title: Co-spread of metal and antibiotic resistance within ST3-IncHI2 plasmids from E. coli isolates of food-producing animals.
abstract: Concerns have been raised in recent years regarding co-selection for antibiotic resistance among bacteria exposed to heavy metals, particularly copper and zinc, used as growth promoters for some livestock species. In this study, 25 IncHI2 plasmids harboring oqxAB (20/25)/blaCTX-M (18/25) were found with sizes ranging from ∼260 to ∼350 kb and 22 belonged to the ST3-IncHI2 group. In addition to blaCTX-M and oqxAB, pcoA-E (5/25) and silE-P (5/25), as well as aac(6')-Ib-cr (18/25), floR (16/25), rmtB (6/25), qnrS1(3/25) and fosA3 (2/25), were also identified on these IncHI2 plasmids. The plasmids carried pco and sil contributed to increasing in the MICs of CuSO4 and AgNO3. The genetic context surrounding the two operons was well conserved except some variations within the pco operon. The ~32 kb region containing the two operons identified in the IncHI2 plasmids was also found in chromosomes of different Enterobacteriaceae species. Further, phylogenetic analysis of this structure showed that Tn7-like transposon might play an important role in cross-genus transfer of the sil and pco operons among Enterobacteriaceae. In conclusion, co-existence of the pco and sil operons, and oqxAB/blaCTX-M as well as other antibiotic resistance genes on IncHI2 plasmids may promote the development of multidrug-resistant bacteria.
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Liangxing
authors.initials: L
authors.lastname: Fang
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Xingping
authors.initials: X
authors.lastname: Li
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Li
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Shumin
authors.initials: S
authors.lastname: Li
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Liao
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.|Laboratory of Veterinary Pharmacology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, P. R. China.|Jiangsu Co-Innovation Centre for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, the People's Republic of China.
authors.forename: Yahong
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004251:DNA Transposable Elements; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D022761:Gene Transfer, Horizontal; D005798:Genes, Bacterial; D058751:Livestock; D008670:Metals / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D009876:Operon; D010957:Plasmids / Q000145:classification*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D008670:Metals