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Microbiology and Immunology
BIOL200, BIOL343
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Microbiology
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Course Outline
MICROBIOLOGY:• Introduction: Microbial world and the historical roles of the
microbiologist; cell theory, spontaneous generation, biogenesis theory, fermentation, pasteurization and germ theory of the diseases. Koch’s postulates; classification and characteristics of living organisms; basic structure, similarities and differences betweeneukaryotes and prokaryotes
• Microbial growth and nutritional requirements.• Media used for cultivating microorganisms. • Characterization of microorganisms; pure culture techniques.• Preparing microorganisms for light microscopy.• Characterization of microorganisms.• Control of Microorganisms: principles and physical agents;
fundamentals of microbial growth control;
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Course outline
• Chemical control agents: major groups of disinfectants and antiseptics; evaluation of antimicrobial activity.
• Microbiology of natural water, and waste water.• Microbiology of food. Preservation. Aseptic
handling and processing; Microbial spoilage of foods; microbial cells as food;
• Single-Cell Proteins• Virology: virus morphology; classification.
Bacteriophage life cycle; • Diseases caused by viruses. • Viruses cultivation methods.
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Course outline
IMMUNOLOGY• Overview of Immunology• Anatomy and biology of immune system• Antigens and Antibody• Complement system• Antigen-Antibody reactions • Hypersensitivity• Immunodeficiency and autoimmunity
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What is microbiology?
• study of organisms too small to be clearly seen by the unaided eye (i.e., microorganisms)
• these organisms are relatively simple in their construction and lack highly differentiated cells and distinct tissues
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Microbiology
• Study of microscopic (living ) things• E.g.
viruses, bacteria, algae, protists, fungi
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The Importance of Microorganisms
• most populous group of organisms and are found everywhere on the planet
• play a major role in recycling essential elements
• source of nutrients and some carry out photosynthesis
• benefit society by their production of food, beverages, antibiotics and vitamins
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Microbes Are Everywhere!• In ponds
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Microbes Are Everywhere!
• In thermal areas
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Microbes Are Everywhere!
• In ice
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Microbes Are Everywhere!
• In salt
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Microbes Are Everywhere!
• In water, viruses outnumber bacteria by 2-10:1
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Microbes Are Everywhere!
• In the deeps
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Microbes Are Everywhere!
• In the soil
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And with other organisms
• With plant roots
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And with other organisms
• In coral
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And with other organisms
• In clams
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And with other organisms
• In lichens
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And with other organisms
• With cows and termites
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And with other organisms
• With fish
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Microbes Recycle Key Elements
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Microbes Recycle Key
Elements
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We Use Existing Microbes
• To make foods
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We Use Existing Microbes
• To make alcohol
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We Use Existing Microbes
• To clean up oil spills
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We Use Existing Microbes
• To turn trash into soil
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Microbiology
• The study of of organisms too small to be seen without magnification– bacteria– viruses– fungi– protozoa – helminths (worms) – algae
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Branches of study within microbiology
• Immunology• Public health microbiology & epidemiology• Food, dairy and aquatic microbiology• Biotechnology• Genetic engineering & recombinant DNA
technology
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Microbes are involved in
• nutrient production & energy flow• Decomposition• Recycling chemical elements• production of foods, drugs & vaccines• Bioremediation (can be defined as any process that uses
microorganisms, fungi, green plants or their enzymes to return the natural
environment altered by contaminants to its original condition )• causing disease
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Microorganisms in our life
• Humans and many animals depend on microorganisms in their intestines for digestion and the synthesis of some vitamins (group B)
• Commercial application (chemical synthesis (biotransformation) – acetone, organic acids, alcohols, drugs)
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Microorganisms in our life
• The Food industry (producing vinegar, alcoholic beverages, soy sauce, buttermilk, cheese, yogurt, bread)
• The pharmaceutical industry (produce many kinds of drugs by employing m/o)
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Microorganisms in our life
Pathogens• Only minority of microorganism is
pathogenic• Practical knowledge of pathogenic m/o is
necessary for medicine and health related science.
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Impact of pathogens
• Nearly 2,000 different microbes cause diseases
• 10 B infections/year worldwide• 13 M deaths from infections/year worldwide
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The Future of Microbiology:Challenges and opportunities for future
microbiologists
• infectious disease• new and improved industrial processes• microbial diversity and microbial
ecology– less than 1% of earth’s microbial population
has been cultured
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Types of microorganisms
• Bacteria• Fungi (yeast and molds)• Protozoa• Microscopic algae• Viruses• Non-cellular entities, sometimes regarded as
being at the border between life and non-life
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Characteristics of microbes
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Classification schemes • five kingdom scheme includes Monera, Protista, Fungi,
Animalia and Plantae with microbes placed in the first three kingdoms (Whitakker’s system)
• three domain alternative, based on a comparison of ribosomal RNA, divides microorganisms into Bacteria (true bacteria), Archaea and Eucarya(eucaryotes) (Woese’s system)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 39
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Types of microorganisms
• Bacteria (plural) , Bacterium (singular) -Are relatively simple single celled organism.• Bacteria cells are called prokaryotes
(Greek – pro nucleus – no nucleus), because their genetic material is not enclosed in a special nuclear membrane.
