Antibiotics in animals
One factor that I am going to place some emphasis is the use of antibiotic in the food industry. Here is a list of several antibiotics that have played an extremely important role in resistance occurring through this modality.

• Avoparcin in Europe.
• Virginiamycin in the United States.
• Ceftiofur, which is a third generation cephalosporin, in the United States.
• Penicillins and tetracyclines in the United States.
• Quinolones in the United States.

Here is a bit of an overview. The food industry use of antimicrobials in animals consists of about 40-50 percent of all antibiotics used in this country. Cleverly, the antibiotics are called "antimicrobial growth promoters," or AGPs. The reason why they are so desirable is that they increase growth and "feed efficiency" in animals by 2-4 percent. If you are a livestock farmer, 2-4 percent may be more than even your profit margin. To the farmer, there could be perceived negative ramifications to not using antimicrobial growth promoters.

Dr. Randy Regal discusses how antibiotics used in the food supply affect the humans who consume them. (1:44 min)

The first grim tale here is with regards to avoparcin. Avoparcin is a glycopeptide related to vancomycin. You might recall the discussion in an earlier session about vancomycin-resistant enterococcus (VRE) and the fear of vancomycin-resistant Staph (VRSA). Avoparcin is a drug very similar to vancomycin and it was used in animals in Europe for a few years. The European Union did ban it in 1997; however, by the time it was banned, avoparcin use had resulted in colonization rates of VREs as high as 12-28 percent in a healthy population of Belgians. Now the 12-28 percent resistance may not mean much, but if you compare that with a healthy US population, the colonization rate is about 1 percent. That is extremely high. The good news is that there has been some decline in the rates in Belgium and other areas of Europe since the banning of avoparcin by the European Union.

The next AGP on the list is virginiamycin. Now virginiamycin is related to Synercid, which is an antibiotic that was just marketed for VRE in the US in 1999, and this is after we went 10 years in US hospitals without having any antibiotics to treat VRE. Yet here it is, literally, out in our food chain. Virginiamycin has been used in US animals since 1974. It was banned by the European Union in 1998. One study by L. Clifford McDonald that appeared in The New England Journal of Medicine in 2001 found that about 17-87 percent of chickens tested in supermarkets in four different states, harbored this streptogram or quinupristin/dalfopristin-resistant organism.

In 1997-1998, cipro was the drug of choice for Campylobacter, but resistance to the drug rose to 13.4 percent. In Sweden, for example, resistance grew from less than 2 percent to 29 percent in just a few years, and in Spain in 1989 it accelerated from 7.5 percent resistance to 50 percent resistance. According to one study, all these cases were attributed to the use of the other quinolone antibiotics that are related to cipro in poultry feed.

Now who is playing chicken with the FDA? Well, we should give the FDA some credit.. In response to the increased fluoroquinolone resistance and the subsequent public health risk to humans, the FDA in October of 2000 requested a ban on fluoroquinolones--cipro derivatives--used in livestock. Abbott Pharmaceuticals acquiesced, but Bayer chose to challenge the ruling about enrofloxacin, a ciprofloxacin derivative, in court. The situation is continuing to play itself out.

	Discussion
	Should governments monitor and/or report to the public on the use of antibiotic drugs in the food supply? {Dis: For example, should grocery stores be required by law to clearly label foods that were raised with help of AGPs?}

The European Union, meanwhile, is moving to ban the use of all AGPs by the year 2006. Currently, none of the four agents still used are related to agents used in humans. Remember they removed avoparcin and some of the others in 1997-1998, and the four drugs that are left should be history by the year 2006. In March of 2002, US House Democrats introduced a bill to phase out eight classes of antibiotics for AGPs over the next two years. These eight classes are antibiotics that are related to antibiotics used in humans. I am very happy to say that one of these is the use of the fluoroquinolones in poultry.

Antibiotics in cleaning products
Another contributing factor to the proliferation of multi-resistant bacteria is the current market mayhem toward the use of antibacterial products in soaps, body washes, hand lotions, dishwashing liquids, and window cleaners. You will notice now so many of these products on the market are "antibacterial." This creates a real problem because the general public is taking sub-therapeutic amounts of these antiseptics. Most people are probably not getting adequate exposure using these to really kill bacteria.

	Thinking Point
	Make a list of all your cleaning and medical supplies in your home. By looking at the manufacturers' labels, how many contain antibiotics?

However, with the widespread use of these antiseptics in these products we are proliferating resistance. For example, many organisms found in our environment are now resistant to one commercially available antiseptic called triclosan from such widespread use of these products in our communities. Right now, it is considered a positive marketing ploy to make products "antibacterial." This should be reconsidered.