Lessons from the past: a personal view.

We know a great deal about the diversity of the genetic and biochemical mechanisms of antibiotic resistance and are thus well equipped by this experience to study new phenomena as they appear in the future. In addition, we have identified relationships between epidemiological patterns in resistance and major external events that we believe are responsible for the development of resistance, namely antibiotic use and the creation of opportunities for the spread of resistance determinants and resistant organisms, although we have tended to ignore these anomalies. However, perhaps because of the latter circumstance, there remain skeptics, both among those who have a particular interest in the subject and, more important, among physicians in general, who are often not persuaded of the relationships between their use of antibacterial drugs and the patterns and prevalence of antibiotic resistance observed by epidemiologists.