Fate of antibiotic resistance genes in sewage treatment plant revealed by metagenomic approach

Fate of antibiotic resistance genes in sewage treatment plant revealed by metagenomic approach

Accepted Manuscript Fate of Antibiotic Resistance Genes in Sewage Treatment Plant Revealed by Metagenomic Approach Ying Yang , Bing Li , Shichun Zou ,...

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Accepted Manuscript Fate of Antibiotic Resistance Genes in Sewage Treatment Plant Revealed by Metagenomic Approach Ying Yang , Bing Li , Shichun Zou , Herbert H.P. Fang , Tong Zhang PII:

S0043-1354(14)00372-8

DOI:

10.1016/j.watres.2014.05.019

Reference:

WR 10673

To appear in:

Water Research

Received Date: 7 February 2014 Revised Date:

12 May 2014

Accepted Date: 13 May 2014

Please cite this article as: Yang, Y., Li, B., Zou, S., Fang, H.H.P., Zhang, T., Fate of Antibiotic Resistance Genes in Sewage Treatment Plant Revealed by Metagenomic Approach, Water Research (2014), doi: 10.1016/j.watres.2014.05.019. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

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Fate of Antibiotic Resistance Genes in Sewage Treatment Plant

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Revealed by Metagenomic Approach

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Ying Yanga, Bing Lia, Shichun Zoub, Herbert H.P. Fanga, Tong Zhanga,*

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a

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University of Hong Kong, Hong Kong SAR, China

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b

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Yat-Sen University, Guangzhou 510000, China

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*

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Address: Environmental Biotechnology Laboratory, Department of Civil Engineering,

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Environmental Biotechnology Laboratory, Department of Civil Engineering, The

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Corresponding author

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Institute of Marine Science and Technology, School of Marine Sciences, Sun

The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China

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Email: [email protected]

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Tel: +852-2857 8551

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Fax: +852-2859 8987

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ACCEPTED MANUSCRIPT ABSTRACT

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Antibiotic resistance has become a serious threat to human health. Sewage treatment

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plant (STP) is one of the major sources of antibiotic resistance genes (ARGs) in

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natural environment. High-throughput sequencing-based metagenomic approach was

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applied to investigate the broad-spectrum profiles and fate of ARGs in a full scale STP.

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Totally, 271 ARGs subtypes belonging to 18 ARGs types were identified by the broad

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scanning of metagenomic analysis. Influent had the highest ARGs abundance,

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followed by effluent, anaerobic digestion sludge and activated sludge. 78 ARGs

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subtypes persisted through the biological wastewater and sludge treatment process.

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The high removal efficiency of 99.82% for total ARGs in wastewater suggested that

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sewage treatment process is effective in reducing ARGs. But the removal efficiency of

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ARGs in sludge treatment was not as good as that in sewage treatment. Furthermore,

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the composition of microbial communities was examined and the correlation between

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microbial community and ARGs was investigated using redundancy analysis.

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Significant correlation between 6 genera and the distribution of ARGs were found and

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5 of the 6 genera included potential pathogens. This is the first study on the fate of

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ARGs in STP using metagenomic analysis with high-throughput sequencing and

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hopefully would enhance our knowledge on fate of ARGs in STP.

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Keywords: Antibiotic resistance genes; Sewage treatment plant; Metagenomic

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analysis; Bacterial community

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ACCEPTED MANUSCRIPT 1. Introduction

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The intensive use of antibiotics for medical treatment, veterinary or agriculture

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proposes resulted in the continuous release of antibiotics into the environment and

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subsequently the widespread of antibiotic resistance. The escalating of antibiotic

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resistance has become a serious threat to human health because of the reduced

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susceptibility of disease-causing microorganisms to antibiotics in medical treatment

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(Abuzaid et al., 2012; Noguchi et al., 2007). Reports on the global spread of antibiotic

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resistance genes (ARGs) are still on the rise (Allen et al., 2010; Zhang et al., 2006;

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Zhang et al., 2009b; Laxminarayan et al., 2013). ARGs have been detected in natural

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water bodies and drinking water (Jiang et al., 2013; Xu et al., 2014), soil (Su et al.,

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2014) and even deep ocean sediment (Chen et al., 2013), nit nd 0

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ACCEPTED MANUSCRIPT DNA extraction. The pellet of influent and the membrane of effluent samples were

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used for DNA extraction directly. DNA extraction was conducted using FastDNA®

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Spin kit for Soil (MP Biomedicals, CA, USA). DNA of influent samples collected

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from July, August, September of 2011 were pooled as one influent DNA sample

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while DNA of influent samples collected from November, December of 2011 and

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January of 2012 were pooled as another DNA sample to avoid monthly fluctuation of

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ARGs in the influent. Similar to influent, DNA of effluent collected from July,

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August, September of 2011 were pooled as one DNA sample and DNA of effluent

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collected from November, December of 2011 and January in 2012 were pooled as

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another effluent DNA sample. Since the microbial composition in AS or ADS is

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relatively stable, DNA samples from sludge were not composited. AS samples

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collected from January 2011 and March 2012, and ADS samples collected from

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September 2011 and March 2012 were used for DNA extraction, separately. DNA

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concentration and purity were determined by microspectrophotometry (NanoDrop

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ND-1000, NanoDrop Technologies, Willmington, DE). In summary, two DNA

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samples were used to study ARGs in each kind of sample, including influent, effluent,

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AS and ADS.

