SCOPE AND HISTORY OF MICROBIOLOGY

1. SCOPE AND HISTORY OF MICROBIOLOGY CHAPTER 1

2. Bio 308 General Microbiology Notes and syllabus are on web site: http://bio.as.uky.edu/users/shellys My e-mail: shellys@uky.edu Phone: 859-257-3870 Text Book: Microbiology- Principles and Explorations Jacquelyn G. Black- 7 or 8th edition

3. Chapter 1 Scope and History of Microbiology Microbes have a major impact on human health In 1962, the U.S. Surgeon General, William H. Stewart, stated, “ The war against infectious disease has been won.” In the subsequent decades, emerging diseases and increasing antibiotic resistance have made it clear that in reality not only is the war far from won, its outcome is not longer certain The above (1962) is the basic climate that I started my Ph.D. studies in microbiology

4. Ebola In West Africa Is 'Totally Out Of Control,' Medical Group Says DAKAR, Senegal (AP) — The Ebola outbreak ravaging West Africa is "totally out of control," according to a senior official for Doctors Without Borders, who says and the medical group is stretched to the limit in its capacity to respond. "The reality is clear that the epidemic is now in a second wave," Janssens said. "And, for me, it is totally out of control." The outbreak, which began in Guinea either late last year or early this year, had appeared to slow before picking up pace again in recent weeks, including spreading to the Liberian capital for the first time. "I'm absolutely convinced that this epidemic is far from over and will continue to kill a considerable amount of people, so this will definitely end up the biggest ever," he said. The outbreak shows no sign of abating and that governments and international organizations were "far from winning this battle," Unni Krishnan, head of disaster preparedness and response for Plan International, said Friday. But Janssens' description of the Ebola outbreak was even more alarming, and he said that he didn't think enough was being done to respond to it. "There needs to be a real political commitment that this is a very big emergency," he said. "Otherwise, it will continue to spread, and for sure it will spread to more countries." With more than 40 international staff currently on the ground and four treatment centers, Doctors Without Borders has reached its limit to respond, he said, even though the situation requires more. It's the first time in an Ebola epidemic where (Doctors Without Borders) teams cannot cover all the needs, at least for treatment centers," he said.

5. Speaking Up About an Uncomfortable Condition Bowels, especially those that don’t function properly, are not a popular topic of conversation. Most of the 1.4 million Americans with inflammatory bowel disease — Crohn’s disease or ulcerative colitis — suffer in silence. In Crohn’s disease, the immune system attacks cells in the digestive tract, most often the end of the small intestine and first part of the colon, or large intestine. Sufferers may experience bouts of abdominal pain, cramps and diarrhea, often accompanied by poor appetite, fatigue and anxiety. Two concurrent avenues of high-powered research are supported by the Crohn’s and Colitis Foundation of America. One is the C.C.F.A. Genetics Initiative, in which scientists are exploring more than 100 genetic factors now known to influence the risk of By combining findings from the two initiatives, experts now know that certain genes affect the types of bacteria living in the gut; in turn, these bacteria influence the risk of getting an inflammatory bowel disease. By combining findings from the two initiatives, experts now know that certain genes affect the types of bacteria living in the gut; in turn, these bacteria influence the risk of getting an inflammatory bowel disease. Genes identified thus far appear to account for about 30 percent of the risk of developing an I.B.D., according to Dr. Sartor, who is the chief medical adviser of the foundation. Studies of twins underscore the role of genetics. When one identical twin has Crohn’s disease, the other has a 50 percent chance of also developing it.In the general population, the risk among siblings of a Crohn’s patient is only 5 percent. Diet is one obvious factor that affects both the composition of the gut biota and also its function,” he said, referring to the microorganisms that inhabit the gut. “Bacteria eat what we eat, and every bacterium has certain food preferences.” Another major contributor to the rise in Crohn’s disease in particular is the widespread, often inappropriate use of antibiotics, Dr. Sartor said.

6. Dash of Salt Does No Harm. Extremes Are the Enemy. For years, we have known that diets high in salt can be bad for people with high blood pressure. A study published recently in The New England Journal of Medicine confirmed this fact. It monitored more than 100,000 people in 18 countries and found that people who consumed more sodium generally had significantly higher blood pressures than those who did not. Another manuscript in the same journal looking at the same study population went even further. It found that people who consumed more than 7 grams of sodium per day had a significantly higher chance of death than people who ate 3-6 grams per day. People consuming high levels of sodium had higher rates of heart attacks, heart failures and strokes as well. These results confirm that people who eat too much salt should eat less of it. The problem with the way we respond to such information, though, is that we often run too far and too fast in the other direction. Americans consume, on average, 3.4 grams of sodium per day, or about the equivalent of three and a half tablespoons of soy sauce. This is on the low end of the “safe zone” of 3-6 grams in the study. The United States Food and Drug Administration thinks that’s not low enough. It recommends 2.3 grams per day. The World Health Organization says it should be 2.0 grams. The American Heart Association goes even further and recommends we consume no more than 1.5 grams. Rates of mortality and cardiovascular events, depending on grams of sodium excretion per day Rates of mortality and cardiovascular events, depending on grams of sodium excretion per day In this study in which sodium intake was estimated on the basis of measured urinary excretion, an estimated sodium intake between 3 g per day and 6 g per day was associated with a lower risk of death and cardiovascular events than was either a higher or lower estimated level of intake. As compared with an estimated potassium excretion that was less than 1.50 g per day, higher potassium excretion was associated with a lower risk of death and cardiovascular events. (Funded by the Population Health Research Institute and others.)- graph on following slide

