Chapter 1 Chapter 1 Outline Introduction What is

  • Slides: 49
Download presentation
Chapter 1

Chapter 1

Chapter 1 Outline • Introduction • What is microbiology? • Why study microbiology? •

Chapter 1 Outline • Introduction • What is microbiology? • Why study microbiology? • First microorganisms on Earth • Earliest known infectious diseases • Pioneers in the science of microbiology • Careers in microbiology GLBH 205 - Microbiology 2

What is Microbiology? • Biology is the study of living organisms • Microbiology is

What is Microbiology? • Biology is the study of living organisms • Microbiology is an advanced biology course • Microbiology is the study of microbes, which are extremely small (microscopic) living organisms and certain non-living entities • Living microbes are known as cellular microbes or microorganisms; examples include bacteria, archaea, some algae, protozoa, and some fungi • Non-living microbes are known as acellular microbes or infectious particles; examples include viroids, prions, and viruses • Microorganisms are ubiquitous (they are found virtually everywhere) GLBH 205 - Microbiology 3

Acellular and Cellular Microbes GLBH 205 - Microbiology 4

Acellular and Cellular Microbes GLBH 205 - Microbiology 4

What is Microbiology? • The microbes that cause disease are sometimes referred to as

What is Microbiology? • The microbes that cause disease are sometimes referred to as “germs” • The scientific term for disease-causing microbes is pathogens • Microbes that do not cause disease are called nonpathogens; the vast majority of microbes are nonpathogens GLBH 205 - Microbiology 5

What is Microbiology? • Microbes that live on and in our bodies are referred

What is Microbiology? • Microbes that live on and in our bodies are referred to as our indigenous microflora • Some members of our indigenous microflora are opportunistic pathogens • Opportunistic pathogens are microbes that can cause disease, but usually do not; they can be thought of as microbes that are awaiting the opportunity to cause disease • Pathogens cause two categories of diseases: infectious diseases and microbial intoxications GLBH 205 - Microbiology 6

Categories of Diseases Caused by Pathogens GLBH 205 - Microbiology 7

Categories of Diseases Caused by Pathogens GLBH 205 - Microbiology 7

Why Study Microbiology? • Microorganisms play significant roles in our lives; they are essential

Why Study Microbiology? • Microorganisms play significant roles in our lives; they are essential for life on this planet • Photosynthetic algae and bacteria (such as cyanobacteria) produce much of the oxygen in our atmosphere • Microorganisms are involved in the decomposition of dead organisms and waste products • Saprophytes are organisms that live on dead and/or decaying organic matter • The use of microbes to clean up toxic wastes and other industrial waste products is known as bioremediation GLBH 205 - Microbiology 8

Microbes as Saprophytes GLBH 205 - Microbiology 9

Microbes as Saprophytes GLBH 205 - Microbiology 9

Why Study Microbiology? • Many microbes play essential roles in various elemental cycles; e.

Why Study Microbiology? • Many microbes play essential roles in various elemental cycles; e. g. , the carbon, nitrogen, oxygen, sulfur, and phosphorous cycles • Algae and bacteria serve as food for tiny animals; they are important links in food chains • Microbes that live in the intestinal tracts of animals aid in the digestion of food and produce beneficial substances • For many years, microorganisms have been used as “cell models”; the more that scientists learned about microbial cells, the more they learned about cells in general GLBH 205 - Microbiology 10

They are important links in food chains Humans are on the top of the

They are important links in food chains Humans are on the top of the food chain GLBH 205 - Microbiology 11

GLBH 205 - Microbiology 12

GLBH 205 - Microbiology 12

Microbes and Nitrogen Fixation GLBH 205 - Microbiology 13

Microbes and Nitrogen Fixation GLBH 205 - Microbiology 13

Why Study Microbiology? • Microbes are used in many industries; e. g. , food,

Why Study Microbiology? • Microbes are used in many industries; e. g. , food, beverage, chemical, and antibiotic industries and in genetic engineering • In genetic engineering, a gene or genes from one organism is/are inserted into a bacterial or yeast cell; the cell that receives the new gene(s) is then capable of producing the gene product(s) coded for by the new gene(s) • The use of living organisms or their derivatives to make or modify useful products or processes is call biotechnology GLBH 205 - Microbiology 14

