Dominant denitrifying bacteria are important hosts of antibiotic resistance genes in pig farm anoxic-oxic wastewater treatment processes

Yiwen Yang; Ruiting Wu; Jiaxin Hu; Sicheng Xing; Chunbo Huang; Jiandui Mi; Xindi Liao

Environment International (Oct 2020)

Dominant denitrifying bacteria are important hosts of antibiotic resistance genes in pig farm anoxic-oxic wastewater treatment processes

Yiwen Yang,
Ruiting Wu,
Jiaxin Hu,
Sicheng Xing,
Chunbo Huang,
Jiandui Mi,
Xindi Liao

Affiliations

Yiwen Yang: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
Ruiting Wu: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
Jiaxin Hu: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
Sicheng Xing: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
Chunbo Huang: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
Jiandui Mi: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agriculture University, Guangzhou 510642, China
Xindi Liao: Guangdong Laboratory for Lingnan Modern Agriculture, South China Agricultural University, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Tropical Agricultural Environment, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, South China Agriculture University, Guangzhou 510642, China; Corresponding author at: College of Animal Science, South China Agricultural University, Guangzhou 510642, China.

Journal volume & issue: Vol. 143
p. 105897

Abstract

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The anoxic-oxic (A/O) wastewater treatment process that is widely used in pig farms in China is an important repository for antibiotic resistance genes (ARGs). However, the distribution of ARGs and their hosts in the A/O process has not been well characterized. In this study, the wastewaters in the anoxic and oxic tanks for A/O processes were collected from 38 pig farms. The concentrations of 20 subtypes of ARGs, 5 denitrification-related genes, 2 integrons, and bacterial community composition were investigated. Bacterial genome binning was performed using metagenome sequencing. In this study, 20 subtypes of ARGs and integrons were detected in all sampling sites. A total of 16 of the 20 subtypes of ARGs were detected with the highest abundance in anoxic tanks, and sul1 was detected with a maximum average abundance of 19.21 ± 0.24 log10 (copies/mL). Cooccurrence patterns were observed for some genes in the pig farm A/O process, such as sul1 and intl1, sul1 and tetG, and tetO and tetW. There was a significant cooccurrence pattern between the dominant denitrifying bacteria and some ARGs (blaTEM, ermB, tetC, tetH and tetQ), so the dominant denitrifying bacteria were considered to be potential ARG hosts. In addition, 170 highly abundant bacterial genome bins were assembled and further confirmed that the denitrifying bacteria Brachymonas, Candidatus Competibacter, Thiobacillus and Steroidobacter were the important ARG hosts in the pig farm A/O process, providing a useful reference for the surveillance and risk management of ARGs in pig farm wastewater.

Published in Environment International

ISSN: 0160-4120 (Print)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/environment-international

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