Kosher Chickens Found to Have Higher Levels of Antibiotic-Resistant Bacteria

Raw chicken marketed as kosher may harbor up to twice as much antibiotic-resistant E. coli as poultry raised conventionally, according to a new study funded by Northern Arizona University.

The study’s results may fly in the face of the generally accepted notion that kosher meat is safer than meat raised to other standards. According to a survey cited by The New York Times in 2010, 62 percent of those who buy kosher foods do so for quality reasons, compared to 15 percent who buy kosher for religious reasons.

Between April and June 2012, NAU researchers purchased 213 samples of raw chicken from 15 retail locations in New York City among four categories: conventional, organic, raised without antibiotics (RWA) and kosher. After screening each sample for E. coli and then testing that E. coli’s resistance to 12 common antibiotics, the team was a little surprised by what they found, said Jack Millman, the study’s lead author.

First, it’s important to note that the majority of E. coli strains, including those found on raw chicken, are not harmful to humans. Millman said the study screened for all strains of E. coli, and he was not certain what percentage was Shiga toxin-producing strains – the variety harmful to human health. While some harmful E. coli has been associated with chicken in previous studies and outbreaks, chicken is far more commonly associated with pathogens such as Salmonella and Campylobacter.

The study found that resistance rates were lowest among RWA chicken meat, while conventional and organic had virtually the same frequency. Kosher chicken, on the other hand, had nearly twice as much resistant E. coli as conventional and organic.

More than half of all the E. coli strains collected exhibited resistance to at least one antibiotic. Antibiotic resistance of E. coli on conventional chicken was at 55 percent, RWA at 58 percent, organic at 60 percent, and kosher at 76 percent.

Across the board, resistant strains taken from kosher chicken were also resistant to a significantly larger variety of antibiotics in comparison to the other three categories.