites from urbanised to natural areas. A total of 96 female bees (12 per site) were sampled two weeks after emergence for microbiological and molecular analyses. Microbial cultures from the bee surface and gut yielded 94 bacterial isolates, assessed for AMR. DNA extracted from the recovered bacterial isolates was analysed by PCR for the detection of ARGs. The highest prevalence of antimicrobial resistance was observed for aztreonam, cefotaxime, colistin, and nalidixic acid, with several strains showing multidrug resistance. Resistance to cefoxitin, chloramphenicol, and gentamicin was linked to human-associated bacteria. In contrast, resistance to trimethoprim/sulfamethoxazole was more frequently detected in gut isolates than in bacteria recovered from the bee surface. Genes conferring resistance to colistin, β-lactams, and tetracyclines were the most prevalent. ARG occurrence was detected across all environments and reached its highest frequency in the agricultural site. Urban areas showed higher trimethoprim/sulfamethoxazole resistance, while colistin and beta-lactam resistance genes were widely distributed. These findings highlight O. bicornis as a reliable bioindicator for AMR surveillance, aligning with previous research on Apis mellifera. The study underscores the need to monitor ARG epidemiology, especially in suburban environments, to guide strategies addressing the global AMR emergence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