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2.3 Illumina sequencing and bioinformatics analysis

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High-throughput sequencing was conducted using Illumian Hiseq 2000 at Beijing

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Genomics Institute (BGI, Shenzhen, China). Approximately 6 µg of each DNA

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sample was used for library construction. The sequencing strategy was index

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PE101+8+101 cycle (Paired-End sequencing, 101-bp reads and 8-bp index sequence).

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ACCEPTED MANUSCRIPT The generated metagenomic data was first filtered to remove reads containing three or

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more ambiguous nucleotides, or with quality score below 30, or with sequence length

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less than 100 bp. A customized python script was used to remove artificial replicates

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generated by the platforms of high-throughput sequencing, which may lead to

inot 1525(r)2.80439(e-2.16436(o)-74295-0.29558517i

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incorrect conclusions in the subsequent datoit

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(Fig. S3). At genus level, the differences of bacterial communities became more divergent

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(Table S8). For influent samples, the most abundant genus was Streptococcus

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belonging to the phylum of Firmicutes (12.7%). For effluent samples, the most

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abundant genus shift to Mycobacterium of the phylum of Actinobacteria with a much

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higher percentage (30.7%). The most abundant genus in AS was Nitrospira (8.76%), a

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nitrite-oxidizing bacteria. However, the most abundant genus in anaerobic digestion

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sludge was Kosmotoga (36.1%), which was a genus mainly found in anaerobic marine

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environments (Swithers et al., 2011).

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The composition of microbial communities would affect the occurrence and

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abundance of ARGs, but the information on the impact of microbial community

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composition on ARGs profiles in environmental samples was still very limited.

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Although broad profile of ARGs and composition of microbial communities can be

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revealed by metagenomic analysis, the correlation between them was very

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complicated. Hence multi-parametric analysis was applied to assess the influence of

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the microbial communities on the distribution of ARGs in wastewater treatment

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process in this study, which might shed some light on these complex relations and

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provide some information to the control of ARGs in environment through wastewater

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treatment process.

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The correlation was examined through RDA based on percentages of the 283

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genera and abundances of the 78 identified persistent ARGs in the samples collected

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from ST STP. Genera were analyzed as the environmental factors for ARGs. As 19

ACCEPTED MANUSCRIPT shown in Fig. 4, among the 283 identified genera, 6 genera including Flavobacterium

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(G1), Poriferibacter (G2), Bacteroides (G3), Acinetobacter (G4), Actinobaculum (G5)

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and Streptococcus (G6), were significantly correlated with the distribution of ARGs in

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ST STP samples (P=0.002), indicating that these genera possibly played important

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roles in shaping the ARGs profiles in ST STP.

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Except Poriferibacter, all the other 5 genera belonged to human or aquaculture

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pathogens, indicating that the existence of pathogens is one important factor on ARGs

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distribution in STP environment. ARGs have been frequently detected in the

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pathogens of those genera. In detail, the multidrug resistance gene mexB were

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detected in the aquaculture pathogenic Flavobacterium spp. (Clark et al., 2009).

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Multiple ARGs, including cepA, cfxA, cfiA, ermB, ermF, ermG, linA, mefA, msrSA,

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tetQ, tetX and bexA, were detected in the human opportunistic pathogen Bacteroides

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strains (Eitel et al., 2013). Resistance genes of RND efflux pump or OXA-type

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carbapenemases were detected in Acinetobacter strains (Farahani et al., 2013;

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Wieczorek et al., 2008). Quinolone resistance genes were detected in Actinobaculum

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strains (Cattoir et al., 2010) and resistance genes for macrolide and tetracycline were

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detected in Streptococcus strains (Pavlovic et al., 2010; Seppala, 2003).

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The persistent ARGs can be grouped as 3 clusters according to the RDA results

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(Fig. 4, ARGs subtypes in each cluster were listed in Table S9). Cluster 1 was

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positively affected by Flavobacterium (G1) and Poriferibacter (G2). Cluster 2 was

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positively affected by all of the 6 genera. Cluster 3 was significantly affected by

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Bacteroides (G3), Acinetobacter (G4), Actinobaculum (G5) and Streptococcus (G6) in 20

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2011. Quantification and characterization of β-lactam resistance genes in 15 sewage treatment plants from

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East Asia and North America. Applied Microbiology and Biotechnology 95(5), 1351-1358.

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revealed by 16S rDNA 454 pyrosequencing. Applied Microbiology and Biotechnology 97(6), 2381-2690.

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Ye, L., Zhang, T., 2012. Bacterial communities in different sections of a municipal wastewater treatment plant

Zhang, R., Eggleston, K., Rotimi, V., Zeckhauser, R.J., 2006. Antibiotic resistance as a global threat: evidence

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from

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http://dx.doi.org/10.1186/1744-8603-2-6.

China,

Kuwait

and

the

United

States.

Globalization

and

Health.

SC

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Zhang, T., Zhang, M., Zhang, X.X., Fang, H.H.P,, 2009a. Tetracycline resistance genes and tetracycline resistant

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lactose-fermenting Enterobacteriaceae in activated sludge of sewage treatment plants. Environmental

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Science & Technology 43(10), 3455-3460.

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mobile genetic elements in activated sludge. PLoS ONE. http://dx.doi.org/10.1371/journal.pone.0026041

Zhang, X. X., Zhang, T. and P.Fang, H.H.P., 2009b. Antibiotic resistance genes in water environment. Applied

Microbiology and Biotechnology 82(3), 397-414.

