Feinstein introduces Senate antibiotic bill

Jul 5, 2013

Following recent congressional rumblings on the topic of antimicrobial use in food animals, U.S. Sen. Dianne Feinstein, D-CA, introduced the “Preventing Antibiotic Resistance Act of 2013” to the Senate on June 27. The bill—which lacked a number at the time of writing—is the Senate version of H.R. 1150, “Preservation of Antibiotics for Medical Treatment Act of 2013,” introduced in the House by Rep. Louise Slaughter, D-NY. Among other things, the Senate bill would require a phasing out of antimicrobials used nontherapeuticly.

In the official announcement from Feinstein’s office, the bill “safeguards use of antibiotics in agriculture” and claims antibiotics are “misused in animal agriculture.”

“When antibiotics are fed in low doses to animals, only the strongest, most resistant bacteria are left behind to reproduce. By the time these resistant pathogens make their way from the animals into our communities, the infections can be costly to treat or untreatable all together.”

Both the bill itself and Feinstein’s statements run amok with statistics about antimicrobial use in animal agriculture, some of which conflict with other official statistics on the topic.

Feinstein’s announcement cited a recent study published in the medical journal Clinical Infectious Diseases which purportedly found high levels of antibiotic-resistant bacteria in retail meat. She further decried the use of antimicrobials in animal agriculture saying, “The irresponsible use of antibiotics is dangerous, and tens of thousands of people in the U.S. die each year from antibiotic resistant infections. We must preserve the efficacy of these life-saving drugs by carefully restricting their overuse in our agriculture products.”

The Food and Drug Administration (FDA), however, reports that first-line treatments for all four major food-borne illness-causing bacteria tracked by the National Antimicrobial Resistance Monitoring System (NARMS)—Salmonella, Enterococcus, E. coli and Campylobacter—are still effective. FDA also called it “inaccurate and alarmist” to characterize bacteria resistant to one, or even a few, antimicrobials as “superbugs,” something Feinstein’s announcement does readily.

An FDA article regarding such “alarmist” interpretations of antibiotic resistance information pointed out the following:

• In the critically important class of antimicrobials, the 2011 data [NARMS Retail Meat Report] showed no fluoroquinolone resistance in Salmonella from any source. This is the drug of choice for treating adults with Salmonella.

• Trimethoprim-sulfonamide is another drug used to treat Salmonella infections and resistance remains low (0-3.7 percent).

• Fluoroquinolone resistance in Campylobacter has stopped increasing and remained essentially unchanged since the FDA withdrew the use of this drug class in poultry in 2005.

• Macrolide antibiotic resistance in retail chicken isolates remains low, with 2011 results at 0.5 percent of Campylobacter jejuni and 4.3 percent of Campylobacter coli. The macrolide antibiotic erythromycin is the drug of choice for treating Campylobacter infections.

• Multidrug resistance is rare in Campylobacter. Only nine out of 634 Campylobacter isolates from poultry were resistant to 3 or more antimicrobial classes in 2011. However, gentamicin resistance in Campylobacter coli markedly increased from 0.7 percent in 2007 (when it first appeared in the NARMS retail meat report) to 18.1 percent in 2011. Gentamicin has been suggested as a possible second-line therapy for Campylobacter infections, although it is not commonly used.

• Resistance to third-generation cephalosporins, which are used to treat salmonellosis, has increased in Salmonella from chicken (10- 33.5 percent) and turkey (8.1-22.4 percent) meats when comparing 2002 and 2011 percentages. FDA has already taken action by prohibiting certain extra-label uses of cephalosporins in cows, pigs, chickens and turkeys, and is continuing to closely monitor resistance to these drugs.

If Feinstein’s bill makes it into law, non-therapeutic uses of “medically important antimicrobials” would be phased out of use in foodproducing animals within two years of the bill’s passage. This would be done via a withdrawal of non-therapeutic use approval of the antimicrobials in question. The bill would also amend the language of the “Federal Food, Drug, and Cosmetic Act” to require use of antimicrobials in livestock to be used only in the treatment of clinically diagnosable diseases.

Feinstein is quick to point out that only those classes of antimicrobials used in humans would be affected— “Any drug not used in human medicine is left untouched by this legislation…”—and that the bill would not affect the ability of veterinarians to treat sick animals or “a herd of animals that are likely to become sick.”

The Humane Society of the United States was quick to praise the move, characterizing the non-therapeutic use of antimicrobials as used “to promote growth and to keep animals alive in unhealthy and inhumane conditions on industrial factory farms.” The group also trotted out the oft-quoted number of animal agriculture accounting for 70 percent of antibiotics in the U.S. with no mention of the vast differences of scale between human and animal use which is an important and often ignored detail where antimicrobial sales and use are concerned. — Kerry Halladay, WLJ Editor