Prevalence of antibiotic resistance genes and bacterial pathogens along the soil–mangrove root continuum

• Published in: Journal of hazardous materials 2021-04, Vol.408, p.124985-124985, Article 124985
• Main Authors: Wang, Cheng, Hu, Ruiwen, Strong, P.J., Zhuang, Wei, Huang, Weiming, Luo, Zhiwen, Yan, Qingyun, He, Zhili, Shu, Longfei
• Format: Article
• Language: English
• Subjects: Antibiotic resistance genes (ARGs); Dissemination; Mobile genetic elements (MGEs); Pathogens; Root compartments
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.124985

Plants roots are colonised by soil bacteria that are known to be the reservoir of antibiotic resistance genes (ARGs). ARGs can transfer between these microorganisms and pathogens, but to what extent these ARGs and pathogens disseminate from soil into plant is poorly understood. Here, we examined a high-resolution resistome profile along the soil–root continuum of mangrove saplings using amplicon and metagenomic sequencing. Data revealed that 91.4% of total ARGs were shared across four root–associated compartments (endosphere, episphere, rhizosphere and unplanted soil). Rather than compartment-selective dynamics of microbiota, the resistome was disseminated in a continuous fashion along the soil–root continuum. Such dissemination was independent of underlying root–associated bacterial and fungal microbiota, but might be facilitated by a multiplicity of mobile genetic elements. As the multiple-drug resistant pathogens, Vibrio vulnificus, pathogenic Escherichia coli and Klebsiella pneumoniae consistently predominated across four compartments, indicating the potential dissemination of antibiotic pathogens along the soil–root continuum. Through deciphering the profile and dynamics of the root–associated resistome and pathogens, our study identified the soil–root continuum as an interconnected sink through which certain ARGs and pathogens can flow from soil into the plant. [Display omitted] •A large portion of resistome was shared across four root–associated compartments.•Persistent resistome is independent of divergent root–associated microbial taxa.•An abundance of MGEs potentially facilitate the dissemination of resistome.•Dominant pathogens persist along the soil–root continuum.