Overview of Molecular Diagnosis in Medical Microbiology

Clinical microbiology diagnosis became objectively possible at the end of 19th century with the seminar contributions of researchers such as Louis Pasteur, Robert Koch and other colleagues. The concept of diagnosis then was the ‘culture and isolate’ paradigm, which accelerated to a large extent the growth of bacteriology, as a number of bacteria were able to fulfill the Koch’s postulates, but delayed the growth of other fields of microbiology most especially virology because viruses were not culturable outside of host cells. This paradigm, together with the application of micros-copy, serology and the use of animal models in research in the early 20th century, constituted the ‘first revolution’ in the field of microbiology that is referred to as the conventional microbiological diagnosis. Although this conventional diagnosis has remained valuable, assessments have shown that many of the conventional techniques are not demonstrably ‘fit for purpose’ in the 21st century. This has necessitated the consideration of complementary or alternative technologies, the molecular diagnosis, which has ushered in a ‘second revolution’ in microbiology that is as profound as the first in its impact on our understanding of the microbe-human interactions in health and disease. In this mini-review, an overview of the technologies underlying molecular diagnosis in microbiology is presented. The application of these molecular methods in clinical microbiology laboratory to ensure accurate, reliable and timely release of microbiological test results for better patients’ management and outcome is highlighted.