The use of molecular biology techniques for diagnostic microbiology and hospital epidemiology

Clinical microbiologists and hospital epidemiologists have traditionally been concerned with the isolation and identification of organisms for diagnosis in individual patients, and the detection of transmission of such organisms from patient to patient. The use of molecular biology techniques, such as nucleic acid probing and amplification, provides the potential for revolutionizing how we diagnose infecting pathogens and determining the relation between nosocomial isolates. In clinical microbiology, this means that we will be able to detect smaller amounts of DNA or RNA of pathogens than is currently possible, that the time required to identify and determine the antimicrobial susceptibility of slow-growing pathogens will be dramatically reduced, and that the diagnosis of nonculturable organisms will become possible. In hospital epidemiology, the use of such techniques has already provided tests with exceptional discriminatory power. Molecular techniques allow more efficient typing of all pathogens, and permit discrimination between strains of organisms that were previously phenotypically identical or uncharacterizable. Currently, cost and complexity limit the applicability of these techniques; however, they are likely to be developed for routine laboratory use in the next decade, and their impact will be considerable.