Next Article in Journal
A Deep Learning Framework for Flash-Flood-Runoff Prediction: Integrating CNN-RNN with Neural Ordinary Differential Equations (ODEs)
Previous Article in Journal
Sustainable Water Optimization Tool (SUWO): An Optimization Framework for the Water–Energy–Food–Ecosystem Nexus
Previous Article in Special Issue
Ecological Shifts and Functional Adaptations of Soil Microbial Communities Under Petroleum Hydrocarbon Contamination
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Water
Volume 17
Issue 9
10.3390/w17091282
water-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Differences of Occurrence, Distribution, and Factors Influencing Antibiotic Resistance Genes Between Freshwater and Seawater in China

by
Pei Jiang
1,2,3,
Jiali Chang
4,
Yu Xia
5,
Xia Li
1,2,3,
Liping Li
1,2,3,
Xinhui Liu
1,2,3 and
Le Fang
1,2,3,*
1
Research and Development Center for Watershed Environmental Eco-Engineering, Beijing Normal University, Zhuhai 519087, China
2
School of Environment, Beijing Normal University, Beijing 100875, China
3
Key Laboratory of Coastal Water Environmental Management and Water Ecological Restoration of Guangdong Higher Education Institutes, Beijing Normal University, Zhuhai 519087, China
4
Department of New Energy Materials and Chemistry, Leshan Normal University, Leshan 614004, China
5
Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
*
Author to whom correspondence should be addressed.
Water 2025, 17(9), 1282; https://doi.org/10.3390/w17091282
Submission received: 19 March 2025 / Revised: 18 April 2025 / Accepted: 22 April 2025 / Published: 25 April 2025
(This article belongs to the Special Issue Water Safety, Ecological Risk and Public Health)
Browse Figures
Versions Notes

Abstract

:
The accumulation of antibiotic resistance genes (ARGs) in aquatic systems jeopardizes public health and ecological environments. This study investigates ARGs dissemination in freshwater and seawater, focusing on the sources, prevalence and influencing factors. In freshwater, ARGs primarily originate from medical/pharmaceutical wastewaters, industrial operations, agriculture, and livestock sectors. By contrast, in addition to the above sources, seawater is contaminated by mariculture and terrestrial runoff. Comparative analysis indicates that fresh water hosts multidrug resistance, bacitracin resistance, sulfonamides, aminoglycosides, and beta-lactams, whereas seawater exhibits a wider range of ARGs encompassing sulfonamides, tetracyclines, aminoglycosides, beta-lactams, quinolones, macrolides, and chloramphenicol resistance genes. There was a stronger correlation between antibiotics and ARGs in seawater than in freshwater, especially in farmed waters. Human activities significantly contribute to ARGs pollution in both freshwater and seawater. Urbanization influences ARGs pollution in freshwater, while offshore distance and coastal economic development dictate ARGs selection pressure in seawater. This study shed lights on the current ARGs pollutant status in marine and freshwater ecosystems in China, providing a scientific foundation for water health preservation and ecosystem safeguarding measures.

1. Introduction

Since the 1940s, antibiotics have been widely used in animal husbandry, the fishing industry, and in clinical treatment for healing or preventing bacterial illness [1]. But the abuse of antibiotics increases environmental pressure and intensifies resistance of antibiotics to bacteria [2]. Thus, antibiotic resistance genes have appeared as an emerging pollutant. The rapid occurrence and diffusion of ARGs in natural ecosystems diminishes the therapeutic effect against human and animals and has generated multidrug superbugs [3].
Riverine systems are the major environmental carrier of ARGs [4]. Pollutants from various sewage treatment plants enter the river and are carried downstream by the river or into lakes and oceans. A study of ARGs in multiple media throughout China shows that the abundance of ARGs in surface water is about 102–108 copies/mL, with sulfonamide- and tetracycline-resistant genes being dominant [5]. Lakes, as major freshwater resources with slower flow rates, lead to the accumulation of ARGs. Luo et al. [6], integrating ARGs from lakes in China, found that the relative abundance and detection frequency of sulfonamide-resistant gene sul1 was the highest, which was consistent with rivers. Considering hydrological connectivity, more current research focuses on basins. In freshwater, people focus on river–lake–reservoir systems, while in seawater, they focus on the coastal area and marine farms. Liu et al. [7] investigated the distribution of ARGs in key sea areas, including Bohai Sea, Yellow Sea, East China Sea, and South China Sea. Their conclusions suggest that the quinolone-resistant gene qnrA and the tetracycline-resistant gene tetX are the dominant ARGs in seawater. A study of ARGs in Chinese mariculture farms in sea areas showed that β-lactam-, multidrug-, and tetracycline-resistant genes were epidemic in farms [8]. Previous studies have shown that the dominant ARGs in freshwater and seawater are inconsistent. However, there is no comprehensive discussion on differences of ARGs between freshwater and seawater.
The differentiation of physicochemical index, trophic pattern, and microbial community structure in freshwater and seawater form two disparate kinds of multifarious aquatic environments [9]. Physically, the salinity of seawater would alter the bacterial community structure [10], leading to the discrepancy of ARGs. As in a study of the inhabited Antarctic, the major species of ARGs in freshwater are multidrug and rifamycin, while that in seawater were antipeptides, multidrug, and beta-lactam [11]. Most noteworthy is the coastal zone, which is a transition region of fresh water and salty water along a continuous hydrological geographical pattern. However, research has focused on the variation of ARGs in coastal zones, and emphasis on their transmission across freshwater and salty water are limited and scattered, especially for the spatial differences and driving factors, which determine the hazard of ARGs from surface freshwater runoff to the sea. Therefore, it is significant to carry out an inclusive review focusing on the fate of ARGs in the sea.
This study reviews the discrepancy of sources, occurrence, and the fate-effecting factors of ARGs between freshwater and seawater areas in China. For critical and comprehensive analysis, data were collected from studies of river–-lake–reservoir systems in freshwater and the sea along coastlines throughout China, including mariculture and nonmariculture areas. The findings could provide guidance references to further comprehend the differences of distribution of ARGs on a regional scale and help craft a strategy for monitoring ARGs and ARB (antibiotic resistance bacteria).

2. Methods

As shown in Figure 1, this study collected the relevant information from 7 years regarding the occurrence and distribution of ARGs in freshwater and seawater through Pubmed, Google Scholar, Web of Science, and Elsevier. The key search words included the following: antibiotic resistance gene, antibiotic resistance, antibiotic contamination, seawater ARGs emission, ARGs in groundwater, ARGs in river, aquaculture, mariculture, etc. Previous research articles afforded complete information regarding targeted ARGs and environmental parameters from the Yarlung Zangbo River in western China to the Taihu Lake in eastern China and coastal waters from the Bohai Sea and Yellow Sea in the north to the East and South China Sea. The freshwater basin mainly focuses on the interprovincial freshwater basins, while the seawater contained noncultured seawater and cultured seawater areas in coastal waters. The selected freshwater regions represent critical environmental challenges: the Pearl River Delta exemplifies the conflict between urban expansion and water source conservation; Southern Fujian serves as a study area for balancing watershed development and ecological service functions; the Yangtze Delta and Huang-Huai Basin highlight integrated water management in economically intensive zones; and Northeast China demonstrates aquatic ecosystem restoration in legacy industrial regions. Marine areas span China’s entire coastal waters, including representative estuaries such as Feiyun and Jiaojiang, with a focus on human activity hotspots like aquaculture belts, shipping hubs, and coastal industrial zones, where ecological changes directly impact marine resource sustainability and coastal livelihoods. In addition to deeply understanding the dominant factors influencing the distribution of ARGs in freshwater and seater, differences in anthropogenic sources of ARGs in freshwater and seawater are described. While ARGs are ubiquitous in the environment as natural bacterial survival mechanisms, this study specifically addresses acquired ARGs that exacerbate environmental contamination through anthropogenic activities. For better comparison and understanding, the information of occurrence of ARGs in both freshwater and seawater are presented in tabulated table form.

3. ARGs Profiling in Freshwater

Commonly used human antibiotics in clinical settings primarily consist of beta-lactams, quinolones, macrolides, and sulfonamides, which collectively account for 80–85% of therapeutic applications [12]. For veterinary use, tetracyclines dominate antibiotic usage (40–50% of total veterinary antibiotics), followed by sulfonamides, fluoroquinolones, and macrolides [13]. The widespread application of these antibiotics has led to a surge in the abundance of associated or diverse ARGs in the environment. This study conducts a detailed regional analysis to dissect these patterns.