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Zhang, T., Zhang, X.X., Ye, L., 2011. Plasmid metagenome reveals high levels of antibiotic resistance genes and

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ACCEPTED MANUSCRIPT

Table for

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Fate of Antibiotic Resistance Genes in Sewage Treatment Plant

3

Revealed by Metagenomic Approach

4

Ying Yanga, Bing Lia, Shichun Zoub, Herbert H.P. Fanga, Tong Zhanga,*

5

a

6

University of Hong Kong, Hong Kong SAR, China

7

b

8

University, Guangzhou 510000, China

9

*

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1

Environmental Biotechnology Laboratory, Department of Civil Engineering, The

M AN U

Corresponding author

SC

Institute of Marine Science and Technology, School of Marine Sciences, Sun Yat-Sen

Address: Environmental Biotechnology Laboratory, Department of Civil Engineering,

11

The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China

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Email: [email protected]

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Tel: +852-2857 8551

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Fax: +852-2859 8987

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List of Table

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Table 1 - Removal efficiency from influent to effluent, and from AS to ADS

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ACCEPTED MANUSCRIPT Table 1 - Removal efficiency from influent to effluent, and from AS to ADS

ADS N/A 4.40 4.00 1.18 1.88 N/A 0.47 N/A N/A 11.1 3.98 0.42 0.89 3.41 13.6 0.04 0.23 1.89 47.4

Water 99.22 99.89 99.76 99.83 99.77 99.81 99.02 99.94 99.90 99.93 99.89 99.90 99.43 98.09 99.93 99.91 99.96 99.92 99.82

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AS N/A 3.15 3.30 3.03 2.59 N/A 0.79 N/A 0.03 2.04 4.58 0.03 0.63 3.50 4.86 0.02 0.01 1.38 29.9

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Effluent 0.03 3.19 15.4 2.41 6.36 0.04 5.50 0.02 0.07 3.34 10.5 0.14 8.72 15.9 7.56 0.08 0.04 3.28 82.6

Sludge N/A 30.16 39.39 80.53 63.71 N/A 70.25 N/A 100 -172.1 56.55 -600.0 29.37 51.29 -39.92 0 -1050 31.52 20.74

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Acridine Acriflavine Aminoglycoside Bacitracin Beta-lactam Bicyclomycin Chloramphenicol Fosfomycin Fosmidomycin MLS Multidrug Polymyxin Quinolone Sulfonamide Tetracycline Trimethoprim Vancomycin Others Total

Influent 0.05 39.1 84.5 18.4 36.0 0.27 7.30 0.41 0.88 58.4 122 1.78 19.9 10.8 138 1.12 1.37 55.0 595

Removal efficiency /%

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Average abundance/ppm

ARGs type

* The removal efficiency with negative value indicated that the ARGs were enriched after

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treatment.

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ACCEPTED MANUSCRIPT Fig. 3 - Average abundances of ARG subtypes in influent, effluent, AS and ADS. From influent to effluent, subtypes with removal rate larger than 99.99% were marked with “**”. Subtypes with removal rate larger than 99.90% were

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marked with “*”. From AS to ADS, subtypes with removal rate larger than 90% were marked with “◎”, subtypes that were enriched by more than 10 times

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(removal rate lower than -1000%) were marked with “◇”.

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ACCEPTED MANUSCRIPT Fig. 4 - Redundancy analysis (RDA) identified the correlation of genera and ARGs in samples collected in ST WWTP. Six genera were significantly correlated with the distribution of ARGs (P=0.002). They are Flavobacterium (G1),

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Poriferibacter (G2), Bacteroides (G3), Acinetobacter (G4), Actinobaculum (G5) and Streptococcus (G6). The persistent ARGs can be grouped into 3 clusters according to the RDA result. ARGs subtypes in each cluster are

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summarized in Table S9.

ACCEPTED MANUSCRIPT Highlights: Biological wastewater treatment removed 99.8% of antibiotic resistance genes.



Anaerobic digestion removed 20.7% of antibiotic resistance genes from sludge.



Persistence of 78 antibiotic resistance subtypes was identified.



Significant correlation between 6 genera and antibiotic resistance genes was

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found.

ACCEPTED MANUSCRIPT Supplementary Materials for

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Fate of Antibiotic Resistance Genes in Sewage Treatment Plant

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Revealed by Metagenomic Approach

4

Ying Yanga, Bing Lia, Shichun Zoub, Herbert H.P. Fanga, Tong Zhanga,*

5

a

6

University of Hong Kong, Hong Kong SAR, China

7

b

8

Yat-Sen University, Guangzhou 510000, China

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*

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1

Environmental Biotechnology Laboratory, Department of Civil Engineering, The

M AN U

Corresponding author

SC

Institute of Marine Science and Technology, School of Marine Sciences, Sun

Address: Environmental Biotechnology Laboratory, Department of Civil Engineering,

11

The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China

12

Email: [email protected]

13

Tel: +852-2857 8551

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Fax: +852-2859 8987

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ACCEPTED MANUSCRIPT List of Tables

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Table S1 - Detailed information of the samples

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Table S2 - Monitor parameters of influent and effluent samples from Shatin WWTP

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Table S3 - Abundances of ARG types in influent, effluent, AS and ADS

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Table S4 - Percentage of ARGs types in influent, effluent, AS and ADS.

