title: The association between occurrence of plasmid-mediated quinolone resistance and ciprofloxacin resistance in Escherichia coli isolates of different origins.
abstract: This study was performed to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and characterize the ciprofloxacin resistance in Escherichia coli isolated from different sources in China. PMQR determinants were detected by PCR amplification and sequencing in 2297 E. coli isolates randomly collected from animals, food and humans during 2004 to 2011. MICs of ciprofloxacin were determined by agar dilution method. Of the 2297 E. coli isolates, 43.6% harbored at least one PMQR gene. The most common PMQR gene was oqxAB (29.3%), followed by qnr (13.6%), aac(6')-Ib-cr (11.6%), and qepA (3.3%). 12.0% isolates carried two or more PMQR genes. The prevalence of PMQR genes in food animal isolates increased over time, from 38.7% in 2004 to 69.8% in 2011. The prevalence of PMQR/ciprofloxacin resistance among isolates from pig, chicken, duck, companion animals, animal food and human volunteers were 65.2%/69.6%, 42.4%/60.0%, 59.4%/65.0%, 28.6%/57.5%, 29.3%/25.6%, and 14.0/8.7%, respectively. Most isolates carrying qnr along showed susceptible to ciprofloxacin, and only 21.6% the isolates exhibited resistance to ciprofloxacin, which was significantly lower than those carrying other PMQR genes (65.2-89.9%) and those that do not (43.1%) (p<0.01). In conclusion, high frequency of ciprofloxacin resistance and PMQR genes was observed among E. coli isolates of different origins in China, with oqxAB being the most frequent. qnr-positive E. coli isolates have relatively low ciprofloxacin resistance rate compared with other PMQR determinants-carrying isolates and PMQR-negative isolates.
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Tong
authors.initials: T
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Zhenling
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Lili
authors.initials: L
authors.lastname: Rao
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Dandan
authors.initials: D
authors.lastname: He
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Luchao
authors.initials: L
authors.lastname: Lv
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Zeng
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
authors.forename: Minsha
authors.initials: M
authors.lastname: Feng
authors.affiliation: College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China. Electronic address: jhliu@scau.edu.cn.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Liu
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002681:China; D002939:Ciprofloxacin / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics; D005516:Food Microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D015995:Prevalence; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D015363:Quinolones; D002939:Ciprofloxacin
keywords: Animal reservoirs; Escherichia coli; Food animals; Quinolones; Resistance gene