Presentation on theme: "Title Dr. Gary Andersen USD 500 Kansas City Kansas Public Schools 913-279-2211"— Presentation transcript:
Title Dr. Gary Andersen USD 500 Kansas City Kansas Public Schools
Two Truths and a Lie I have wrestled and alligator. I have knocked down an elk. I have chased off a bear with a frying pan.
I. Key Terms A. Microbiology - the logic of small living things. B. Microbiologist - specialist in the field. There are 3 general branches: 1. Virologist- study viruses 2. Bacteriologist – study bacteria 3. Immunologist - study immune system C. Microscopy - observing minute objects with a microscope How small?
D. Cell - the most basic microscopic unit of structure and function of all living things. Robert Hooke - Micrographia (1665) British natural philosopher coined the term cella which means small room. Note: a cell contains DNA and RNA! E. Organism - any individual living thing composed of one cell or more. F. Microorganism - any microscopic living organism G. Microbe - a microscopic medically significant organism H.Pathogen – any disease causing organism includes, parasites, fungi, bacteria and viruses. I. Germ – (colloquial) disease causing organism.
J. Etiological agent - disease causing microbe usually in reference to a virus. K. Etiology - the microbial cause or origin of any disease L. Virulence - the degree of pathogenicity which varies depending on the strain of microbe. M. Parasite - any organism that lives upon or within another organism at whose expense it gains some advantage. N. Virus - Latin term for poison refers to a non-living infectious agent. Contains either DNA or RNA, never both! Obligate Intracellular Molecular Parasites
O. strains (see pg. 234) - microbes that belong to the same species but are further subdivided based on unique chemicals found either on the cell surface, or being secreted as exotoxins. For example, there is a difference between the type of toxin produced by the strain of E.coli in the U.S., and the strain found in water in Mexico!
The Importance of Microbes 1 Maintain fertility and texture of the soil
The Importance of Microbes 2 Clean up dead organic material.
The Importance of Microbes 3 Absorb heat and light in the oceans influencing life and the weather. Also absorb carbon modifying greenhouse gas effects. GAsp08
The Importance of Microbes 4 Form the basis for the oceanic food/energy chain.
The Importance of Microbes 5 Fix atmospheric gaseous nitrogen into the soil in forms that can be used. (NH 3 NO 2, NO 3 )
The Importance of Microbes 6 Modify the atmosphere with various gas production. (ex. Methane)
The Importance of Microbes 7 Can extract minerals from ore.
I. Five Kingdoms of Life (note: viruses are not included!) See chart on page 237. A. Taxonomy - system of classification which forms the basis for studying evolutionary relationships. B. Carolus Linneaus – (Swedish botanist) developed system called BINOMIAL NOMENCLATURE for naming organisms (1735). K,P C, O, F, G, S Plant and Animal Kingdoms only at first. Used Latin names. Ex. Homo sapiens (genus) (species). Eventually the microscopic world was classified in the late 1800s. Ex. Escherichia coli (E.coli) (Genus) (Species). Discovered in 1890 by Dr. Theodor Escherich. coli - found in the colon of animals..
C.Five Kingdom System ( Whitaker). 1.Kingdom Prokaryotae (or Monera) a.k.a. BACTERIA! a. false-nucleus - no membrane around the DNA. No cell organelles. b. Average 1.0 micrometer in size c.Rigid cell wall made of peptidoglycan d.Reproduce by binary fission. e.3.9 – 4.0 billion years old
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Note: THE EUKARYOTIC KINGDOMS: ALL HAVE A TRUE NUCLEUS!! (see pg 95) 2. Kingdom Protista - (protozoans) a.Contains a true nucleus, membranous organelles, ex. mitochondria, endoplasmic reticulum, Golgi apparatus, vacuoles etc. Compartmentalized processes. The only single celled euks! (See the virtual cell at the web address below) b.Reproduce by mitosis. c.Ex. Amoeba, paramecium, algae, etc. (average 10 micrometers in size) d. ~ billion years old. The first euks! e. The mitochondria in eukaryotes is very similar to a bacteria in size and function. Theory of Endosymbiosis. f. People who study protists are called protozoologists.
Protozoa photos Euglena Amoeba Paramecium
g.Medically significant protozoans: 1. Giardia lamblia – chronic diarrhea 2. Plasmodium vivax – malaria 3. Trichomonas vaginalis – vaginosis in females and urethritis in males.