3.1. Major Sources

As shown in Figure 2, domestic sources, agriculture, hospitals, pharmaceutical plants, and wastewater plant effluents comprise the principal sources of acquired ARGs in freshwater ecosystems [4], particularly hospital wastewater was identified as a notable hotspot. Antibiotic residue levels and ARGs abundance in untreated hospital wastewater exceed those observed elsewhere [14]. ARGs detected in effluents ranged from 100 to 10−4 copies/16S rRNA genes, posing substantial risks to recipient waters [14]. Despite rigorous disinfection protocols, current methods fail to completely eliminate pathogens, potentially leading to treated water harboring elevated antibiotic resistance. The same concerns apply to pharmaceutical wastewater. Genes resistant to carbapenems, polymyxins, and tetracycline have been estimated from both the inlet and outlet of medical wastewater treatment systems [15]. In downstream water from facilities related to antibiotic production, concentrations of resistant isolates are typically higher than upstream, as evidenced by rivers receiving wastewater from drug formulation facilities [16].
Animal farming and aquaculture exploit antibiotics for therapy, prophylaxis, and proliferation [17], subjecting selection pressure on ARB and ARGs. ARGs were discovered in animal and aquatic gut/fecal globally, exacerbating their dissemination [18]. For instance, ARGs genomic copy numbers in Parke River, exposed to poultry breeding wastewater, increased fivefold compared to reference rivers [19]. Tang et al. [20] found that the abundance of wastewater ARGs from hospitals and slaughterhouses was significantly higher compared to those in the receiving waters. In Chinese freshwater pond culture systems, researchers noted ARGs abundance exceeding global hospital wastewater medians [21]. Therefore, managing livestock wastewater and reusing poultry-reclaimed water are key strategies for ARGs control. In municipal wastewater treatment plants, wastewater from diverse sources shows substantial reduction in ARGs and mobile genetic elements (MGEs) by 1–2 and 2–3 orders of magnitude [22], yet biological treatment techniques may inadvertently promote ARGs transmission [23,24]. Given artificial sources, comprehensive wastewater resistome assessment within a One Health framework is essential for effective ARGs human transmission control.

3.2. Occurrence and Distribution of ARGs in Freshwater

ARGs thrive across Chinese freshwaters such as rivers, lakes, reservoirs, groundwater, and sediments, as outlined in Table 1 [4]. Rivers serve as transmission channels for multiple ARGs [25]. A sample collection of the Yarlung Tsangpo River identified 119 ARGs persisting against 34 antibiotics, with 80 in unspoiled zones and 119 types in highly urbanized areas. Notably, urbanized areas and dam-regulated zones exhibited 3.54-fold and 1.55-fold higher ARB relative abundance, respectively, compared to pristine regions [26]. The Minjiang River and East Taihu basin both displayed aminoglycoside-, multidrug-, beta-lactam-, and sulfonamide-resistance, while the highest mean relative abundance of ARGs in Minjiang ranges from 1.76 × 10−2 to 2.53 × 10−2 copies/16S rRNA gene [27]. In comparison, Wang et al. [28] observed bacitracin, macrolides–lincosamides–streptogramins (MLS), vancomycin, sulfonamides, and multidrug resistance gene dominance in the Yellow River–Wei River–Fen River confluence. Sulfonamides were prevalent in the Pearl River basin, with ARGs absolute abundance in groundwater reaching 8.50 × 105 to 2.65 × 1010 copies/L and relative abundance in surface water up to 3 copies/16S rRNA gene [29]. The Liaohe region had the elevated ARGs abundance, spanning from 1.48 × 10−5 to 9.89 × 10−2 copies/16S rRNA gene [30]. Therefore, multidrug resistance, sulfonamides, tetracyclines, and aminoglycosides are key ARGs of concern in river waters, while the ARGs abundance in the sequence is city > river > lake [31].
Groundwater, an essential fresh water source globally [32], harbors ARGs from untreated discharge [33], reclaimed water recharge [34], surface runoff, landfill leachate [35], mining wastewater [36], etc. A global study detected 37 classes and 1413 species of ARGs in 330 groundwater samples [37]. ARGs concentration in Maozhou River groundwater varied from 1.23 × 108 to 8.89 × 109 copies/L during the wet season and from 8.50 × 105 to 2.65 × 109 copies/L during the dry season [38].
Comprehensive watershed assessments considering nutrients and pollutants are required to understand ARGs evolution and spread in aquatic settings [31]. Pollution history imprints on sediment indicate ARGs polluter status via sediment sampling. ARGs presence in sediments exhibit no significant change compared to water bodies but will be varied within a single water system. In the Baiyangdian-Fuhe river watershed, river sediment and ARGs abundance surpasses lake sediment [39]. ARGs concentration at the Yellow River’s tributary junction exceeds elsewhere [28], potentially due to pollutant transport acceleration at this point. Particulate matter and nutrients in sediment fuel both bacterial proliferation and ARGs capture [40], while fostering the co-occurrence of ARGs [28].
In brief, research in China indicates multidrug, bacitracin, sulfonamides, aminoglycosides, and beta-lactam resistance genes as predominant ARGs in freshwater. Freshwater ARGs absolute abundance ranges from 107 to 1011 copies/L with the sediment magnitude being 1010 copies/g. Freshwater ARGs relative abundance fluctuates from 10−8 to 10−2 copies/16S rRNA gene, whereas in sediment, it ranges from 10−3 to 10−2 copies/16S rRNA gene.
Table 1. Occurrence of ARGs in freshwater.
Table 1. Occurrence of ARGs in freshwater.
RegionWater SystemQuantitative MethodEnvironmental MediumDominant Resistance Gene SpeciesAbundance of Resistance GenesRemarkReference
Tibet regionYarlung Tsangpo River basinMetagenomic sequencingRiver surface waterbacitracins3.51 × 10−4~3.64 × 10−4 copies/16S rRNA geneTotal abundance[26]
North ChinaChishui River basinRT-qPCRRiver surface waterSulfonamides, tetracycline7.70 × 107 copies/LMaximum absolute abundance[41]
Liaohe river basinHT-qPCRRiver surface waterMultidrug resistance genes, sulfonamides, aminoglycosides, beta-lactam1.48 × 10−5~9.89 × 10−2 copies/16S rRNA gene-[30]
Baiyangdian Lake-Fuhe RiverRT-qPCRFluvial-lake sedimentsulfonamides1 × 10−3~6 × 10−3 copies/16S rRNA genesul2 abundance[39]
East ChinaEast Taihu basinHT-qPCRRiver surface waterSulfonamides, multidrug resistance, aminoglycosides--[31]
Lake surface water
Fluvial sediment
West Taihu basinHT-qPCRRiver surface waterSulfonamides, multidrug resistance, and aminoglycosides3.14 ± 0.2 × 10−8~6.3 ± 0.4 × 10−2 copies/16S rRNA geneRelative abundance range[42]
Lake surface water
Reservoir surface water
Central ChinaHuaihe river basinHT-qPCRFluvial sedimentSulfonamides, aminoglycosides, beta-lactam, multidrug resistance, MLS, and tetracyclineMain stream 2.26 × 10−2 copies/16S rRNA gene
Tributary 1.35 × 10−2 copies/16S rRNA gene		-[25]
Yellow River-Wei River-Fenhe River basinMetagenomic sequencingRiver surface waterbacitracins1.86 × 10−2~7.26 × 10−2 copies/16S rRNA geneDominant ARGs relative abundance range[28]
Honghu basinMetagenomic sequencingFluvial-lake surface waterMultidrug resistance, bacitracin, and rifamycin resistance--[43]
Fluvial-lake ground waterMultidrug resistance, and bacitracins
South ChinaMinjiang River basinHT-qPCRRiver surface waterAminoglycosides, multidrug resistant, beta-lactam, and sulfonamides1.76~3.76 × 10−2 copies/16S rRNA geneDominant ARGs relative abundance range[27]
Pearl River basinRT-qPCRRiver surface waterSulfonamides sul1 and sul2≥3 copies/16S rRNA geneDominant ARGs relative abundance range[29]
Fluvial sedimentsulfonamides sul1≥1 copies/16S rRNA gene
Maozhou River BasinHT-qPCRRiver groundwaterSulfonamides, multidrug resistance, and aminoglycosidesWet season 1.23 × 108~8.89 × 1010 copies/L
Dry season 8.50 × 105~2.65 × 1010 copies/L		Total absolute abundance[38]
River surface waterSulfonamides, multidrug resistance, and aminoglycosides1.91 × 1010 copies/LMaximum absolute abundance
Fluvial sedimentMultidrug resistant, sulfonamides, aminoglycosides and beta-lactam1.10 × 1010 copies/gMaximum absolute abundance

