Plasmids and the spread of antibiotic resistance

The term plasmid was first coined in 1952 by Joshua Lederberg to encompass all extra-chromosomal hereditary determinants¹. One of the first plasmids discovered allowed the movement of genes from one bacterial strain to another, creating a sort of ‘bacterial sex’ or ‘fertility’ so that the entity responsible was called the ‘fertility factor’ or F-factor². Plasmids carrying antibiotic resistance were soon discovered and became a topic of intense research which contributed to the development of cloning vectors that underpinned the gene cloning revolution in the 1970s. Although the problems created by plasmids were clear to many from the beginning, we do not yet have ways to control their acquisition and spread of resistance.