Antibiotic susceptibility testing of bacteria isolated from animals

The responsible use of veterinary antimicrobial agents requires that the most appropriate antibiotic be selected for use in the treatment of animal diseases. The American Veterinary Medical Association has developed judicious-use guidelines for dogs, cats, horses, cattle, swine, poultry, and fish so that the veterinarian can maintain product effectiveness, use antimicrobials safely, and minimize selection of resistant pathogens (http://www.avma.org/scienact/jtua/default.asp). One recommendation is that susceptibility testing be performed on bacterial pathogens isolated from animals to guide the selection of the appropriate antimicrobial agent. The key role of the veterinary diagnostic laboratory is predicated on the capability to conduct standardized antimicrobial susceptibility testing and, using validated interpretive criteria, to guide the veterinary practitioner in the selection of the most appropriate antibiotic. The Clinical and Laboratory Standards Institute (formerly NCCLS) Veterinary Antimicrobial Susceptibility Testing subcommittee has developed these laboratory methods and interpretive criteria.