FDA Cautions Interpretation of Antimicrobial Resistance Data
April 22, 2013
The Food and Drug Administration’s (FDA) Center for Veterinary Medicine today issued a statement cautioning the interpretation of antimicrobial resistance data. Recently, the Environmental Working Group (EWG) issued a report of its interpretation of the 2011 Retail Meat Annual Report of the National Antimicrobial Resistance Monitoring System (NARMS).
“While FDA is always concerned when we see antimicrobial resistance, we believe the EWG report oversimplifies the NARMS data and provides misleading conclusions,” FDA noted.
The statement said that FDA did not believe that EWG fully considered important factors that put these results in context, including:
- whether the bacterium is a foodborne pathogen. The report highlights resistance to Enterococcus, but this is not considered a foodborne pathogen. Instead, we include it because its behavior is helpful in understanding how resistance occurs.
- which drug(s) the bacterium is naturally resistant to. For example, most Enterococcus faecalis is naturally resistant to the antibiotic class of lincosamides. Because we know and expect to see this resistance, we are not as concerned with resistance in this species the way we would be with resistance in true pathogens like Salmonella and Campylobacter.
- why NARMS includes certain drugs in its testing design. We include some antibiotics for epidemiology purposes– to track the spread of certain bacteria or certain genes. But resistance to these antibiotics doesn’t reflect a danger to public health.
- whether the antibiotics that are commonly used to treat patients are still effective. NARMS data indicates that first-line treatments for all four bacteria that we track (Salmonella, Enterococcus, Escherichia coli and Campylobacter) are still effective.
- what the 2011 data indicate relative to similar data reported for prior years.
“Additionally, we believe that it is inaccurate and alarmist to define bacteria resistant to one, or even a few, antimicrobials as “superbugs” if these same bacteria are still treatable by other commonly used antibiotics,” the FDA statement continued. “This is especially misleading when speaking of bacteria that do not cause foodborne disease and have natural resistances, such as Enterococcus.”