3. Kindgom Fungi a. People who study fungi are called mycologists b. Multicellular eukaryotes c. Note: the prefix myco = fungi d.Ex. Yeast: Candida albicans microscopic fungi causes vaginosis, or thrus e.Ex. Mushrooms - often edible macroscopic fungi. f.Molds – such as Aspergillis flavus
Fungi Photos Slime mold Yeast
4. Kingdom Plantae - (botany/botanist) a.Photosynthetic – the only non-disease causing euks! b.Cells with cell walls c.Primarily multicellular eukaryotes d.Provide oxygen and glucose to us via photosynthesis! Ex. Green algae 5. Kingdom Animalia - (zoology/zoologist) a. Life stages: eggs, larvae and adult. b. all multicellular euks with no cell wall. c.organ systems d.Flatworms, hookworms, roundworms, and tapeworms studied in Parasitiology.
III. Major Groups of Bacteria - DNA sequencing will change prokaryotic taxonomy. Pgs show the latest systems of taxonomic classification. A simpler version consists of 8 groups. A. Eubacteria - true bacteria. There are roughly 2000 genera of bacteria, 1600 are eubacteria. Most have peptidoglycan in their cell wall, stain easily and feed on dead cells. Ex. E.coli
Streptococcus GA F 08
B.Spirochetes – 1. Flexible cell walls 2. Spring and coil locomotion 3.Ex. Treponema pallidum – syphilis 4.Ex. Borelia burgdorferi – Lymes disease C. Actinomycetes – ray or beam – fungus fungus- like bacteria filamentous appearance microscopically. Mycobacteria tuberculosis causes tuberculosis, and Mycobacteria leprae - leprosy. Streptomyces – soil bacteria used to make antibiotics
Spirochetes – Flexible and coil-springlike. Spirochetes
Actinomycetes – filimentous with fungus like characteristics Actinomycetes
D. Rickettsia - Virus-like bacteria Infect cells lining the capillaries (intracellular). Transmitted by insects (arthropods). Defective bacteria - leaky plasma membranes, very small micrometers. Ex. Rocky Mountain Spotted Fever, typhus, Q fever. E. Chlamydia - virus-like (intracellular) Spread from one human to the next. Very small: micrometers. Defective bacteria - cant make their own ATP. Complicated reproductive cycle. Diseases: blindness, urethritis, and pneumonia. sp08
F. Mycoplasma - Sometimes form long strands that resemble fungi in microscopic appearance. No cell walls - instead contains sterols. Ameboid locomotion - disease: walking pneumonia The smallest bacteria micrometers
G.Cyanobacteria, Photosynthetic, formerly blue- green algae. 2 H 2 O + CO 2 + sunlight CH 2 O + H 2 O + O 2 Formed O 2 in the earths atmosphere. Important nitrogen- fixers. 3.9 billion year old fossils in Australia.
Cyanobacteria Cyanobacteria bloom
H. Archaeobacteria - Discovered in 1977 by Carl Woese. Primitive bacteria, Grow in range of environmental conditions. Eukaryotic-like cell wall and reproductive enzymes. Thermoacidophiles - live at 105 C, low pH, found in geysers, vents in the ocean floor and Antartica. Halophiles - live in extreme salinity (high salt concentration above 10%). Methanogens - convert waste water into methane. Used in waste water management Related to oldest protocells found in fossils of Greenland? ~3.9 billion yrs. old. Many bacteriologists consider them a separate kingdom due to an unusual RNA sequences. GA
Archaeobacteria Thermophiles growing in Yellowstone hot springs.
Life on Mars? Magnified view of objects in Martian meteorite found in Antarctica. (Archaeobacteria like?)
IV. The Scope of Microbiology A. Medical micro - infectious disease diagnosis and treatment. There are roughly 2000 species of bacteria. Only ~ 200 are pathogenic. B. Ecological - most bacteria live in soil and water. They form the basis of our food chain. Bacteria recycle: 1. Nitrogen - found in DNA, RNA and the plasma membrane of animals and protein 2. Sulfur - found in 2 of 20 amino acids. (Amino acids are the building blocks for proteins).
3. Carbon - found in all living things. 4. Oxygen - found in the atmosphere and vital for making ATP. C. Evolutionary - bacteria are considered the first living things on our planet. Their role has been to regulate the number of all species on the planet. The oldest bacteria are thought to be ~3.9 billion years old. The earths crust is thought to be ~4.0 billion years old.
