This sounds really wild.
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Researchers from Yale and the University of Connecticut report detecting genes relating to bacterial resistance to antibiotics in the manure of dairy cows.

The findings create some concern that introduction of these genes into the environment as manure is used as fertilizer could lead to the emergence of antibiotic-resistant pathogens in humans or animals. The research results are published in the April 22 issue of mBio the online open-access journal of the American Society for Microbiology (ASM).

The resistance genes were frequently found in clusters and originated from a taxonomically diverse set of species, suggesting that some microorganisms in manure harbor multiple resistance genes.