Microbiology for the Health Sciences: Introduction, Overview and History. Scope of Microbiology. Topic 1 - Introduction. Topics

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1 Microbiology for the Health Sciences: Topic 1 - Introduction OpenStax Bauman Cowan Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Introduction, Overview and History Topics Scope of Microbiology Importance of Microorganisms Characteristics of Microorganisms History of Microbiology Taxonomy 2 Scope of Microbiology Immunology Public health microbiology & epidemiology Food, dairy and aquatic microbiology Agricultural microbiology Biotechnology Genetic engineering & recombinant DNA technology 3 1

2 From the Modern Age of Microbiology 4 Table 1.3 Importance of Microbiology First bacteria Photosynthesis and decomposition Human use of microorganisms Infectious diseases 5 Bacteria appeared approximately 3.5 billion years ago. Fig. 1.1 Evolutionary timeline 6 2

3 Microbes are involved in photosynthesis - account for >50% of the earth s oxygen. Decomposition nutrient recycling. Fig. 1.2 Microbial habitats 7 Microbes - extract copper from ore, synthesize drugs and enzymes, bioremediate contamination. Fig. 1.3 Microbes at work 8 The most common infectious diseases worldwide. Fig. 1.4 Worldwide infectious disease statistics 9 3

4 Characteristics of Microorganisms Prokaryotic no nucleus and organelles Eukaryotic nucleus and organelles (mitochondria, etc..) 10 There is a difference between the cell structure of a prokaryote and eukaryote. Viruses are neither but are considered particles. Fig. 1.5 Cell structure 11 There are six main types of microorganisms: 1.) bacterium, 2.) Fungus, 3.) Algae, 4.) Virus, 5.) Protozoan, 6.) Helminths. Fig. 1.6 The six types of microorganisms 12 4

5 Microorganisms vary in size - 1µm to 200 nm. Fig. 1.7 The size of things 13 Some Microbiological History Ancient Chronology Progress 14 Early History - Fermentation! Egypt >2800 BC: Beer, Wine 15 5

6 Ancient Sewers 2800 BC Crete, Pakistan, Scotland - Toilets and Sewers 315 AD Rome: Public Lavatories w/ flowing water The Cloaca Maxima (in red), ran through ancient Rome. Engineering marvel carried waste away from city to the river Tiber. 16 Ancient History: Thinkers & Observers Thucydides, ~375 BC (historian) observed Athenian plague were immune to reinfection. Hippocrates, ~350 BC the father of Western medicine, : diseases had natural, not supernatural, causes Marcus Terentius Varro, ~20 BC said: disease caused by certain minute creatures... which cannot be seen by the eye. Aristotle, ~384 AD: spontaneous generation? 17 Communicable Disease? Isolation of Individuals: Leper colonies (Mycobacterium leprae) Abandoning villages: Black Plague (Yersinia pestis) has killed 200 million! Small pox (Variola) killed 1/3 of Europe in 1348! 18 6

7 Progress 1590 Hans & Zacharius Janssen: Lens makers- first compound microscope 1665 Robert Hooke- views and describes fungi 1676 Anthony van Leeuwenhoekobserved first microscopic organism, now blood cells and protozoans visible 19 Microorganisms were first observed by Antonie van Leeuwenhoek, using a primitive microscope. Fig. 1.9 Leeuwenhoek s microscope 20 What Does Life Really Look Like? Antoni van Leeuwenhoek (Dutch) Began making and using simple microscopes Often made a new microscope for each specimen Examined water and visualized tiny animals, fungi, algae, and single-celled protozoa he called animalcules By end of 19th century, called microorganisms 21 7

8 More Progress in Tools 1883 Carl Zeiss and Ernst Abbe make advancements in microscopy lenses and techniques Ernst Ruska- first EM scope 22 History of Microbiology Spores and sterilization Spontaneous generation Aseptic technique Germ theory 23 Spores and sterilization Some microbes in dust and air were resistant to high heat. Spores were later identified. The term sterile was introduced which meant completely eliminating all life forms from objects or materials. 24 8

9 Spontaneous generation (3.1) Early belief that some forms of life could arise from vital forces present in nonliving or decomposing matter. (flies from manure, etc.) 25 Spontaneous Generation Discussion Francesco Redi - demonstrated maggots were offspring of flies, not spontaneous generation. John Needham - argued microbes arise spontaneously in broth from a life force. Lazzaro Spallanzani - broth experiments aimed to disprove those of Needham. 26 Spontaneous Generation? 1600 s Francesco Redi (Tuscany) does rotting meat experiment looking for maggots 3 jars: 1. Covered 2. Uncovered 3. Meshed 27 9

10 Do Microbes Cause Disease? 1546 Girolamo Fracastoro wrote about contagion 1835 Agostino Bassi de Lodi linked a fungi with a silkworm disease the first recognized contagious agent of animal disease! Louis Pasteur uses swan necked-flasks to show bacteria do not arise spontaneously. He showed microbes caused fermentation and spoilage, and disproved spontaneous generation. 29 Scientists searched for answers to four questions Is spontaneous generation of microbial life possible? What causes fermentation? What causes disease? How can we prevent infection and disease? 30 10