4. Sources and Distribution of ARGs in Seawater

4.1. Major Sources

The nearshore sea acts as an integral connection between freshwater and marine ecosystems [44], intensifying the propagation and evolution of acquired ARB and ARGs via anthropogenic influences. These encompass medical treatments, industrial production, domestic wastewater discharge, and recreational activities, all contributing to elevated ARGs in seawater.
Mariculture wastewater emerges as a substantial ARGs contributor. He et al. (2023) report farm antibiotic levels exceeding those of nonfarm areas [8], making these regions highly susceptible to ARGs pollution. Traditional and recirculating aquaculture methods differ in their impact on seawater ARGs. Conventional farms released untreated wastewater, causing severe marine pollution. Recirculating farms, while recycling wastewater, still pose risks from excreta and bait discharged [45]. For instance, the majority of marine farms on Jeju Island, South Korea, utilize a flow-through system, discharging feed, residual antibiotics, and excrement directly into the marine ecosystem [46]. Rivers and surface runoff also need to be noted. Carney et al. [47] observed that heavy rainfall augmented surface runoff, subsequently increasing targeted ARGs. Urbanized areas receiving more urban outflow and stormwater runoff experienced heightened ARGs impact, indicating that urban beaches and stormwater overflow can facilitate ARGs transportation and concentration in seawater. Furthermore, marine discharge, a globally prevalent sewerage solution which intends to dilute pollutants, can also diminish anthropogenous ARGs input via oceanic hydrodynamics once discharged [44,47].
Therefore, ARGs primarily originate from wastewater generated from medical, industrial, domestic, and animal husbandry activities. In seawater, additional anthropogenic inputs from coastal activities, mariculture, rivers, and surface runoff further contribute to ARGs diversity. Seawater accommodates a wider array of ARGs than freshwater does (Figure 2). Considering the marine ecosystems’ vulnerability to external stressors, careful consideration of environmental sustainability is crucial to prevent irreversible harm from wastewater discharges.

4.2. Occurrence of ARGs in Seawater

Seawater ARGs absolute abundance spans 103 to 1013 copies/L in seawater versus 103 to 108 copies/g in sediment, exhibiting substantial coastal variation. Seawater ARGs relative abundance varies from 10−4 to 10−2 copies/16S rRNA gene. In comparison to freshwater, seawater ARGs biodiversity is richer, corroborating the source hypotheses for ARGs for both aquatic systems. Bacitracin-resistant genes are less frequently detected in seawater, typically occurring naturally in bacterial populations [26]. They are more prevalent in pristine waters like the Yarlung Zangbo River, comprising its primary ARGs [26].
Estuaries, sites of inland water–ocean intersection, act as ARGs dissemination hubs due to high antibiotic discharge [48]. Table 2 presents a comparative analysis of ARGs studies conducted in China’s coastal zones. Bohai Bay, a coastal region of eastern China, is severely impacted by industrial pollution, predominantly harboring sulfonamide- and tetracycline-resistant genes [49]. Wu et al. [50] utilized metagenomics sequencing to explore differences among urban rivers, estuaries, and Bohai Bay, pinpointing the dominance of multidrug-, beta-lactam-, and aminoglycoside-resistant genes, with microbial counts spanning from 132 ± 3.2 to 110 ± 6.3. These findings underscore regional variation in ARGs distribution within oceans. For instance, disparate results were observed in gulf, nearshore, and offshore waters [49,50,51]. Quinolone- and sulfonamide-resistant genes predominate in the Yellow Sea, with elevated levels observed within its waters and bed sediments relative to the Bohai area [51]. Similarly, sulfonamide-resistant genes were 100% detected in Wailingding Island and Miaowan Island in the Hainan area [52]. Receiving wastewater from diverse sources in the East China Sea, sul2, tetW, and dfrA13 were prevalent in Hangzhou Bay, Xiangshan Bay, and Taizhou Bay [53].
Table 2. Occurrence of ARGs in seawater.
Table 2. Occurrence of ARGs in seawater.
Territorial Sea AreaDistrictEnvironmental MediumQuantitative MethodDominant Resistance Gene SpeciesAbundance of Resistance GenesReference
The Bohai SeaLiaodong Bay, Bohai Bay, Laizhou Bay, Bohai Strait and central Bohai SeaSedimentHT-qPCRSulfonamides and tetracyclines1.27 × 105 copies/g~4.94 × 108 copies/g[49]
Urban rivers, estuaries, Bohai BaySedimentMetagenomic sequencingMultidrug resistant, β-lactam, and aminoglycoside-[50]
Liaodong Bay, Bohai Bay, Laizhou Bay, Bohai Strait and central Bohai SeaSurface waterRT-qPCRSulfonamides and tetracyclines2.05 × 105 copies/L~7.25 × 106 copies/L[51]
Sediment-4.67 × 103 ~5.41 × 105 copies/g
The Yellow SeaThe Yellow SeaSedimentRT-qPCR-3.88 × 105~1.08 × 107 copies/g[51]
Surface waterQuinolones and sulfonamides2.11 × 104~8.00 × 106 copies/L
The East China SeaYangtze EstuarySedimentRT-qPCRSulfonamides (sul1), Chloramphenicol (copA)2.02 × 108~2.2 × 108 copies/g[54]
Yongjiang RiverSurface waterHT-qPCRMultidrug resistant, aminoglycosides, and sulfonamides3.18 × 103~2.57 × 109 copies/L[55]
Hangzhou BaySedimentRT-qPCRTetracyclines, sulfonamides, and trimethoprim6.25 × 10−4~1.39 × 10−2 copies/16S rRNA gene[53]
Xiangshan Bay2.37 × 10−3~1.82 × 10−2 copies/16S rRNA gene
Taizhou Bay2.79 × 10−3 copies/16S rRNA gene
The South China SeaGlobal areaSurface waterRT-qPCRTetracyclines (tetM)1.82 × 108~5.9 × 1012 copies/L[44]
Pearl River Delta3.87 × 1013 copies/L
East Guangdong2.18 × 1013 copies/L
West Guangdong1.90 × 1013 copies/L
Outer Lingding Island, Temple Bay islandSurface waterRT-qPCRSulfonamides (sul1), Quinolones (qnrD, floR)7.34 × 104 copies/L~1.33 × 107 copies/L[52]
Dapeng BaySurface waterRT-qPCRChloramphenicol (floR, cmlA), and Sulfonamides (sul1)
Chloramphenicol (floR, cmlA), and Sulfonamides (sul1)		1.27 × 105 copies/L~1.26 × 109 copies/L[56]
Sediment1.03 × 106 copies/g~3.47 × 107 copies/g
The noncultured coastal multidrug resistance gene detection rate is lower than in cultured areas (Table 3). Higher seawater ARGs absolute abundance may attribute to anthropogenic interference and pollution, while lower seawater ARGs absolute abundance may result from seawater dilution. In addition, Xu et al. [44] quantified 21 targeted ARGs in Guangdong and South China’s coastal waters, observing the highest levels in the Pearl River Delta region. As per seawater findings, the South China Sea primarily harbors tetracycline, sulfonamides, and chloramphenicol ARGs. In the Dapeng Bay culture, yacht tourism and domestic savage discharge area, Li et al. [56] investigated 10 ARGs, with floR, cmlA, and sul1 being the most abundant.
Marine farming grounds harbor dense levels of resistance contaminants. Open-water mariculture systems induce substantial accumulation of ARGs within farms, surrounding waters, sediment, and fish tissues [57]. Numerous studies have examined ARGs in Chinese coastal mariculture zone. The overall ARGs count in mariculture regions (8.52 × 107 to 3.58 × 1010 copies/L) was notably elevated compared to nonmariculture sites (5.56 × 106 to 7.34 × 109 copies/L) (p < 0.05) [8]. Multidrug, beta-lactam, and aminoglycosides resistance predominant in Dongshan Bay seawater per Cui et al.’s [58] metagenomic sequencing. Along coastal farms in China, sulfonamide-resistant genes were prevalent, as revealed by Gao et al. [59], with sequencing revealing that bacA, an aminoglycoside-resistant gene, contributes substantially to all ARGs besides Penglai and Qingdao. In addition to these predominant ARGs, numerous others exist, warranting specific consideration due to their diversity. A recent study identified resistance to virtually all healthcare and livestock antibiotics in 262 ARGs species detected via HT-qPCR across various coastal provinces’ mariculture farms. Among all ARGs, a total of 10, 26, and 19 ARGs were classified as high-risk, Rank I risk, and Rank II risk categories, respectively [8]. Therefore, beta-lactam-resistant (19.6%) and fluoroquinolone-resistant (17.1%) genes display significant diversity among ARGs.
Table 3. Occurrence of ARGs in mariculture zone.
Table 3. Occurrence of ARGs in mariculture zone.
LocationsDetection MethodSample TypeDominant Resistance Gene SpeciesAbundance of Resistance Genes in Aquaculture WaterReference
Dongshan BayMetagenomic sequencingFarm seawaterMultidrug resistant, beta-lactamases, and aminoglycosides-[58]
Dalian, Tangshan, Penglai, Lianyungang, Qidong, Xiangshan, Ningde, Dongshan, Zhanjiang and LingshuiRT-qPCR
Illumina high-throughput sequencing		Farm sedimentSulfonamides and aminoglycosides-[59]
Liaoning, Shandong, Jiangsu, Zhejiang, Fujian, Guangdong, Guangxi, HainanHT-qPCRFarm seawater-8.52 × 107~3.58 × 1010 copies/L[8]
Nonfarm seawater-5.56 × 106~7.34 ×109 copies/L
Hainan (Province)qPCRFarm seawaterSulfonamides (sul1, sul2), macrolides (ereA and aadA)0.09~0.39 copies/16S rRNA gene[60]
Farm sediment0.07~0.76 copies/16S rRNA gene
Grouper gillsTetracycline and chloramphenicol8.5 × 10−5~1.9 copies/16S rRNA gene
Grouper gut4.7 × 10−6~7.4 copies/16S rRNA gene
Notably, mariculture findings, illustrated in Figure 3b, underscore ARGs prevalence and distribution. Farmed vs. nonfarmed oceanic ARGs species count disparity exists, with farm ARGs species distribution being more uniform. This suggests that elevated ARGs occurrence in mariculture zones may correlate with high single antibiotic usage. High antibiotic levels foster ARGs selection and proliferation, particularly multidrug-resistant genes. Frequent resistance gene exchange in mariculture settings may stimulate the emergence of diverse multidrug-resistant genes.

