:History of Microbiology: Important events

A summary of the events that led to the development of microbiology (bacteriology) that started from the 16th century and continues even during the 21st century. Details include year of discovery, contributors, and discoveries in the field of microbiology.

1. UNIVERSITY OF MYSORE, MANASAGANGOTHRI TOPIC : IMPORTANT EVENTS IN THE DEVELOPMENT OF BACTERIOLOGY PRESENTED BY: TEJASWINI PETKAR, 1 ST MSC

2. CONTENTS INTRODUCTION HISTORICAL DEVELOPMENT OF BACTERIOLOGY BACTERIOLOGY IN THE PRESENT WORLD CONCLUSION REFERENCES

3. INTRODUCTION Microorganisms were first observed using primitive microscopes as early as the late 16OOs. Since then major developments have been made in the understanding of bacterial physiology, ecology, and systematics . The discoveries over the last century have demonstrated that microbiology is a central scientific discipline with practical applications in agriculture, medicine, bioremediation, biotechnology, engineering, and other fields. Thus microbiology has had a long, rich history, initially centered in the causes of infectious diseases but now including practical applications of the science. Many individuals have made significant contributions to this development of microbiology.

4. 16 TH CENTURY The historical development of bacteriology began in the 16 th century. In 1546 prior to the invention of the microscope, the study of microbiology was pioneered by  Girolamo Fracastoro when he proposed the theory of contagious diseases. He proposed a scientific  germ theory  of  disease  more than 300 years before its  empirical  formulation by  Louis Pasteur  and  Robert Koch . He believed that diseases were spread through contact between individuals. He developed this theory while treating cases of syphilis. In 1590, Hans and Zacharias Janssen invented the first compound microscope (one having two sets of lens). They put several lenses in a tube and made a very important discovery. The object near the end of the tube appeared to be greatly enlarged, much larger than any simple magnifying glass could achieve by itself. Their first microscopes were more of a novelty than a scientific tool since maximum magnification was only around 9X and the images were somewhat blurry. Although no Jansen microscopes survived, an instrument made for Dutch royalty was described as being composed of "3 sliding tubes, measuring 18 inches long when fully extended, and two inches in diameter". The microscope was said to have a magnification of 3X when fully closed, and 9X when fully extended. The two used sunlight to illuminate the object under study.

5. 17 TH CENTURY The development of microbiology in this century began with the debate of spontaneous generation theory : From the earliest times, people believed in spontaneous generation- that living organisms could develop from non living matter. Aristotle (394-322 BC) thought some of the simpler invertebrates could arise by spontaneous generation. This view was finally challenged by Italian physician Francesco Redi (1626-1697). He conducted an experiment to refute the theory. Francesco Redi showed that maggots do not spontaneously arise from decaying meat. To prove this he designed a simple controlled experiment, now referred to as the “ Redi Experiment.”    In 1665, Robert Hooke , English scientist advanced the cell theory of biology. He studied fungi and discovered cells. Unicellular life was first described just a few years after Hooke recorded his observations of the microscopic world. Antony Van Leeuwenhoek was a Dutch merchant who polished grains of sand into lenses which were able to magnify 300 times and added a simple focus mechanism. With his microscope, Van Leeuwenhoek viewed rain and pond water, infusions made from peppercorns, and scrapings from his teeth in the year 1674 and termed the tiny microorganisms as ‘ animalcules’.In 1676, Van Leeuwenhoek sent his drawings to the Royal Society of London.

6. 18 TH CENTURY The conflict concerning the spontaneous generation theory still continues in this century . In 1745, John Needham ( 1713–1781) published a report of his own experiments, in which he briefly boiled broth infused with plant or animal matter, hoping to kill all preexisting microbes which failed as in reality, he likely did not boil the broth enough to kill all preexisting microbes. Lazzaro Spallanzan i (1729–1799) did not agree with Needham’s conclusions, however, and performed hundreds of carefully executed experiments using heated broth.Spallanzani’s results contradicted the findings of Needham: heated but sealed flasks remained clear, without any signs of spontaneous growth, unless the flasks were subsequently opened to the air. This suggested that microbes were introduced into these flasks from the air. Their conflict led to the theory that all life came from existing life forms requiring some vital force (later to be known as oxygen).

