Changing Patterns of Antimicrobial Sensitivity Patterns in Equine Isolates Submitted to a UK Laboratory: 1999-2012

Aims: Antimicrobial resistance (AMR) is considered one of the key developing health concerns globally. Knowledge of AMR and changes in resistance patterns over time may allow for more appropriate empirical antimicrobial use and may help prevent the development of multidrug resistance (MDR). 

Methods: Records from The Royal Veterinary College Diagnostic Laboratory between 1999 and 2012 were searched for equine samples from which a either Escherichia coli or Streptococcus spp. was identified. Sensitivity to enrofloxacin, ceftiofur, gentamicin, penicillin G, trimethoprim sulfamethoxazole (TMPS) and tetracyclines was noted. Isolates were divided into those identified between 1999–2004 (‘Early’) and 2007–2012 (‘Late’). The proportion of isolates resistant to each antimicrobial, and MDR isolates (resistant to 3 or more antimicrobial classes) was compared between time periods. [...]