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Table S5 - Abundances and percentages of the top 10 ARGs subtypes from non-persistent ARGs in influent

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Table S6 - Average abundances and removal rate of the persistent ARG subtypes

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Table S7 - Removal efficiency of ARGs in previous studies and this study.

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Table S8 - Top 5 genera in the influent, effluent, AS and ADS

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Table S9 - Persistent ARGs subtypes in each cluster in RDA

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Table S10 - Total abundances of ARGs in different clusters from RDA

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ACCEPTED MANUSCRIPT List of Figures

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Fig. S1 Flowchart of the ST WWTP and the sampling site of the samples of influent

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(IN-1 and IN-2), effluent (EF-1 and EF-2), activated sludge (AS-1 and AS-2)

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and anaerobic digestion sludge (ADS-1 and ADS-2).

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Fig. S2 Percentage of the persistent ARGs types in influent, effluent, AS and ADS.

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Fig. S3 Microbial compositions at phylum level in influent, effluent, AS and ADS.

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AS-2

March 2012

30,634,077

ADS-1

September 2011

11,825,380

ADS-2

March 2012

32,744,699

IN-2 EF-1 Effluent EF-2 Activated sludge Anaerobic digestion sludge

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Influent

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IN-1

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Number of clean metagenomic sequences

AS-1

Sampling time Composite sample collected from July, August and September 2011Composite sample collected from November, December 2011 and January 2012 Composite sample collected from July, August and September 2011 Composite sample collected from November, December 2011and January 2012 January 2011

31,035,681 34,003,203 33,083,035 27,948,384 49,149,488

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Name

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Type

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Table S1 - Detailed information of the samples

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Table S2 - Water quality parameters of influent and effluent samples from Shatin WWTP

pH

CBOD (mg/L)

SCOD (mg/L)

COD (mg/L)

TSS (mg/L)

NH3-N (mg/L)

TKN-N (mg/L)

NOX-N (mg/L)

Ortho-PO4 (mg/L)

TP (mg/L)

July 2011

7.2

310

63

740

430

21

43

<2.8

1.5

5.1

August 2011

7.2

>360

110

1040

430

27

54

<2.9

1.9

5.8

September 2011

7.3

>360

120

860

450

32

61

<1.6

<2.5

7.8

November 2011

7.1

360

110

920

490

27

41

4.6

1.8

6.2

December 2011

7.4

350

120

880

470

35

67

<2.9

3.0

8.7

January 2012

7.6

370

120

920

510

33

73

<1.7

3.5

8.5

TSS (mg/L)

NH3-N (mg/L)

TKN-N (mg/L)

NOX-N (mg/L)

Ortho-PO4 (mg/L)

TP (mg/L)

Cl(mg/L)

E. coli (/100mL)

430

21

43

<2.8

1.5

5.1

<108

8

430

27

54

<2.9

1.9

5.8

<110

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Effluent

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Sampling month

SC

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Influent

COD (mg/L)

pH

July 2011

7.2

310

63

740

August 2011

7.2

>360

110

1040

September 2011

7.3

>360

120

860

450

32

61

<1.6

<2.5

7.8

<114

12

November 2011

7.1

360

110

920

490

27

41

4.6

1.8

6.2

<105

5

December 2011

7.4

350

120

880

470

35

67

<2.9

3.0

8.7

204

3

January 2012

7.6

370

120

920

510

33

73

<1.7

3.5

8.5

240

4

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SCOD (mg/L)

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CBOD (mg/L)

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MLS : Macrolide-lincosamide-streptogramin. N/A : not available.

0.05 39.1 84.5 18.4 36.0 0.27 7.30 0.41 0.88 58.4 122 1.78 19.9 10.8 138 1.12 1.37 55.0 595

0.06 3.60 21.6 1.66 5.56 N/A 8.43 0.03 0.06 4.53 12.1 0.21 6.77 6.89 9.25 0.09 N/A 3.23 84.0

N/A 2.79 9.27 3.15 7.16 0.07 2.58 N/A 0.07 2.15 8.95 0.07 10.7 24.9 5.87 0.07 0.04 3.33 81.2

0.03 3.19 15.4 2.41 6.36 0.04 5.50 0.02 0.07 3.34 10.5 0.14 8.72 15.9 7.56 0.08 0.04 3.28 82.6

N/A 2.36 3.93 2.40 3.52 N/A 0.94 N/A 0.02 2.64 3.36 0.02 0.47 3.01 4.94 0.04 0.02 1.16 28.8

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0.06 45.1 62.9 21.5 40.7 0.38 7.29 0.59 1.15 49.7 156 2.56 32.9 12.9 158 1.26 1.71 69.4 664

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0.03 33.0 106 15.3 31.4 0.16 7.31 0.23 0.61 67.1 88.6 1.00 6.93 8.64 117 0.97 1.03 40.6 526

EF_1

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Acridine Acriflavine Aminoglycoside Bacitracin Beta-lactam Bicyclomycin Chloramphenicol Fosfomycin Fosmidomycin MLS Multidrug Polymyxin Quinolone Sulfonamide Tetracycline Trimethoprim Vancomycin Others Total

Influent IN_2 Average

Abundance/ppm Effluent Activated sludge EF_2 Average AS_1 AS_2 Average

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IN_1

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ARG type

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Table S3 - Abundances of ARG types in influent, effluent, AS and ADS