7. (a) Francesco Redi , who demonstrated that maggots were the offspring of flies, not products of spontaneous generation. (b) John Needham, who argued that microbes arose spontaneously in broth from a “life force.” ( c) Lazzaro Spallanzani , whose experiments with broth aimed to disprove those of Needham.

8. 19 TH CENTURY It is known as the golden era of microbiology especially during the time of Louis Pasteur – the modern father of microbiology. In 1839, Theodor Schwann also examined the question of spontaneous theory, which led to its eventual disproof. He influenced Lister in his work regarding antiseptic applications as well as Louis Pasteur’s germ theory. John Snow (15 March 1813 – 16 June 1858), a British physician, traced the source of cholera to the municipal water supply of London during an 1854 outbreak. He reasoned that by avoiding the contaminated water source, people could avoid the disease. Snow’s recommendations were adopted and the spread of disease was halted. In 1868 based on his epidemiological studies, Armauer Hansen demonstrated that certain rods represented the infectious origin of leprosy. This is the first time that a chronic infectious disease in humans was shown to be related to Bacillus. Ferdinand Julius   Cohn (1828-1898) was the first to recognize and study bacteriology as a separate science. Cohn developed a system for classifying bacteria and discovered the importance of heat-resistant  endospores .

9. The debate over spontaneous generation continued well into the nineteenth century, with scientists serving as proponents of both sides. To settle the debate, the Paris Academy of Sciences offered a prize for resolution of the problem. Louis Pasteur , a prominent French chemist who had been studying microbial fermentation and the causes of wine spoilage, accepted the challenge. In 1858, Pasteur filtered air through a gun-cotton filter and, upon microscopic examination of the cotton, found it full of microorganisms, suggesting that the exposure of a broth to air was not introducing a “life force” to the broth but rather airborne microorganisms. Pasteur’s set of experiments( swan neck flask experiments) irrefutably disproved the theory of spontaneous generation and earned him the prestigious Alhumbert Prize from the Paris Academy of Sciences in 1862. In a subsequent lecture in 1864, Pasteur articulated “ Omnevivum ex vivo ” (“ life only comes from life”). In this lecture, Pasteur recounted his famous swan-neck flask experiment, stating that “ life is a germ and a germ is life .” 

10. In 1861, Louis Pasteur introduced the terms “aerobic” and “anaerobic” in describing the growth of yeast at the outlay of sugar in the presence or absence of oxygen. He observed that more alcohol was produced in the absence of oxygen when sugar is fermented. The phenomenon was later termed the Pasteur Effect . In 1876 Robert Koch  publishes a paper on his work with  anthrax , pointing explicitly to a bacterium as the cause of this disease. This validates the germ theory of disease. In 1877 Robert Koch dries films of bacteria, stains them with methylene blue and then photographs them. He uses cover slips to prepare permanent visual records. In 1877 Jean Jacques Theophile Schloesing  proves that nitrification is a biological process in the soil by using chloroform vapors to inhibit the production of nitrate. One of the greatest practical applications of this knowledge was in the treatment of sewage. In 1877 John Tyndall  publishes his method for fractional sterilization and clarifies the role of heat resistant factors (spores) in putrefaction. Tyndall's conclusion adds a final footnote to the work of Pasteur and others in proving that spontaneous generation is impossible.

