Effects of Antimicrobial Use in Concetrated Animal Feeding...

Introduction The development and dissemination of bacterial resistance to 3rd generation cephalosporin antimicrobials is of significant importance to public health and domestic livestock production alike. The World Health Organization recognizes the extended-spectrum cephalosporin antimicrobials as â€Å"critically important† and their use in food animal production is coming under increasing scrutiny (1). Reports of recovery of blaCMY-2 and blaCTX-M resistance genes in bacterial isolates from U.S. livestock, fresh retail meat, and human diagnostic samples represent a potential pathway for the selection and distribution of cephalosporin-resistant pathogens and subsequent zoonotic infection of humans (2-5). Background There is widespread concern†¦show more content†¦The annual report only contains information on total amount of antimicrobials sold each year and does not describe food animal species, indication for treatment, dosage, or route of administration (7). Further, a significant portion of the annual reported tonnage (28-30%) is made up of the ionophore antimicrobial class, which is not utilized in human medicine and is not likely to significantly contribute to antimicrobial resistance of bacteria of public health concern (8). The FDA reported sales of cephalosporin antimicrobials as 41,328 kg, 24588 kg, and 26,611 kg for the years 2009, 2010, and 2011 respectively (7). Figure 1 While the understanding of the contribution of antimicrobial use in CAFOs to resistant pathogens in human and animal infections is still developing, the precautionary principle is frequently cited in public health literature. This principle advocates the cessation of antimicrobial uses in food animal production which could negatively impact public health and has prompted a multitude of proposed and enacted regulatory restrictions of antimicrobial use in livestock species in the last two decades. The FDA has issued multiple orders restricting the veterinary use of fluoroquinolones and cephalosporins in food-producing animals in response to evidence of increasing prevalence of antimicrobial resistant bacteria in livestock and humans. These efforts have commonly targeted the extra-label drug usage