• Most of bacteria have a cell wall –composition of carbohydrates and proteins -peprtidoglycan
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Shapes of bacterial cells
• Rods
• Spherical (cocci)
• Spiral
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Shapes of microorganisms
• Some bacteria could be individual
• Some could form clasters, chains, pairs or other groupings
• Important charachteristic of a particular genus
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Types of microorganismsArchaea
• Archaea – like bacteria also prokariotes• Could be without any cell wall, or if they have
it – the wall lack peptidoglycan• Often found in extreme environment• Not known to cause any human desease• According the environment, where they can
be found, divided into 3 main groups
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Archaea – 3 groups
1. Methanogens – produce methane as a waste product of respiration
2. Extreme Halophilessalt loving
They can live in extreme salty environment such as Dead Sea, Great Salt Lake
3. Extreme thermophiles (thermo – heat) –live in hot (90 C) sulfurous water as hot springs (geisers)
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Selected methanogenes
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Fungi
• Singular Fungus• Are eukaryotes• Cell contain a distinct nucleus, containing
the genetic material (DNA), surrounded by a special envelope, called the nuclear membrane
• Could be unicellular or multicellular
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Multicellular fungi
• Large multicellular –are mushrooms, they can look like plants, but they unable to do photosynthesis
• Cell walls composed mostly from chitin
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Unicellular fungi
• Yeasts, molds• Visible masses of
molds are mycelia (cottony growth on bread)
• Many are pathogenic and infect plants and animals.
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Protozoa
• The microorganisms called protozoa [s., protozoan; Greek protos, first, and zoon, animal] are studied in the discipline called protozoology. A protozoan can be defined as a usually motile eucaryotic unicellular protist. Protozoa are directly related only on the basis of a single negative characteristic—they are not multicellular. All, however, demonstrate the basic body plan of a single protistan eucaryotic cell.
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Protozoa
• Have a variety of shapes
• Could live individually or as a parasites (organism that can take the nutrients from living host)
• Move by pseudopods, flagella, cilia
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Algae
• Singular - alga• Photosynthetic eukaryotes with wide
variety of shapes• Abundant in fresh water, soil, associated
with plants.• Play very important role in the balance of
nature
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Algae morphology
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Algae shapes
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Algae Micrographs
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Viruses
• Viruses are simple, acellular entities consisting of one or more molecules of either DNA or RNA enclosed in a coat of protein (and sometimes, in addition, substances such as lipids and carbohydrates). They can reproduce only withinliving cells and are obligately intracellular parasites.
• Compare – all living things contain DNA and can reproduce as a self-sufficient unit
• Viruses are not considered to be living, because outside of living host, they are inert.
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Size and morphology of viruses
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Metric system
• The metric system is a way of measuring things by using multiplesor fractions of ten, called factors of ten or the power of ten.
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Units and prefixes
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Comparative sizes
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Comparative sizes
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Antonie van Leeuwenhoek
• First to observe living microbes
• his single-lens magnified up to 300X
(1632-1723)
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Scientific Method
• Form a hypothesis - a tentative explanation that can be supported or refuted by observation & experimentation
• A lengthy process of experimentation, analysis & testing either supports or refutes the hypothesis.
• Results must be published & repeated by other investigators.
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• If hypothesis is supported by a growing body of evidence & survives rigorous scrutiny, it moves to the next level of confidence - it becomes a theory
• Evidence of a theory is so compelling that the next level of confidence is reached - it becomes a Law or principle
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Spontaneous generation
Early belief that some forms of life could arise from vital forces present in
nonliving or decomposing matter. (flies from manure, etc)
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Louis Pasteur
• Showed microbes caused fermentation & spoilage
• Disproved spontaneous generation of m.o.
• Developed aseptic techniques.
• Developed a rabies vaccine.
(1822-1895)
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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.
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Robert Koch
• Established a sequence of experimental steps to show that a specific m.o. causes a particular disease.
• Developed pure culture methods.
• Identified cause of anthrax, TB, & cholera.
(1843-1910)
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Taxonomy - system for organizing, classifying & naming living things
• Domain - Archaea, Bacteria & Eukarya
• Kingdom - 5• Phylum or Division• Class • Order• Family• Genus• species
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3 domains
• Eubacteria -true bacteria, peptidoglycan• Archaea –odd bacteria that live in extreme
environments, high salt, heat, etc• Eukarya- have a nucleus, & organelles
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Naming micoorganisms
• Binomial (scientific) nomenclature • Gives each microbe 2 names
– Genus - noun, always capitalized– species - adjective, lowercase
• Both italicized or underlined– Staphylococcus aureus (S. aureus)– Bacillus subtilis (B. subtilis)– Escherichia coli (E. coli)
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Naming and classifying microorganisms (Nomenclature)
• Established in 1735 by Linnaeus• Names of m/o are LatinizedEscherichia (1) coli (2) - example• Each microorganism has two names:1. The genus (plural – genera), always
capitalized.2. Special epithet or Species name, not
capitalizedThe name of m/o in a text always supposed to be
BOLDED or underlined
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Naming of microorganismsExamples:
• Azotobacter vinelandii• Rhodococcus rhodochrous• Azospirillum brasilense• Staphylococcus aureus• Escherichia coli
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Naming of microorganisms
• The name of m/o could be the honor of the resercher, or part of description
golden
aureusStaphylococcus
sphereClasterarrangment
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Hierarchical Arrangement in Taxonomy
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Taxonomic ranks
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Evolution- living things change gradually over millions of years
• Changes favoring survival are retained & less beneficial changes are lost.
• All new species originate from preexisting species.
• Closely related organism have similar features because they evolved from common ancestral forms.
• Evolution usually progresses toward greater complexity.
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