11. In 1878 Thomas Burrill   demonstrates for the first time a bacterial disease of plants;  Micrococcus amylophorous   causes pear blight. In 1878 Joseph Lister publishes his study of lactic fermentation of milk, demonstrating the specific cause of milk souring. His research is conducted using the first method developed for isolating a pure culture of a bacterium, which he names Bacterium lactis . In 1879 Albert Neisser   identifies  Neisseria gonorrhoeae , the pathogen that causes gonorrhea.   In 1880 Louis Pasteur develops a method of attenuating a virulent pathogen, the agent of chicken cholera, so it would immunize and not cause disease. This is the conceptual break-through for establishing protection against disease by the inoculation of a weakened strain of the causative agent. Pasteur uses the word "attenuated" to mean weakened. As Pasteur acknowledged, the concept came from Jenner's success at smallpox vaccination. Louis Pasteur thus developed vaccines between 1880 and 1885. In 1881 Robert Koch  struggles with the disadvantages of using liquid media for certain experiments. He turns to gelatin, which is added to culture media; the resulting mixture is poured onto flat glass plates and allowed to gel. The plate technique is used to isolate pure cultures of bacteria from colonies growing on the surface of the plate. Koch publishes his  Methods for the Study of Pathogenic Organisms  in which he describes his success with solidified culture media.

12. In 1881 Paul Ehrlich  refines the use of the dye methylene blue in bacteriological staining and uses it to stain the tubercule bacillus. He shows the dye binds to the bacterium and resists decoloration with an acid alcohol wash.  In 1882 Angelina Fannie  and  Walther Hesse  in Koch's laboratory use agar, an extract of algae, as a solidifying agent to prepare solid media for growing microbes. In 1882, Robert Koch  isolates the tubercule bacillus, Mycobacterium tuberculosis. The search for the tubercule bacillus is more difficult than was the search for the cause of anthrax. In 1883 Edward Theodore Klebs  and  Fredrich Loeffler  independently discover Corynebacterium diphtheriae , which causes diphtheria. In 1883 Lysse Gayon  and  Gabriel Dupetit  isolate in pure culture two strains of denitrifying bacteria. In 1884, Robert Koch puts forth what will become his best-known work, a set of postulates, or standards of proof involving the tubercle bacillus.

13. In 1884 IlyaIlich Metchnikoff  demonstrates that certain body cells move to damaged areas of the body where they consume bacteria and other foreign particles. He calls the process phagocytosis . In 1884 Hans Christian J. Gram  develops a dye system for identifying bacteria [the Gram stain]. Bacteria which retain the violet dye are classified as gram-positive. The distinction in staining is later correlated with other biochemical and morphological differences. In 1884 Charles Chamberland  develops an unglazed porcelain filter that retains bacteria. In 1885 Paul Ehrlich espouses the theory that certain chemicals, such as dyes, affect bacterial cells and reasoned that these chemicals could be toxic against microbes, work that lays the foundation for his development of arsenic as a treatment for syphilis. In 1885, Theodor Escherich  identifies a bacterium,that is a natural inhabitant of the human gut, which he names Bacterium coli. He shows that certain strains are responsible for infant diarrhea and gastroenteritis. In 1886, Theobald Smith  and  D. E. Salmon  inject heated killed whole cell vaccine of hog cholera into pigeons and demonstrate immunity to subsequent administration of a live microbial culture. In 1887, Sergei Winogradsky  studies Beggiatoa and determines that it can use inorganic H2S as an energy source and CO2 as a carbon source. He establishes the concept of autotrophy and its relationship to natural cycles.

14. In 1887 Julius Richard Petri  working in Koch's laboratory, introduces a new type of culture dish for semi-solid media. The dish has an overhanging lid that keeps contaminants out. In 1888, The  Institut Pasteur ( Pasteur institute)  is founded in France in November.  In 1888 Emile Roux  and  Alexandre Yersin  show that Cornyebacterium diphtheriae affects tissues and organs by a toxin. They use a filtrate from cells that can directly kill laboratory animals. In 1888 MartinusBeijerinck  uses enrichment culture, minus nitrogenous compounds, to obtain a pure culture of the root nodule bacterium Rhizobium , demonstrating that enrichment culture creates the conditions for optimal growth of a desired bacterium.  In 1889, A. Charrin  and  J. Roger  discover that bacteria can be agglutinated by serum.  In 1889, Kitasato  obtained the first pure culture of the strict anaerobic pathogen, the tetanus bacillus  Clostridium tetani . In 1890, Emil von Behring  and  Shibasaburo Kitasato  working together in Berlin in 1890 announce the discovery of diphtheria antitoxin serum, the first rational approach to therapy of infectious diseases. In 1890 Sergei Winogradsky  succeeds in isolating nitrifying bacteria from soil. During the period 1890-1891, Winogradsky performs the major definitive work on the organisms responsible for the process of nitrification in nature.

