microbiology test one

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microbiology test one
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  1. What is Microbiology?
    -Microbiology is the study of one celled microscopic organisms that you cannot see with the naked eye

    -Bacteria, algae, fungi and viruses that can not be scene with the naked eye.
  2. What is a prokaryote?
    dna organized in a single chromosome. No nucleus. No mitosis
  3. What is a eukaryote?
    Sna organized in multiple chromosomes inside a nucleus. Mitotic division.
  4. Examples of eucaryotic
    • protozoa
    • fungi
    • slime molds
    • algae
  5. Two Distinct Cell Types Prokaryotes and Eukaryotes
    These microscopic organisms are divided into two groups based on cell structure

    • Eukaryotes (also spelled eucaryotes) –"eu" = true, + "caryos" = nucleus
    • –Protista

    Prokaryotes (also spelled procaryotes) –"pro" = before, + ”caryos" = nucleus –Lower Protista –bacteria
  6. Eucaryotic: Cytoplasmic Structure
    • Endoplasmic Reticulum:System of large sacs and smaller tubes responsible for macromolecular p transport
    • –Smooth ER: W/O ribosomes, involved with lipid and steroid synthesis.
    • –Rough ER: W ribosomes, involved in protein synthesis
  7. Eucaryotic: Surface Layers
    Cell membrane: Complex lipoprotein structure

    Cell wall: Rigid/ Mod rigid polysaccaride structure
  8. Eucaryotic: Cytoplasmic Structure
    Mitochondria:Production of ATP and aerobic metabolism, animal cells.

    Chloroplasts:Contain pigments and enzymes used in photosynthesis
  9. Eucaryotic: Nucleus
    Well-defined surrounded by nuclear membrane

    Control center for growth and development

    Contains chromosomes, rna, nuclear membrane continuous with er
  10. Eucaryotic: Cytoplasmic Structure
    Ribosomes: Responsible for protein synthesis

    Lysosomes: Responsible metabolism of ingested organic material
  11. Eucaryotic: Cytoplasmic Structure
    Plasmid: Circular DNA form chromosome that may confer antibiotic resistance (bacteria’s ability to produce toxins)

    Mesosomes:
  12. Eucaryotic: Motility Organelles
    Cilia: –Move in coordinated waves –Numerous on cell exterior

    Flagella: –Singular or present in small numbers –Move in undulating motion –Longer than cilia
  13. Algae
    Eucaryotic
  14. Fungi
    Eucaryotic
  15. Eucaryotes Review
    • More advanced
    • Reproduce by mitosis
    • Have a nucleus and cell membrane
    • Contain membrane bound large organelles (mitochondria, lysosomes, ribosomes, etc.)
    • sizes - 5 micrometers to 100 micrometers
  16. PROCARYOTIC EXAMPLES
    • Blue green algae
    • bacteria
    • rickettsiae
    • mycoplasma
  17. Slime mold
    Eucaryotic
  18. Procaryotic: Surface Layers
    • Capsule or Slime Layer –Outer most layer surrounding the outside of cell produced by the cell itself –common in pathogenicorganisms pathogenic organisms
    • If clearly detectable called a capsule, if not called a SLIME LAYER
    • Contributes to a organisms to cause disease by inhibiting the ability of host phagocytosis cells to engulf the organism. (may or may not)
  19. Procaryotics
    • "pro" = before, + "karyos" = nucleus
    • Nucleoid region with one long circular DNA
    • Simple architecture not understood until EM technology in 1940's
    • Typical sizes: 1 u m diameter = 1 micron = 10^-3 mm
  20. Procaryotic:Surface Layers Capsule Function
    • Varies widely to density, thickness and chemical composition
    • Prevents virus attachment
    • Functions as external nutrient storage
    • Prevents phagocytosis
    • In pnemococcal organism the capsule is antigenic, induces the synthesis of specific antibodies, which can be used for identification in the lab
  21. Procaryotic:Surface Layers Capsule Function
    • Not all bacteria have them
    • A layer outside the cell wall ahydrophilicgel of polysaccharides –a hydrophilic gel of polysaccharides
    • Total layer = capsule
    • Partial enclosure = slime layer
  22. Procaryotic:Surface Layers Capsule Function
    • Help protect the bacteria
    • –impede digestion by leukocytes
    • –Capsulesaidincolonization Capsules aid in colonization
    • assist the cell to attach to surfaces
  23. Cell Walls
    • Cell wall: Mod rigid to very rigid
    • –Protects cell from bursting
    • –Maintain cell shape, essential to survival
    • Cell wall in gram-positive bacteria
    • –High lipid count, stainspurple/blue/violet in gram stain stain
    • –Murein network: Peptide chains attached to larger polysaccharide chains
    • Cell wall in a gram-negative bacteria, complex –stains pink/red
    • CW
    • –Inner space –Periplasmic space
    • –Middle layer –-thin peptidoglycan strong
    • –Outer layer – Lipopolysaccaride LPS
  24. Two Types of Cell Walls
    a. Gram-positive bacteria have simple, thick cell walls. Their cell walls are composed of a relatively large amount of peptidoglycan.

