The use of antibiotics in food animal production slightly increased and antibiotic resistant bacteria in meat products remained an issue 2011, according to two sets of data released by the U.S. Food and Drug Administration on Tuesday.
Antimicrobial drug sales data reported to the FDA showed a small uptick over 2010 numbers, up about 2.3 percent to 29.9 million pounds total. There were differences between different classes of antimicrobials. For Sulfas, a class of drugs used to treat infections in humans, the number of pounds sold dropped by 36 percent, compared to 2010. On the other hand, Ionophores, which are not used in human medicine, increased by nearly 8 percent.
See a breakdown of FDA’s antimicrobial sales data here.
“Every year, the usage has crept up, when every year the industry says they’re using less,” said Gail Hansen, senior officer of the Pew Campaign on Human Health and Industrial Farming. “Somewhere there’s a disconnect.”
Between 2010 and 2011, the FDA reports that the pounds of antibiotics sold for human use stayed relatively the same at 7.7 million pounds. Over the same period, total meat and poultry production increased about .2 percent.
On the same day that FDA released antimicrobial sales data, the agency also released the 2011 report on retail meat by the National Antimicrobial Resistance Monitoring System – which is coordinated between the FDA, the Centers for Disease Control and Prevention and 11 state public health laboratories. NARMS is meant to serve as a “reference point identifying and analyzing trends in antimicrobial resistance among these organisms.”
According to the NARMS data, the overall prevalence of Salmonella in ground turkey and chicken is down by a couple percentage points, but the prevalence of Campylobacter in chicken is up significantly, from nearly 39 percent found to be contaminated in 2010 to nearly 46 percent contaminated in 2011.
NARMS also looks at Enterococcus and Escherichia coli; for nearly all types of meat, these bugs were also found less frequently in 2011. The latter was found in chicken nearly 78 percent of samples in 2010 and 71 percent of samples in 2011. In ground turkey, the rate went from 80 to 76, in ground beef it dropped from nearly 59 percent to nearly 45 percent.
Drug resistance among Salmonella isolates increased all around. In 2010, the percentage of isolates that showed drug resistance was about 50 percent, while in 2011 it had increased to nearly 55 percent.
Resistance to cephalosporins, a class of drugs the FDA restricted in early 2012, increased between 2002 and 2011. Third generation cephalosporin resistance increased, in chicken from 10 to 33 percent and in ground turkey from 8 to 22 percent.
Hansen said Pew would be watching the resistance data in the wake of the FDA’s action on that class of drugs.
“We hope that this will be one of those instances where you remove the drug and the resistance will go down, but there are no guarantees,” she said.
The NARMS data also indicate that there was a significant increase in ampicillin resistance over the last decade among retail chicken, from nearly 17 percent to around 40 percent, and in ground turkey isolates from 16 percent to 58 percent. Ampicillin can be used in human medicine to treat infections, including Salmonella.
More than 27 percent of all chicken isolates showed resistance to five or more classes of antibiotics and in ground turkey isolates researchers found 10 different serotypes with resistance to six or more classes of antibiotics.
The Animal Health Institute, which represents veterinary pharmaceutical companies, said it wasn’t ready to comment on the reports.
“It’s a lot of data, it will take some time to go through,” said Ron Phillips, vice president of public and legislative affairs for AHI.
FDA is considering asking for more data on antimicrobial drug use to help the agency better track the connection between using antibiotic in food animal production and the antibiotic resistant pathogens found on meat products.
This article originally incorrectly cited data on cephalosporin resistance for 2010 to 2011, but has been corrected to indicate the numbers are for 2002 to 2011.
Photo by Stephen Ausmus courtesy of USDA’s flickr.© Food Safety News