What is Medical Microbiology?
Medical Microbiology covers and integrates the fields of immunology, bacteriology, virology, mycology, and parasitology, each of which has been identified. Significant independent developments over the last few decades. The common bond between them is focusing on the causes of infectious diseases and on the host ‘s reactions to the pathogens. Although the advent of antibiotics and vaccines has certainly taken away the fear of many infectious diseases, the threat of infection remains a fact of life: new pathogens are constantly being discovered; strains of “old” ones have developed antibiotic resistance, making therapy increasingly difficult; incurable infectious diseases (AIDS, rabies) are still with us.
What is the importance of medical microbiology?
Medical microbiology deals with pathogenic organisms that cause immense misery to human beings. In addition to the study of pathogenic bacteria, viruses, parasites, and fungi, Immunology and its research are also discussed. Medical microbiology plays a significant role in the production of vaccines for the majority of pathogenic organisms. It also deals with microbial metabolism and numerous other aspects of molecular biology in the pathogenic microbial world. It also contributes significantly to the interaction of organisms with antibiotics, antivirals, antifungal, and antiparasitic drugs. In short, it is a study of all pathogenic microorganisms and their interactions.
Microbiology is the study of organisms that can only be seen through a microscope.
A Brief History of Microbiology
Microbiology has had a long and rich history, initially centered on the causes of infectious diseases but now incorporating practical science applications. Many individuals contributed significantly to the development of microbiology.
Historians are uncertain who made the first observations of microorganisms, but the microscope was available in the mid-1600s, and Robert Hooke, an English scientist, made key observations. He is reputed to have found fungi strands among the collections of cells that he has seen. A Dutch merchant named Anton van Leeuwenhoek made careful observations of microscopic organisms in the 1670s and the decades thereafter, which he called animalcules. Van Leeuwenhoek revealed the microscopic world to scientists of the day until his death in 1723 and is considered one of the first to provide accurate descriptions of protozoa, fungi, and bacteria.
The Discovery Era of Microbiology
An English scientist of the 17th Century was the first to use the lens to observe the smallest tissue unit called ‘cells.’ Soon thereafter, the Dutch amateur biologist Anton van Leeuwenhoek, using his own home-made microscopes, observed what he called “animalcules.”
Antonie van Leeuwenhoek
The first person to be observing and accurately describing microorganic animals (bacteria and protozoa), called ‘animalcules’ (little animals) in 1676 was Antonie van Leeuwenhoek (1632-1723) of Delft, Holland (The Netherlands).
He was actually a Dutch linen merchant but spent much of his spare time building simple microscopes made up of double convex lenses held between two silver plates. He built over 250 small, powerful microscopes that could magnify about 50-300 times.
Leeuwenhoek was the first person to provide accurate and correct bacterial and protozoa descriptions using a microscope that he created himself. Because of this exceptional microbiological contribution, he ‘s considered the “Dad of Microbiology.”
Leeuwenhoek is also considered as the father of bacteriology and protozoology (protistology).
He has written over 200 letters, transmitted to the Royal Society in London for a period of 50 years as a sequence of 1674-1723 letters.
Transition Period of Microbiology
When micro-organisms were known to exist, most scientists believed that by spontaneous generation such simple life forms could surely emerge. That is, life was thought to spring spontaneously from mud and lakes, or anywhere with sufficient nutrients. This concept was so compelling that it lasted until the end of the 19th century.
The main aspects were to resolve the controversy over spontaneous generation, which includes experiments mainly with Francesco Redi, John Needham, Lazzaro Spallanzani, and Nicolas Appert, etc., and to know the transmission of the disease, which mainly involves the work of Ignaz Semmelweis and John Snow.
The Golden Age of Microbiology
The microbiology golden age started with the work of Louis Pasteur and Robert Koch who had their own research institute. More importantly, there was the worldwide acceptance of their work by the scientific community and a willingness to continue and expand the work. Throughout this time, we see the real start of microbiology as a biological discipline.
