Understanding foodborne microbial hazards for smarter food policies

One in six Americans contracts a foodborne illness each year (CDC). Such illness can mean an unpleasant day of vomiting, diarrhea, fever, and/or worse— hospitalization or death in rare cases. “There’s something that can be said about the problem of foodborne illness, that can’t be said of many other public health problems of the day” said Elisabeth Hagan, Under Secretary for Food Safety at USDA, who opened a January 25th foodborne hazards conference convened at the Pew Charitable Trusts offices in Washington DC, “and that is: Foodborne illness is preventable.

The day-long conference “Managing the Risk of Foodborne Hazards: STECs and Antibiotic-Resistant Pathogens” was organized jointly by Pew and the Center for Science in the Public Interest (CSPI). Hagan and other conference speakers focused their attention on antibiotic-resistant pathogens and shiga toxin-producing Escherichia coli (E. coli). A key message that I heard from several speakers was that we know enough today to develop policies that can enable action in addressing the most pressing foodborne hazards.

Ground BeefCentral to the development of smarter food policies is incorporating our understanding the ecology of foodborne microbes. For example, understanding the ecology of toxin-producing E. coli strains can improve our ability to detect the right types of E. coli in tainted foods. In another example, nontherapeutic use of antibiotics in food animal production creates a persistent collection of antibiotic-resistant bacterial genes or a ‘resistome’ on farms that is difficult to dismantle. Antibiotic-resistance genes transferred to pathogenic bacteria creates a health hazards for animal workers, slaughterhouse workers, farm neighbors, and to consumers who handle or prepare raw meat in their kitchens.

Antibiotic-resistant pathogens

The Pew/CSPI conference focused on antibiotics in food animals because in 2009 nearly 80% by weight of all antimicrobials were sold for use in food animal, and the remaining 20% by weight were used in human medicine, as reported last year by Ralph Loglici on the Livable Future Blog.

Resistance is an inevitable result of using antibiotics on food animals or humans. In the words of Quijing Zhang of Iowa State University, “[it is] always going to happen.” Once gut bacteria become resistant to antibiotics, they can trade the blueprints for resistance to other beneficial bacteria or with pathogenic bacteria in a giant microbial swap meet called ‘the resistome.’

 The microbial world’s resistome and our own human-centered biome collide more often than we think—just talk to a health care provider about hospital-acquired antibiotic resistant infections or read the latest 2008 report on the quality of retail meats from the U.S. National Antimicrobial Resistance Monitoring System.

 When humans take antibiotics or animals are given antibiotics, these are individual decisions—and as Dr. Stuart Levy of Tufts University pointed out, “[these individual decisions have] societal effects when antibiotics are mismanaged, such that every dose of antibiotics has a consequence.” Levy underscores the severity of current practices, saying, “the fact that we are still practicing [the use of antibiotics in animal production] is an embarrassment and a mistake.”

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