“It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them… There is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.”As a biologist, Fleming knew that evolution was inevitable: sooner or later, bacteria would develop defenses against the compounds the nascent pharmaceutical industry was aiming at them. But what worried him was the possibility that misuse would speed the process up. Every inappropriate prescription and insufficient dose given in medicine would kill weak bacteria but let the strong survive. (As would the micro-dose “growth promoters” given in agriculture, which were invented a few years after Fleming spoke.) Bacteria can produce another generation in as little as twenty minutes; with tens of thousands of generations a year working out survival strategies, the organisms would soon overwhelm the potent new drugs.
Fleming’s prediction was correct. Penicillin-resistant staph emerged in 1940, while the drug was still being given to only a few patients. Tetracycline was introduced in 1950, and tetracycline-resistant Shigella emerged in 1959; erythromycin came on the market in 1953, and erythromycin-resistant strep appeared in 1968. As antibiotics became more affordable and their use increased, bacteria developed defenses more quickly. Methicillin arrived in 1960 and methicillin resistance in 1962; levofloxacin in 1996 and the first resistant cases the same year; linezolid in 2000 and resistance to it in 2001; daptomycin in 2003 and the first signs of resistance in 2004.
With antibiotics losing usefulness so quickly — and thus not making back the estimated $1 billion per drug it costs to create them — the pharmaceutical industry lost enthusiasm for making more. In 2004, there were only five new antibiotics in development, compared to more than 500 chronic-disease drugs for which resistance is not an issue — and which, unlike antibiotics, are taken for years, not days. Since then, resistant bugs have grown more numerous and by sharing DNA with each other, have become even tougher to treat with the few drugs that remain. In 2009, and again this year, researchers in Europe and the United States sounded the alarm over an ominous form of resistance known as CRE, for which only one antibiotic still works.
Health authorities have struggled to convince the public that this is a crisis. In September, Dr. Thomas Frieden, the director of the U.S. Centers for Disease Control and Prevention, issued a blunt warning: “If we’re not careful, we will soon be in a post-antibiotic era. For some patients and some microbes, we are already there.” The chief medical officer of the United Kingdom, Dame Sally Davies — who calls antibiotic resistance as serious a threat as terrorism — recently published a book in which she imagines what might come next. She sketches a world where infection is so dangerous that anyone with even minor symptoms would be locked in confinement until they recover or die. It is a dark vision, meant to disturb. But it may actually underplay what the loss of antibiotics would mean.
by Maryn McKenna, Medium | Read more:
Image: Eneas De Troya