4.3. ARGs Difference Between Freshwater and Seawater

Figure 4 illustrates the selection of ARGs quantified in freshwater and seawater using high-throughput quantitative polymerase chain reaction (HT-qPCR). Targeted ARGs in seawater studies employing HT-qPCR parallel those in freshwater, with variations primarily in detection rates and abundance (Figure 4). Key freshwater ARGs include multidrug-, bacitracin-, sulfonamide-, aminoglycoside-, and beta-lactam-resistant genes, while seawater predominantly harbors aminoglycoside-, beta-lactam-, macrolide-, MLS-, tetracycline-, vancomycin-, and multidrug-resistant genes. Notably, sulfonamide-resistant genes exhibit high detection frequencies across both habitats, though their subtype diversity remains limited due to few identified genetic variants.
Methodological considerations are critical for interpreting these patterns. Metagenomics and qPCR employ distinct quantification principles: the former relies on sequencing depth and bioinformatic normalization, while the latter uses reference genes or standard curves. Metagenomics outputs relative gene abundance, whereas qPCR provides absolute quantification (copies per unit) or relative values normalized to 16S rRNA. Cross-method comparisons are inherently challenging. A practical approach is to focus on frequently targeted ARGs common in metagenomic databases. Data harmonization—via spike-in standards for metagenomics and 16S rRNA normalization for qPCR—enables comparative analysis. Correlation assessments can further validate trend consistency.
Unclassified emerging ARGs underscore the need for vigilance against novel resistance types. Trimethoprim resistance, though rarely quantified, is widespread in marine systems. Resistance genes such as bacitracin (bacA) and rifamycin warrant cautious interpretation. For example, bacA only confers resistance to bacitracin in bacteria when overexpressed [61], but bacA was part of the standard chromosomal gene repertoire in many bacteria [26]. And many bacteria were identified as its host [62]. Abundance detection alone does not prove its harmfulness. The same goes for rifamycin-resistant genes. Over 95% of rifamycin resistance is triggered by mutation in rpoB gene [63,64]. However, resistance mutation in essential genes have negative effects on main physiological functions [65]. The fitness cost of resistance mutation dictates a difference in bacterial phenotype in clinical and natural settings. Therefore, the harm of ARGs in water environments should combine with clinical analysis.
Water 17 01282 g003
Figure 3. Types of ARGs in coastal regions (a) and marine aquaculture farm (b) detected using metagenome [58,66].
Figure 3. Types of ARGs in coastal regions (a) and marine aquaculture farm (b) detected using metagenome [58,66].
Water 17 01282 g003
Water 17 01282 g004
Figure 4. Types of ARGs in freshwater (a) and seawater (b) monitored with HT-qPCR in different research [8,25,27,30,31,38,42,67,68,69,70,71,72,73].
Figure 4. Types of ARGs in freshwater (a) and seawater (b) monitored with HT-qPCR in different research [8,25,27,30,31,38,42,67,68,69,70,71,72,73].
Water 17 01282 g004

5. Factors Affecting Fate Characteristics of ARGs in Freshwater and Seawater

5.1. Freshwater Environment

Antibiotics generally influence ARGs, yet, in freshwater, they lack a noteworthy connection [74]. This contention, however, is disputed by research suggesting antibiotic selection pressures influence watershed ARGs alternations or synergize with heavy metal exposure influencing ARGs prevalence [41].
Land-use changes and extensive human activity largely determine the fate of ARGs. For instance, in the Minjiang River, intensive human activities can elevate river ARGs abundance over reservoir levels [27]. Urbanization, altering land-use, accelerates the dissemination of ARGs and influences their composition, especially high ARGs densities near urban sites in the Yarlung Zangbo River. Moreover, studies in the Jiulong River suggest that greater distance from urban centers corresponds to higher ARGs abundance [73]. ARGs abundance in the South China River basin fluctuates with seasonal shifts, temperature, and precipitation, while in the Shanghai water source reservoir, ARGs peak during the wet season [42]. Seasonal changes and gradients significantly affect ARGs abundance in the river–reservoir systems due to hydrological changes and temperature fluctuations [67]. Furthermore, ARGs abundance in groundwater of Honghu area increases in the dry season, likely due to abundant hydrologic conditions associated with seasonality. And the resistome risk scores were also significantly higher in groundwater (p < 0.05) [75]. Thus, understanding environmentally driven ARGs flux requires a holistic approach considering various factors.
Socioeconomic variables including city population, urban expansion, economic strength, and wastewater plant emissions concurrently exert considerable impacts alongside natural ones like contextual water quality, geographical features, and microbial communities [76,77,78]. Productivity, wastewater composition, agriculture/livestock patterns, and water treatment strategies further shape ARGs species, quantity, and biodiversity in freshwater settings [76,77,78]. Restoring watersheds can help mitigate ARGs pollution [31]. Addressing ARGs pollution necessitates a thorough examination of both natural and anthropogenic factors at the watershed level to comprehend its complex dynamics within hydrological networks.

5.2. Seawater Environment

The influence of antibiotics on seawater differs markedly between common and cultivated marine regions. Common seas show insignificant correlations between ARGs and antibiotics, excluding sulfonamides and tetracyclines [51], while significant correlations occur in cultivated ones. Numerous farming surveys point towards a direct relationship between antibiotic presence and ARGs abundance/variation in cultivating areas (direct effects = 0.234 and 0.068) [8]. Nutrient sugars, heavy metals, and other factors also play crucial roles in determining seawater characteristics. The unique role of salinity in seawater is noteworthy, accounting for 63.7% of the total variance in the South China Sea [52].
Offshore distance, tide, hydrology, and human activities further affect ARGs in common marine areas. Farming methods and types are key considerations in cultivated areas. A pollution gradient of ARGs extends from estuaries to the open ocean [49]. ARGs diversity and abundance diminish in estuaries like the Jiaojiang River and Xixi River [69]. Tide movements and gates modify ARGs species and abundance [55]. For instance, Haihe tidal gate studies revealed increased extracellular ARGs and decreased intracellular ARGs due to salinity fluctuations [71].
Temperature and hydrological seasonality influence ARGs composition and distribution in seawater, mirroring freshwater environments [79]. Human activities significantly shape ARGs distribution, as seen in Wailingding Island of Hainan where different resistance genes dominate during dry and rainy seasons [52]. The rising trend of sul2 and tetM genes in the Yangtze River estuary over a decade indicates a strong correlation with economic development [54].
Mariculture has led to certain estuarine culture zones becoming highly contaminated with ARGs. Conventional practices like seawater ponds, cage culture, and hanging nets directly introduce antibiotics and ARGs [80,81,82]. ARGs interactions and accumulation patterns in mariculture environments are complex, varying with farming methods and antibiotic use. Fish can ingest ARBs from the environment, with the gut acting as a major ARGs transmission site [83]. ARGs distribution differences are influenced by fish farming practices [82]. Hence, fish harvesting and farming activities may expose individuals to varying ARGs levels.

