Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Vertical transport of antibiotic resistance genes in soil affected by rainfall and physical-chemical factors
based on one-dimensional soil column experiments
Jin Yuchen1, Liu Shuguang1,2, Lou sha1,2*, Radnaeva Larisa Dorzhievna3, Nikitina Elena3, Makhinov Aleksey Nikolavich4, Araruna JoséTavares5
1.Department of Hydraulic Engineering, Tongji University, Shanghai, China
2.Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, China
3.Laboratory of chemistry of natural systems, Baikal Institute of Nature Management of Siberian branch of the Russian Academy of sciences,
Republic of Buryatia, Russia
4.Institute of Water and Ecological Problems FEB RAS, Khabarovsk, Russia
5.Pontifical Catholic University of Rio de Janeiro, Brazil

this vertical transmission (Chen, 2017; Li, 2018). In rainy seasons, ARGs
can be washed downward to soil layers affected by the rainfall, andmigrate into the vadose soil (Sun, 2019), which would result in theenrichment of ARGs in the soil and increase the environmental risk (Qiu,2021).
During the rainfall, microorganisms in rainwater are intercepted by thesoil, which can affect the transfer of ARGs in the environment (Wang,2021). The physical and chemical properties in soil also affect theintegration process of ARGs. Exogenous ARGs may integrate withmicrobial communities in different soil environments and produce new
drug resistance (Pérez-Valdespino, 2021). Rainwater can promote thespread and diffusion of ARGs to soil (Wang, 2021).
In previous studies, the abundance of ARGs were compared in the water
environment before and after rainfall based on field survey, which have
proved that ARGs’ abundance in surface soil were strongly related withthe rainfall. For example, Andrea et al. (Di Cesare, 2017) found that theabundance of ARGs increased during rainfall, and moderate rainfall(4mm/h) had a significant impact on the abundance of potentially drugresistant bacteria and ARGs in aquatic microbial community.
There also have some researchers who constructed laboratory scalesimulation experiments to study the changes of ARGs in soil under theinfluence of rainfall. Soil columns have been used to examine theenvironmental fate and movement of ARGs. Bioactive DNA may betransmitted over a considerable distance in saturated soil and continuous
flowing groundwater (Poté, 2003). Sun and co-workers simulated thevertical migration process of ARGs from the surface to deeper soil layer
through a 60-day soil column experiment (Sun, 2019). ARGs in different
media were also compared by applying polyvalent phage and biochar.
Qiu and his colleagues studied the influence of biochar on the leaching
behavior of ARGs through soil column experiment (Qiu, 2021). It was
found that biochar amendment might compete with ARGs for adsorption
sites leading to the failure in inhibiting the vertical transport of someARGs. Garder (2014) reported vertical transport of ARGs in soil byanalyzing the concentration of erm(B) and erm(F) in drainage water.
Kampouris et al. conducted a 35-day soil column experiment to compare
the effects of different irrigation methods on the propagation of ARGs insoil (Kampouris, 2021). In microcosm experiments with various types ofABSTRACT
The whole world is currently facing a serious health threat resulting fromthe multi-environmental spreading of antibiotic resistance genes (ARGs),
which is a new type of high-profile pollutant. Especially in highly
urbanized regions, human activities produce pollution and discharge into
the water environment and atmosphere, leading to ARGs pollution.
These ARGs may infiltrate into soil and leach into groundwater causedby hydrodynamic process of rainfall. However, the dynamic behavior ofARGs in soil during or after the rain was still not revealed, due to multifactors and the complex biochemical process. The objectives of thisstudy included 16S rRNA gene, intI1 gene and 4 ARGs, and it was aimed
to characterize the vertical transport of targeted ARGs (sul1, tetA, tetM,tetQ) following different rainfall intensity. Based on the soil column
experiments, the correlation between ARGs and rainfall intensities wasdiscussed, suggesting that simulated rainfall increase the abundance ofARGs in the soil. Moreover, the vertical profiles of ARGs’ abundance inthe soil changed significantly after the simulated rainfall, and there wasa very high possibility that ARGs could migrated to deep soil. Theseresults described the vertical migration of ARG in soil under rainfall
conditions, which can provide useful information for the prevention andcontrol of the ARG migration towards deep soil and groundwater.

KEY WORDS: antibiotic resistance genes; vertical transport; rainfall;
one-dimensional soil column experiments.

INTRODUCTION
As an emerging contaminant in the environment, antibiotic resistancegenes (ARGs) can harbor in bacteria, especially pathogenic bacteria,
which have raised the concerns to the environment and human health(Cui, 2018; Ezzariai, 2018; Berendonk, 2015; Pruden, 2006). One of theimportant transmission pathways for ARGs in the environment occurs at
the air-soil interface and spreads towards subsurface soil (Christou, 2017;Frey, 2015; Szekeres, 2018). Environmental factors such as precipitation
and rainfall intensity play a crucial role in ARGs’ proliferation during933