15. In 1891, Paul Ehrlich  proposes that antibodies are responsible for immunity. In 1892, William Welch  and  George Nuttall  identify  Clostridium perfringens , the organism responsible for causing gangrene.  In 1894, Richard Pfeiffer  observes that a heat stable toxic material bound to the membrane of  Vibrio Cholerae  is released only after the cells are disintegrated. He calls the material endotoxin , to distinguish it from filterable material released by bacteria.  In 1894, Alexandre Yersin  isolates  Yersinia ( Pasteurella ) pestis , the organism that is responsible for bubonic plague.  Shibasaburo Kitasato  also observes the bacterium in cases of plague.  In 1894, Martinus Beijerinck  isolates the first sulfate-reducing bacterium,  Spirillum desulfuricans  ( Desulfovibrio desulfuricans ).  In 1895, Sergei Winogradsky  isolates the first free-living nitrogen-fixing organism,  Clostridum pasteurianum . In 1896, Max Gruber  and  Herbert Durham  extend the 1889 observation of  Charrin  and  Roger  to show the agglutination of bacteria by serum is specific. This was recognized as a new disease diagnostic tool. In 1897, Paul Ehrlich  proposes his "side-chain" theory of immunity and develops standards for toxin and antitoxin. In 1897, Waldemar Haffkine  produces immunity against the plague with killed organisms. In 1897, Almwroth Wright  and  David Sample  develop an effective vaccine with killed cells of Salmonella typhi to prevent typhoid fever.

16.  In 1898, Ules Bordet  discovers that hemolytic sera acts on foreign blood in a manner similar to the action of antimicrobic sera on microbes by precipitating the material from solution. He shows there are two factors, a heat-labile substance found in normal blood and a bacteriocidal material present in the blood of immunized animals. Bordet is awarded the Nobel Prize in Medicine or Physiology in 1919.  In 1898, B. R. Schenck  presents the first unequivocal case of sporotrichosis and includes a description of the organism that was first isolated from the patient. This organism was later named  Sporotrichum schenckii .

17. 20 th CENTURY In 20th century, microbiological research continued at an ever-increasing pace and many of the missing details in biochemical, medical, and environmental microbiology were uncovered. However, microbiology became increasingly fragmented. The unity that Pasteur originally brought to the discipline by applying similar approaches tomedical and environmental microbiology was replaced by specialized subdisciplines .

18. In 1901 , Jules Bordet  and  Octave Gengou  develop the complement fixation test. They show that any antigen-antibody reaction leads to the binding of complement to the target antigen. In 1901, E. Wildiers  publishes the first description of a microbial growth factor, opening the field of vitamin research. He finds that a water soluble extract of yeast has a compound that is required for the growth of yeast. The material is later found to be a B vitamin.  In 1905, Franz Schardinger  isolates aerobic bacilli which produce acetone, ethanol, and acetic acid. These are important industrial chemicals.  In 1905, Fritz R. Schaudinn  and  Erich Hoffman  identify  Treponema pallidum , the cause of syphilis. The bacterium is isolated from fluid leaking from a syphylitic chancre and is spiral in appearance.  In 1905, Shigetane Ishiwata  discovers that the cause of a disease outbreak in silkworms is a new species of bacteria, later called  Bacillus thuringiensis , or Bt. Ishiwata called the organism "Sotto- Bacillen ." ("Sotto" in Japanese signifies sudden collapse.)  In 1906, August von Wasserman  describes the "Wasserman reaction" for the diagnosis of syphilis in monkeys. The test uses complement fixation and becomes the basis for the general uses of complement tests as diagnostics. In 1906, N. L. Sohngen  presents groundbreaking work on methane-using and methane-producing bacteria. This is the first proof that methane can serve as an energy and carbon source.

