Molecular Detection of Mycobacterium Tuberculosis: Impact on Patient Care (Beckman Conference‪)‬

Molecular approaches to the diagnosis of disease have begun to have a major influence on current clinical management of various disorders. In particular, detection of human microbial pathogens has been impacted by nucleic acid-based techniques, primarily amplification assays. Numerous amplification-based assays have been developed to offer improvements in the detection of slow-growing or unculturable organisms, or when information not provided by conventional diagnostic approaches is needed. Quantitative measurement of serum or plasma concentrations of several viruses is becoming increasingly useful for monitoring of disease response to treatment. Because of the potential and widespread application of molecular testing in microbiology, several commercial methods have been developed, whereas methods for nonmicrobiologic applications remain few. However, there are several critical differences between nucleic acid-based testing and conventional microbiology. Nucleic acid-based tests generally target only a single organism, whereas cultures generally are more broad in coverage. Although the molecular assay might rule out a single microbe, continued analysis in culture may be required to detect other relevant organisms. Additionally, antimicrobial resistance studies may be required, also necessitating further analysis in culture. In some cases, molecular epidemiologic studies may also be required to investigate disease spread. Thus, with few exceptions, molecular assays do not negate the need for performance of routine cultures.