title: Multidrug resistant, extended spectrum β-lactamase (ESBL)-producing Escherichia coli isolated from a dairy farm.
abstract: Escherichia coli strains were isolated from a single dairy farm as a sentinel organism for the persistence of antibiotic resistance genes in the farm environment. Selective microbiological media were used to obtain 126 E. coli isolates from slurry and faeces samples from different farm areas. Antibiotic resistance profiling for 17 antibiotics (seven antibiotic classes) showed 57.9% of the isolates were resistant to between 3 and 15 antibiotics. The highest frequency of resistance was to ampicillin (56.3%), and the lowest to imipenem (1.6%), which appeared to be an unstable phenotype and was subsequently lost. Extended spectrum β-lactamase (ESBL) resistance was detected in 53 isolates and blaCTX-M, blaTEM and blaOXA genes were detected by PCR in 12, 4 and 2 strains, respectively. Phenotypically most isolates showing resistance to cephalosporins were AmpC rather than ESBL, a number of isolates having both activities. Phenotypic resistance patterns suggested co-acquisition of some resistance genes within subsets of the isolates. Genotyping using ERIC-PCR demonstrated these were not clonal, and therefore co-resistance may be associated with mobile genetic elements. These data show a snapshot of diverse resistance genes present in the E. coli population reservoir, including resistance to historically used antibiotics as well as cephalosporins in contemporary use.
authors: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
authors: Delveen R
authors: DR
authors: Ibrahim
authors: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
authors: Christine E R
authors: CE
authors: Dodd
authors: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
authors: Dov J
authors: DJ
authors: Stekel
authors: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK.
authors: Stephen J
authors: SJ
authors: Ramsden
authors: School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Loughborough, Leicestershire LE12 5RD, UK jon.hobman@nottingham.ac.uk.
authors: Jon L
authors: JL
authors: Hobman
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics*; D002417:Cattle; D002511:Cephalosporins / Q000494:pharmacology*; D003612:Dairying; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000235:genetics*; D005243:Feces / Q000382:microbiology; D005838:Genotype; D020071:Interspersed Repetitive Sequences / Q000235:genetics; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002511:Cephalosporins; D029968:Escherichia coli Proteins; D000667:Ampicillin; C048795:AmpC beta-lactamases; D001618:beta-Lactamases; C000602253:beta-lactamase CTX-M, E coli
keywords: Escherichia coli; cattle slurry; extended spectrum beta-lactamase resistance; multidrug resistance