Fuente: PubMed "apis cerana" Pestic Biochem Physiol. 2026 May;220:107059. doi: 10.1016/j.pestbp.2026.107059. Epub 2026 Mar 11.ABSTRACTThe gut microbiota of honeybees has been increasingly recognized as a reservoir of antibiotic resistance genes (ARGs). However, comprehensive comparisons of ARG profiles between honeybees and bumblebees inhabiting the same environments are limited. Moreover, the diversity of mobile genetic elements (MGEs) in bee gut microbiomes and their potential role in mediating the horizontal transfer of ARGs have not yet been fully elucidated. In this study, metagenomic sequencing of 48 gut samples from farmed Apis mellifera, Apis cerana, and Bombus terrestris across four regions in China revealed 127 ARG subtypes, which collectively conferred resistance to nine major antibiotic classes. We found that A. mellifera, which carried the highest load of ARGs, concurrently harbored the greatest abundance of MGEs among the three species. Although ARG abundance varied significantly by region, no consistent geographical pattern emerged across the bee species. Importantly, strong positive correlations were detected between the abundances of ARGs and MGEs, particularly between the insertion sequence gene Tn3 and plasmid gene IncQ1. Metagenome-assembled genome analyses further confirmed the co-occurrence of ARGs (sul2, aph(3″)-Ib, and aph(6)-Id) with MGEs (Tn3 and IncQ1) across the three bee species, providing direct evidence that horizontal gene transfer mediated by MGEs contributes to the dissemination of ARGs within bee gut microbiomes. Overall, these findings highlight the critical role of the bee microbiome as a reservoir for ARGs and as a bioindicator for environmental pollutants, providing important insights into the mechanisms of ARG dissemination in ecosystems.PMID:42034426 | DOI:10.1016/j.pestbp.2026.107059