An Introduction to Antimicrobial Susceptibility Screening

The development of rapid molecular diagnostics has coincided with a period of increasing challenges in hospital infection control and with the emergence of antimicrobial resistance as a major issue in community infections. The “golden age” of antibiotics from the 1940s to 1970s promised to the cure of all bacterial infections with a drug for every bug. Predictions were even made of the demise of Clinical Microbiology as a diagnostic discipline [1]. They were somewhat overstated. The reality we now face is very different with the emergence over the last quarter century of an impressive variety of antimicrobial resistance mechanisms in an ever increasing number of bacterial pathogens. This situation has arisen due to selective pressure provided by the widespread use (and, to varying degrees, misuse) of antibiotics in both the hospital and the community and due to the ability of bacteria to transfer genetic material coding for resistance horizontally by multiple mechanisms. Fortunately, the rapid evolution of bacterial genomics and of molecular diagnostic methods has provided us with the tools for rapid response to this emerging problem.