Nucleic Acid-based Diagnosis and Epidemiology of Infectious Diseases

Abstract

In this chapter, the immense contribution of nucleic acid discovery to the diagnosis and molecular epidemiology of pathogenic microorganisms and its relevance for veterinary and human health will be discussed. The development of nucleic acid detection, amplification, and sequencing techniques, principally after the introduc‐ tion of polymerase chain reaction (PCR), allowed the improvement of different strategies to diagnose and to quantify infectious microbiological agents in a variety of organisms and biological samples. Pos-PCR associated techniques such as fragment enzyme restriction and sequence analysis permit the determination of nucleic acid sequence diversity to detect drug resistance, to associate pathogen genetic markers with disease outcome, and to predict temporal and spatial distribution of microorganisms which can be used to prevent and treat infectious diseases efficiently. The principal methods used in the detection of nucleic acids, the advantages and drawbacks of single- and multiple-copy genes for use in diagnosis by amplification, and the application of pos-PCR techniques in drug resistance identification are dis‐ cussed in Section 1.1. Section 1.2 discusses the sequencing methods used to recog‐ nize genetic variability, the implication of this variability to pathology and virulence, and the importance of genetic variability determination in disease control and vaccines. The contribution of molecular diagnosis and epidemiology for the treatment and prevention of infectious diseases is also considered.