11 How about Fermentation? Spoiled wine air caused fermentation? living organisms caused fermentation? Vintners $$ for research to promote production of alcohol but prevent spoilage during fermentation This debate also linked to debate over spontaneous generation 31 Disease Knowledge Grows 1847 Ignaz Semmelweiss- Hungarian physician- made his physicians wash hands between patients (child-bed fever) 1857 Louis Pasteur- (among many things ) proposes germ theory 1867 Joseph Lister- Introduces antiseptics in surgery (carbolic acid) 32 Pasteur s Germ Theory of Disease Many diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc

12 Robert Koch verified the Germ theory (Koch s postulates). 34 Koch s Postulates 1876 Robert Koch cultivates Anthrax using blood serum. Publishes postulates: Agent must be present in every case Agent must be isolated and cultured in vitro Disease must be produced when a pure culture is inoculated into susceptible host Agent must be recoverable from infected host 35 Koch was a busy man! Simple staining techniques First photomicrograph of bacteria First photomicrograph of bacteria in diseased tissue Techniques for estimating CFU/ml Used steam to sterilize media Used Petri dishes Techniques to transfer bacteria Determined bacteria as distinct species 36 12

13 Example Bacterial colonies on agar 37 Figure 1.16 Aseptic Technique great idea! Joseph Lister first introduced the technique to reduce microbes in a medical setting and prevent wound infections. Based his work on Pasteur s research results. 38 Ideas to Prevent Infection and Disease? Semmelweis and hand washing Lister s antiseptic technique Nightingale and nursing Snow infection control and epidemiology Jenner s vaccine field of immunology Ehrlich s magic bullets field of chemotherapy 39 13

14 Summary - The Golden Age of Microbiology 40 Table 1.2 Who worked on what? Scientific disciplines and applications 41 Figure 1.19 Taxonomy (1.2) A system for organizing, classifying & naming living things. Primary concerns of taxonomy are classification, nomenclature, and identification

15 Microbial Classification Carolus Linnaeus developed taxonomic system for naming plants and animals, grouped similar organisms together Grouped Leeuwenhoek s microorganisms into six categories: Fungi Protozoa Algae Bacteria Archaea Small multicellular animals 43 Levels of Classification Domain Phylum or Division Class Order Family Genus species 44 Classification & Evolutionary Trends Classification schemes allow for a universal tree of life phylogenetic tree. Living things change gradually over millions of years Changes favoring survival are retained & less beneficial changes are lost

16 Historical Taxonomy 46 Monerans Fungi Protists Plants Animals The old 5 Kingdoms The five-kingdom system was standard until molecular biology techniques to developed the Domain system Traditional Whittaker system of classification 47 The new Domains idea (thanks Dr. Woese!) Developed after the five-kingdom system Eubacteria -true bacteria, peptidoglycan Archaea (Dr. Carl Woese) odd bacteria that live in extreme environments, high salt, heat, etc. Eukarya- have a nucleus, & organelles 48 16

17 The Domain system Developed by Dr. Woese rrna sequence information is basis 49 Relationships: Kingdom is inclusive genus and species less inclusive 50 Nomenclature what's in a name? Binomial (scientific) nomenclature Genus Bacillus, always capitalized species - subtilis, lowercase Both italicized or underlined Bacillus subtilis (B. subtilis) 51 17

18 Identification The process of discovering and recording the traits (physical, biochemical, genetic) of organisms, thereby, placing them in a taxonomic scheme. 52 Quick Overview of Microorganism Groups (1.3) Virus & Bacteriophage Bacteria (Archae & Eubacteria) Fungi Protozoans Algae Helminths 53 Phage (bacterial virus) infects a bacterium 54 Figure

19 Bacteria and Archaea Unicellular, no nuclei smaller than eukaryotes Found everywhere there is sufficient moisture; some isolated from extreme environments Reproduce asexually Two kinds Bacteria Archaea 55 Fungi Eukaryotic (membrane-bound nucleus) Heterotrophic/Cell walls Molds & Yeasts 56 Example Fungus: (a) Penicillium chrysogenum, (b) Saccharomyces cerevisiae 57 Figure

20 What the heck is a Protozoan? Single-celled eukaryotes Similar to animals in nutrient needs and cellular structure Live freely in water; some in animal hosts Asexual (most) and sexual repro Most motile via: Pseudopods Cilia Flagella 58 So what about Algae? Unicellular or multicellular Photosynthetic Simple reproductive structures Categorized on pigmentation, storage products, composition of cell wall Diatoms Spirogyra 59 Parasitic worm in blood, immature stage 60 Figure

21 Bartonella sp. Unculturable? Bartonella sp. : fastidious gramnegative, facultative intracellular parasite bacteria responsible for bacillary angiomatosis, trench fever, cat scratch disease, and endocarditis