How does antibiotic resistance develop?

October's case study looked at figuring out the best treatment options for an increasingly antibiotic-resistant organism causing pneumonia in an ICU patient. A recent article in the Washington Post, "FDA Rules Override Warnings About Drug," includes a great graphic illustrating how antibiotic resistant bacteria develop.

The article is one of many responses from the popular media and the scientific community about the pending approval by the FDA of the use of cefquinome, a 4th generation cephalosporin antibiotic, in cattle, and the potential and very likely increase in bacterial resistance associated with using this antibiotic more widely.

The basic idea is that you use the antibiotic in cows, the bacteria in those cows starts developing resistance, and then that resistance is transmitted to humans when they consume beef contaminated with the resistant organisms (the biggest two would be E. coli and Salmonella spp.).

A FDA panel met in Sept 2006 to discuss risks and benefits of approval for this agent, and the slides from the session provide more information on risks, benefits, how cefquinome works, etc.

(spotted via Mike the Mad Biologist)