19. In 1907, Erwin Smith  and  C.O. Townsend  discover that the cause of crown galls is a bacterium called  Agrobacterium tumefaciens .  In 1909, Howard Ricketts  shows that Rocky Mountain spotted fever is caused by an organism that is intermediate in size between an virus and a bacterium. This organism, Rickettsia , is transmitted by ticks. Ricketts dies from typhus, another rickettsial disease, in 1910.  In 1909, Sigurd Orla -Jensen  proposes that physiological characteristics of bacteria are of primary importance in their classification. A primary example is a monograph he later publishes on lactic acid bacteria that establishes the criteria for assignment.  In 1910, Charles Henry Nicolle  demonstrates that typhus fever is transmitted from person to person by the body louse. This information was used in both world wars to reduce the incidence of typhus. Nicolle is awarded the Noble Prize in Medicine or Physiology in 1928.   In 1910, Paul Ehrlich announces the discovery of an effective cure ( Salvarsan ) for syphilis, the first specific chemotherapeutic agent for a bacterial disease. Ehrlich was a researcher in Koch's lab, where he worked on immunology. In 1906 he became head of the Research Institute for Chemotherapy. He sought an arsenic derivative. The 606th compound worked. He brought news of the treatment to London, where Fleming became one of the few physicians to administer it. A more soluble form, Neosalvarsan , is introduced in 1912.  In 1915, Frederick Twort discovered the first bacteriophage . His discovery was something of an accident; he had spent several years growing viruses and noticed that the bacteria infecting his plates became transparent.  

20. In 1915, M. H. McCrady  establishes a quantitative approach for analyzing water samples for coliforms using the most probable number, multiple-tube fermentation test.  In 1917, Felix d'Herrelle  independently describes bacterial viruses and coins the name " bacteriophage ."  In 1918, Alice Evans  establishes that members of the genus  Brucella . are responsible for the diseases of Malta Fever, cattle abortion, and swine abortion. She reports that the bacteria are bacilli and not micrococci .  In 1919, James Brown  uses blood agar as a medium to study the hemolytic reactions for the genus Streptococcus and divides it into three types, alpha, beta, and gamma.  In 1920, The  SAB (Science Advisory Board) committee  presents a report on the  Characterization and classification of Bacterial Types  that becomes the basis for the classic work of  D. H. Bergey , later published in 1923.  In 1924, Albert Calmette  and  Camille Guerin  introduce a living non-virulent strain of tuberculosis (BCG) to immunize against the disease. This is the result of work begun in 1906 on attenuating a strain of bovine tuberculosis bacillus. More than 200 subcultures were grown before the resulting strain was tested.  In 1926, Thomas Rivers  distinguishes between bacteria and viruses, establishing virology as a separate area of study. This paper was published after he presented it at an SAB meeting held in December of 1926. 

