Abstract
Antibiotic resistance genes (ARGs) became an emerging contaminant, and were found to accumulate in natural and man-made environments. A comprehensive understanding of the diversity and abundance of ARGs in pristine environments is critical for defining the baseline levels of environmental ARGs. However, there is limited information available on the ARG profiles of pristine environments, especially for shallow-sea hydrothermal vents ecosystems. Here, we combined 16S rRNA gene full-length amplicon sequencing and high-throughput quantitative PCR (HT-qPCR) to study the bacterial communities, and ARG abundance and diversity in the shallow-sea hydrothermal vent ecosystem of the Kueishantao Islet. The results of the 16S rRNA gene amplicon sequencing showed that several sulfur-cycling related bacterial genera, including Thiomicrorhabdus, Thioreductor, Sulfurovum, Sulfurimonas and Lebetimonas, dominated in the water column of the shallow-sea system. Temperature was the significant factor shaping the bacterial communities. The results of HT-qPCR analysis showed that the Kueishantao shallow-sea system harbored the lowest diversity (average 10 ARG subtypes) and abundance (average 1.0 × 10−3 copy per bacterial cell) of ARGs compared with other pristine (i.e., Tibet lake sediments, marine water and sediments) and anthropogenic-disturbed (i.e., drinking water reservoirs, urban ponds and wastewater treatment plants) environments. Procrustes analysis demonstrated a concordant pattern between the compositions of bacterial communities and ARGs in the shallow-sea system, while variation partition analysis revealed that the shared effects of physicochemical and bacterial communities explained >80% of the variation in the composition of ARGs. These results suggest that the vent bacterial communities and local environmental factors played an important role in shaping the distribution of the ARG profiles. Our study provides the first comprehensive overview of the background level of ARGs in a shallow-sea hydrothermal vent ecosystem.
Highlights
Antibiotic resistance genes (ARGs) are a group of ancient genetic elements, and have been recovered from 30,000-year-old Beringian permafrost sediments [1,2]
A plethora of studies have revealed the biogeographic distribution of ARGs in various anthropogenicdisturbed environments [20,21,22,23], there is limited information about the ARG profiles in pristine habitats, especially for the shallow-sea hydrothermal vents, which is essential for defining the baseline level of environmental ARGs
A total of 250 ARG subtypes, which belong to eight major ARG types (i.e., aminoglycoside, β-lactamase, chloramphenicol, Macrolide-Lincosamie-Streptogamin B (MLSB), multidrug, sulfonamide, tetracycline and vancomycin resistance genes), occurred in the 232 samples from multiple pristine and anthropogenic-disturbed environments in this study
Summary
Antibiotic resistance genes (ARGs) are a group of ancient genetic elements, and have been recovered from 30,000-year-old Beringian permafrost sediments [1,2]. Mounting evidence suggests that the biotic processes, including the vertical genetic transfer (VGT) and horizontal genetic transfer (HGT), are the primary mechanisms controlling the proliferation and dissemination of ARGs [11]. The former and latter are mainly mediated by microbial communities and mobile genetic elements (MGEs), respectively [12]. Abiotic factors, such as chemical pollutants (non-antibiotic pharmaceuticals and metalloids etc.), may cause the spread of ARGs through the promotion of the HGT or co-selection processes [8,11]. A plethora of studies have revealed the biogeographic distribution of ARGs in various anthropogenicdisturbed environments [20,21,22,23], there is limited information about the ARG profiles in pristine habitats, especially for the shallow-sea hydrothermal vents, which is essential for defining the baseline level of environmental ARGs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
