Livestock & poultry producers are asking, “What’s the big deal about antibiotics?”. Over the last few years the interest of consumer and media groups on how antibiotics are used in livestock and poultry has exploded. It seems that every fast-food chain is racing to develop a policy on use in their supply chain. Mainstream media has regular exposés on the topic. And Industry publications are regularly covering how to use antibiotics appropriately.
Everyone has an opinion on how you should use antibiotics– but why the sudden interest? A dramatic and persistent rise in antibiotic resistant pathogens in human medicine is behind all the attention. This phenomenon is occurring globally, although different regions and countries are struggling with different bug-drug combinations, and is common enough that illnesses which were previously curable with antibiotics can no longer be treated. In essence, human medicine is getting a glimpse of the post-antibiotic era. And it is terrifying.
But what does this have to do with how antibiotics are used on your farm, ranch or flock? The concern is that antibiotic use in agriculture is contributing to this human medicine problem. How can that be? Well, there are three connections you should be aware of. Today’s post will touch on each briefly. Future posts will investigate each in more detail.
The most direct link is through resistant foodborne pathogens. The main threats are Salmonella spp. and Campylobacter spp. These bacteria are present in the guts of healthy animals. A seven-step chain of events can link the use of an antibiotic in an food-animal to more severe food-borne illness in a person.
The second link between on-farm antibiotic use and human health is slightly more abstract. Full appreciation requires understanding how resistance develops and transmits among bacteria. Although an oversimplification, it is enough to know that bacteria have a unique ability to share genes with other bacteria. Typically, a set or collection of genes is passed simultaneously. This set of genes can infer resistance to multiple different families of antibiotics so the acquiring bacteria becomes multi-resistant instantaneously. The concern relating to agriculture is that bacteria from the guts of animals again could pass this resistance to bacteria in the human gut.
Every time an antibiotic is used, it selects for resistance in bacteria. Because agriculture is among the major users of antimicrobials, we are also contributing to the burden of resistance in the world. Bacteria in animal waste enter our shared environment through farmland, watershed and aerosol. This contribution to global resistance could theoretically impact human health.
From the direct and measurable to the hypothetical, agriculture is tied to the threat of antimicrobial resistance. This means we have a responsibility to practice good antimicrobial stewardship, to measure and address this problem within our own industries, and to contribute to solution-seeking for this pressing One-Health issue.