Test 4

  1. Selective Toxicity
    Want drugs that harm the microbe, not the human host
  2. General sequence of events for disease pathogenesis
    • portals of entry
    • adherence infection and growth
    • penetration of host
    • damage of host cell
    • portals of exits
  3. ID50
    infectious dose # of microbes needed to cause infection in 50% exposed
  4. Virulence factors
    Characteristics that allow a microbe to cause disease
  5. Route of infection (Most common)
    • Penetration of mucous membrane
    • Penetration of the skin
  6. What are adhesions where are they found abd what are they used for?
    Alow microbes bind to specific cell types. Bind receptors naturally found on certin cells
  7. Straregies to evade host defenses and example organisms
    • Hiding within host cell
    • evasion of complement
    • evasion of phagocyotsis
    • avoiding Abs
    • exoenzymes
    • AG variation
  8. How do Microbes cause disease? AKA mechanisma of pathogenicity
    using host nutrients, direct damage by invasion. producing toxins, inducing hypersensitivity reactions
  9. LD50
    Lethal dose for 50% exposed - A messurement to compare potency of different toxins
  10. Define endotoxin
    Are part of the outer portion of the cell wall G- bacteria only liberated when bacteria dies
  11. (exotoxins)
    A-B toxins
    • Host target tissue is the nervous system
    • Result paralisis
    • Ex. Batululinum toxin blocks transmisson to muscle
  12. (exotoxins)
    Membrane- damaging toxins
    • Toxins that forms in the cell membrane
    • host target tissue: cell membrane phospholipids
    • Results unstable host cell membrane cell lysis
    • Ex. C. difficile
  13. (exotoxins)
    • Targets T cell receptors
    • results Triggers massive cytokine release too much information
    • Ex. Staphylcoccus TSST
  14. DIC disseminated intravascular clotting
    can block small capillaries
  15. Sterile sites in the body
    Blood, CSF, Bladder, muscle, solid tissue, lungs
  16. Pathology
    scientific study of disease
  17. Pathogenesis
    describes how a disease develops; how a microbe causes disease
  18. Virulence
    the degree to which a microbe can cause disease
  19. Etiology
    Cause of disease
  20. Primary infection
    cause disease in anyone heathy person
  21. Secondary infection
    weakend form prior infection like bronchities
  22. Opportunistic pathogen
    weaker pathogen causes disease in a weak host
  23. Immunocomprimised hosts
    HIV positive, cancer pts, Chrones illness, malnurished
  24. Infection
    Is the invasion or colonization of the body by pathogenic microorganisms.
  25. Diease
    occurs when an infection results in any change from a state of health
  26. Duration of disease: Acute
    develops rapidly lasts a short while - influenza
  27. Duration of diseaese: chronic
    develops slowly body reaction less severe continue for a long time
  28. Duration of disease: latent
    • remains inactive for some time then becomes active produce symptoms of disease
    • ex shingles
  29. Disease carriers
    Carry the diesase but show no symptoms
  30. Sepsis
    Toxic inflammatory condition arising from the spread of microbes
  31. Bacteremia
    presence of bacteria in the blood
  32. Viremia
    presence of viruses in the blood
  33. Toxemia
    presence of toxin in the blood
  34. Septicemia
    blood posioning, multiple pathogens in the blood
  35. Disease progression
    • Incubation period
    • Prodromal period
    • Period of illness
    • Period of decline
    • Period of convalescence (recovery)
  36. Disease reservoirs
    Humans, water, Animals, enviornment
  37. Zoonoses (zoonotic disease)
    • Animal to human
    • Ex: boubonic pleague - rats
  38. How can diseases be transmitted?
    • Contact transmission (direct or indirect)
    • Droplet
    • Vehicle Transmission (one sorce infects many people)
    • Waterborne
    • Foodborne
    • Airborne
    • Vector (insects)
