Is the idea that disinfectants “train” microbes to become resistant any different?
A team at the National University of Ireland studied the response of bacterium Pseudomonas aeruginosa to a disinfectant. P. aeruginosa commonly infects those already ill, resulting in opportunistic infections in hospital patients—so it is already a prime target of hospital disinfectants. But when subjected to “increasing amounts of disinfectant” in the lab, P. aeruginosa cultures developed resistance not only to the disinfectant but also to the antibiotic ciprofloxacin—even though the cultures were never exposed to ciprofloxacin. The resistant P. aeruginosa had a mutation that let them “pump out” harmful substances—be they disinfectants or antibiotics—from their cells. They also had developed a particular resistance to ciprofloxacin. The danger the scientists point out is that disinfectants used in hospitals can be counterproductive (potentially), ensuring that whatever microbes do reach patients will already be resistant to antibiotics. Ironically, however, the problem was made worse