N/A 3.95 2.68 3.66 1.66 N/A 0.65 N/A 0.03 1.44 5.81 0.03 0.78 3.98 4.77 N/A N/A 1.60 31.0

N/A 3.15 3.30 3.03 2.59 N/A 0.79 N/A 0.03 2.04 4.58 0.03 0.63 3.50 4.86 0.02 0.01 1.38 29.9

Anaerobic digestion sludge ADS_1 ADS_2 Average N/A 3.72 5.92 1.27 2.54 N/A 0.51 N/A N/A 14.5 3.72 0.59 1.27 2.79 18.5 0.08 0.25 2.54 58.2

N/A 5.07 2.08 1.10 1.22 N/A 0.43 N/A N/A 7.67 4.24 0.24 0.52 4.03 8.58 N/A 0.21 1.25 36.6

N/A 4.40 4.00 1.18 1.88 N/A 0.47 N/A N/A 11.1 3.98 0.42 0.89 3.41 13.6 0.04 0.23 1.89 47.4

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Table S4 - Percentage of ARGs types in influent, effluent, AS and ADS.

MLS : Macrolide-lincosamide-streptogramin. N/A : not available.

0.01 6.54 14.8 3.08 6.04 0.04 1.24 0.07 0.14 10.1 20.2 0.29 3.13 1.79 23.1 0.19 0.23 9.08

0.07 4.28 25.7 1.98 6.62 N/A 10.0 0.04 0.07 5.40 14.4 0.25 8.06 8.20 11.0 0.11 N/A 3.85

N/A 3.44 11.4 3.88 8.82 0.09 3.17 N/A 0.09 2.65 11.0 0.09 13.1 30.7 7.23 0.09 0.04 4.10

0.04 3.86 18.5 2.93 7.72 0.04 6.61 0.02 0.08 4.02 12.7 0.17 10.6 19.5 9.12 0.10 0.02 3.97

AS_1

AS AS_2

Average

N/A 8.19 13.6 8.33 12.2 N/A 3.25 N/A 0.07 9.17 11.6 0.07 1.62 10.4 17.2 0.14 0.07 4.02

N/A 12.7 8.62 11.8 5.36 N/A 2.10 N/A 0.11 4.63 18.7 0.11 2.52 12.8 15.4 N/A N/A 5.15

N/A 10.5 11.1 10.1 8.79 N/A 2.67 N/A 0.09 6.90 15.2 0.09 2.07 11.6 16.3 0.07 0.04 4.59

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0.01 6.80 9.47 3.24 6.12 0.06 1.10 0.09 0.17 7.49 23.5 0.39 4.95 1.94 23.8 0.19 0.26 10.4

Effluent EF_2 Average

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0.01 6.28 20.2 2.91 5.96 0.03 1.39 0.04 0.12 12.8 16.8 0.19 1.32 1.64 22.3 0.18 0.20 7.71

EF_1

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Acridine Acriflavine Aminoglycoside Bacitracin Beta-lactam Bicyclomycin Chloramphenicol Fosfomycin Fosmidomycin MLS Multidrug Polymyxin Quinolone Sulfonamide Tetracycline Trimethoprim Vancomycin Others

Influent IN_2 Average

EP

IN_1

ADS ADS_1 ADS_2 Average N/A 6.40 10.2 2.18 4.36 N/A 0.87 N/A N/A 24.9 6.40 1.02 2.18 4.80 31.8 0.15 0.44 4.36

N/A 13.8 5.67 3.00 3.33 N/A 1.17 N/A N/A 20.9 11.6 0.67 1.42 11.0 23.4 N/A 0.58 3.42

N/A 10.1 7.92 2.59 3.85 N/A 1.02 N/A N/A 22.9 8.99 0.84 1.80 7.90 27.6 0.07 0.51 3.89

AC C

ARG type

RI PT

Percentage/%

S7

ACCEPTED MANUSCRIPT

Abundance/ppm

Others Multidrug Multidrug MLS Multidrug Multidrug Multidrug Tetracycline

0.35

8.50

N/D

0.19

7.77

0.38

0.02

7.47

0.52

0.04

7.20 6.70

0.28 N/D

6.20 5.88 4.02 4.05 66.8

0.18

Percentage/% 0.42

Activate Sludge N/D

Anaerobic Digestion Sludge 0.07

1.50

N/D

0.67

0.33

N/D

1.28

0.46

0.07

N/D

N/D

1.22

0.63

0.12

N/D

0.02 0.16

N/D 0.74

1.18 1.20

0.34 N/D

0.07 0.56

N/D 1.50

0.22

0.01

N/D

1.02

0.26

0.04

N/D

0.23 0.25 0.13 2.36

N/D N/D 0.03 0.47

0.04 N/D N/D 1.01

0.95 0.67 0.70 11.2

0.28 0.30 0.16 2.85

N/D N/D 0.11 1.64

0.07 N/D N/D 1.97

SC

Aminoglycoside

9.01

Anaerobic Digestion Sludge 0.04

M AN U

acrA bifunctional enzyme aacA_aphD dimethyladenosine transferase outer membrane protein TolC mdtO mefE (bicyclomycin) multidrug efflux system mdtL mdfA tetA(39) Total

Effluent

TE D

Acriflavine

Influent

Activate Sludge N/D

Influent

Effluent

1.50

EP

ARGs subtype

AC C

ARGs type

RI PT

Table S5 - Abundances and percentages of the top 10 ARGs subtypes from non-persistent ARGs in influent

