Research into mice infected with salmonella, a bacteria often the cause of food-borne illness, poses “ominous questions about the widespread, routine use of sub-therapeutic doses of antibiotics in livestock,” says the Stanford Medical School. When scientists gave oral antibiotics to the mice, so-called superspreaders, mice that had been shedding high amounts of salmonella in their feces, remained healthy. The other mice got sick, rather than better, and also shed high levels of salmonella which was as infectious as from the superspreaders.
If the results hold up for livestock, said Denise Monack, senior author of the study, in a Stanford news release, “it would have obvious public health implications. We need to think about the possibility that we’re not only selecting for antibiotic-resistant microbes, but also impairing the health of our livestock and increasing the spread of contagious pathogens among them and us.”
The researchers got the same results from two antibiotics, streptomycin and neomycin.