    b. Gram-negative bacteria have less peptidoglycan and are more complex. They have a peptidoglycan layer surrounded by the plasma membrane and an outer membrane.

    -Gram-negative bacteria are typically more resistant to host immune defenses and antibiotics.
  25. Gram-Positive Bacteria
    • Gram-Positive Bacteria
    • -Broad, diverse group
    • -Antibiotic producing bacteria are in this group -Example shown is Streptomyces (streptomycin) -And (next slide)
  26. Mycoplasma
    Gram positive bacteria

    Mycoplasma shown covering a human cell; some species of mycoplasmas cause walking pneumonia
  27. Gram-negative cell wall
    Outer layer is Lipopolysaccaride

    LPS is responsible for severe symptoms gram-negative infection such as vascular collapse, hemorrhage, shock, and leukopenia.

    Because of these effects LPS is often known as endotoxin.
  28. Procaryotic: Surface Layers
    Cell Wall –Mycoplasma is the only bacteria that does not have a cell wall.

    For this reason mycoplasma is sensitive to environment and must require special conditions for growth in the laboratory.

    Cell wall provides an ideal selective target for antibiotics. Inhibit cell wall synthesis. Membrane ruptures -dies
  29. Procaryotic: Cytoplasmic Structures
    • ER is absent
    • Mitochondria are absent
    • Chloropolasts and lysosomes are absent
    • Mesosomes –Found in cell membrane and allow for attachment of DNA in cell division (found mostly in gram positive bacteria)
  30. Procaryotic Nucleus
    Nucleus

    No distinct nucleus

    • Cell may contain one or more regions of nuclear material called nucleoids
    • No mitosis apparatus
    • Chromosomes exist freely in cytoplasma – may be circular or attach to cell membrane
  31. Procaryotic: Cytoplasmic Structures
    • 80% water
    • Proteins, lipids, carbohydrates, nucleic acids electrolytesandenzymes acids, electrolytes and enzymes.
    • Ribosomes –slightly smaller than eucaryotic Concentration of molecules is very high – this results in a high osmotic pressure
  32. Procaryotes Reproduction
    REPRODUCE BY BINARY FISSION
  33. Procaryotes Reproduction
    Prokaryotes grow and adapt rapidly-The doubling time for E. coliis 20 minutes. Start with one E. colicell. After 48 hours of doubling every 20 minutes, the mass of E. coliwould be 10,000 times the mass of the earth.

    • Bacteria do not have gene transfer by sexual reproduction, but do transfer genes. Why? This is an aid in adapting (evolving). 1. Three (3) ways for genes to be transferred between cells:
    • a. Transformation–cell takes up genes from the surrounding environment.
    • b. Conjugation–direct transfer of genes from one prokaryote to another. Use the sex pilus to conjugate.
    • c. Transduction–viruses transfer genes between prokaryotes.
  34. Procaryotic: Motility Organelles
    • Many prokaryotes are motile
    • -Some exceed speeds 100 times their body length per second.
    • Modes of movement –Note the three types:
    • a. Flagellum-basal apparatus rotates the flagellum and propels the cell
    • b. Corkscrew movement of spirochetes (helical)
    • c. Some prokaryotes glide over jets of slimy secretions.