D. FOOD MICRO Bacteria and/or yeast are fermented for: 1. Alcohol - beer and wine industry 2. Bread 3. Vinegar, pickles and sauerkraut 4. Cheese 5. Yogurt
E. BIOTECHNOLOGY 1. Agriculture - used to control crop insects. 2. Bioremediation - a field of environmental biotechnology where bacteria are used to clean up toxic wastes. Ex. Oil spills. 3. Pharmacology - developing anti- microbics (antibiotics and other chemotherapeutic substances) to destroy pathogens. 4. Vaccines - developing weakened strains of pathogenic bacteria or viruses in order to protect (immunize) against infection. 5. Snow for ski resorts (artificial)
6. Forensics - analyzing DNA left as evidence in criminal investigations (PCR test). 7. Genetic engineering - transfer of genes (DNA) from one organism to another 8. Bioinformatics - the application of computer information science to complex biological problems (genomics, proteomics, glycomics) ex. at Stowers Institute in K.C.!
V. History of Microbiology A.Antony van Leeuwenhoek – , Dutch, The father of microbiology. The first to draw bacterial morphology (shapes) as seen with a microscope in 1600.
–Robert Hooke , - Devised the compound microscope. Published micrographia which included drawings of cork undermagnification. He coined term cells.
–Louis Pasteur , (French), helped to disprove spontaneous generation and developed vaccines for anthrax and rabies, The father of modern microbiology.
–Robert Joseph Lister , (British), famous surgeon who used carbolic acid to sterilize surgical tools and dressings Carbolic Acid Sprayer in Surgery
E.Robert Koch (German) proved the germ theory of disease by developing Kochs Postulates. Discovered the etiology of anthrax, cholera and tuberculosis F.Theobald Smith (American) 1880s originated the insect vector concept (Texas Cattle Fever), invented the fermentation tube, diphtheriae vaccine (serum sickness, toxin-antitoxin combination), & discovered the Salmonella. Father of American microbiology.
F. Kochs Postulates - p Isolate - bacteria from diseased host fluids. Streak Plate (p 160) technique to observe bacterial colonies on nutrient agar, and cell shape under the microscope. In vitro. 2.Propagate - growth large amounts of isolated microbe in nutrient media. In vitro. 3.Inoculate - suitable healthy animal host with isolated suspected pathogen. Reproduce the original disease symptoms. In vivo. 4.Reisolate – repeat step 1. In vitro. Ga f 08
5. Koch discovered the etiology of: a) Cholera; Vibrio cholerae b) Tuberculosis; Mycobacteria tuberculosis c) Anthrax; Bacillus anthracis
VI. Anatomy of Prokaryotes Chap. 4 I. Morphology - the study of cell shape and structure. 3 types of basic bacterial cell morphology. p. 79 A. Coccus - sphere shape. (common types of cocci arrangements.) all non-motile 1.Diplococci - ex. Streptococcus pneumoniae. #1 killer in U.S. by bacteria. 2.Tetrads – packets of 4 3.Sarcina – cube shaped 4.Streptococci – chains (Streptococcus pyogenes - strep throat) (Streptococcus mutans – cavities) 5.Staphylococci – irregular clusters or clumps, ex. Staphylococcus aureus (skin infxn./bedsores)
Morphology and plane of cell division
Sarcinia lutea (16,000X)
B. Bacillus - rod shape (3 arrangements) usually motile. 1. Streptobacilli – chains, ex. Bacillus anthracis 2. Palisade – hinged, ex. Corynebacterium diphtheriae 3.Filamentous – Mycobacteria tuberculosis.
C. Curved Forms - (3 types) always motile (see pg ) 1.Vibros - Comma shape - ex. Vibrio cholerae (cholera) 2.Spirilla- Rigid spiral - ex. Spirillum minus (rat bite fever) 3.Spirochetes -Flexible spiral - spring and coil ex. Treponema pallidum the cause of syphilis.
Generalized Bacterial Cell Flagella Ribosome (small granular) Cytoplasm Fimbriae Or Pili Plasma membrane Cell Wall Capsule (on some) Nucleoid
II. STRUCTURE OF PROKARYOTES A. Flagella (java applet of euk. motion),(motion of prok. Flagella), (types of prok. Motion) (java applet of euk. motion)(motion of prok. Flagella)(types of prok. Motion) 1. Structure - composed of a protein called flagelin. Has 3 parts, the basal body, hook and filament. P Function: MOTILITY (2 varieties) a. Chemotaxis - chemical attraction and movement to nutrients b. Phototaxis - attraction to light. Brownian Motion – Random motion of microscopic objects due to the random collisions of molecules in the environment. java appletjava applet
Structure of Two Different Bacterial Flagella Gram-negative bacteriumGram-positive bacterium
3. Flagella in bacteria rotate like a propeller. Flagella in eukaryotic cells (found in Kingdoms Protista, Plantae, Fungi and Animalia) undulate. B. Fimbriae - (or Pili) 1. Smaller than flagella, used for specific attachment to host tissues. Not for motility. 2. Sex Pili – p. 93 number fewer than 10 per cell. They elongate during conjugation and function as genetic transfer mechanisms.