5.3. Comparison of Factors in Two Kinds of Water Bodies

Analyzing the fate of ARGs across both fresh and sea basins, the key determinants are antibiotics, bacterial communities, MGEs, heavy metals, water quality indices, human activity, and seasonality. Natural factors such as geographical location and physical/chemical attributes create unique water system considerations. Essential freshwater considerations encompass land usage, while common seawater influencers are tidal fluctuations and salinity. It is noteworthy that the distinct salinity levels of freshwater and seawater shape their respective microbial communities, which play a critical role in regulating the distribution of ARGs. However, systematic investigations into this salinity-mediated regulatory mechanism remain limited.
The predominantly studied determinants of the fate of ARGs are MGEs, bacterial communities, heavy metals, and water quality metrics. A significant positive correlation exists between MGEs and ARGs in both aquatic systems; further evidence of their combined effect lies within the shared occurrence network between MGEs and bacterial taxa. Heavy metals exert comparable effects on ARGs, but evidence suggests indications of possible synergy with ARGs. Water quality index’s complexity limits single definitive interpretation, making it better suited for modeling via principal component analysis. Nutrients (e.g., N and P) are typical water quality metrics linked to bacterial population size, potentially indirectly impacting ARGs distribution through community shape.
Despite some similarities, influence exerted on ARGs deviates substantially in fresh and seawater. This divergence may partly originate from salinity-driven microbial community differences, as highlighted earlier. Antibiotics, once considered joint ARGs drivers, manifest differently in each body of water, perhaps due to detected antibiotic levels disparity. Factors influencing ARGs profiles are vital for understanding environmental evolution (Figure 5). Correlation analysis and model simulations are prevalent methods used to evaluate impact of determinants on the fate of ARGs. Nevertheless, critical gaps persist—particularly in unraveling how salinity gradients mechanistically bridge microbial ecology and ARGs dynamics—necessitating targeted studies beyond current correlation-based approaches. The exploration of various factors and indicator establishment assesses the interplay between natural and anthropogenic influences.

6. Conclusions and Prospects

Our study thoroughly scrutinizes the origins and prevalent statuses of ARGs in China’s freshwater and seawater regions, with an emphasis on the key variables impacting ARGs variant patterns. ARGs predominantly stem from medical/pharmaceutical wastewaters, industrial wastewater, and animal agricultural effluents. Here, prominent genotype profiles include multidrug-, bacitracin-, sulfonamide-, aminoglycoside-, and beta-lactam-resistant genes. In contrast, the source of ARGs in marine environments are supplemented by coastal aquaculture, terrestrial river inflows, and surface runoffs. This diverse input pattern yields more varied marine ARGs notably sulfonamides, tetracyclines, aminoglycosides, β-lactams, quinolones, macrolides, and chloramphenicol. Despite this, oceanic ARGs abundance generally trails freshwater species. Human activities significantly sway the ARGs landscape in both freshwater and seawater ecosystems. Urbanization levels and offshores distances/coastal economic intensity contribute substantially to freshwater environments, while estuarine tide dynamics and mariculture cultivation methodologies play the lead roles in marine environments.
Moreover, study variances arise due to differing quantification techniques, potentially affecting data consistency. While targeted quantitative methods select common genotypes, varying gene categories and subtypes limit data comparability. Additionally, our synthesis of existing literature highlights a critical gap: risk assessments specifically targeting ARGs rather than antibiotics remain notably scarce. Furthermore, pathogens and virulence factors linked to ARGs have received limited attention, representing a priority area for future research to comprehensively evaluate ecological and public health implications. Future research should delve into determining dominant ARGs in various aquatic habitats and explore ARGs occurrence and distribution variance between water and sediment. This could deepen our comprehension of ARGs ecosystem dynamics and facilitate more reliable cross-study comparisons.

Author Contributions

P.J.: Writing—original draft, Investigation, Data curation. J.C.: Methodology, Data curation. Y.X.: Validation, Formal analysis. X.L. (Xia Li): Data curation, Validation. L.L.: Conceptualization, Data curation. X.L. (Xinhui Liu): Funding acquisition, Formal analysis. L.F.: Writing—reviewing and editing, Visualization, Supervision, Funding acquisition. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by Key Technology Research and Development Program of Shandong Province (grant number 2021CXGC011201), National Natural Science Foundation of China (grant numbers 52200142) and Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control (No. 2023B1212060002). This work was financially supported by Major Scientific and Technological Innovation Projects of Shandong Province (2021CXGC011201)) and the Supplemental Funds for Major Scientific Research Projects of Beijing Normal University, Zhuhai (ZHPT2023001).

Data Availability Statement

Data reported in this work will be available on request.

Conflicts of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Abbreviation

Abbreviation of fresh and sea water in this study
MZMaoZhou River basin
JLJiulongjiang River basin
ETHEast Taihu Lake basin
SZJinghang Canal, Wusong River, Taipu River, Yangcheng Lake and Cao Lake
SRRBeiling River, Xunwu River, Reservoir Fengshuba
MJMinjiang River
HHHuaihe River basin
LHLiaohe River basin
MH16 Chinese estuaries from north to south
MABohai sea, Yellow sea, East China sea, South China sea
ESHaihe Estuary located in the west of Bohai Bay
DDXixi River and Jiaojiang River in East China sea
SVOujiang estuary, Aojiang estuary, and Feiyunjiang estuary in the East China sea
MI92 lake water and 30 seawater in global