7. http://www.nytimes.com/2014/08/26/upshot/dash-of-salt-does-no-harm-extremes-are-the-enemy.html?abt=0002&abg=0http://www.nytimes.com/2014/08/26/upshot/dash-of-salt-does-no-harm-extremes-are-the-enemy.html?abt=0002&abg=0

8. Microbes help maintain the balance of nature- mostly microorganisms decompose releasing nitrogen or breaking down industrial wastes or breaking down cellulose in the digestive tract of grazing animals. Microorganisms are important in many human endeavors: Foods(fermentation products (a long list that will be dealt with later in the course), antibiotics, products of genetic engineering, removal of toxic wastesand on and on. In future years many industrial processes carried out by chemical reactions will be done by bacterial (e.g., plastics). In addition, very recent studies suggest that the microflora in the gut, in particular, influences our health and behavior.

9. Roles of Microbes • Pathogens • Food chain • Autotrophs • Decomposers • Digestive • Foods and fermentation • Antibiotics • Biotechnology • Bioremediation • Disease Research

10. Microbe Types • Prokaryotes – 2 Domains/Superkingdoms • Bacteria • Some pathogens • Science of Bacteriology • Archaea • Environmental extremophiles • Novel biochemistry

11. Viruses (Acellular) • Simple structure • Capsid • Nucleic acid • Obligate intracellular growth • Science of Virology • Smaller relatives • Viroids • Prions

12. Germ Theory • Theory definition • Koch • Culture • Postulates • Semmelweiss • Lister

13. Fields of Microbiology • Infection Control • Chemotherapy • Industrial Microbiology • Biotechnology • Biofilms and health

14. THE GERM THEORY OF DISEASE-microorganisms can invade other organisms and cause disease. Because the prevailing theory of the day was spontaneous generation, i.e., that life forms arouse from non-living things, e.g., fruit flies are made from bananas. Thus, it was difficult for people to believe the germ theory. The demonstration by a number of individual that life only come from preexisting life put an end to the idea of spontaneous generation. It is worthwhile mentioning that spontaneous generation, although totally incorrect, follows Occam’s razor ( "All other things being equal, the simplest solution is the best.“).

15. Although Occam’s razor is a good general idea- It only becomes science when it is testable. In addition to testability science is hypothesis driven. A hypothesis is a tentative explanation to account for an observed condition or event. Hence, a testable hypothesis is one for which evidence can be collected to support or refute the hypothesis. In science, a theory is a mathematical or logical explanation, or a testable model of the manner of interaction of a set of naturalphenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or otherwise falsified through empirical observation. It follows from this that for scientists "theory" and "fact" do not necessarily stand in opposition. For example, it is a fact that an apple dropped on earth has been observed to fall towards the center of the planet, and the theories commonly used to describe and explain this behavior are Newton's theory of universal gravitation (see also gravitation), and general relativity. An explanation that cannot be tested is not science.

16. Louis Pasteur, a chemist, is considered as a giant in the history of microbiology. In addition to his contribution to the spontaneous generation/germ theory debate he contributed a great deal to the development of the field of microbiology. • A. Pasteurization of wine so that pure seed cultures could be used in wine production • B. major contribution to the germ theory of disease in demonstrating that microorganisms caused silk worm disease and Anthrax.. • C. He developed a rabies vaccine (and thereby demonstrated the value of vaccination) and on and on. • It is worthwhile mentioning that Pasteur popularized the correct explanation of many things he was not the initial author of any of the above ideas. • Robert Koch – developed a method for pure culture. Probably as important as his work on tuberculosis, for which he was awarded a Nobel Prize (1905), are Koch's postulates, which say that to establish that an organism is the cause of a disease, it must be: • found in all cases of the disease examined, 2) prepared and maintained in a pure culture capable of producing the original infection, 3) even after several generations in culture be retrievable from an inoculated animal and cultured again. We will visit Koch’s postulates again when we discuss disease. • The finding that there are asymptomatic carriers of typhoid and cholera made Koch modify the third part of his postulates to be less dogmatic.

