Molecular diagnosis of infectious diseases

Infectious diseases are one of the leading causes of mortality and morbidity with a significant impact on health and the economy of the world. They are existing for centuries and are caused by human pathogens. Since pathogens are normally found in complex communities, the diagnosis of polymicrobial and fungal infections is increasingly challenging in the clinical setting. Traditionally, diagnosis of bacterial or fungal infections relied solely on culture-based techniques, and cultures have been considered the gold standard of pathogen detection. However, some organisms may not be easily detectable by conventional culture methods used in most laboratories. These many factors, including growth environment, morphological, and biochemical characters, make accurate diagnosis and treatment of infections a challenge. The recent development of molecular techniques has provided a new avenue for pathogen identification. Here, we discuss the current development of molecular detection for species identification in clinical samples, especially the improvement of those nucleic acid-based techniques. Furthermore, we also introduce the application of MALDI-TOF MS in identifying the microorganisms. Together, these techniques have significantly improved the accuracy and efficiency of identifying microorganisms.