References

  1. Larsson, D.G.J.; Flach, C.F. Antibiotic resistance in the environment. Nat. Rev. Microbiol. 2022, 20, 257–269. [Google Scholar] [CrossRef] [PubMed]
  2. Kim, D.-W.; Cha, C.-J. Antibiotic resistome from the One-Health perspective: Understanding and controlling antimicrobial resistance transmission. Exp. Mol. Med. 2021, 53, 301–309. [Google Scholar] [CrossRef] [PubMed]
  3. Nadeem, S.F.; Gohar, U.F.; Tahir, S.F.; Mukhtar, H.; Pornpukdeewattana, S.; Nukthamna, P.; Moula Ali, A.M.; Bavisetty, S.C.B.; Massa, S. Antimicrobial resistance: More than 70 years of war between humans and bacteria. Crit. Rev. Microbiol. 2020, 46, 578–599. [Google Scholar] [CrossRef] [PubMed]
  4. Singh, R.; Singh, A.P.; Kumar, S.; Giri, B.S.; Kim, K.-H. Antibiotic resistance in major rivers in the world: A systematic review on occurrence, emergence, and management strategies. J. Clean. Prod. 2019, 234, 1484–1505. [Google Scholar] [CrossRef]
  5. Xu, Z.; Jia, Y.; Huang, B.; Zhao, D.; Long, X.; Hu, S.; Li, C.; Dao, G.; Chen, B.; Pan, X. Spatial distribution, pollution characteristics, and health risks of antibiotic resistance genes in China: A review. Environ. Chem. Lett. 2023, 21, 2285–2309. [Google Scholar] [CrossRef]
  6. Luo, Y.; Liu, C.; Wang, Y.; Yang, Y.; Mishra, S. Occurrence, distribution and their correlation with different parameters of antibiotics and antibiotic resistance genes in lakes of China: A review. Mar. Pollut. Bull. 2023, 193, 115189. [Google Scholar] [CrossRef]
  7. Liu, X.; Wei, H.; Wang, H.; Zhang, Y.; Song, H.-L.; Zhang, S. A review of spatial distribution of typical antibiotic resistance genes in marine environment surrounding China. Mar. Pollut. Bull. 2024, 203, 116482. [Google Scholar] [CrossRef]
  8. He, L.-X.; He, L.-Y.; Gao, F.-Z.; Zhang, M.; Chen, J.; Jia, W.-L.; Ye, P.; Jia, Y.-W.; Hong, B.; Liu, S.-S.; et al. Mariculture affects antibiotic resistome and microbiome in the coastal environment. J. Hazard. Mater. 2023, 452, 131208. [Google Scholar] [CrossRef]
  9. Zhang, K.; Zhang, Y.; Xin, R.; Zhang, Y.; Niu, Z. Variation pattern of terrestrial antibiotic resistances and bacterial communities in seawater/freshwater mixed microcosms. Chemosphere 2018, 200, 201–208. [Google Scholar] [CrossRef]
  10. Xu, Y.; You, G.; Zhang, M.; Peng, D.; Jiang, Z.; Qi, S.; Yang, S.; Hou, J. Antibiotic resistance genes alternation in soils modified with neutral and alkaline salts: Interplay of salinity stress and response strategies of microbes. Sci. Total Environ. 2022, 809, 152246. [Google Scholar] [CrossRef]
  11. Zhang, T.; Ji, Z.; Li, J.; Yu, L. Metagenomic insights into the antibiotic resistome in freshwater and seawater from an Antarctic ice-free area. Environ. Pollut. 2022, 309, 119738. [Google Scholar] [CrossRef] [PubMed]
  12. Duan, L.; Liu, C.; Wang, D. The General Population’s Inappropriate Behaviors and Misunderstanding of Antibiotic Use in China: A Systematic Review and Meta-Analysis. Antibiotics 2021, 10, 497. [Google Scholar] [CrossRef] [PubMed]
  13. Liu, X.; Steele, J.C.; Meng, X.-Z. Usage, residue, and human health risk of antibiotics in Chinese aquaculture: A review. Environ. Pollut. 2017, 223, 161–169. [Google Scholar] [CrossRef] [PubMed]
  14. Wang, Q.; Wang, P.; Yang, Q. Occurrence and diversity of antibiotic resistance in untreated hospital wastewater. Sci. Total Environ. 2018, 621, 990–999. [Google Scholar] [CrossRef]
  15. Zhu, L.; Shuai, X.-Y.; Lin, Z.-J.; Sun, Y.-J.; Zhou, Z.-C.; Meng, L.-X.; Zhu, Y.-G.; Chen, H. Landscape of genes in hospital wastewater breaking through the defense line of last-resort antibiotics. Water Res. 2022, 209, 117907. [Google Scholar] [CrossRef]
  16. González-Plaza, J.J.; Blau, K.; Milaković, M.; Jurina, T.; Smalla, K.; Udiković-Kolić, N. Antibiotic-manufacturing sites are hot-spots for the release and spread of antibiotic resistance genes and mobile genetic elements in receiving aquatic environments. Environ. Int. 2019, 130, 104735. [Google Scholar] [CrossRef]
  17. He, Y.; Yuan, Q.; Mathieu, J.; Stadler, L.; Senehi, N.; Sun, R.; Alvarez, P.J.J. Antibiotic resistance genes from livestock waste: Occurrence, dissemination, and treatment. NPJ Clean Water 2020, 3, 4. [Google Scholar] [CrossRef]
  18. Zhao, Y.; Yang, Q.E.; Zhou, X.; Wang, F.-H.; Muurinen, J.; Virta, M.P.; Brandt, K.K.; Zhu, Y.-G. Antibiotic resistome in the livestock and aquaculture industries: Status and solutions. Crit. Rev. Environ. Sci. Technol. 2020, 51, 2159–2196. [Google Scholar] [CrossRef]
  19. Semedo, M.; Song, B. Sediment metagenomics reveals the impacts of poultry industry wastewater on antibiotic resistance and nitrogen cycling genes in tidal creek ecosystems. Sci. Total Environ. 2023, 857, 159496. [Google Scholar] [CrossRef]
  20. Tang, Y.; Liang, Z.; Li, G.; Zhao, H.; An, T. Metagenomic profiles and health risks of pathogens and antibiotic resistance genes in various industrial wastewaters and the associated receiving surface water. Chemosphere 2021, 283, 131224. [Google Scholar] [CrossRef]
  21. Wang, C.; Liu, X.; Yang, Y.; Wang, Z. Antibiotic and antibiotic resistance genes in freshwater aquaculture ponds in China: A meta-analysis and assessment. J. Clean. Prod. 2021, 329, 129719. [Google Scholar] [CrossRef]
  22. Sun, H.; Zhang, H.; Wu, D.; Ding, J.; Niu, Y.; Jiang, T.; Yang, X.; Liu, Y. Deciphering the antibiotic resistome and microbial community in municipal wastewater treatment plants at different elevations in eastern and western China. Water Res. 2023, 229, 119461. [Google Scholar] [CrossRef] [PubMed]
  23. Bengtsson-Palme, J.; Hammaren, R.; Pal, C.; Ostman, M.; Bjorlenius, B.; Flach, C.F.; Fick, J.; Kristiansson, E.; Tysklind, M.; Larsson, D.G.J. Elucidating selection processes for antibiotic resistance in sewage treatment plants using metagenomics. Sci. Total Environ. 2016, 572, 697–712. [Google Scholar] [CrossRef]
  24. Li, D.C.; Gao, J.F.; Zhang, S.J.; Gao, Y.Q.; Sun, L.X. Emergence and spread patterns of antibiotic resistance genes during two different aerobic granular sludge cultivation processes. Environ. Int. 2020, 137, 105540. [Google Scholar] [CrossRef]
  25. Zhang, K.; Xin, R.; Zhao, Z.; Li, W.; Wang, Y.; Wang, Q.; Niu, Z.; Zhang, Y. Mobile genetic elements are the Major driver of High antibiotic resistance genes abundance in the Upper reaches of huaihe River Basin. J. Hazard. Mater. 2021, 401, 123271. [Google Scholar] [CrossRef]
  26. Liu, S.; Wang, P.; Wang, C.; Wang, X.; Chen, J. Anthropogenic disturbances on antibiotic resistome along the Yarlung Tsangpo River on the Tibetan Plateau: Ecological dissemination mechanisms of antibiotic resistance genes to bacterial pathogens. Water Res. 2021, 202, 117447. [Google Scholar] [CrossRef]
  27. Huang, Y.; Wang, F.; Li, Y.; Yue, C.; Zhang, Y.; Zhou, P.; Mu, J. Influence of anthropogenic disturbances on antibiotic resistance gene distributions along the Minjiang River in Southeast China. J. Environ. Manag. 2022, 323, 116154. [Google Scholar] [CrossRef]
  28. Wang, Y.; Li, H.; Li, Y.; Guo, H.; Zhou, J.; Wang, T. Metagenomic analysis revealed sources, transmission, and health risk of antibiotic resistance genes in confluence of Fenhe, Weihe, and Yellow Rivers. Sci. Total Environ. 2023, 858, 159913. [Google Scholar] [CrossRef]
  29. Gao, F.-Z.; He, L.-Y.; Hu, L.-X.; Chen, J.; Yang, Y.-Y.; He, L.-X.; Bai, H.; Liu, Y.-S.; Zhao, J.-L.; Ying, G.-G. The variations of antibiotics and antibiotic resistance genes in two subtropical large river basins of south China: Anthropogenic impacts and environmental risks. Environ. Pollut. 2022, 312, 119978. [Google Scholar] [CrossRef]
  30. Gao, H.; Zhao, F.; Li, R.; Jin, S.; Zhang, H.; Zhang, K.; Li, S.; Shu, Q.; Na, G. Occurrence and distribution of antibiotics and antibiotic resistance genes in water of Liaohe River Basin, China. J. Environ. Chem. Eng. 2022, 10, 108297. [Google Scholar] [CrossRef]