17. WORK TOWARD CONTROLLING INFECTIONS 1. IgnazSemmelwis (Devils, Doctors and Drugs is a very interesting biography of Semmelweis). He was an obstetrician who pioneered aseptic technique and died of sepsis. His trials at trying to popularize the idea that aseptic technique could defeat childbed fever (streptococcal infection that accompanies childbirth) is a classic example of the difficulty in trying to establish a new principle in the medical community. 2. Lister (who was later made a Lord because of his findings) applied carbolic acid (phenol) to aseptic technique in the operating room 3. Domagk- Sulfa drugs- 1939 4. Fleming, Chain and Florey- Penicillin-1945

18. Immunology-Milestones • Elie Mechnikoff- Cellular Immunology- identified white blood cells as phagocytic immune agents of the blood. • Edward Jenner- showed that an 8 year old could be protected against small pox by introduction of cowpox virus obtained from the lesions of milk maids that had contracted cowpox. Termed the word vaccination (vacca-latin name for cow). • Pasteur use a dried spinal cord of rabbits infected with rabies to develop an anti-rabies vaccine. Drying of the spinal cord effectively attenuates (weakens) the virus. • Gerald M Edleman and Rodney Porter-for their discoveries concerning the chemical structure of antibodies- 1972 • Cesar Milstein, Georges Kohler and Niels Jerne-for theories concerning the specificity in development and control of the immune system and the discovery of the principle for production of monoclonal antibodies- 1984 • Tonegawa- for his discovery of the genetic principle for generation of antibody diversity-Received the Nobel prize in 1987. • Doherty and Zinkernagel- Recognition of virus-infected cells by immune defenses. Drs. Doherty and Zinkernagel discovered that T cells simultaneously recognize MHC self-protein and a foreign antigen on the surface of virally infected cells. - We will learn about these findings in the immunology part of the course. Received the Nobel prize in 1996.

19. Bacterial genetics molecular biology-Nobel Prizes The Nobel Prize in Physiology or Medicine 1933 Thomas H. Morgan The Nobel Prize in Physiology or Medicine 1933 Thomas H. Morgan "for his discoveries concerning the role played by the chromosome in heredity“- First Nobel Prize in what would become Molecular Biology/Molecular Genetics Morgan was born in Lexington, Kentucky, to Charlton Hunt Morgan and Ellen Key Howard Morgan.[2][4] Part of a line of Southern planter elite on his father's side, Morgan was a nephew of Confederate General John Hunt Morgan and his great-grandfather John Wesley Hunt had been the first millionaire west of the Allegheny Mountains. Through his mother, he was the great-grandson of Francis Scott Key, the author of the "Star Spangled Banner", and John Eager Howard, governor and senator from Maryland.[

20. Bacterial genetics molecular biology-Nobel Prizes • 1. Lederberg- Bacterial Conjugation- 1959 • 2. Watson Crick and Wilkins- Structure of DNA- 1962 • 3. Jacob, Lwoff and Monod - mRNA-1965 • 4. Berg- Recombinant DNA-1980 • Smith Nathans and Arber- Restriction enzymes for cutting DNA • Sharp and Roberts- Splicing-1993 • Prusiner- Prions-1997 • Barry J. Marshall and Robin Warren"for their discovery of the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease“-2005 • 11. Craig Mello and Andrew Fire of Stanford University received the Nobel Prize for the discovery of RNAi • 12. 2007 Mario Capecchi, Sir Martin Evans and Oliver Smithies- for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells. • 13. 2008 Luc Montagnier and Francoise Barre-Sinoussi work on identifying the virus that causes AIDS. HaraldZurHausen- human papilloma virus is the major cause of cervical cancer • 14. 2009 Nobel Prize in Chemistry awards VenkatramanRamakrishnan, Thomas A. Steitz and Ada E. Yonath for having showed what the ribosome looks like and how it functions at the atomic level. All three have used a method called X-ray crystallography to map the position for each and every one of the hundreds of thousands of atoms that make up the ribosome. • 2010 Robert G. Edwards for the development of in vitro fertilization • 2011 Nobel Prize in Medicine- Bruce Beutler, Jules Hoffman and Ralph Steinman- "for their discoveries concerning the activation of innate immunity" and the other half to Ralph M. Steinman "for his discovery of the dendritic cell and its role in adaptive immunity". • The Nobel Prize in Physiology or Medicine 2012 was awarded jointly to Sir John B. Gurdon and Shinya Yamanaka "for the discovery that mature cells can be reprogrammed to become pluripotent“ • The Nobel Prize in Physiology or Medicine 2013 was awarded jointly to James E. Rothman, Randy W. Schekman and Thomas C. Südhof"for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells".