693 / 2024-09-19 08:13:17

Research on antibiotic resistance genes in wild and artificially bred green turtles (Chelonia mydas)

Chelonia mydas,Antibiotic resistance genes,Mobile genetic elements,Human pathogenic bacteria,Sea turtle conservation

Sea turtles, as "flagship species" and "umbrella species" in marine ecosystems, are not only valued for their ecological importance but also play a crucial role in biodiversity conservation and ecosystem health monitoring. However, overfishing of eggs and adult specimens have led to a significant decline in the green sea turtle (Chelonia mydas) population. Artificial breeding is crucial in conserving endangered sea turtle populations, having demonstrated efficacy in expanding, rewilding, releasing, and restoring wild green turtle populations, yet it risks introducing antibiotic resistance genes (ARGs) to wild populations and ecosystems. This study employed metagenomic techniques to compare the distribution characteristics of ARGs in wild and artificially bred C. mydas. The findings revealed that the total abundance of ARGs in C. mydas that have been artificially bred was significantly higher than that in wild individuals. Through Principal Coordinate Analysis (PCoA) and Adonis analysis, we uncovered significant differences in the composition of ARG subtypes between the two environments, specifically that artificially bred green turtles carried 102 unique ARG subtypes, while wild green sea turtles carried 13 unique ARG subtypes. Linear discriminant analysis effect size (LEfSe) further revealed that 9 ARG subtypes were significantly enriched in wild C. mydas and 26 in artificially bred C. mydas. Additionally, the abundance of mobile genetic elements (MGEs) co-occurring with ARGs in artificially bred C. mydas was significantly higher than in wild C. mydas. In the analysis of bacteria carrying ARGs, wild C. mydas exhibited greater bacterial diversity. Furthermore, in artificially bred C. mydas, we discovered 23 potential human pathogenic bacteria (HPB) that contain antibiotic resistance genes. In contrast, in wild C. mydas, only one type of HPB carrying an antibiotic resistance gene was found. The findings of this study not only enhance our understanding of the distribution and dissemination of ARGs within the gut microbial communities of C. mydas, but also provide vital information for assessing the potential impact of releasing artificially bred C. mydas on the spread of antibiotic resistance.