The changes in antibiotic resistance genes during 86 years of the soil ripening process without anthropogenic activities

• Published in: Chemosphere (Oxford) 2021-03, Vol.266, p.128985-128985, Article 128985
• Main Authors: Tang, Xingyao, Shen, Min, Zhang, Yanzhou, Zhu, Dewei, Wang, Huanli, Zhao, Yongqiang, Kang, Yijun
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotic resistance genes (ARGs); Bacterial community; China; Drug Resistance, Microbial - genetics; Genes, Bacterial; Humans; Metagenomic analysis; Mobile genetic elements (MGEs); Mudflat; Soil
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2020.128985

This study aimed to reveal the baseline of natural variations in antibiotic resistance genes (ARGs) in soil without anthropogenic activities over the decades. Nine soil samples with different time of soil formation were taken from the Yancheng Wetland National Nature Reserve, China. ARGs and mobile genetic elements (MGEs) were characterized using metagenomic analysis. A total of 196 and 192 subtypes of ARGs were detected in bulk soil and rhizosphere, respectively. The diversity and abundance of ARGs were stable during 69 years probably due to the alkaline pH soil environment but not due to antibiotics. Increases in ARGs after 86 years were probably attributed to more migrant birds inhabited compared with other sampling sites. Multidrug was the most abundant type, and largely shared by soil samples. It was further shown that soil samples could not be clearly distinguished, suggesting a slow process of succession of ARGs in the mudflat. The variation partitioning analysis revealed that the ARG profile was driven by the comprehensive effects exhibited by the bacterial community, MGEs, and environmental factors. Besides, pathogenic bacteria containing ARGs mediated by migrant birds in the area with 86 years of soil formation history nearing human settlements needed special attention. This study revealed the slow variations in ARGs in the soil ripening process without anthropogenic activities over decades, and it provided information for assessing the effect of human activities on the occurrence and dissemination of ARGs. •ARGs in mudflat over decades without anthropogenic activities were revealed.•Little variations in ARGs in the soil ripening process over decades.•Increases in ARGs were probably attributed to migrant birds inhabited.•Marine is an important source of ARGs and MGEs.