Metagenomic insights into the abundance and composition of resistance genes in aquatic environments: Influence of stratification and geography

• Published in: Environment international Vol. 127; pp. 371 - 380
• Main Authors: Yang, Yuyi, Li, Zan, Song, Wenjuan, Du, Linna, Ye, Chen, Zhao, Bo, Liu, Wenzhi, Deng, Danli, Pan, Yongtai, Lin, Hui, Cao, Xinhua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.06.2019; Elsevier
• Subjects: Bacitracin resistance genes; Mercury resistance genes; Metagenomic analysis; Principal coordinates analysis; Stratification; Bacitracin resistance genes; Metagenomic analysis; Stratification; Mercury resistance genes; Principal coordinates analysis
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2019.03.062

A global survey was performed with 122 aquatic metagenomic DNA datasets (92 lake water and 30 seawater) obtained from the Sequence Read Archive (SRA). Antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) were derived from the dataset sequences via bioinformatic analysis. The relative abundances of ARGs and MRGs in lake samples were in the ranges ND (not detected)–1.34 × 100 and 1.22 × 10−3–1.98 × 10−1 copies per 16S rRNA, which were higher than those in seawater samples. Among ARGs, multidrug resistance genes and bacitracin resistance genes had high relative abundances in both lake and sea water samples. Multi-metal resistance genes, mercury resistance genes and copper resistance genes had the greatest relative abundance for MRGs. No significant difference was found between epilimnion and hypolimnion in abundance or the Shannon diversity index for ARGs and MRGs. Principal coordinates analysis and permutational multivariate analysis of variance (PERMANOVA) test showed that stratification and geography had significant influence on the composition of ARGs and MRGs in lakes (p < 0.05, PERMANOVA). Coastal seawater samples had significantly greater relative abundance and a higher Shannon index for both ARGs and MRGs than deep ocean and Antarctic seawater samples (p < 0.05, Kruskal-Wallis one-way ANOVA), suggesting that human activity may exert more selective pressure on ARGs and MRGs in coastal areas than those in deep ocean and Antarctic seawater. [Display omitted] •Global survey of resistance genes in lakes and seas was carried out.•The relative abundances of ARGs and MRGs in lakes were higher than seas.•Stratification had influences on the composition of ARGs and MRGs in lakes.•Human activity exerts great selective pressure on ARGs and MRGs in coastal areas.•High relative abundance of ARG and MRG types in lakes and seas was identified.