Typical application of biodispersant to remediate an oil spill http: //en. wikipedia. org/wiki/US_Microbics#George_Robinson GLBH

Typical application of biodispersant to remediate an oil spill http: //en. wikipedia. org/wiki/US_Microbics#George_Robinson GLBH 205 - Microbiology 15

More on Why to Study Microbiology… • Use of microbes as “cell models” –

More on Why to Study Microbiology… • Use of microbes as “cell models” – E. Coli is one of the most studied • Microbes cause two categories of diseases: 1. Infectious disease – This is the leading cause of death in the world and the 3 rd leading cause of death in the US (after heart disease and cancer). 2. Microbial intoxication GLBH 205 - Microbiology 16

GLBH 205 - Microbiology 17

GLBH 205 - Microbiology 17

First Microorganisms on Earth Scientists tell us … • Fossils of primitive microorganisms date

First Microorganisms on Earth Scientists tell us … • Fossils of primitive microorganisms date back about 3. 5 billion years ago. • Candidates for the first microorganisms on Earth are archaea and cyanobacteria. • Infectious diseases of humans and animals have existed for as long as humans and animals have inhabited the planet. • Earliest known account of pestilence occurred in Egypt in about 3180 BC. GLBH 205 - Microbiology 18

Earliest Observations • • • Bacteria and protozoa were the first microbes to be

Earliest Observations • • • Bacteria and protozoa were the first microbes to be observed by humans Earliest observations recorded in 1665 The earliest microbiologists: 1. Anton van Leeuwenhoek (1632 – 1723) 2. Louis Pasteur (1822 – 1895) 3. Robert Koch (1843 – 1910) GLBH 205 - Microbiology 19

The First Observations • 1665: Robert Hooke reported that living things were composed of

The First Observations • 1665: Robert Hooke reported that living things were composed of little boxes, or cells – Ground for the cell theory • 1858: Rudolf Virchow said cells arise from preexisting cells • Cell theory: All living things are composed of cells and come from preexisting cells GLBH 205 - Microbiology 20

Pioneers in the Science of Microbiology Anton van Leeuwenhoek (1632 -1723) – “Father of

Pioneers in the Science of Microbiology Anton van Leeuwenhoek (1632 -1723) – “Father of Microbiology” – Not a trained scientist! – Made many simple single-lens microscopes – Observed ”animalcules” (bacteria and protozoa) GLBH 205 - Microbiology 21

Pioneers in the Science of Microbiology Louis Pasteur (1822 -1895) – French chemist who

Pioneers in the Science of Microbiology Louis Pasteur (1822 -1895) – French chemist who made numerous contributions to microbiology – Investigated different fermentation products – Developed the pasteurization process – Discovered life forms that could exist without oxygen (anaerobes) – Developed several vaccines, including rabies and anthrax vaccines GLBH 205 - Microbiology 22

Debate on Spontaneous Generation • Francisco Redi (1668) demonstrated that maggots appear on decaying

Debate on Spontaneous Generation • Francisco Redi (1668) demonstrated that maggots appear on decaying meat only when flies are able to lay eggs on the meat • John Needham (1745) claimed microorganism arise spontaneously from heated nutrient broth • Lazzaro Spallanzani (1765) repeated Needham’s experiments and suggested that it was due to airmicroorganisms entering the broth. • Rudolf Virchow (1858) introduced “biogenesis” concept where living cells arise only from preexisting cells. GLBH 205 - Microbiology 23

Evidence Pro and Con 1668: Francesco Redi filled 6 jars with decaying meat Conditions

Evidence Pro and Con 1668: Francesco Redi filled 6 jars with decaying meat Conditions Results Three jars covered with fine net Three open jars No maggots Maggots appeared From where did the maggots come? What was the purpose of the sealed jars? Spontaneous generation or biogenesis? GLBH 205 - Microbiology 24