C. CAPSULE 1.An outer thick polysaccharide coating that prevents phagocytosis. 2.Forms only when plenty of nutrients are available. Very few bacteria have capsules. 3.Pathogenic ex. Streptococcus pneumoniae, Strep. mutans, Neisseria meningitidis, Bordetella pertussis. 4.Bacillus anthracis forms a rare protein (D-glutamic acid) capsule.
D. CELL WALL 1. Provides shape and prevents lysis. 2 general types of cell walls. a. Gram + (pg 83-84) 1. Violet in Gram Stain 2. Chemical composition: N- Acetylmurmamic acid (NAM) and N-acetylglucosamine (NAG) sugar backbone. 3. L-lys & D-ala. amino acids (polypeptide glycine bridge). 4. Polypeptides and sugar make up 70% of the Gram + cell wall (peptidoglycan) 5. Resistant to Ethyl Alcohol, sensitive to penicillin and lysozyme.
b. Gram - 1. Red in Gram Stains. 2. More complicated than Gram + 3. Chemical composition: Outer lipopolysaccharide surface contains various O polysaccharide antigens 4. Outer membrane mostly phospholipids. 5. Thin Peptidoglycan 20%. 6. Sensitive to ethyl alcohol, resistant to penicillin and lysozyme. 7. Lipid A is a toxic chemical for humans.
Phospholipid Structure glycerol
Phospholipids Lipid A Porin (channel for small molecule passage). Antigenic O polysaccharide chains
E.Plasma (Cytoplasmic) Membrane p Functions: a. Encloses cytoplasm b. Point of attachment for the DNA helps ensure binary fission. c. Place where ATP is made. d.Provides selective permeability for nutrients transported into the cell. Ex. Glucose, amino acids and triglycerides. 2.Composition: phospholipid bilayer. a.Hydrophillic head: glycerol + Phosphorus, polar b.Hydrophobic tails: fatty acids, non- polar.
The Fluid-Mosaic Model of the Membrane Structure
F. Cytoplasm - the internal matrix of The cell consisting of dissolved solutes: nucleic acids, amino acids, glycerol, fatty acids and simple sugars like glucose. Place where metabolism occurs. G. Nucleoid – (in bacteria only) a single circular macromolecule of double stranded DNA. Contains the genetic information necessary to express all the enzymes used to reproduce and maintain cell functions. GA
H. Plasmid - a separate small piece of DNA found only in bacteria that have conjugated. The genes are non-essential on the plasmid. It replicates separate from the nucleoid. Sometimes plasmids carry genes for antibiotic resistance. I. Ribosomes - small granular structures in the cytoplasm that can only be seen with an electron microscope. This is where protein synthesis takes place. Contains RNA. J. Inclusions – large granular structures in the cytoplasm used for storage of sugar or phosphate.
K. Endospores -dormant or resting cells p Function - allows 2 genus of gram + bacteria (Bacillus and Clostridium) a means of survival under extremely harsh environmental conditions. Not the same as spores found in plants or fungi.
2. ENDOSPORE RESISTANCE a.Desiccation – drying out b.Toxic chemicals except hydrogen peroxide and ethylene oxide c.Antibiotics d.Most forms of radiation e.Boiling in water for one hour.
3. STERILIZATION Problems with endospores A.All surgical instruments must be sterilized due to possible endospore contamination. B.Autoclave is steam heat at 120 degrees Celsius for 20 minutes. 15 lbs pressure C.Chemiclave is with ethylene oxide used to sterilize pacemakers and other heat sensitive materials.
4. ENDOSPORE CHEMICAL COMPOSITION a.Calcium dipicolinate coats and seals the peptidoglycan.
5. ENDOSPORE LIFE CYCLE a.Sporogenesis – the process of generating an endospore inside Clostridium or Bacillus. b.Sporulation – the release of the endospore from Clostridium or Bacillus bacterium. c.Germination – the return to the active vegetative state of bacteria when normal conditions exist. Oldest germinating spore was claimed to be 250 million years.
6. TWO MEDICALLY SIGNIFICANT SPORE PRODUCING GENERA a.Clostridium – an anaerobic bacteria. Germinates only in absence of oxygen as in necrotic tissue. 3 major diseases causing species: C. tetani (tetanus), C. perfringens (gas gangrene), and C. botulinum (botulism). b.Bacillus is an aerobic endospore forming bacteria. B. cereus – gastroenteritis, and B. anthracis – anthrax in sheep and cattle.
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