title: Degradation of cefquinome in spiked milk as a model for bioremediation of dairy farm waste milk containing cephalosporin residues.
abstract: OBJECTIVE
  The aims of this work were to develop a model of dairy farm waste milk and to investigate methods for the bioremediation of milk containing cefquinome residues.
  
  
  RESULTS
  Unpasteurized milk and UHT milk that had both been spiked with cefquinome at a concentration of 2 μg ml(-1) were used as a model for waste milk containing cephalosporin residues. Adjustment of the spiked UHT milk to pH 10 or treatment with conditioned medium from bacterial growth producing cefotaximase, were the most effective methods for decreasing the cefquinome concentrations within 24 h. A large-scale experiment (10 l of cefquinome-spiked unpasteurized milk) suggested that fermentation for 22 h at 37°C followed by heating at 60°C for 2 h was sufficient to decrease cefquinome concentrations to below the limit of quantification (<125 μg kg(-1) ) and to kill the majority of the enriched bacterial population.
  
  
  CONCLUSIONS
  One or a combination of the bioremediation methods described may have potential as a practical treatment for dairy farm waste milk.
  
  
  CONCLUSIONS
  Treatment of waste milk to decrease cephalosporin residue concentrations and also to kill bacteria prior to feeding to dairy calves could decrease the risk of selection for ESBL bacteria on dairy farms.
authors: Animal & Plant Health Agency (APHA), Addlestone, Surrey, KT15 3NB, UK.
authors: R A
authors: RA
authors: Horton
authors: L P
authors: LP
authors: Randall
authors: V
authors: V
authors: Bailey-Horne
authors: K
authors: K
authors: Heinrich
authors: M
authors: M
authors: Sharman
authors: L A
authors: LA
authors: Brunton
authors: R M
authors: RM
authors: La Ragione
authors: J R
authors: JR
authors: Jones
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002417:Cattle; D002511:Cephalosporins / Q000378:metabolism*; D003612:Dairying; D004926:Escherichia coli / Q000254:growth & development; D005285:Fermentation; D006358:Hot Temperature; D008892:Milk / Q000737:chemistry*; D008954:Models, Biological; D014866:Waste Products; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D014866:Waste Products; C071167:beta-lactamase CTX-2; D001618:beta-Lactamases; C068212:cefquinome
keywords: bioremediation; cefquinome; dairy calves; extended-spectrum β-lactamase; waste milk