Louis Pasteur is known as the “Father of Modern Microbiology / Father of Bacteriology.
The French chemist Louis Pasteur finally put the concept of spontaneous generation into rest in an inspired set of experiments involving a goosenecked flask. When he boiled broth in a straight-necked flask and left it exposed to air, organisms grew. Nothing grew when he was doing this with his goose-necked flask. This second flask ‘s S-shape trapped dust particles from the air, which prevented them from reaching the broth. By showing that he could allow air to reach the flask but not the particles in the soil, Pasteur proved that it was the organisms developing in the broth in the dust.
Pasteur, thus finally resolved the controversy of spontaneous generation versus biogenesis in 1858 and proved that microorganisms are not generated spontaneously from inanimate matter but originate from other microorganisms.
He also found that microbes produced fermentation of fruits and grains that resulted in alcohol, and also determined that bacteria were responsible for spoiling wine during fermentation. In 1862, Pasteur suggested that mild heating at 62.8 ° C (145 ° F) for 30 minutes rather than boiling was sufficient to destroy the undesirable organisms without ruining the product ‘s taste, the process was called pasteurisation. Pasteurization was commercially introduced into the United States in 1892. His research had contributed to the establishment of the disease germ theory.
John Tyndall (1820 – 1893): An English physicist, in 1877, handed a final blow to the spontaneous generation. He carried out experiments in an aseptically built box to show that the germs were indeed borne by dust. He demonstrated that if there was no dust, the sterile broth remained free of microbial growth for an indefinite period, even if it was exposed directly to air. In the hay infusion, he discovered a highly resistant bacterial structure, later named endospore. To destroy these spores, sustained boiling or intermittent heating was required to make the infusion completely sterilized, a process known as Tyndallisation.
Around the same time as Pasteur was doing his experiments, a doctor named Robert Koch was working to find the causes of some very nasty animal diseases (first anthrax, and then tuberculosis). He received the first direct demonstration of the bacteria’s function in causing disease. He was a German physicist who in 1876 was the first to isolate the anthrax bacillus (Bacillus anthracis, the cause of anthrax). He perfected the technique of isolating bacteria in pure culture.
In 1881, he also introduced the use of solid culture media by using gelatin as a substantiating agent. He discovered tuberculosis at Mycobacterium in 1882. He proposed Koch’s postulate which was published in 1884 and is the foundation stone of disease germ theory and is still in use today to explain the etiology (specific cause) of an infectious disease.
Fanne Eilshemius Hesse
Fanne Eilshemius Hesse (1850 – 1934) was one of Koch’s first assistants to propose the use of agar in culture media. Due to its higher melting (i.e. 96 ° C) and solidifying (i.e. 40-45 ° C) points, agar was superior to gelatin than gelatin and was not attacked by most bacteria. In 1887, another assistant to Koch, Richard Petri, invented the Petri dish (plate), a container used for media of solid culture. Thus Robert Koch, Fannie Hesse, and Richard Petri ‘s contribution made it possible to isolate pure micro-organism cultures and directly stimulate progress in all areas of microbiology.
The era of Molecular Biology in the 20th Century
By the end of 1900, the science of microbiology had grown to adolescence and had become a branch of the more inclusive field of biology.
In later years, the microorganism was chosen as the ideal tool for studying different life processes, and thus an independent discipline of microbiology, molecular biology, was born.
The relative simplicity of the microorganism, its short life span, and genetic homogeneity provided an authentic simulated model for understanding the physiological, biochemical, and genetic intricacies of living organisms.
The field of molecular biology has made great strides in understanding the genetic code, how DNA is regulated, and how RNA is translated into proteins. Until this point, research focused mainly on plant and animal cells, which are much more complex than bacterial cells. When researchers switched to studying these processes in bacteria, many of the secrets of genes and enzymes began to be revealed.
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