21. In 1928, Frederick Griffith  discovers transformation in bacteria and establishes the foundation of molecular genetics. In 1929, Alexander Fleming publishes the first paper describing penicillin and its effect on gram positive microorganisms. In 1933, Ernst Ruska develops the electron microscope.  In 1934, Ladislaus Laszlo Marton  is the first to examine biological specimens with the electron microscope, which achieves magnifications of 200-300, 000X. Later in 1937, he publishes the first electron micrographs of bacteria.  In 1935, Gerhard J. Domagk uses a chemically synthesized antimetabolite - Prontosil , to kill Streptococcus in mice. It is later shown that Prontosil is hydrolyzed in vivo to an active compound, sulfanilamide.  In 1940, Selman Waksman  and  H. Boyd Woodruff  discover actinomycin , the first antibiotic obtained pure from an actinomycete , leading to the discovery of many other antibiotics from that group of microorganisms. After  Rene Dubos  discovered two antibacterial substances in soil, Waksman decided to focus on the medicinal uses of antibacterial soil microbes.  In 1940, Frank McFarlane Burnet  proposes that descendents of antigen reacting cells produce antibodies specific to the antigen.  In 1943, Salvador Luria  and  Max Delbruck  provide a statistical demonstration that inheritance in bacteria follows Darwinian principles.   In 1944, Oswald Avery ,  Colin MacLeod , and  Maclyn McCarty  show that DNA is the transforming material in cells. In 1946, Joshua Lederberg  and  Edward L. Tatum  publish on conjugation in bacteria.

22. In 1953, James Watson  and  Francis Crick  publish a description of the double-helix structure of DNA. In 1957, Francois Jacob  and  Elie Wollman  provide evidence of the circular nature of the chromosome in  Escherichia coli  after analyzing data from interrupted mating experiments.   In 1958  the rapid development of penicillin-resistance by staphylococci led to the compound 05865 (later known as vancomycin )  being fast-tracked for approval by the FDA.  It became the best weapon against bacteria that were no longer vulnerable to other drugs.  In 1960  the new antibiotic methicillin was introduced. In 1961 strains of Staphylococcus aureus resistant to Methicillin (MRSA) were first reported. In 1990 the SARII group of bacteria was first identified. This group constituted about a third of the single-celled organisms in the ocean. On Aug 3 2000, it was reported that scientists had developed the genetic blueprint of the cholera bacterium. From 2000 onwards researches have contributed to apply the microbiological techniques in order to define new infections and to persue effective treatments and methods of prevention.

23. BACTERIOLOGY IN THE PRESENT WORLD   The long span of four hundred and fifty years of microbiology has brought amazing insight into the biology of microorganisms and has also brought with it new challenges, which have both positive and negative effects upon the society.  New discoveries have opened a door for understanding how a cell works at the most fundamental level, and newly discovered bacteria stretch the already overwhelming picture of microbial diversity.  The understanding of bacterial evolution has advanced with the use of genomic technologies and has provided new perspectives on the relationships between microorganisms. Bacteria play more positive roles than simply causing infectious diseases. The majority of bacteria are seen as rulers of the world because of their essential and important beneficial roles that can provide humanity with an even better and more healthful existence.

24.   CONCLUSION Bacteriology was established in the 1880s as the science of disease germs. However, experimental explorations in the world of microorganisms had started already in the seventeenth century, and botanists and zoologists in the eighteenth century had tried to structure and classify the world of the invisible living organisms. With the German physician Robert Koch the science of microorganisms moved into the realm of medicine. Medical bacteriology promoted laboratory medicine and Louis Pasteur in Paris developed techniques to attenuate microorganisms in order to produce vaccines. Bacteriology has also developed in relation to agriculture, water (pollution) and biotechnology. Non‐medical approaches to the micro‐world contributed to a broader understanding of microorganisms not only as pathogens but as essential entities in ecological life cycles. At the turn of the twenty‐first century, reductionist views of host–parasite relation gave way to more complex, process‐orientated and environmentalist approaches.

25. REFERENCES http://www.newagepublishers.com/samplechapter/001638.pdf https://www.bioexplorer.net/history_of_biology/microbiology/ https://www.asm.org/images/Membership/archives/signifeventstop26list.pd http://www.els.net/WileyCDA/ElsArticle/refId-a0003073.html https://www.asm.org/index.php/71-membership/archives/7852-significant-events-in-microbiology-since-1861#Year1861 Joshua Lederbergl ., (1992); History Of Microbiology; Encyclopedia of Microbiology; Academic Press. Inc. Volume 2; 419-437