Analysis of Antibiotic Resistance Genes in Water Reservoirs and Related Wastewater from Animal Farms in Central China

This study aimed to explore the phenotype and relationship of drug resistance genes in livestock and poultry farm wastewater and drinking water reservoirs to provide evidence for the transmission mechanisms of drug resistance genes, in order to reveal the spread of drug resistance genes in wastewater from intensive farms in Central China to urban reservoirs that serve as drinking water sources and provide preliminary data for the treatment of wastewater from animal farms to reduce the threat to human beings. DNA extraction and metagenomic sequencing were performed on eight groups of samples collected from four water reservoirs and four related wastewaters from animal farms in Central China. Metagenomic sequencing showed that the top 20 AROs with the highest abundance were <i>vanT</i>_gene, <i>vanY</i>_gene, <i>adeF</i>, <i>qacG</i>, <i>Mtub_rpsL_STR</i>, <i>vanY</i>_gene_, <i>vanW</i>_gene, <i>Mtub_murA_FOF</i>, <i>vanY</i>_gene, <i>vanH</i>_gene, <i>FosG</i>, <i>rsmA</i>, <i>qacJ</i>, <i>RbpA</i>, <i>vanW</i>_gene, <i>aadA6</i>, <i>vanY</i>_gene, <i>sul4</i>, <i>sul1</i>, and <i>InuF</i>. The resistance genes mentioned above belong to the following categories of drug resistance mechanisms: antibiotic target replacement, antibiotic target protection, antibiotic inactivation, and antibiotic efflux. The resistomes that match the top 20 genes are <i>Streptococcus agalactiae</i> and <i>Streptococcus anginosus</i>; <i>Enterococcus faecalis</i>; <i>Enterococcus faecium</i>; <i>Actinomyces viscosus</i> and <i>Bacillus cereus</i>. <i>Enterococcus faecium</i>; <i>Clostridium tetani</i>; <i>Streptococcus agalactiae</i> and <i>Streptococcus anginosus</i>; <i>Streptococcus agalactiae</i> and <i>Streptococcus anginosus</i>; <i>Acinetobacter baumannii</i>, <i>Bifidobacterium bifidum</i>, <i>Bifidobacterium breve</i>, <i>Bifidobacterium longum</i>, <i>Corynebacterium jeikeium</i>, <i>Corynebacterium urealyticum</i>, <i>Mycobacterium kansasii</i>, <i>Mycobacterium tuberculosis</i>, <i>Schaalia odontolytica</i>, and <i>Trueperella pyogenes</i>; <i>Mycobacterium avium</i> and <i>Mycobacterium tuberculosis</i>; <i>Aeromonas caviae</i>, <i>Enterobacter hormaechei</i>, <i>Vibrio cholerae</i>, <i>Vibrio metoecus</i>, <i>Vibrio parahaemolyticus</i>, and <i>Vibrio vulnificus</i>; <i>Pseudomonas aeruginosa</i> and <i>Pseudomonas fluorescens</i>; <i>Staphylococcus aureus</i> and <i>Staphylococcus equorum</i>; <i>M. avium</i>, <i>Achromobacter xylosoxidans</i>, and <i>Acinetobacter baumannii</i>; <i>Sphingobium yanoikuyae</i>, <i>Acinetobacter indicus</i>, <i>Morganella morganii</i>, <i>Proteus mirabilis</i>, <i>Proteus vulgaris</i>, <i>Providencia rettgeri</i>, and <i>Providencia stuartii</i>. Unreported drug resistance genes and drug-resistant bacteria in Central China were identified in 2023. In the transmission path of drug resistance genes, the transmission path from aquaculture wastewater to human drinking water sources cannot be ignored. For the sake of human health and ecological balance, the treatment of aquaculture wastewater needs to be further strengthened, and the effective blocking of drug resistance gene transmission needs to be considered.