Antimicrobial resistance in veterinary medicine ? issues and controversies from an Australian perspective

Abstract

Antimicrobial resistance in veterinary isolates came to renewed prominence in the late 1990s in response to the recognition of an association between the use of avoparcin as a growth promotant in livestock feeds and vanA vancomycin resistance in enterococcal pathogens in humans 1. Since then there have been many regulatory changes in many countries that have resulted in a reduction in use of antimicrobial growth promoters (AGPs) in livestock feeds. The EU has banned the use of most growth promoters and in Australia post-JETACAR avoparcin (a glycopeptide) has been voluntarily withdrawn from the market by the manufacturer (in 2000), recommendations have been made to restrict the use of virginiamycin (a streptogrammin) to a prescription-only medicine for treatment and prevention of some specific conditions, and a review of macrolide AGPs is in the wings. In addition, many of the industries have voluntarily reduced or ceased their use of some of these products. For example, the pig industry stopped use of avoparcin in 1997 and the use of virginiamycin has been curtailed in the meat chicken industry.