[Molecular biology in the diagnosis of infectious diseases].

Since its introduction a decade ago, the polymerase chain reaction (PCR) has been largely utilized as a powerful research tool in microbiology. More recently, the simplification and the automatization of the PCR coupled with the recent development of several other nucleic amplification techniques has brought the introduction of molecular biology into the routine clinical laboratory. The PCR techniques offer new exciting perspectives in the field of microbiology in terms of clinical diagnosis and there are at least three areas in which this technology is expected to have a significant impact in the clinical microbiology laboratory over the next decade : 1) direct detection and identification of organisms that are slow-growing or those currently lacking a system for in vitro cultivation; 2) identification of genotypic markers of microbial resistance to specific antibiotics; 3) direct identification of microorganisms based upon amplification and sequence analysis of common sequence elements. This review also briefly discusses the various problems that must be overcome prior to routine use of PCR in the clinical laboratory.