GENERATION OF DNA PROBES FOR DETECTION OF MICROORGANISMS BY POLYMERASE CHAIN-REACTION FINGERPRINTING

Identification of medically relevant microorganisms is important for d iagnosis, treatment and prevention of infectious diseases. This has in itiated the development of a large number of identification and typing techniques based on phenotypic and genetic characteristics. In genera l, these last mentioned nucleic acid-mediated techniques provide more detailed and consistent information on strain-specific characteristics . However, the development of clinically useful microbial DNA/RNA prob es requires nucleotide sequence information and a set of well defined reference organisms for test validation in comparison with the current gold standard. This is a requirement for the development of accurate nucleic acid hybridisation and/or amplification tests. Recently, it ha s been demonstrated that polymerase chain reaction (PCR)-mediated gene tic typing of microorganisms can lead to the immediate isolation of sp ecies-specific DNA probes by comparison of DNA fingerprints. This comb ines the sensitivity of PCR with the specificity of DNA probing withou t the need to generate nucleic acid sequence information prior to prob e development. The implications of this procedure for clinical microbi ology and epidemiological surveillance will be discussed. It is shown that specific probes can be developed for various taxonomic levels and that detection and identification can be combined into a single, fast procedure. The versatility and widely applicable principles of this p rocedure will be highlighted and exemplified by some newly developed t ests and a review of the current literature.