The U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS) issued a public health alert today after a joint investigation by state public health officials and the Centers for Disease Control and Prevention identified ground beef as the source of a multi-drug-resistant strain of Salmonella.  At least 38 people in Arizona, California, Hawaii, Nevada, and New Mexico became ill with Salmonella Newport infections after consuming the ground beef between September 19 and November 5, 2007.

FSIS stated in its public health alert:

This alert is being issued after an exhaustive and continuing investigation whereby FSIS could not identify specific establishments, lots and products that would be subject to a recall. FSIS has no reason to believe that these products are still available for sale in commerce.

Consumers that may have purchased these fresh ground beef products between Sept. 19 and Nov. 5, 2007, and stored them in the freezer should look for and discard or destroy these products if they find them. . . .

This particular strain of Salmonella is resistant to many commonly prescribed drugs, which can increase the risk of hospitalization or possible treatment failure in infected individuals.

Antimicrobial Resistance in Salmonella Bacteria

Antimicrobial resistance in bacteria is an emerging and increasing threat to human health. Physicians should be aware that antimicrobial resistance is increasing in foodborne pathogens and that patients who are prescribed antibiotics are at increased risk for acquiring antimicrobial resistant foodborne infections. In addition, “[i]increased frequency of treatment failures for acute illiness and increased severity of infection may be manifested by prolonged duration of illness, increased frequency of bloodstream infections, increased hospitalization or increased mortality.”

The use of antimicrobial agents in the feed of food animals is estimated by the FDA to be over 100 million pounds per year. Estimates range from 36% to 70% of all antibiotics produced in the United Sates are used in a food animal feed or in prophylactic treatment to prevent animal disease. The use of antibiotics is thought to promote growth and to prevent disease in beef, pork, and poultry production as well as on fish farms and some fruit and vegetable farms.

According to the National Antimicrobial Resistance Monitoring System (NARMS), Campylobacter has been recovered from 47% of chicken breasts tested in recent studies. In the same NARMS studies, five mulit-drug resistant strains of Salmonella Newport were recovered from ground beef, ground turkey and pork chops. According to the report, “[a]ntimicrobial resistance among these foodborne bacteria is not uncommon and often associated with the use of antimicrobial agents in food animals.” Ceftriaxone-resistant Salmonella has also been reported (Fey et al., 2000). The emergence of multidrug-resistant Salmonella typhimurium in the United States is another example of a drug-resistant bacteria spreading from animals to humans (Glynn et al., 1998).

The use of antibiotics in feed for food animals, on animals prophylactically to prevent disease, and the use of antibiotics in humans unnecessarily must be reduced. European countries have reduced the use of antibiotics in animal feed and have seen a corresponding reduction in antibiotic-resistant illnesses in humans.