    Many prokaryotes move toward or away from a stimulus = taxis. Chemotaxisis the movement toward or away from a chemical.
  35. Procaryotic: Bacterial Endospores
    • Aerobic Bacillus, Clostridium, Sporosarcina
    • Intermediate form of the organism that develops in response to adverse environmental conditions environmental conditions
    • Regenerate to a vegetative cell when conditions improve.
    • Resist dryness, heat and poor nutrition
    • Function as a protective coat around nucleic material
  36. How abundant are microbes?
    • Note: surprising answer: we are not used to realities we cannot see.
    • ubiquitous and prolific
    • most common in soils, esp. where any potential food.
    • Also in water and air
  37. Why is microbiology important?
    • Disease. –Since discovery of infectious microbes, much time effort and resources spent fighting and preventinginfectiousdiseases preventing infectious diseases . controlled by sanitation, preventive medicine,
    • Agriculture. –microbes vital in processing materials in soil, e.g. nitrogen, sulfur, etc.
  38. Where are microbes not found?
    Only inside tissues of organisms, kept at bay by defensive mechanisms.
  39. Even so, challenges common (cut finger, get infected).
  40. What do microbes do?
    • Microbial "behavior" is very simple:
    • EAT, GROW, AND DIVIDE.
    • Growth rates can be phenomenally
    • fast:
    • –e.g. some bacteria can reproduce double every 20 min. under optimal conditions.
  41. Food and drink.
    • Microbial fermentation responsible for
    • –alcoholic beverages, breads, pickles, cheeses, etc.
    • –Control of food and drink spoilage is major concern of food industry.
  42. Chemical products.
    Microbes have incredible variety of metabolic tricks; – used to produce acetone and other commercial solvents, pharmaceuticals, antibiotics, preservatives, etc.
  43. Biotechnology.
    • Genetic engineering
    • Ability to move genes freely from one organism to another
    • Select genes of interest and amplify their expression.
    • Bacteria are natural hosts for such activities.
  44. Size micrometers
    • Mycoplasma 0.4 um
    • Haemophilus influenza 1.2 um
    • Staphylococcus aureus 0.9 um
    • E coli 1.5 um
    • Bacillus Megaterium 4 um
    • red blood cell um
  45. Classify First by Shape
    • SHAPE under microscope
    • FIVE BASIC SHAPES
    • • COCCI -spherical shape
    • • BACILLI -rod shaped
    • • VIBRIOS -comma
    • • SPIRILLUM –spiral
    • • FUSIFORM -spindle
  46. Gram + Bacillus Anthracis
    • GRAM POSITIVE
    • SECRETES EXOTOXINS
    • SPORE FORMER
    • Causes skin infections
    • Septicemia
    • Meningitis
    • Pneumonia
  47. Gram + clostridium botulinum
    • Rod shaped, pairs
    • Gram positive
    • Anaerobe
    • Spore Former
    • Secretes exotoxins It causes a toxic food poisoning knows a botulism
  48. Source of clostridium botulinum
    • FOUND IN SOIL
    • FECES
    • POORLY CANNED OR PRESERVED FOODS
  49. Method of transmission of Clostridium botulinum
    Ingestion or puncure wounds
  50. Clinical presentation of Clostridium botulinus infection
    • TOXINS ARE INGESTED FROM CONTAMINATED FOOD
    • ◦ canned foods vegetables, fish, fruits

    • SYMPTOMS ARE ABRUPT 18 TO 36 HOURS AFTER INGESTION
    • ◦ Nausea , vomiting , abdominal cramps, diarrhea

    • Frequently precede neurologic symptoms
    • DESCENDING WEAKNESSAND PARALYSIS
  51. Gram + Clostridium Tetani
    • Produces tetanus
    • Rod shapped in pairs
    • Spore formiing
    • DESCENDING WEAKNESS AND PARALYSIS
  52. Gram + Streptococcus pneumoniae
    • Gram positive
    • cocci
    • in pairs diplo and chains
    • may produce capsules
    • aerobic bacteria
    • commonly found in the nasopharynx
  53. Method of transmission of Streptococcus pneumoniae
    • Touch
    • Airborne route