  31. Yang, J.; Xiang, J.; Xie, Y.; Yu, K.; Gin, K.Y.-H.; Zhang, B.; He, Y. Dynamic distribution and driving mechanisms of antibiotic resistance genes in a human-intensive watershed. Water Res. 2022, 222, 118841. [Google Scholar] [CrossRef] [PubMed]
  32. Zainab, S.M.; Junaid, M.; Xu, N.; Malik, R.N. Antibiotics and antibiotic resistant genes (ARGs) in groundwater: A global review on dissemination, sources, interactions, environmental and human health risks. Water Res. 2020, 187, 116455. [Google Scholar] [CrossRef] [PubMed]
  33. Kampouris, I.D.; Alygizakis, N.; Klümper, U.; Agrawal, S.; Lackner, S.; Cacace, D.; Kunze, S.; Thomaidis, N.S.; Slobdonik, J.; Berendonk, T.U. Elevated levels of antibiotic resistance in groundwater during treated wastewater irrigation associated with infiltration and accumulation of antibiotic residues. J. Hazard. Mater. 2022, 423, 127155. [Google Scholar] [CrossRef] [PubMed]
  34. Guan, X.; Guo, Z.; Wang, X.; Xiang, S.; Sun, T.; Zhao, R.; He, J.; Liu, F. Transfer route and driving forces of antibiotic resistance genes from reclaimed water to groundwater. Environ. Pollut. 2023, 330, 121800. [Google Scholar] [CrossRef]
  35. Huang, F.-Y.; Zhou, S.-Y.-D.; Zhao, Y.; Zhou, X.-Y.; Li, H.; Zhang, X.; Su, J.-Q. Dissemination of antibiotic resistance genes from landfill leachate to groundwater. J. Hazard. Mater. 2022, 440, 129763. [Google Scholar] [CrossRef]
  36. Zou, H.-Y.; He, L.-Y.; Gao, F.-Z.; Zhang, M.; Chen, S.; Wu, D.-L.; Liu, Y.-S.; He, L.-X.; Bai, H.; Ying, G.-G. Antibiotic resistance genes in surface water and groundwater from mining affected environments. Sci. Total Environ. 2021, 772, 145516. [Google Scholar] [CrossRef]
  37. Liu, C.; Chen, J.; Shan, X.; Yang, Y.; Song, L.; Teng, Y.; Chen, H. Meta-analysis addressing the characterization and risk identification of antibiotics and antibiotic resistance genes in global groundwater. Sci. Total Environ. 2023, 860, 160513. [Google Scholar] [CrossRef]
  38. Wu, D.-L.; Zhang, M.; He, L.-X.; Zou, H.-Y.; Liu, Y.-S.; Li, B.-B.; Yang, Y.-Y.; Liu, C.; He, L.-Y.; Ying, G.-G. Contamination profile of antibiotic resistance genes in ground water in comparison with surface water. Sci. Total Environ. 2020, 715, 136975. [Google Scholar] [CrossRef]
  39. Zhao, Z.; Li, C.; Jiang, L.; Wu, D.; Shi, H.; Xiao, G.; Guan, Y.; Kang, X. Occurrence and distribution of antibiotic resistant bacteria and genes in the Fuhe urban river and its driving mechanism. Sci. Total Environ. 2022, 825, 153950. [Google Scholar] [CrossRef]
  40. Stange, C.; Yin, D.; Xu, T.; Guo, X.; Schafer, C.; Tiehm, A. Distribution of clinically relevant antibiotic resistance genes in Lake Tai, China. Sci. Total Environ. 2019, 655, 337–346. [Google Scholar] [CrossRef]
  41. Wu, T.; Zhang, Y.; Wang, B.; Chen, C.; Cheng, Z.; Li, Y.; Wang, B.; Li, J. Antibiotic resistance genes in Chishui River, a tributary of the Yangtze River, China: Occurrence, seasonal variation and its relationships with antibiotics, heavy metals and microbial communities. Sci. Total Environ. 2022, 846, 157472. [Google Scholar] [CrossRef] [PubMed]
  42. Zhang, Y.; Shen, G.; Hu, S.; He, Y.; Li, P.; Zhang, B. Deciphering of antibiotic resistance genes (ARGs) and potential abiotic indicators for the emergence of ARGs in an interconnected lake-river-reservoir system. J. Hazard. Mater. 2021, 410, 124552. [Google Scholar] [CrossRef] [PubMed]
  43. Zhang, L.; Ji, L.; Liu, X.; Zhu, X.; Ning, K.; Wang, Z. Linkage and driving mechanisms of antibiotic resistome in surface and ground water: Their responses to land use and seasonal variation. Water Res. 2022, 215, 118279. [Google Scholar] [CrossRef] [PubMed]
  44. Xu, K.; Wang, J.; Gong, H.; Li, Y.; Zhou, L.; Yan, M. Occurrence of antibiotics and their associations with antibiotic resistance genes and bacterial communities in Guangdong coastal areas. Ecotoxicol. Environ. Saf. 2019, 186, 109796. [Google Scholar] [CrossRef]
  45. Wang, J.-H.; Lu, J.; Wu, J.; Zhang, Y.; Zhang, C. Proliferation of antibiotic resistance genes in coastal recirculating mariculture system. Environ. Pollut. 2019, 248, 462–470. [Google Scholar] [CrossRef]
  46. Jo, H.; Raza, S.; Farooq, A.; Kim, J.; Unno, T. Fish farm effluents as a source of antibiotic resistance gene dissemination on Jeju Island, South Korea. Environ. Pollut. 2021, 276, 116764. [Google Scholar] [CrossRef]
  47. Carney, R.L.; Labbate, M.; Siboni, N.; Tagg, K.A.; Mitrovic, S.M.; Seymour, J.R. Urban beaches are environmental hotspots for antibiotic resistance following rainfall. Water Res. 2019, 167, 115081. [Google Scholar] [CrossRef]
  48. Zheng, D.; Yin, G.; Liu, M.; Chen, C.; Jiang, Y.; Hou, L.; Zheng, Y. A systematic review of antibiotics and antibiotic resistance genes in estuarine and coastal environments. Sci. Total Environ. 2021, 777, 146009. [Google Scholar] [CrossRef]
  49. Zhang, Y.; Lu, J.; Wu, J.; Wang, J.; Lin, Y. Occurrence and distribution of antibiotic resistance genes in sediments in a semi-enclosed continental shelf sea. Sci. Total Environ. 2020, 720, 137712. [Google Scholar] [CrossRef]
  50. Wu, C.; Zhang, G.; Zhang, K.; Sun, J.; Cui, Z.; Guo, Y.; Liu, H.; Xu, W. Strong variation in sedimental antibiotic resistomes among urban rivers, estuaries and coastal oceans: Evidence from a river-connected coastal water ecosystem in northern China. J. Environ. Manag. 2023, 342, 118132. [Google Scholar] [CrossRef]
  51. Lu, J.; Zhang, Y.; Wu, J.; Wang, J.; Zhang, C.; Lin, Y. Occurrence and spatial distribution of antibiotic resistance genes in the Bohai Sea and Yellow Sea areas, China. Environ. Pollut. 2019, 252, 450–460. [Google Scholar] [CrossRef] [PubMed]
  52. Liu, S.; Su, H.; Pan, Y.F.; Xu, X.R. Spatial and seasonal variations of antibiotics and antibiotic resistance genes and ecological risks in the coral reef regions adjacent to two typical islands in South China Sea. Mar. Pollut. Bull. 2020, 158, 111424. [Google Scholar] [CrossRef] [PubMed]
  53. Chen, J.; Su, Z.; Dai, T.; Huang, B.; Mu, Q.; Zhang, Y.; Wen, D. Occurrence and distribution of antibiotic resistance genes in the sediments of the East China Sea bays. J. Environ. Sci. 2019, 81, 156–167. [Google Scholar] [CrossRef] [PubMed]
  54. Guo, X.-P.; Zhao, S.; Chen, Y.-R.; Yang, J.; Hou, L.-J.; Liu, M.; Yang, Y. Antibiotic resistance genes in sediments of the Yangtze Estuary: From 2007 to 2019. Sci. Total Environ. 2020, 744, 140713. [Google Scholar] [CrossRef]
  55. Zheng, C.-L.; Zhu, D.; Xu, Y.-Y. Co-driving factors of tidal effect on the abundance and distribution of antibiotic resistance genes in the Yongjiang Estuary, China. Environ. Res. 2022, 213, 113649. [Google Scholar] [CrossRef]
  56. Li, W.; Su, H.; Cao, Y.; Wang, L.; Hu, X.; Xu, W.; Xu, Y.; Li, Z.; Wen, G. Antibiotic resistance genes and bacterial community dynamics in the seawater environment of Dapeng Cove, South China. Sci. Total Environ. 2020, 723, 137027. [Google Scholar] [CrossRef]
  57. Wang, X.; Lin, Y.; Zheng, Y.; Meng, F. Antibiotics in mariculture systems: A review of occurrence, environmental behavior, and ecological effects. Environ. Pollut. 2022, 293, 118541. [Google Scholar] [CrossRef]
  58. Cui, G.; Liu, Z.; Xu, W.; Gao, Y.; Yang, S.; Grossart, H.-P.; Li, M.; Luo, Z. Metagenomic exploration of antibiotic resistance genes and their hosts in aquaculture waters of the semi-closed Dongshan Bay (China). Sci. Total Environ. 2022, 838, 155784. [Google Scholar] [CrossRef]
  59. Gao, Q.; Li, Y.; Qi, Z.; Yue, Y.; Min, M.; Peng, S.; Shi, Z.; Gao, Y. Diverse and abundant antibiotic resistance genes from mariculture sites of China’s coastline. Sci. Total Environ. 2018, 630, 117–125. [Google Scholar] [CrossRef]
  60. He, L.-X.; He, L.-Y.; Gao, F.-Z.; Wu, D.-L.; Ye, P.; Cheng, Y.-X.; Chen, Z.-Y.; Hu, L.-X.; Liu, Y.-S.; Chen, J.; et al. Antibiotics, antibiotic resistance genes and microbial community in grouper mariculture. Sci. Total Environ. 2022, 808, 152042. [Google Scholar] [CrossRef]
  61. Ghachi, M.E.; Bouhss, A.; Blanot, D.; Mengin-Lecreulx, D. The bacA Gene of Escherichia coli Encodes an Undecaprenyl Pyrophosphate Phosphatase Activity. J. Biol. Chem. 2004, 279, 30106–30113. [Google Scholar] [CrossRef] [PubMed]
