Antimicrobial resistance in equine faecal Escherichia coli isolates from North West England

Annals of Clinical Microbiology and Antimicrobials

Research

Malcolm Bennett¹  Nicola J Williams²  Peter D Clegg²  Keith E Baptiste³  Mohamed O Ahmed⁴ 

[1] Department of Animal and Population Health, School of Veterinary Science, University of Liverpool,Leahurst, Chester High Road, CH64 7TE, Neston, UK;Department of Comparative Molecular Medicine, School of Veterinary Science, University of Liverpool,Leahurst, Chester High Road, CH64 7TE, Neston, UK;Department of Large Animal Sciences, Faculty of Life Sciences, University of Copenhagen, 2630, Taastrup, Denmark;Department of Microbiology and Parasitology, Faculty of Veterinary Medicine, Al Fateh University, PO Box 13662, Tripoli, Libya;Department of Comparative Molecular Medicine, School of Veterinary Science, University of Liverpool,Leahurst, Chester High Road, CH64 7TE, Neston, UK;

关键词: Faecal Sample;    Nalidixic Acid;    Minimum Inhibitory Concentration;    Resistant Isolate;    Mobile Genetic Element;   

DOI  :  10.1186/1476-0711-9-12

 received in 2010-01-22, accepted in 2010-04-07,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundEscherichia coli isolates of equine faecal origin were investigated for antibiotic resistance, resistance genes and their ability to perform horizontal transfer.MethodsIn total, 264 faecal samples were collected from 138 horses in hospital and community livery premises in northwest England, yielding 296 resistant E. coli isolates. Isolates were tested for susceptibility to antimicrobial drugs by disc diffusion and agar dilution methods in order to determine minimum inhibitory concentrations (MIC). PCR amplification was used to detect genes conferring resistance to: ampicillin (TEM and SHV beta-lactamase), chloramphenicol (catI, catII, catIII and cml), tetracycline (tetA, tetB, tetC, tetD, tet E and tetG), and trimethoprim (dfrA1, dfrA9, dfrA12, dfrA13, dfr7, and dfr17).ResultsThe proportion of antibiotic resistant isolates, and multidrug resistant isolates (MDR) was significantly higher in hospital samples compared to livery samples (MDR: 48% of hospital isolates; 12% of livery isolates, p < 0.001). Resistance to ciprofloxacin and florfenicol were identified mostly within the MDR phenotypes. Resistance genes included dfr, TEM beta-lactamase, tet and cat, conferring resistance to trimethoprim, ampicillin, tetracycline and chloramphenicol, respectively. Within each antimicrobial resistance group, these genes occurred at frequencies of 93% (260/279), 91%, 86.8% and 73.5%, respectively; with 115/296 (38.8%) found to be MDR isolates. Conjugation experiments were performed on selected isolates and MDR phenotypes were readily transferred.ConclusionsOur findings demonstrate that E. coli of equine faecal origin are commonly resistant to antibiotics used in human and veterinary medicine. Furthermore, our results suggest that most antibiotic resistance observed in equine E. coli is encoded by well-known and well-characterized resistant genes common to E. coli from man and domestic animals. These data support the ongoing concern about antimicrobial resistance, MDR, antimicrobial use in veterinary medicine and the zoonotic risk that horses could potentially pose to public health.

【 授权许可】

CC BY   
© Ahmed et al; licensee BioMed Central Ltd. 2010