S8

ACCEPTED MANUSCRIPT

Table S6 - Average abundances and removal rate of the persistent ARG subtypes

acrB aadA aminoglycoside 2-N-acetyltransferase aminoglycoside 3-phosphotransferase * aminoglycoside 6-phosphotransferase * aminoglycoside acetyltransferase aminoglycoside resistance protein * aminoglycoside resistance protein A * aminoglycoside resistance protein B * streptomycin phosphotransferase_strB undecaprenol kinase undecaprenyl-diphosphatase beta-lactamase class A beta-lactamase NPS-1 OXA gene OXA-10 OXA-46 penicillin binding protein * penicillin-binding protein 2 *

Aminoglycoside

Beta-lactam

AC C

EP

Bacitracin

Effluent

AS

ADS

30.1 7.34 0.02 1.36 25.8 5.42 1.65 27.0 1.55 1.25 3.92 10.1 4.80 3.94 2.21 0.31 1.92 0.11 2.36 1.05

2.84 6.16 0.04 0.05 1.14 4.99 0.10 1.81 0.09 0.36 1.19 0.80 0.39 1.59 0.70 0.05 1.86 0.08 0.04 0.02

3.15 0.81 0.01 0.02 0.86 0.38 0.04 0.68 0.06 0.24 1.70 1.07 0.16 0.21 0.95 0.02 0.17 0.05 0.05 0.01

4.35 0.81 0.05 0.08 0.99 0.60 0.02 0.81 0.13 0.06 0.74 0.40 0.19 0.15 0.30 0.04 0.23 0.03 0.07 0.03

SC

Acriflavine

Influent

M AN U

ARG Subtype

TE D

ARG Type

RI PT

Average Abundance/ppm

Removal Rate/% From From AS Influent to to ADS Effluent 99.88 31.02 98.91 49.76 97.12 -125.2 99.96 -107.8 99.94 42.29 98.81 21.29 99.92 79.18 99.91 40.60 99.92 -0.41 99.63 88.03 99.60 78.22 99.90 81.14 99.89 40.89 99.48 65.64 99.59 84.06 99.81 -29.53 98.74 30.91 99.10 68.82 99.98 31.29 99.98 -50.10

VEB-1

1.01

0.32

0.56

0.34

99.59

69.89

VEB-3

0.09

0.05

0.10

0.05

99.37

77.95 S9

ACCEPTED MANUSCRIPT

AC C

Multidrug

EP

TE D

MLS

0.05 0.05 0.21 0.22 0.15 0.08 0.12 0.04 0.44 0.05 0.04 0.19 0.75 0.08 0.04 0.02

0.08 0.05 0.02 0.03 0.33 0.02 0.58 0.34 1.41 0.34 0.16 1.86 0.69 2.59 1.41 0.26

99.41 99.90 99.74 99.88 99.92 99.94 99.99 99.87 94.39 99.61 99.99 99.98 99.81 99.99 99.98 99.98

20.21 51.10 96.40 93.18 -12.51 90.39 -139.1 -359.7 -62.18 -221.4 -83.79 -382.2 54.38 -1493 -1629 -532.1

15.9

2.03

0.85

1.23

99.83

27.32

9.79 3.98 2.85 2.84 2.16 0.34 1.60 14.8 4.10

0.33 0.21 0.19 0.17 0.63 0.03 0.95 2.04 0.18

0.18 0.02 0.02 0.01 1.45 0.12 0.16 1.38 0.02

0.08 0.02 0.02 0.02 0.76 0.06 0.06 1.08 0.03

99.96 99.93 99.92 99.92 99.62 99.87 99.23 99.82 99.94

78.96 53.22 53.22 24.95 73.87 75.67 81.90 60.92 6.450

RI PT

0.16 0.10 0.20 0.14 0.09 0.26 0.19 0.17 1.72 0.14 0.02 0.17 0.50 0.03 0.03 0.02

SC

0.36 1.30 0.99 1.55 1.50 5.31 16.3 1.68 0.40 0.47 2.78 9.27 3.36 4.47 2.39 1.23

M AN U

Chloramphenicol

VIM-11 chloramphenicol acetyltransferase * chloramphenicol and florfenicol exporter cmlA9 florfenicol exporter * ABC-type efflux carrier * ermB * ermF erythromycin esterase erythromycin esterase type 1 erythromycin ribosome methylase ** macB ** macrolide transporter macrolide-efflux protein mef gene * mefA * hydrophobe_amphiphile efflux-1 (HAE1) family protein mdtF * mdtG * mdtH * mdtN * mexB mexD mexF multidrug efflux protein multidrug resistance protein D *

S10

ACCEPTED MANUSCRIPT

0.05 0.02 0.01 0.07 0.13 0.03 0.63 0.86 2.64

0.28 0.13 0.05 0.05 0.07 0.42 0.89 0.35 3.06

99.96 99.66 99.93 99.73 99.88 99.90 99.42 99.83 97.55

-163.8 -211.7 -125.2 65.91 72.95 -689.1 28.58 79.72 41.93

0.92

0.05

0.09

0.19

99.93

-4.060

31.1 2.72 0.28 1.25 0.63 2.12 0.73 3.10 33.3 3.85 9.57 7.59 0.19 31.2 0.25 32.6 1.80 0.14

0.31 0.12 0.19 2.53 0.02 0.19 0.05 0.36 0.65 0.02 0.66 0.42 0.34 1.18 0.02 1.61 0.07 0.19

