Impact of Antibiotic Use in Adult Dairy Cows on Antimicrobial Resistance of Veterinary and Human Pathogens: A Comprehensive Review

Abstract

Antibiotics have saved millions of human lives, and their use has contributed significantly to improving human and animal health and well-being. Use of antibiotics in food-producing animals has resulted in healthier, more productive animals; lower disease incidence and reduced morbidity and mortality in humans and animals; and production of abundant quantities of nutritious, high-quality, and low-cost food for human consumption. In spite of these benefits, there is considerable concern from public health, food safety, and regulatory perspectives about the use of antimicrobials in food-producing animals. Over the last two decades, development of antimicrobial resistance resulting from agricultural use of antibiotics that could impact treatment of diseases affecting the human population that require antibiotic intervention has become a significant global public health concern. In the present review, we focus on antibiotic use in lactating and nonlactating cows in U.S. dairy herds, and address four key questions: (1) Are science-based data available to demonstrate antimicrobial resistance in veterinary pathogens that cause disease in dairy cows associated with use of antibiotics in adult dairy cows? (2) Are science-based data available to demonstrate that antimicrobial resistance in veterinary pathogens that cause disease in adult dairy cows impacts pathogens that cause disease in humans? (3) Does antimicrobial resistance impact the outcome of therapy? (4) Are antibiotics used prudently in the dairy industry? On the basis of this review, we conclude that scientific evidence does not support widespread, emerging resistance among pathogens isolated from dairy cows to antibacterial drugs even though many of these antibiotics have been used in the dairy industry for treatment and prevention of disease for several decades. However, it is clear that use of antibiotics in adult dairy cows and other food-producing animals does contribute to increased antimicrobial resistance. Although antimicrobial resistance does occur, we are of the opinion that the advantages of using antibiotics in adult dairy cows far outweigh the disadvantages. Last, as this debate continues, we need to consider the consequences of "what would happen if antibiotics are banned for use in the dairy industry and in other food-producing animals?" The implications of this question are far reaching and include such aspects as animal welfare, health, and well-being, and impacts on food quantity, quality, and food costs, among others. This question should be an important aspect in this ongoing and controversial debate.

Technological failures caused by cephalexin in set-type sheep’s milk yogurt

“…As a result, inadequate use of an extrapolation tool with cephalexin could cause milk contamination. This would imply serious consequences not only for public health (Dewdney et al, 1991;Oliver, Murinda, & Jarayao, 2011), but also in the manufacturing process of fermented products, where the sensitivity of lactic acid bacteria starters to betalactams has been previously demonstrated (Berruga, Molina, Novés, Roman, & Molina, 2007;Berruga, Novés, Molina, Roman, & Molina, 2008;Cogan, 1972;Packham, Broome, Limsowtin, & Roginski, 2001).…”

Risk factors associated with the antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis

“…Several mechanisms of resistance to the available antimicrobial drugs have been described; however, many aspects of antimicrobial resistance development and dissemination remain uncertain. Resistance among mastitis pathogens has been reported for nearly four decades, but despite this, there is no scientific evidence to determine whether it is an emergent phenomenon or is in progress (Oliver et al 2011).…”

Escherichia coli from Nigeria exhibit a high prevalence of antibiotic resistance where reliance on antibiotics in poultry production is a potential contributing factor

“…The relative contribution of these three sectors to the evolution and amplification of antibiotic resistance is not clearly understood (McDermott et al, 2002;Oliver et al, 2011) although it probably varies with different countries. Indeed, many of the highly complex issues in developing countries that influence antibiotic use practices in human medicine (Okeke et al, 1999) are likely to apply to both veterinary and food-animal applications.…”