History of Medical Microbiology Lecture 2 PDF

History of Medical Microbiology LECTURE 2: Ms. Peters Theory of Spontaneous Generation The theory of ‘spontaneous generation’ or that life simply arose from nonliving material of life from nonliving matter. First posited by Greek Phi...

History of Medical Microbiology LECTURE 2: Ms. Peters Theory of Spontaneous Generation The theory of ‘spontaneous generation’ or that life simply arose from nonliving material of life from nonliving matter. First posited by Greek Philosopher Aristotle (384–322 BC) According to him, it was: “readily observable that fleas from putrid matter, mice from dirty hay, maggots from meat left in open air spontaneously appeared” Theory of Spontaneous Generation Italian physician Francesco Redi (1626–1697), performed an experiment in 1668 that was one of the first to refute the idea that maggots spontaneously generate on meat left out in the open air. He concluded that maggots were the off springs of flies. They did not spontaneously arise. Theory of Spontaneous Generation Father of medical microbiology, made a series of “swan-neck” flasks in which he boiled broth to sterilize it. His design allowed air inside the flasks to be exchanged with air from the outside, but prevented the introduction of any airborne microorganisms If a life force besides the airborne microorganisms were responsible for microbial growth within the sterilized flasks, it would have access to the broth, whereas the microorganisms would not. He correctly predicted that sterilized broth in his swan-neck flasks would remain sterile as long as the swan necks remained intact. However, should the necks be broken, microorganisms would be introduced, contaminating the flasks and allowing microbial growth within the broth.  Theory of Spontaneous Generation Other Contributions by louis Pasteur in medical microbiology include: Fermentation- In 1854, while he was working at Lille, Pasteur investigate fermentation processes and he noticed that the fermentation processes are carried out by a living microorganism. Pasteurization - He noticed that the spoiling of beverages such as milk is caused by some unwanted microorganisms. Thus, he invented a process in which the microorganisms could be destroyed by heating between 60° and 100°C temperature. Germ Theory of Diseases- Pasteur and a minority of other scientists believed that diseases were caused by microorganisms—germ theory. Anthrax vaccine -1881 Rabies -Louis Pasteur first produced the vaccine of rabies virus Germ Theory of Disease The germ theory of disease, devise by Louis Pasteur states that diseases are caused by microorganisms such as bacteria, viruses, protozoa, or fungi. Based on three main principles: 1. Microbes can causse diseases in the body 2. Microbes can spread from one person to another 3. A specific microbe exists or each microbe will always cause the same illness Antonie van Leeuwenhoek (1632 – 1723) Father of Modern Microbiology Considered to be the first acknowledged microscopist and microbiologist Dutch microscopist; first to observe and describe microorganisms, which he referred to as animalcules (from Latin animalculum = "tiny animal“) His researches on lower animals refuted the theory of spontaneous generation His observations helped lay the foundations for bacteriology and protozoology. Joseph Lister (1827 – 1912) Father of Modern Surgery Introduced the concepts of antiseptics and preventive medicine Studied surgical outcomes after sterilization of surgical instruments, the surgeon’s hand, patient’s skin and sutures with carbolic acid (an antiseptic). Lister experimented with this substance by dipping a pad in carbolic acid solution and applying it to the wound of an 11-year-old boy. Four days later, when replacing the pad, he observed that the bones were fusing with no signs of infection Robert Hooke (1635-1703) Known for his discovery of plant cells. He coined the term “cells” for biology He examined plant material under his microscope and observed the presence of “pores” or “cells”. Hooke believed that the ‘cells’ existed only in plants, as Hooke and his scientists observed these structure only in plant matter. These findings were published in Micrographia which contained detailed illustrations of biological material; mainly plants that were made with the compound microscope Ignaz Semmelweis (1818-1865) Hungarian gynecologist described