  39. What is a fomite?
    An object that can spread disease
  40. Mechanical Vector
    Microbe carried on the surface of the insect
  41. Biological Vector
    Microbe replicates with in the insect
  42. What is a nosocomial infection?
    • Hospital aquired infection
    • EX: most common UTIs
  43. Give examples of sources of organisms for nosocomial infections
    • Misplaced own flora
    • Hospital enviornment
    • Health care workers
  44. What is an emerging infectious disease(EID)? Factors?
    • Disease that has an increased number of infections over the past 20 years
    • EX: Avian flu (H5N7), Swine flu (H1N1)
    • Climate fluctuations and changes
  45. Morbidity
    Number od disease causes
  46. Mortality
    number of deaths from a specific disease
  47. Incidence
    Number of new infections in a certin time period
  48. Prevalence
    Number of people sick with a disease (new and ongoing) in a time frame
  49. Endemic
    Always present in a population
  50. Epidemic
    Sudden increase of disease in one population
  51. Pandemic
    World wide
  52. Types of epidemiological studies
  53. Types of epidemiological studies Analytical
    Analyzes diease treands or outbreaks.
  54. Types of epidemiological studies Experimental
    Tests a Hypothesis
  55. Types of epidemiological studies case reporting
    Reports specifi cases of disease outbreak
  56. Drug synergism
    enhance benifit to pt
  57. Antibiotic drug combo
    • Augmentin- Amoxi and Clavulanic acid
    • TMP-SMZ- Tri meth Sulfa
  58. What mechanisms can bacteria use to become resistant to antibiotics?
    • Inactivation- cleaves beta lactam
    • Alteration of target site- durg no longer binds
    • Decrease uptake of drug - blocks entry
    • Increased elimination of drug - efflux pumps
  59. How does antibiotic resistance spread between bacteria?
    Sharing of plasmids, Transduction, Transformation
  60. What are the 5 targets in the cell for Antibiotics to attack?
    • Inhibit cell wall synthesis (Peptidoglycan)
    • Inhibit protein synthesis (ribosome death)
    • Injure plasma membrane (polymixin B)
    • Inhibit nucleic acid synthesis
    • Inhibits synthesis of essential metabolites (folic acid)
  61. What antibiotics does triple antibiotic ointment contain? Targets?
    • Bacitracin (attacks synthesis of cell wall)
    • Polymyxin B (injures plasma membrane)
    • Neomycin (blocks protein synthesis)
  62. Antibiotics that inhibit the cell wall synthesis
    • Amoxicillin
    • Penicillin
    • Ampicillin
    • Methicillin
    • Augmentin
    • Vancomycin - treat MRSA only G+
  63. Antibiotics that inhibit protein synthesis
    • Streptomycin- TB
    • Tetracycline (doxy)
    • Ethromycin (used if Pts are allergic to penicillin)
  64. Antibiotics that injure plasma membrane
    Polymyxin B (Topical)
  65. Antibiotics that inhibit nucleic acid synthesis
    • Rifampin
    • Ciprofloxacin
  66. Antibiotics that inhibit the synthesis of essential metabolites (folic acid)
    TMP-SMZ trimethoprim sulfamethoxazole
  67. Antifungals that target the plasma membrane. (ergosterol)
    • Amphotericin B
    • Miconazole
    • Fluconazole
  68. Antivirals that are Nucleoside/ Nucleotide analogs
    • Acyclovir- treats herpes/ shingles
    • AZT- treats HIV
  69. Antivirals that inhibit Viral enzymes (make no more)
    • Tamiflu
    • Amantadine and Rimantidine
  70. Inerferons
    Antimicrobial IFN alfa and INF beta cause cell to degrade mRNA which blocks viral replication
  71. Metronidazole
    Antiprotozoan drug interferes with anaerobic metabolism treats amoebic dysentery, giardia, and some anaerobic bacteria.
  72. Chloroquine
    Used to treat Malaria (Plasmodium)
  73. Mebendazole
    Broad spectrum antihelminth inhibits formation of microtubles in the cytoplasm which blacks absorption of nurtrients by the parasites: Trichinellosis, pinworms, roundworms