0.56 0.03 0.08 0.10 0.04 0.02 0.07 0.65 0.88 0.02 0.15 1.14 0.05 0.59 0.20 0.67 0.01 0.51

1.95 0.06 0.21 0.62 0.13 0.04 0.16 0.23 4.85 0.22 0.35 0.77 0.06 3.33 0.02 1.11 0.02 0.09

99.99 99.94 99.14 97.39 99.97 99.88 99.92 99.85 99.97 99.99 99.91 99.93 97.67 99.95 99.92 99.94 99.95 98.29

-73.64 -0.07 -28.69 -203.6 -60.19 -29.53 -10.51 82.35 -175.3 -436.9 -14.57 66.20 38.57 -180.4 96.10 17.54 24.95 91.32

RI PT

0.27 0.52 0.02 0.12 0.27 0.14 8.72 0.33 15.6

AC C

EP

Tetracycline

TE D

M AN U

Sulfonamide

8.14 1.98 0.33 0.56 3.04 1.78 19.4 2.54 8.24

SC

Polymyxin Quinolone

multidrug transporter * norM RND multidrug efflux transporter * sdeY efflux transporter bifunctional polymyxin resistance protein arnA quinolone resistance protein sul2 sul1 ribosomal protection tetracycline resistance protein * tet32 * tetA * tetA(33) tetA(C) tetA(M) * tetA(Q) tetB(P) * tetG tetM * tetO ** tetQ * tetracycline resistance protein * tetV tetW * tetX * hypothetical protein * proton antiport protein * RND protein

Others

S11

ACCEPTED MANUSCRIPT

6.87

1. MLS : Macrolide-lincosamide-streptogramin. 2. **: subtypes with removal rate larger than 99.99% from influent to effluent.

0.21

0.02

RI PT

2.00

0.40

0.03

0.02

99.86

53.22

0.43

99.93

-551.3

SC

transporter, monovalent cationproton antiporter-2 (CPA2) family UDP-glucuronic acid decarboxylase_UDP-4-amino-4-deoxy-L-arabinose formyltransferase *

M AN U

3. *: subtypes with removal rate between 99.90% and 99.99% from influent to effluent. 4.

: subtypes with removal rate between 90.00% and 99.90% from activated sludge to anaeorbic digestion sludge.

5.

: subtypes that were enriched by more than 10 times (removal rate lower than -1000%) from activated sludge to anaerobic digestion

AC C

EP

TE D

sludge.

S12

ACCEPTED MANUSCRIPT

Table S7 - Removal efficiency of ARGs in previous studies and this study.

tetB

---

---

---

60 ~ 92

tetC

---

---

---

---

tetG

---

---

---

---

tetL

---

---

---

tetM

> 99

68 ~ 99

tetO

> 99

tetQ

SC

tetA

Water (Chen and Zhang, 2013a) ---

ARGs

This study/%

RI PT

Removal efficiency in previous studies/% Water Water Water Sludge (Chen and (Liu et al., (Nõlvak et al., (Diehl and LaPara, Zhang, 2013b) 2013) 2013) 2010) ----49 ~ 98 90~99

Sludge (Ma et al., 2011) ---

Persistent ARGs

Water

Sludge

99.94

-0.07

---

100

100

---

-525 ~ 75

97.39

-203.6

---

-66 ~ 92

99.85

82.35

---

98

---

100

N. A

-77 ~ 82

68

---

---

99.97

-175.3

68 ~ 99

-46 ~ 57

---

90~99

-233 ~ 83

99.9

-436.9

> 99

68 ~ 99

---

---

---

---

99.99

-14.57

tetW

> 99

68 ~ 99

-50 ~ 67

---

99

-525 ~ 75

99.95

-180.4

tetX

---

---

---

---

99

-122 ~ 94

99.92

96.10

sulI

90 ~ 99

50 ~ 97

---

-298 ~ 75

---

84 ~ 99

97.55

41.93

sulII

---

---

---

---

---

45 ~ 90

99.83

79.72

ermB

---

---

---

21 ~ 60

---

-233 ~ 73

99.99

-139.1

ermF

---

---

---

---

-1900 ~ 86

99.87

-359.7

AC C

EP

TE D

M AN U

---

---

ampC ------90 ~ 92 ----99.95 N.A qnrS ------87 ~ 97 ----100 N.A The abundance of ARGs used in the calculating removal efficiency was estimated from the bar chart in the previous studies if the abundance of ARGs were not clearly reported in numbers. S13

ACCEPTED MANUSCRIPT Table S8 - Top 5 genera in the influent, effluent, AS and ADS