as the “savior of mothers” and “father of infection control” discovered that the incidence of puerperal fever could be drastically cut by the use of hand disinfection by medical caregivers in obstetrical clinics. He instituted a policy of using a solution of chlorinated lime (modern calcium hypochlorite, the compound used in today’s common household chlorine bleach solution) for washing hands between autopsy work and the examination of patients. Robert Koch (1843-1910) German physician and one of the founders of bacteriology. He discovered the anthrax disease cycle (1876) and the bacteria responsible for tuberculosis (1882) and cholera (1883). Known for developing Koch’s postulates After demonstrating that Bacillus anthracis caused anthrax (in mice) Robert Koch cont. Koch’s postulates; a series of procedures by which a specific microorganisms can cause specific infectious disease. It states: 1. A specific microorganism is always associated with a given disease. 2. The microorganism can be isolated from the diseased animal and grown in pure culture in the laboratory. 3. The cultured microbe will cause disease when transferred to a healthy animal. 4. The same type of microorganism can be isolated from the newly infected animal. Edward Jenner (1749-1823) British physician known as Father of vaccination Developed the concept of vaccination by immunizing an eight-year-old boy against smallpox using cowpox fluid. He later injected smallpox virus repeatedly into the boy, proving that he was indeed immune. John Snow (1813 – 1858) British anesthesiologist ; Father of Epidemiology Conducted studies in the 1800s when an epidemic of cholera erupted in the Golden Square of London in which he demonstrated that contaminated water was the key source of the epidemics He began his investigation by determining where in this area persons with cholera lived and worked and He marked each residence on a map of the area (spot map) His conclusion that contaminated water from the Broad Street pump was the source of the disease. This led to the removal of the handle and the cessation of the epidemic. Alexander Fleming ( 1881 – 1955) Credited with the discovery of penicillin in 1928 During a series of experiments with staphylococcus aureus, an uncovered petri dish became contaminated with mould spores. Fleming observed that the bacteria in proximity to the mould colonies were dying He isolated the mould and identified it as Penicillium sp. He found it to be effective against all Gram-positive pathogens, which are responsible for diseases such as scarlet fever, pneumonia, gonorrhea, meningitis etc. This discovery began the era of antibiotics Hans Christian Gram (1853- 1938) Danish microbiologist, Hans Christian Gram in 1884 developed the ‘gram staining technique’ Crystal violet was used to identify bacteria as gram-positive (purple stain retained) or gram-negative (stain is washed away) the Gram classification is fundamental to bacteria identification, classification, taxonomy, and drug therapy It is also useful in deciding how to treat infections since some antibiotics are active only against gram-positive bacteria and others against gram-negative bacteria. William Augustus Hinton (1883 – 1959) American bacteriologist, pathologist and educator. A pioneer in the field of public health Hinton developed a flocculation test for syphilis in 1927. He became internationally known as an expert in the diagnosis and treatment of syphilis.  Other Contributors Albert Leon Charles Calmette (1863–1933): Antituberculosis and BCG Vaccination Charles J H Nicolle (1866–1936): Pioneer of Typhus Studies Oswald Theodore Avery (1877–1955): Microbiological Genetic Transmission and DNA Frederick Griffith (1879–1941): Discovery of Transformation Gerhardt J Domagk (1895–1964): Pioneer of Sulfur Drug Chemotherapy Paul Henry de Kruif (1890–1971): Gas Gangrene Research and Historian of Microbiology William C Frazier (1894–1991): Pioneer of Dairy and Food Microbiologist Ira Lawrence Baldwin (1895–1999): Pioneer of Agricultural Microbiology and Education Max Theiler (1899–1972): Yellow Fever Vaccine Developer René Jules Dubos (1901–1982): Pioneer of Bacterial Antibiotics and Environmental Microbiology Barbara McClintock (1902–1992): Pioneer of Microcellular Directed Genetics George W Beadle (1903–1989): Pioneer of Biochemical Genetics Edward Lawrie Tatum (1909–1975): Pioneer of Molecular Genetics