LECTURE 12 The development of bacteriology and immunology in the 20th century. The beginning of virusology

• • •

The development of bacteriology The development of immunology The development of virusology

The development of bacteriology and immunology in the 20th century. The beginning of virusology     Microbiology is concerned with the structure, function, and classification of these organisms and with ways of controlling and using their activities. Its foundations were established in the later 19th century, with the work of Louis Pasteur and Robert Koch. Since then, many disease-causing microorganisms have been identified and means of controlling their harmful effects have been developed. In addition, means of channeling the activities of various microorganisms to benefit medicine, industry, and agriculture have been discovered. Molds, for example, produce antibiotics, notably penicillin. The 17th-century discovery of living forms existing invisible to the naked eye was a significant milestone in the history of science, for from the 13th century onward it had been postulated that “invisible” entities were responsible for decay and disease.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    The word microbe was coined in the last quarter of the 19th century to describe these organisms, all of which were thought to be related. As microbiology eventually developed into a specialized science, it was found that microbes are a very large group of extremely diverse organisms.

Daily life is interwoven inextricably with microorganisms. In addition to populating both the inner and outer surfaces of the human body, microbes abound in the soil, in the seas, and in the air. Abundant, although usually unnoticed, microorganisms provide ample evidence of their presence— sometimes unfavourably, as when they cause decay of materials or spread diseases, and sometimes favourably, as when they ferment sugar to wine and beer, cause bread to rise, flavour cheeses, and produce valued products such as antibiotics and insulin. Microorganisms are of incalculable value to the Earth’s ecology, disintegrating animal and plant remains and converting them to simpler substances that can be recycled in other organisms.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    Microbiology essentially began with the development of the microscope. Although others may have seen microbes before him, it was Antonie van Leeuwenhoek, a Dutch draper whose hobby was lens grinding and making microscopes, who was the first to provide proper documentation of his observations. His descriptions and drawings included protozoans from the guts of animals and bacteria from teeth scrapings. His records were excellent because he produced magnifying lenses of exceptional quality. Leeuwenhoek conveyed his findings in a series of letters to the British Royal Society during the mid-1670s. Although his observations stimulated much interest, no one made a serious attempt either to repeat or to extend them. Leeuwenhoek’s “animalcules,” as he called them, thus remained mere oddities of nature to the scientists of his day, and enthusiasm for the study of microbes grew slowly. It was only later, during the 18th-century revival of a long-standing controversy about whether life could develop out of nonliving material, that the significance of microorganisms in the scheme of nature and in the health and welfare of humans became evident

The development of bacteriology and immunology in the 20th century. The beginning of virusology   

Progress in the 20th century

All of these developments occurred in Europe. Not until the early 1900s did microbiology become established in America. Many microbiologists who worked in America at this time had studied either under Koch or at the Pasteur Institute in Paris. Once established in America, microbiology flourished, especially with regard to such related disciplines as biochemistry and genetics. In 1923 American bacteriologist David Bergey established that science’s primary reference, updated editions of which continue to be used today.

Since the 1940s microbiology has experienced an extremely productive period during which many disease-causing microbes have been identified and methods to control them developed. Microorganisms have also been effectively utilized in industry; their activities have been channeled to the extent that valuable products are now both vital and commonplace.

The development of bacteriology and immunology in the 20th century. The beginning of virusology        The study of microorganisms has also advanced the knowledge of all living things. Microbes are easy to work with and thus provide a simple vehicle for studying the complex processes of life; as such they have become a powerful tool for studies in genetics and metabolism at the molecular level. This intensive probing into the functions of microbes has resulted in numerous and often unexpected dividends. Knowledge of the basic metabolism and nutritional requirements of a pathogen, for example, often leads to a means of controlling disease or infection.

The main figures of the 20 microbiology are: th century and their contribution in studying Gaston Ramon Alexander Fleming Howard Florey

The development of bacteriology and immunology in the 20th century. The beginning of virusology            Ernst Boris Chain Selman Abraham Waksman N.S. Heatly Walter Reed, James Caroll and Jenesse Lazear K. Landstainer C. Levaditi J. Salk Albert Sabin Jules Bordet G. Gengou August Wassermann

The development of bacteriology and immunology in the 20th century. The beginning of virusology   Gaston Ramon (September 30, 1886 - June 8, 1963) was a French veterinarian and biologist.

During the 1920s, Ramon made major contributions to the development of effective vaccines for both diphtheria and tetanus. In particular, he developed a method for inactivating the diphtheria toxin and the tetanus toxin using formaldehyde which, in its essentials, is still used in vaccines manufactured today. He also developed a method for determining the potency of the vaccines, an essential element required for the reproducible production of these pharmaceuticals.