Digestion

Firmicutes

Blautia

12.1

Proteobacteria

Acinetobacter

9.56

Actinobacteria

Bifidobacterium

5.56

Proteobacteria

Moraxella

4.74

Actinobacteria

Mycobacterium

30.7

Proteobacteria

Francisella

6.51

Proteobacteria

Vibrio

3.88

Bacteroidetes

Flavobacterium

3.41

Spirochaetes

Leptospira

2.49

RI PT

12.7

Nitrospira

8.76

Actinobacteria

Mycobacterium

7.04

Bacteroidetes

Lewinella

5.08

Planctomycetes

Planctomyces

4.94

Proteobacteria

Denitromonas

4.65

Thermotogae

Kosmotoga

36.1

Synergistetes

Thermovirga

5.34

Actinobacteria

Mycobacterium

5.31

Chloroflexi

Longilinea

3.64

Syntrophomonas

3.23

EP

Sludge

Streptococcus

TE D

Anaerobic

Firmicutes

Nitrospirae Activated Sludge

Percentage/%

M AN U

Effluent

genus

SC

Influent

phylum

AC C

Firmicutes

S14

ACCEPTED MANUSCRIPT Table S9 - Persistent ARGs subtypes in each cluster in RDA

1

ARGs types Aminoglycoside MLS Others Aminoglycoside

2

RI PT

Beta-lactam Multidrug Quinolone Sulfonamide

SC

Tetracycline Acriflavine

Aminoglycoside

AC C

EP

3

TE D

Bacitracin

Beta-lactam

ARGs subtypes aminoglycoside 2-N-acetyltransferase erythromycin esterase RND protein aadA aminoglycoside acetyltransferase class A beta-lactamase OXA-10 mexF norM quinolone resistance protein sul1 tetA(C) tetV acrB aminoglycoside 3-phosphotransferase aminoglycoside 6-phosphotransferase aminoglycoside resistance protein aminoglycoside resistance protein A aminoglycoside resistance protein B streptomycin phosphotransferase_strB undecaprenol kinase undecaprenyl-diphosphatase beta-lactamase NPS-1 OXA gene OXA-46 penicillin binding protein penicillin-binding protein 2 VEB-1 VEB-3 VIM-11 chloramphenicol acetyltransferase chloramphenicol and florfenicol exporter cmlA9 florfenicol export er ABC-type efflux carrier ermB ermF erythromycin esterase type 1 erythromycin ribosome methylase macrolide efflux protein macB macrolide transporter mefA

M AN U

Cluster

Chloramphenicol

MLS

S15

ACCEPTED MANUSCRIPT

SC

RI PT

Multidrug

mef gene hydrophobe_amphiphile efflux-1 (HAE1) family protein mdtF mdtG mdtH mdtN mexB mexD multidrug efflux protein multidrug resistance protein D multidrug transporter multidrug efflux pump sdeY transporter hypothetical protein proton antiport protein transporter, monovalent cationproton antiporter-2 (CPA2) family UDP-glucuronic acid decarboxylase_UDP-4-amino-4-deoxy-L-arabinose formyltransferase bifunctional polymyxin resistance protein arnA dihydropteroate synthase_sul2 ribosomal protection tetracycline resistance protein tetracycline resistance protein tet32 tetA tetA(33) tetA(M) tetA(Q) tetB(P) tetG tetM tetO tetQ tetW tetX

M AN U

Others

AC C

EP

Tetracycline

TE D

Polymyxin Sulfonamide

S16

ACCEPTED MANUSCRIPT Table S10 - Total abundances of ARGs in different clusters from RDA Cluster

Total abundance/ppm Effluent

AS

ADS

1

0.55

1.94

0.95

1.55

2

51.3

43.3

5.16

6.61

3

412

25.7

22.3

36.0

AC C

EP

TE D

M AN U

SC

RI PT

Influent

S17

AC C

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

Fig. S1 - Flowchart of the ST WWTP and the sampling site of the samples of influent (IN-1 and IN-2), effluent (EF-1 and EF-2), activated sludge (AS-1 and AS-2) and anaerobic digestion sludge (ADS-1 and ADS-2).

S18

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

Fig. S2 - Percentage of the persistent ARGs types in influent, effluent, AS and ADS.

S19

EP

TE D

M AN U

SC

RI PT

ACCEPTED MANUSCRIPT

AC C

Fig. S3 - Microbial compositions at phylum level in influent, effluent, AS and ADS.

S20

ACCEPTED MANUSCRIPT REFERENCES Chen, H. and Zhang, M., 2013a. Effects of advanced treatment systems on the removal of antibiotic resistance genes in wastewater treatment plants from Hangzhou, China. Environmental Science & Technology http://dx.doi.org/10.1021/es401091y. Chen, H. and Zhang, M., 2013b. Occurrence and removal of antibiotic resistance genes in municipal wastewater

RI PT

and rural domestic sewage treatment systems in eastern China. Environment International 55, 9-14. Diehl, D.L. and LaPara, T.M., 2010. Effect of temperature on the fate of genes encoding tetracycline resistance and the integrase of class 1 integrons within anaerobic and aerobic digesters treating municipal wastewater solids. Environmental Science & Technology 44(23), 9128-9133.

SC

Liu, L., Liu, C., Zheng, J., Huang, X., Wang, Z., Liu, Y. and Zhu, G., 2013. Elimination of veterinary antibiotics and antibiotic resistance genes from swine wastewater in the vertical flow constructed wetlands.

M AN U

Chemosphere 91(8), 1088-1093.

Ma, Y., Wilson, C.A., Novak, J.T., Riffat, R., Aynur, S., Murthy, S. and Pruden, A., 2011. Effect of various sludge digestion conditions on sulfonamide, macrolide, and tetracycline resistance genes and class I integrons. Environmental Science & Technology 45(18), 7855-7861.

Nõlvak, H., Truu, M., Tiirik, K., Oopkaup, K., Sildvee, T., Kaasik, A., Mander, Ü. and Truu, J., 2013. Dynamics of antibiotic resistance genes and their relationships with system treatment efficiency in a horizontal

AC C

EP

TE D

subsurface flow constructed wetland. Science of The Total Environment 461-462, 636-644.

S21