Medical Microbiology The History EQ Who are the

Medical Microbiology The History EQ: Who are the major contributors to the development of Microbiology?

What is Microbiology? § They study of microbes or microorganisms § Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye.

What is Microbiology? What are some of examples of microbes? § Bacteria, fungi, protozoa, algae, viruses, and some are parasites (helminths) § Some are pathogenic

What is Microbiology? Microbres § When you hear the word bacteria, what comes to your mind? § Not all bacteria cause disease § Most bacterial species cannot cause disease Figure 1. Gram stain of a species of Micrococcus, commonly isolated from the skin and nasal membranes of humans. Figures from: http: //textbookofbacteriology. net/normalflora. html

What is Microbiology? Microbes § Can microorganisms be good for us, beneficial? Explain your answer § Many species play beneficial roles § Production of antibiotics and foodstuffs § Decompose organic waste § Produce industrial chemicals such as ethyl alcohol and acetone § Produce fermented foods such as vinegar, cheese, and bread

Ancient Microbiological History § Ancient people recognized many factors involved in diseases. § Most ancient people documented that some diseases are communicable § Example: When Black Death struck Europe entire villages were abandoned in an effort to escape the highly infectious plague (1347 A. D) § No medical knowledge existed in Medieval England to cope with the disease.

Ancient Microbiological History § The Romans were a hygienic bunch and were concerned with health and cleanliness (waste and sewage). § The Romans invented the first underground sewage system

Ancient Microbiological History § The Romans understood that sewage could cause disease and there for decided to build an underground sewage system which is an idea we still use today. § A network of pipes brought clean water into the city of Rome and removed waste. § Waste flushed from the latrines flowed through a central channel into the main sewage system and thence into a nearby river or stream. § The public bath houses was the place where people went to socialize and do business as well as getting clean.

History of Microbiology? § Discovering organisms § First microbes were observed in 1673 § Robert Hooke- In 1665 reported that living things were composed of little boxes or cells § devised the compound microscope and illumination system § Antoni van Leeuwenhoek- (1673 -1723) § He is considered the father of bacteriology § Made simple microscopes and began observing with them § Discovered bacteria (he called them animalcules)

§ Leeuwenhoek's microscope consisted simply of: § A) a screw for adjusting the height of the object being examined § B) a metal plate serving as the body § C) a skewer to impale the object and rotate it § D) the lens itself, which was spherical

History of Microbiology: Theories § Spontaneous Generation § Many believed in spontaneous generation: § Aristotle synthesized the hypothesis which stated that some vital force contained in given organic matter can create living organisms from inanimate objects. § In basic terms spontaneous generation stated that living organisms arise from non living matter.

History of Microbiology: Theories Spontaneous Generation § Spontaneous generation was disproved in 1668 by Italian Scientist, Francesco Redi. § What are the steps to the scientific method? § If your were Francesco Redi, what experimental design would you create to disprove spontaneous generation? Redi’s Experiment: § Redi’s question: Where do maggots come from? § Hypothesized: Redi suspected that flies landing on the meat laid eggs that eventually grew into maggots § Experiment: Placed meat in three separate jars

History of Microbiology: Theories Disproving Spontaneous Generation: Redi’s Experiment Jar #1 • • • Left open Maggots developed Flies were observed laying eggs on the meat in the open jar Jar #2 • • • Covered with netting Maggots appeared on the netting Flies were observed laying eggs on the netting Jar #3 • • Sealed No maggots developed

History of Microbiology: Theories Spontaneous Generation § The Question: What causes tiny living things to appear in decaying broth? § John Needham- revived theory of spontaneous generation in 1745 § Needham theorized that if he took chicken broth and heated it, all living things in it would die. § After heating some broth, he let a flask cool and sit at a constant temperature. The development of a thick turbid solution of microorganisms in the flask was strong proof to Needham of the existence of spontaneous generation.

History of Microbiology: Theories Spontaneous Generation The Question: What causes tiny living things to appear in decaying broth? § Lazzaro Spallanzani (1729 -1799) § He demonstrated that microorganisms were already in the solution, the container, or the air § He took solutions which he knew would "breed" organisms and boiled them for up to an hour. The flasks were hermetically sealed to keep out contaminated air.

History of Microbiology: Theories Biogenesis § In 1858 German scientist, Rudolf Virchow challenged spontaneous generation with his concept of biogenesis § Living organisms arise from pre-existing life § Virchow presented his idea to the scientific community, but could not back it up with a convincing experiment

History of Microbiology: Theories Settlement of Spontaneous Generation § In 1861, a French scientist by the name of Louis Pasteur demonstrated where microorganisms came from § Father of Medical Microbiology § Demonstrated the microorganisms exist in the air and could contaminate sterile solutions by passing air through cotton filters § The filter trapped tiny particles floating in the air http: //www. microbiologytext. com/index. php? module=Book&func=displayarticle&art_id=27

History of Microbiology: Theories Louis Pasteur’s Swan neck flask experiment http: //www. microbiologytext. com/index. php? module=Book&func=displayarticle&art_id=27 French chemist Louis Pasteur’s design of this experiment settled the argument. Click here for an animation and quiz.

History of Microbiology: Theories Louis Pasteur’s experiments § Louis Pasteur performed numerous experiments to discover why wine and dairy products became sour § He found that bacteria were to blame (lactic acid fermentation) § Pasteur called attention to the importance of microorganisms in everyday life and stirred scientists to think that if bacteria could make the wine “sick, ” then perhaps they could cause human illness.

Golden Age of Microbiology 1857 - 1914 § Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity and antimicrobial medicine § Germ Theory of Disease § Germ theory states that specific microscopic organisms are the cause of specific diseases.