Evidence Pro and Con 1745: John Needham put boiled nutrient broth into covered flasks

Evidence Pro and Con 1745: John Needham put boiled nutrient broth into covered flasks Conditions Results Nutrient broth heated, Microbial growth then placed in sealed flask From where did the microbes come? Spontaneous generation or biogenesis? GLBH 205 - Microbiology 25

Evidence Pro and Con 1765: Lazzaro Spallanzani boiled nutrient solutions in flasks Conditions Results

Evidence Pro and Con 1765: Lazzaro Spallanzani boiled nutrient solutions in flasks Conditions Results Nutrient broth placed in No microbial growth flask, heated, then sealed Spontaneous generation or biogenesis? GLBH 205 - Microbiology 26

Evidence Pro and Con 1861: Louis Pasteur demonstrated that microorganisms are present in the

Evidence Pro and Con 1861: Louis Pasteur demonstrated that microorganisms are present in the air Conditions Results Nutrient broth placed in flask, heated, not sealed Microbial growth Nutrient broth placed in flask, heated, then sealed No microbial growth Spontaneous generation or biogenesis? GLBH 205 - Microbiology 27

The Theory of Biogenesis Pasteur’s S-shaped flask kept microbes out but let air in

The Theory of Biogenesis Pasteur’s S-shaped flask kept microbes out but let air in GLBH 205 - Microbiology Figure 28 1. 3

Fermentation and Pasteurization • Pasteur demonstrated that these spoilage bacteria could be killed by

Fermentation and Pasteurization • Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine • Pasteurization is the application of a high heat for a short time Figure 1. 4 GLBH 205 - Microbiology 29

Pioneers in the Science of Microbiology Robert Koch (1843 -1910) – German physician who

Pioneers in the Science of Microbiology Robert Koch (1843 -1910) – German physician who made numerous contributions to microbiology – Made significant contributions to the germ theory of disease – Discovered that Bacillus anthracis produced spores – Developed methods of fixing and staining bacteria – Developed methods to cultivate bacteria GLBH 205 - Microbiology 30

Koch’s Postulates 1. A particular microbe must be found in all cases of the

Koch’s Postulates 1. A particular microbe must be found in all cases of the disease and must not be present in healthy animals or humans. 2. The microbe must be isolated from the diseased animal or human and grown in pure culture in the laboratory. 3. The same disease must be produced when microbes from the pure culture are inoculated into healthy susceptible laboratory animals. 4. The same microbe must be recovered from the experimentally infected animals and grown again in pure culture. GLBH 205 - Microbiology 31

Koch’s Postulates GLBH 205 - Microbiology 32

Koch’s Postulates GLBH 205 - Microbiology 32

Koch’s Postulates, cont. • If an organism fulfills Koch’s postulates, it has been proven

Koch’s Postulates, cont. • If an organism fulfills Koch’s postulates, it has been proven to be the cause of that particular infectious disease • Koch’s Postulates helped prove the germ theory of disease • Koch gave a tremendous boost to the development of microbiology by stressing laboratory culture and identification of microorganisms • Circumstances do exist in which Koch’s Postulates cannot be fulfilled GLBH 205 - Microbiology 33

Exceptions to Koch’s Postulates • Regarding in-vitro grow/culture of pathogen in or on artificial

Exceptions to Koch’s Postulates • Regarding in-vitro grow/culture of pathogen in or on artificial culture media – Some pathogens will not grow in this media • Viruses, rickettsias, chlamydias that are obligate intracellular pathogens • Bacteria causing leprosy and syphilis – Some fastidious microbes (with complex and demanding nutritional requirements) • Some pathogens are species-specific • Synergistc infections are caused by combined effects of two or more different microbes. • Some diseases are not caused by microbes (e. g. nutritional deficiencies GLBH 205 - Microbiology 34

Careers in Microbiology • A microbiologist is a scientist who studies microbes. • There

