Antonie van Leeuwenhoek, in 1674, first saw what he called “ammalcules”-bacteria and protozoa in biological samples, including those taken from his own body. Many important developments related to clinical microbiology took place during the latter part of the 19th century. In 1875, F.J. Cohn published an early classification of bacteria, using the genus name Bacillus for the first time. Robert Koch described anthrax in 1876, the culture plate technique in 1881 and the aetiology of tuberculosis in 1884. He was awarded the Nobel Prize for his contributions to medicine in 1905. Joseph Lister demonstrated the isolation of bacteria in pure culture, Louis Pasteur introduced the concept of vaccination with attenuated microorganisms and Paul Ehrlich demonstrated the formation of antibodies, all during the 19th century [1]. Since then, medical microbiology has evolved at an explosive rate (ASM, 1999). A wide variety of emerging pathogens continue to be described as various advances are made in medicine (CDC, webpage). During the last two decades, molecular diagnostic techniques have led to a revolution in our abilities to identify, classify and understand microorganisms. Increasing numbers of diagnostic tests, including those commercially available, are based on molecular techniques. Some enthusiasts predict that they may replace culture as the routine laboratory method of investigation [2].
Microbiology is the science concerned with studying all microorganisms. Medical microbiology restricts this to the microbes that live on the human surface, and those there or elsewhere that may invade human tissues or otherwise cause infectious disease. In a nutshell, medical microbiology involves the diagnosis, treatment and control of human infection [3].
Clinical microbiology has matured into a wide-ranging science, not just a service to process specimens and provide results but also to advise on the collection of specimens, the interpretation of results and management of patients, the selection of antimicrobial agents and in the control of hospital-acquired infections. Conventional pathogens are capable of causing infections in previously healthy people. The organisms isolated from clinical specimens may derive from bacteria and fungi that are permanently living on body surfaces (commensals) or from the environment. Opportunistic pathogens are those that usually do not cause disease in normal people, but may cause serious infections in immune compromised patients. Hence, the significance of laboratory findings will depend on how the specimen was collected and needs to be assessed in the context of the clinical situation. Serious nosocomial infections are often caused by commensals and environmental organisms [4]. A clear distinction between a primary pathogen, a commensal and a contaminant is not always clear-cut. This situation is frequently encountered in immunologically compromised patients. As a result, the liaison between the medical microbiologist and the clinician is of paramount importance to ensure a sensible interpretation of laboratory findings.
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one type of infectious protein called prion [5].
Published Date: 2022-09-30; Received Date: 2022-09-02