    The leading cause of Community acquired pneumonia
  54. Clinical presentation of streprococcus pneumoniae
    • BEGINS WITH SORE THROAT, LARYNGITIS
    • TRACHEOBRONCHITIS SPREADS DOWN WARDVIABRONCHI LOBAR WARD VIA BRONCHI -LOBAR
    • ALVEOLAR INVOLVEMENT
    • CONSOLIDATION
    • possible pleural effusion
  55. Gram + Staphylococcus aureus
    • Gram pos cocci
    • seen in grape like clusters
    • aerobic
    • Facultative anaerobe
    • Cuases pneumonia, empyema and wound infections
  56. Source of staphylococcus aureus
    Found as normal flora on skin
  57. Method of transmission of staphylococcus aureus
    • touch
    • contact with contaminated articles
  58. Discuss the types of infections caused by staphylococcus aureus
    • Causes pimples, boils, wound infections
    • pneumonia
  59. Pseudomonas aeruginosa
    • A GRAM NEGATIVE ROD
    • AN OPPORTUNIST
    • Cause 10% HAP infections
  60. Pseudomonas aeruginosa
    • water loving
    • contaminates respiratory equipment
    • pulmonary infections
    • bronchitis and pnewmonia
    • smelly green sputum
  61. Natural source of pseudomonas aeruginosa
    Soil, water, skin, gi tract
  62. method of transmission of pseudomonas aeruginosa.
    • poor hand washing
    • direct contact with contaminated equipment
  63. Clinical population most likely to get an infection caused by Pseudomonas aeruginosa
    • Hospital population
    • RESPONSIBLE FOR NOSOCOMIAL INFECTIONS
    • AN OPPORTUNIST WEAKENED HOST
  64. Serratia marcescens
    • Gram neg rod
    • aerobic
    • water loving, infect rt equipment
  65. Natural source of serratia marcescens
    widely distrubution in nature
  66. method of transmission of serratia marcescens
    • poor handwashing
    • direct contact with contamintated equipment
  67. what population does serratia marcescens infect
    • hospital population
    • responsible for nosocomial infections
    • an opportunist weakened host
  68. Escheichia coli
    • Gram negative rod
    • facultative anaerobie
    • responsible for 45% of all HA infections
  69. source or location of escherichia coli
    feces
  70. transmission of escherichia coli
    poor handwashing
  71. types of infections caused by eschericia coli
    • necroritizing
    • pneumonia
    • wounds
    • uti
    • septicemia
  72. haemophilus influenza
    • gram negative rod
    • normal flora in upper respiratory tract
    • most common cause of epiglottis in children
    • also causes croup
  73. classify bordetella pertussis
    • Gram negative bacillus
    • responsible for whooping cough
    • Transmitted by contact with respiratory tract secretions
  74. Mycobacterium tuberculosis
    • Acid fast, gram + bacillus rods
    • aerobic
  75. Transmission of mycobacterium tuberculosis
    • airborne
    • droplet nucleus
  76. Mycoplasma
    • smallest bacteria
    • gram negative
    • three later membrane
    • no cell wall
    • most common type of atypical pneumonia
  77. how do fungi infect man?
    • spores
    • direct skin penetration
    • athletes foot
  78. fungus pulmonary infection
    • they form spores, and release them into the air
    • they are very tiny and stay in the air for a long time
    • man gets infected by inhaling the fungal spores into the lungs
    • some spores are normal flora
  79. fungal example histomplasmosis
    • Caused by fungi hostoplasma capsulatum
    • found in most countries
    • ENDEMIC IN OHIO AND MISSISSIPPI VALLEYS
    • 50% OF THE PEOPLE IN THESE REGIONS TEST POSITIVE FOR SKIN TEST
    • EFFECTS MOSTLY INFANTS AND ELDERLY
  80. fungus
    blastomycosis
    coccidiomycosis
    Blastomycosis– –Mild self limiting disease

    Respiratory infection may cause pneumonia, pleural effusion and lymph node enlargement.

    Coccidiomycosis – –Three types Three types One mild, one multi -system and one system and one progressive pulmonary
  81. fungus Source and method of infection
    • soil contaminated by droppings of chickens birds and bats
    • inhalation of spores
    • results in lesions in the lungs hilar nodules
    • granulomas, caseation, necrosis
  82. fungus systemic infection
    • can disseminate into other body tissues as well
    • causes multi organ disorders including meningitis
  83. fungus treatment
    amphotericin b
  84. candida albicans
    • is horman in humans
    • found in upper respiratory tract
    • gastrotesitnal
  85. protozoan pathogens
    • pneumocystis carinii
    • yeast like fungus that is protozoan
    • rarely problematic - in most it lies dormant
    • aids or immunocompromised host
    • clinically - abrupt fever, tachypnea, hypoxia, and cyanosis
    • cause alveolar wall thickness
    • Treatment - pentamidine
  86. May becomes pathongenc
    • When patient is immunosupressed
    • Excessive antibiotic therapy
    • steroid therapy
    • aerosolised steroids

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