History of Microbiology Ankur vashishtha . An organism that is so small that can not be seen without the use of a microscope. Medical Microbiology • Deals with the causative agents infectious disease of man, his reaction to such infections, the way in which they produce disease and the method for their diagnosis Plague • The Black Death, a pandemic It reached Europe in the late 1340s, killing an estimated 25 million people. • The first well-documented pandemic which began in 541 A.D. it killed up to 10,000 people a day in Istanbul. • The first breakthrough came in Hong Kong in 1894 when researchers isolated the rod-shaped bacillus responsible—Yersinia pestis. Galileo Galilei (1609) Galileo says the Earth revolves around the Sun . Antony van Leeuwenhoek . (1632-1723) This marks the beginning of Microbiology . One of the first scientists to use a microscope and identify microbes. His simple, single-lens microscope which could amplify the object being viewed 50 – 300 times. 1673-1723, he wrote a series of letters to the Royal Society of London describing the microbes he observed from the samples of rainwater, and human mouth. lens Object A drawing of one of the being viewed microscopes showing the lens, mounting pin Adjusting and focusing screws a screw Leeuwenhoek’s drawings of bacteria from the human mouth. • (1678) Robert hook developed Compound . microscope and confirmed Leeuwenhoek’s observation • For earliest time people had believed in spontaneous generation • Needham (1745) an Irish priest believed in spontaneous generation . • needham’s experiment pick. Theodore Schwann (1810–1882) Louis Pasteur (1822 – 1895) . He established that fermentation was caused by microbial agents. Father of Microbiology. Louis Pasteur working in his laboratory . Pouchet claimed in 1859 who was a proponent of spontaneous generation theory of microbe. This claim provoked Louis Pasteur by his experiments performed in the swan neck flask. Pasteur’s swan neck flasks used in his experiments on the spontaneous generation of microorganisms Conclusion: Microorganisms are not spontaneously generated from inanimate matter, but are produced by other microorganisms . Pasteur developed anthrax vaccine, cholera vaccine. Pasteurization of food. Introduction of sterilization techniques steam sterilizer, autoclave and hot air oven. The importance of microorganisms in disease was not immediately obvious to people, and it took many years for scientists to establish the connection between microorganisms and illness. – Joseph lister Professor of surgery. Indirect evidence that microorganisms were agents of human disease came from the work on the prevention of wound infections. Lister impressed with Pasteur’s studies . developed a system of antiseptic surgery designed to prevent microorganisms from entering wounds. Instruments were heat sterilized, and phenol was used on surgical dressings and at times sprayed over the surgical area. The first direct demonstration of the role of . bacteria in causing disease came from the study of anthrax by the German physician Robert Koch 1843-1910 Figure 14.3, steps 1–2 Figure 14.3, steps 3–4 Figure 14.3, step 5 GERM THEORY OF DISEASE . Association-The microorganisms must be present in every case of the disease but absent from healthy organisms. Isolation-The suspected microorganisms must be isolated and grown in a pure culture. Inoculation-The disease must result when the isolated microorganisms is inoculated into a healthy host. Re-isolation-The same microorganisms must be isolated again from the diseased host. Bacteriological techniques and methods for isolation of pure strains of bacteria. Staining techniques. Identified the specific causative agents of tuberculosis, cholera and anthrax Koch phenomenon • He observed that guinea pigs already infected with tubercle bacillus responded with an exaggerated inflammatory response when injected with the tubercle bacillus or its protein. This hypersensitivity reaction is called Koch’s Phenomenon. Invention of the vaccine Edward Jenner Advising a Farmer to Vaccinate His Family 1749 – 1823 • Scientist who was the pioneer of smallpox vaccine , the world’s first vaccine. • Jenner had used vaccination with material from cowpox lesions to protect people against smallpox • Jenner is often called "the father of immunology Alexander Fleming (1881-1955) Sir Alexander Fleming discovered the antibiotic penicillin. He had the insight to recognize the significance of the inhibition of bacterial growth in the vicinity of a fungal contaminant. • In 1921, fleming discovered an enzyme called . Lysozyme found in tears, saliva. • In 1928, fleming discovered Penicillin produced by a fungus Penicillium notatum. • Fleming wrote numerous papers on bacteriology, Immunology and chemotherapy including original description of Lysozyme. Paul Ehrlich (1854-1915) o Father of chemotherapy. o Applied stains to cells and tissues for study of their function. o Reported the acid-fast nature of tubercle bacillus. o Introduced methods of standardizing toxin and antitoxin. o Proposed side chain theory of antibodies. .