DNA hybridization techniques and their application to the diagnosis of infectious diseases

Several commercial DNA probe assays are widely used in clinical microbiology laboratories. These include culture-confirmation assays for Mycobacterium species, which are recommended by CDC because they are both rapid and accurate, and culture-confirmation assays for N. gonorrhoeae. Probe assays for direct detection of N. gonorrhoeae and C. trachomatis are also widely used in public health and large reference laboratories. In many cases, the probe assays have decreased the time to identification of positive cultures and improved detection of these pathogens because they do not depend on the presence of viable organisms to achieve a positive result. Nucleic acid amplification assays hold promise for the rapid detection and identification of many infectious agents. PCR using universal primers enables researchers to identify new agents of disease that cannot be cultured in vitro; more importantly, PCR provides a method for detecting the presence of any bacterial species, including common organisms, in normally sterile body fluids, such as blood and cerebrospinal fluids. The use of such primers may well give PCR the broad-based approach needed to identify organisms in the clinical microbiology laboratory of the future.