Careers in Microbiology • A microbiologist is a scientist who studies microbes. • There are many career fields within the science of microbiology (e. g. , bacteriology, phycology, protozoology, mycology, parasitology, and virology). • Medical Microbiology – Involves the study of pathogens, the disease they cause and the body’s defenses against disease. – Concerned with epidemiology, transmission of pathogens, diseaseprevention measures, aseptic techniques, treatment of infectious diseases, immunology, and production of vaccines. GLBH 205 - Microbiology 35

Which of the following is the most important element of Koch’s germ theory of

Which of the following is the most important element of Koch’s germ theory of disease? The animal shows disease symptoms when A. B. C. D. E. the animal has been in contact with a sick animal. the animal has a lowered resistance. a microorganism is observed in the animal. a microorganism is inoculated into the animal. microorganisms can be cultured from the animal.

Which of the following statements is the best definition of biogenesis? A. B. C.

Which of the following statements is the best definition of biogenesis? A. B. C. D. E. Nonliving matter gives rise to living organisms. Living cells can only arise from preexisting cells. A vital force is necessary for life. Air is necessary for living organisms. Microorganisms can be generated from nonliving matter.

Which of the following is a beneficial activity of microorganisms? A. Some microorganisms are

Which of the following is a beneficial activity of microorganisms? A. Some microorganisms are used as food for humans. B. Some microorganisms use carbon dioxide. C. Some microorganisms provide nitrogen for plant growth. D. Some microorganisms are used in sewage treatment processes. E. all of the above GLBH 205 - Microbiology 39

Which of the following would be the essential function performed by bacteria? A. B.

Which of the following would be the essential function performed by bacteria? A. B. C. D. E. control insect populations directly provide food for humans decompose organic material and recycle elements cause disease produce human growth hormones such as insulin GLBH 205 - Microbiology 40

Which of the following is an example of bioremediation? A. application of oil-degrading bacteria

Which of the following is an example of bioremediation? A. application of oil-degrading bacteria to an oil spill B. application of bacteria to a crop to prevent frost damage C. fixation of gaseous nitrogen into usable nitrogen D. production by bacteria of a human protein such as interferon E. all of the above GLBH 205 - Microbiology 41

Which of the following statements is true? A. B. C. D. All life requires

Which of the following statements is true? A. B. C. D. All life requires air. Only disease-causing organisms require air. Some microbes do not require air. Pasteur kept air out of his biogenesis experiments. E. Lavoisier was mistaken. GLBH 205 - Microbiology 42

Which of the following statements about E. coli is not true? A. E. coli

Which of the following statements about E. coli is not true? A. E. coli was the first disease-causing bacterium identified by Koch. B. E. coli is part of the normal microbiota of humans. C. E. coli is beneficial in human intestines. D. A disease-causing strain of E. coli causes bloody diarrhea. E. none of the above GLBH 205 - Microbiology 43

Robert Koch A. Developed the microscope B. Discovered penicillin C. Developed the germ theory

Robert Koch A. Developed the microscope B. Discovered penicillin C. Developed the germ theory of disease D. First observed cells GLBH 205 - Microbiology 44

Pasteur A. B. C. D. Disproved spontaneous generation Discovered penicillin Discovered phagocytosis Developed aseptic

Pasteur A. B. C. D. Disproved spontaneous generation Discovered penicillin Discovered phagocytosis Developed aseptic surgery GLBH 205 - Microbiology 45

Who first used microscopes to observe microorganisms? A. B. C. D. Koch Jenner Pasteur

Who first used microscopes to observe microorganisms? A. B. C. D. Koch Jenner Pasteur Van Leeuwenhoek GLBH 205 - Microbiology 46

Who developed a set of postulates to prove that specific microorganisms cause disease? A.

Who developed a set of postulates to prove that specific microorganisms cause disease? A. B. C. D. Jenner Gram Pasteur Koch GLBH 205 - Microbiology 47

Biotechnology can best be defined as a. Using living organisms to clean up pollution

Biotechnology can best be defined as a. Using living organisms to clean up pollution b. Using living organisms to develop desired products c. Using living organisms to treat disease d. Using living organisms to control pests GLBH 205 - Microbiology 48

GLBH 205 - Microbiology 49

GLBH 205 - Microbiology 49