  62. Zhang, R.-M.; Liu, X.; Wang, S.-L.; Fang, L.-X.; Sun, J.; Liu, Y.-H.; Liao, X.-P. Distribution patterns of antibiotic resistance genes and their bacterial hosts in pig farm wastewater treatment systems and soil fertilized with pig manure. Sci. Total Environ. 2021, 758, 143654. [Google Scholar] [CrossRef] [PubMed]
  63. Williams, D.L.; Spring, L.; Collins, L.; Miller, L.P.; Heifets, L.B.; Gangadharam, P.R.J.; Gillis, T.P. Contribution of rpoB mutations to Development of rifamycin cross-resistance in Mycobacterium tuberculosis. Antimicrob. Agents Chemother. 1998, 42, 1853–1857. [Google Scholar] [CrossRef] [PubMed]
  64. Zaw, M.T.; Emran, N.A.; Lin, Z. Mutations inside rifampicin-resistance determining region of rpoB gene associated with rifampicin-resistance in Mycobacterium tuberculosis. J. Infect. Public Health 2018, 11, 605–610. [Google Scholar] [CrossRef]
  65. Koch, A.; Mizrahi, V.; Warner, D.F. The impact of drug resistance on Mycobacterium tuberculosis physiology: What can we learn from rifampicin? Emerg. Microbes Infect. 2019, 3, 1–11. [Google Scholar] [CrossRef]
  66. Zhou, L.; Xu, P.; Gong, J.; Huang, S.; Chen, W.; Fu, B.; Zhao, Z.; Huang, X. Metagenomic profiles of the resistome in subtropical estuaries: Co-occurrence patterns, indicative genes, and driving factors. Sci. Total Environ. 2022, 810, 152263. [Google Scholar] [CrossRef]
  67. Chen, Y.; Su, J.-Q.; Zhang, J.; Li, P.; Chen, H.; Zhang, B.; Gin, K.Y.-H.; He, Y. High-throughput profiling of antibiotic resistance gene dynamic in a drinking water river-reservoir system. Water Res. 2019, 149, 179–189. [Google Scholar] [CrossRef]
  68. Lu, X.-M.; Lu, P.-Z. Seasonal variations in antibiotic resistance genes in estuarine sediments and the driving mechanisms. J. Hazard. Mater. 2020, 383, 121164. [Google Scholar] [CrossRef]
  69. Lu, X.-M.; Peng, X.; Xue, F.; Qin, S.; Ye, S.; Dai, L.-B. Distance dilution of antibiotic resistance genes of sediments in an estuary system in relation to coastal cities. Environ. Pollut. 2021, 281, 116980. [Google Scholar] [CrossRef]
  70. Yang, Y.; Li, Z.; Song, W.; Du, L.; Ye, C.; Zhao, B.; Liu, W.; Deng, D.; Pan, Y.; Lin, H.; et al. Metagenomic insights into the abundance and composition of resistance genes in aquatic environments: Influence of stratification and geography. Environ. Int. 2019, 127, 371–380. [Google Scholar] [CrossRef]
  71. Zhao, Z.; Zhang, K.; Wu, N.; Li, W.; Xu, W.; Zhang, Y.; Niu, Z. Estuarine sediments are key hotspots of intracellular and extracellular antibiotic resistance genes: A high-throughput analysis in Haihe Estuary in China. Environ. Int. 2020, 135, 105385. [Google Scholar] [CrossRef] [PubMed]
  72. Zheng, D.; Yin, G.; Liu, M.; Hou, L.; Yang, Y.; Liu, X.; Jiang, Y.; Chen, C.; Wu, H. Metagenomics highlights the impact of climate and human activities on antibiotic resistance genes in China’s estuaries. Environ. Pollut. 2022, 301, 119015. [Google Scholar] [CrossRef] [PubMed]
  73. Zhou, S.-Y.-D.; Huang, F.-Y.; Zhou, X.-Y.; Lin, C.; Jin, M.-K.; Neilson, R.; Li, H.; Su, J.-Q. Conurbation size drives antibiotic resistance along the river. Sci. Total Environ. 2022, 823, 153822. [Google Scholar] [CrossRef] [PubMed]
  74. Tong, L.; Qin, L.; Guan, C.; Wilson, M.E.; Li, X.; Cheng, D.; Ma, J.; Liu, H.; Gong, F. Antibiotic resistance gene profiling in response to antibiotic usage and environmental factors in the surface water and groundwater of Honghu Lake, China. Environ. Sci. Pollut. 2020, 27, 31995–32005. [Google Scholar] [CrossRef]
  75. Xu, S.; Zhang, T.; Yan, R.; Wang, R.; Yi, Q.; Shi, W.; Gao, Y.; Zhang, Y. Environmental filtering dominated the antibiotic resistome assembly in river networks. Sci. Total Environ. 2022, 834, 155293. [Google Scholar] [CrossRef]
  76. Corno, G.; Yang, Y.; Eckert, E.M.; Fontaneto, D.; Fiorentino, A.; Galafassi, S.; Zhang, T.; Di Cesare, A. Effluents of wastewater treatment plants promote the rapid stabilization of the antibiotic resistome in receiving freshwater bodies. Water Res. 2019, 158, 72–81. [Google Scholar] [CrossRef]
  77. Elder, F.C.T.; Proctor, K.; Barden, R.; Gaze, W.H.; Snape, J.; Feil, E.J.; Kasprzyk-Hordern, B. Spatiotemporal profiling of antibiotics and resistance genes in a river catchment: Human population as the main driver of antibiotic and antibiotic resistance gene presence in the environment. Water Res. 2021, 203, 117533. [Google Scholar] [CrossRef]
  78. Zhang, L.; Ju, Z.; Su, Z.; Fu, Y.; Zhao, B.; Song, Y.; Wen, D.; Zhao, Y.; Cui, J. The antibiotic resistance and risk heterogeneity between urban and rural rivers in a pharmaceutical industry dominated city in China: The importance of social-economic factors. Sci. Total Environ. 2022, 852, 158530. [Google Scholar] [CrossRef]
  79. Wang, J.; Lu, J.; Wu, J.; Feng, Y. Seasonal distribution of antibiotic resistance genes under the influence of land-ocean interaction in a semi-enclosed bay. Chemosphere 2022, 301, 134718. [Google Scholar] [CrossRef]
  80. Jeong, S.H.; Kwon, J.Y.; Shin, S.B.; Choi, W.S.; Lee, J.H.; Kim, S.-J.; Ha, K.S. Antibiotic resistance in shellfish and major inland pollution sources in the drainage basin of Kamak Bay, Republic of Korea. Environ. Monit. Assess. 2021, 193, 471. [Google Scholar] [CrossRef]
  81. Suzuki, S.; Nakanishi, S.; Tamminen, M.; Yokokawa, T.; Sato-Takabe, Y.; Ohta, K.; Chou, H.-Y.; Muziasari, W.I.; Virta, M. Occurrence of sul and tet (M) genes in bacterial community in Japanese marine aquaculture environment throughout the year: Profile comparison with Taiwanese and Finnish aquaculture waters. Sci. Total Environ. 2019, 669, 649–656. [Google Scholar] [CrossRef] [PubMed]
  82. Zhang, M.; Hou, L.; Zhu, Y.; Zhang, C.; Li, W.; Lai, X.; Yang, J.; Li, S.; Shu, H. Composition and distribution of bacterial communities and antibiotic resistance genes in fish of four mariculture systems. Environ. Pollut. 2022, 311, 119934. [Google Scholar] [CrossRef] [PubMed]
  83. Jia, L.; Liu, H.; Zhao, N.; Deng, Q.; Zhu, C.; Zhang, B. Distribution and Transfer of Antibiotic Resistance Genes in Coastal Aquatic Ecosystems of Bohai Bay. Water 2022, 14, 938. [Google Scholar] [CrossRef]
Water 17 01282 g001
Figure 1. Study area of freshwater and seawater.
Figure 1. Study area of freshwater and seawater.
Water 17 01282 g001
Water 17 01282 g002
Figure 2. Artificial source of ARGs in freshwater and seawater.
Figure 2. Artificial source of ARGs in freshwater and seawater.
Water 17 01282 g002
Water 17 01282 g005
Figure 5. Artificial source, occurrence, and fate-effecting factors of ARGs in freshwater and seawater.
Figure 5. Artificial source, occurrence, and fate-effecting factors of ARGs in freshwater and seawater.
Water 17 01282 g005
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Jiang, P.; Chang, J.; Xia, Y.; Li, X.; Li, L.; Liu, X.; Fang, L. Differences of Occurrence, Distribution, and Factors Influencing Antibiotic Resistance Genes Between Freshwater and Seawater in China. Water 2025, 17, 1282. https://doi.org/10.3390/w17091282

AMA Style

Jiang P, Chang J, Xia Y, Li X, Li L, Liu X, Fang L. Differences of Occurrence, Distribution, and Factors Influencing Antibiotic Resistance Genes Between Freshwater and Seawater in China. Water. 2025; 17(9):1282. https://doi.org/10.3390/w17091282

Chicago/Turabian Style

Jiang, Pei, Jiali Chang, Yu Xia, Xia Li, Liping Li, Xinhui Liu, and Le Fang. 2025. "Differences of Occurrence, Distribution, and Factors Influencing Antibiotic Resistance Genes Between Freshwater and Seawater in China" Water 17, no. 9: 1282. https://doi.org/10.3390/w17091282

APA Style

Jiang, P., Chang, J., Xia, Y., Li, X., Li, L., Liu, X., & Fang, L. (2025). Differences of Occurrence, Distribution, and Factors Influencing Antibiotic Resistance Genes Between Freshwater and Seawater in China. Water, 17(9), 1282. https://doi.org/10.3390/w17091282

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop