Feed Lot Magazine Online, The Real Antibiotics Issue -- Part II

Last time we discussed how the emergence of what are known as "super" bacteria have brought renewed interest on the part of activists and government regulators to ban antibiotics used in livestock production. In this issue we will discuss why there has always been so much criticism of antibiotic use in animal production.

A Flawed Theory. For the last 50 years medical schools have taught that the only responsible way to administer antibiotics is in large, therapeutic doses. The theory is that by giving massive doses of antibiotics, you kill all the bacteria in an infection and thereby prevent resistance from occurring. Conversely, the wrong or irresponsible way to give antibiotics is in small, low-level doses. The low doses, which simply control bacterial populations rather than eliminate them are deemed to be the source of resistant bacteria. That is, since the bacteria are not totally destroyed, over time they develop resistance.

This is a very logical theory, and to this day is believed by most practicing physicians and veterinarians. Unfortunately, it is wrong. I say unfortunately, because it would be wonderful if it were true. We could simply be careful to always give large therapeutic doses, and resistant bacteria would not be a problem. But as Britain, and various European countries which have banned low-level antibiotic use have found, the problem of resistant bacteria does not go away when low-level doses are stopped.

The reality is that large therapeutic doses are more prone to cause resistant bacteria than low level doses. The reason is due to random genetic mutation. That is, early-on it was believed that exposure to the antibiotic is what caused resistance. The bacterial population as a whole developed some sort of defense. It is now understood that resistance occurs due to genetic selection. At any given time, a small percentage of any bacterial population is mutating and becoming naturally resistant to any particular antibiotic. Giving massive doses of an antibiotic may kill 99% or even 99.9% of a bacterial population, but not 100%. The result is that the small numbers of bacteria left are all resistant to the antibiotic. There may not be enough left in the patient to manifest themselves as disease, but eventually these bacteria will find their way into the environment. When they reproduce, the entire population that rebounds is resistant.

This is why resistance has occurred for every new human antibiotic put on the market. The plain truth is that resistance to human antibiotics has primarily and foremostly occurred because of overuse of antibiotics in humans, not animals.

Common Sense. You don't need to be a microbiologist or biogeneticist to come to this conclusion. According to FDA, it has only been since about 1995 that the superbugs have emerged as a major problem. Yet the low-level antibiotics that we use in the cattle industry have been in use for a minimum of 20 years; and some of them (the tetracyclines) have a 50 year history.

Likewise, if you look at where most of the infections occur, the inescapable conclusion is the problem is human antibiotics; given at therapeutic doses. That is, the vast majority of resistant bacterial infections occur in hospitals -- Staphylococcus and Streptococcus infections subsequent to surgery. Creating a vicious cycle, hospitals routinely give surgery patients large doses of antibiotics as a precaution, in essence perpetuating the problem.

The reality is that new human antibiotics come out on the market, and for a while they are effective. It takes upwards of $100 million to bring a human antibiotic to market. Most of that cost is in safety testing. Before beginning safety testing, of course, pharmaceutical companies test for effectiveness against bacteria (which in comparision costs virtually nothing). If the drug is effective, then they invest in safety studies. The bottom line is that no pharmaceutical company is going to spend $100 million + on a product that isn't effective. Once on the market, however, after a period of use resistant organisms appear. The bacteria and antibiotics we use in the cattle industry were around long before. But the resistance doesn't occur until after the human drug has been put in use. It doesn't take Sherlock Holmes to figure that one out.

Research cited in this report can be attributed by contacting the author.

He has a syndicated newspaper column, and has rewritten this topic in a manner understandable to the lay public. If you would be willing to submit these articles to your local paper for publishing, please contact Dr. Price at: ph 505-525-1370; fax 505-525-1394 or E-mail nutconsult@zianet.com.