Alexander Fleming (6 August 1881 – 11 March 1955) was a Scottish biologist and pharmacologist. Fleming published many articles on bacteriology, immunology and chemotherapy. His best-known achievements are the discovery of the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the fungus Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Walter Florey and Ernst Boris Chain.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    In 1999, Time Magazine named Fleming one of the 100 Most Important People of the 20th Century for his discovery of penicillin, and stated; "It was a discovery that would change the course of history. The active ingredient in that mold, which Fleming named penicillin, turned out to be an infection-fighting agent of enormous potency. When it was finally recognized for what it was—the most efficacious life-saving drug in the world—penicillin would alter forever the treatment of bacterial infections. By the middle of the century, Fleming's discovery had spawned a huge pharmaceutical industry, churning out synthetic penicillins that would conquer some of mankind's most ancient scourges, including syphilis, gangrene and tuberculosis".

Ernst Boris Chain (19 June 1906 – 12 August 1979) was a German-born British biochemist, and a 1945 co-recipient of the Nobel Prize for Physiology or Medicine for his work on penicillin.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    Chain was born in Berlin to a Russian father who moved from his birthland to study chemistry abroad, and a German Berliner mother. In 1930, he received his degree in chemistry from Friedrich Wilhelm University. He began working on phospholipids at Cambridge University under the direction of Sir Frederick Gowland Hopkins. In 1935, he accepted a job at Oxford University as a lecturer in pathology. During this time he worked on a range of research topics, including snake venoms tumour metabolism, lysozymes, and biochemistry techniques.

In 1939, he joined Howard Florey to investigate natural antibacterial agents produced by microorganisms. This led him and Florey to revisit the work of Alexander Fleming, who had described penicillin nine years previously. Chain and Florey went on to discover penicillin's therapeutic action and its chemical composition. He also theorized the structure of penicillin, which was confirmed by X-ray crystallography done by Dorothy Hodgkin. For this research, Chain, Florey, and Fleming received the Nobel Prize in 1945.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    Selman Abraham Waksman (22 July 1888 – 16 August 1973) was a American biochemist and microbiologist whose research into organic substances—largely into organisms that live in soil—and their decomposition promoted the discovery of Streptomycin, and several other antibiotics. A professor of biochemistry and microbiology at Rutgers University for four decades, his work led to the discovery of over twenty antibiotics (a word which he coined) and procedures that have led to the development of many others. The proceeds earned from the licensing of his patents funded a foundation for microbiological research, which established the Waksman Institute of Microbiology located on Rutgers University's Busch Campus in Piscataway, New Jersey (USA). In 1952 he was awarded the Nobel Prize in Physiology or Medicine in recognition "for his discovery of "streptomycin" the first antibiotic active against tuberculosis", despite the fact that this medicine was indeed discovered by Albert Schatz, one of Waksman's graduate investigators working under his direction.

The development of bacteriology and immunology in the 20th century. The beginning of virusology     Albert Bruce Sabin (August 26, 1906 – March 3, 1993) was an American medical researcher best known for having developed an oral polio vaccine.

With the menace of polio growing, Sabin and other researchers, most notably Jonas Salk in Pittsburgh and Hilary Koprowski and Herald Cox in New York and Philadelphia, sought a vaccine to prevent or mitigate the illness. In 1955, Salk's "killed" vaccine was released for use. It was effective in preventing most of the complications of polio, but did not prevent the initial, intestinal infection. In addition, those who received the Salk vaccine could pass on the polio virus. Sabin first tested his live attenuated oral vaccine in late 1954. From 1956-1960 he worked with Russian colleagues to perfect the oral vaccine and prove its extraordinary effectiveness and safety. The Sabin vaccine worked in the intestines to block the poliovirus from entering the bloodstream. It was in the intestines, Sabin discovered, the poliovirus multiplied and attacked. Thus, the oral vaccine broke the chain of transmission of the virus and made possible the world wide eradication of polio.

The development of bacteriology and immunology in the 20th century. The beginning of virusology     Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with, among other things, the physiological functioning of the immune system in states of both health and disease; malfunctions of the immune system in immunological disorders (autoimmune diseases, hypersensitivities, immune deficiency, transplant rejection); the physical, chemical and physiological characteristics of the components of the immune system in vitro, in situ, and in vivo. Immunology has applications in several disciplines of science, and as such is further divided.

Jules Jean Baptiste Vincent Bordet (1870 –1961) was a Belgian immunologist and microbiologist. The bacterial genus Bordetella is named after him. he described phagocytosis of bacteria by white blood cells. In 1898 he described hemolysis evoked by exposure of blood serum to foreign blood cells.

The development of bacteriology and immunology in the 20th century. The beginning of virusology    In 1900, he left Paris to found the Pasteur Institute in Brussels, and made his discovery that the bacteriolytic effect of acquired specific antibody is significantly enhanced in vivo by the presence of innate serum components which he termed alexine (but which are now known as complement). This mechanism became the basis for complement-fixation testing methods that enabled the development of serological tests for syphilis.

With Octave Gengou he isolated Bordetella pertussis in pure culture in 1906 and posited it as the cause of whooping cough. He became Professor of Bacteriology at the Université Libre de Bruxelles in 1907.

The Nobel Prize in Physiology or Medicine was awarded to him in 1919 for his discoveries relating to immunity.