October 29, 2014
Donald Kennedy, a Stanford University biology professor, had been commissioner of the Food and Drug Administration for less than two months in 1977 when he plunged into a difficult scientific and political debate that remains unresolved today. Kennedy wanted to cut back on the widespread use of antibiotics on farms to make animals grow faster and prevent disease.
A study published last year about the use of tetracyclines on cattle raises this question anew. The research, by a team that included H. Morgan Scott of Texas A&M University and Guy Loneragan of Texas Tech University, showed the use of a tetracycline led to “co-selection,” a process in which the antibiotic expanded the population of bacteria that are resistant to other antibiotics as well. In their experiment, the tetracycline expanded resistance to a cephalosporin, a class of antibiotic that is highly valued in human medicine.