Abstract / Summary
Abstract Antibiotic resistance genes (ARGs) in turtle gut microbiota can transfer to human-associated bacteria, yet herbal medicine is often assumed to be a safer alternative that does not select for ARGs. We compared the gut resistomes of hatchling Chrysemys picta bellii and Mauremys sinensis treated with sodium nifurstyrenate (ABX), Bidens pilosa extract (HERB), or no treatment (CON). Fecal samples collected at 1 week, 2 weeks, and 2 months post-treatment (n=3/group/species) were analyzed by shotgun metagenomics. Across all samples, 234 ARG subtypes (21 types) were detected. In C. picta bellii, HERB increased ARG and mobile genetic element (MGE) abundances 1.7-fold and 3.5-fold relative to CON, whereas in M. sinensis, ARG levels remained comparable among groups, indicating species-specific effects. Both treatments enriched distinct ESKAPE pathogens: ABX enriched Achromobacter (250-fold), while HERB specifically enriched Pseudomonas aeruginosa (476-fold) in M. sinensis and Listeria monocytogenes (402-fold) in C. picta bellii. A strong ARG–MGE correlation was observed in C. picta bellii (Mantel r=0.80, p=0.0006). These results demonstrate that herbal treatment can significantly enrich ARGs, MGEs, and human pathogens in a species-dependent manner, challenging the assumption of its inherent safety for ARG control.