  74. Viral structure
    • Capsomere
    • capsid
    • nucleocapsid
    • nucleic acid
    • envelope
    • Virion
  75. Naked virus
    no lipid enevlope many flat sides hard to kill
  76. Enveloped virus
    Easier to kill with disinfectants, Lipid envelope
  77. What makes animal viruses unique?
    • Entry by pinocytosis or fusion
    • Uncaoting
    • Release by budding or lysis
  78. How are viruses grown in the lab?
    • Animals:
    • in cell culture
    • in embryonated eggs
    • in living animals
    • Bacteriophage:
    • in a host cell lawn
  79. Bacteriophage
    Viruses that infect bacteria
  80. Lytic life cycle
    Always a productive infection = new viruses produced

    • Attachment Via spike proteins on virus bind to specfic proteins on host cell
    • Penetration injection of DNA genome into host bacteria
    • Biosynthesis DNA and protein are produced
    • Maturation Spontaneous assembly
    • Release through cell lysis caused by the enzyme Lysozyne
  81. Latent lifecycle
    • Doesn't kill host.
    • Attachment and entry DNA intergrades into host chromosome
    • Bacteria replicates normally; non productive infection
  82. Phage conversion
    • When the phage integrates into the bacterial chromosome it brings new genes to the bacteria
    • Effect: may incode toxins
    • EX: Clasrtidium botulinum
  83. Steps in animal virus replication
    • Attachment with spike proteins
    • Entry by pinocytosis or fusion
    • Uncoating DNA is released into the host cell
    • Biosynthisis
    • Maturation
    • Release by budding or lysis
  84. Viral Duration: Acute
    • Short duration Virus is released right away
    • EX: Common cold
  85. Viral duration: Persistant
    • Virus remains in tissue
    • EX: Measeles
  86. Viral Duration: Chronic
    • Consistant virus is continually released from host
    • EX: hep B
  87. Viral Duration: Latent
    • Remains dormant in host and can reactivate later
    • EX: Herpes
  88. Antigenic drift in Influenza
    Random point mutations in the H and N genes (small changes)
  89. Antigenic shift in Influenza
    • Occurs when there is genetic recombination between 2 different influenza strains causes new epidemics
    • EX: N1H1 Swine flu
  90. 3 types of fungi
    • yest
    • mold
    • mushrooms
  91. What classifies of fungi
    Cell wall made of chitin
  92. Mycology and Mycosis
    The study of Fungi
  93. Terms that describe Mold: Thallus
    Visable fungal growth, vegetative structures
  94. Terms that describe mold: Hyphe
    Multicellular filaments
  95. Terms that describe Mold: Mycellium
    Mass of Hyphae
  96. Dimorphic fungi
    • 2 morphologies
    • Role in desease: Grows in soil as a mold but once inhaled it grows as a yest
    • EX: Pnenomia
  97. Classification of Fugi
    • Zygomycota
    • Ascomycota
    • Basidiomycota
    • Deuteromycota
  98. Sexual fungal spores
    result from the fusion of 2 nuclei from 1 (+) and 1 (-) mating strain of the same species
  99. Asexual spores
    • Make clones of the parent
    • Conidiospore not inclosed
    • Sporangiospore inclosed clusters
  100. Mycosis: Systemic
    Whole body is effected
  101. Mycosis: Subcutaneous
    • underneath the skin
    • EX: Rose gardener's disease
  102. Mycosis: Cutaneous
    • Caused by dermatophytes that make keratinase degrades protein keratin in skin and nails
    • Attacks the feet
    • EX: Athletes foot
  103. Mycosis: Opportunistic
    EX: Pneumocystis in AIDS pts
  104. Characteristics of Algae
    • Mostly aquatic living top few meters of water
    • Simple eukaryotic photoautotrophs
    • Fix CO2 into organinc carbon released as O2
  105. What is Lichen made of?
    • Algae and Fungi living in a mutualistic symbiotic realationship
    • Algae preforms photsynthesis and feeds both organisims
    • Fungi attaches both to a rock or tree and provids protection
  106. How do algae cause disease
    • Dinoflagellates/ Plankton: Alexandrim, large number of algae cause the red tide causing paralytic shellfish poisoning
    • Domic acid Intoxication: Illness due to toxin ingestion casues neurological disease in people kills marine birds and sea lions
  107. Characteristics of Protozoa
    Inhibit water and soil all are unicellular orgainisms
  108. Classification of protozoa
    By means of motility
  109. Trophozoite (protozoa)
    Growing/feeding stage
  110. Cyst (protozoa)
    Protective form, usally shed in feces.
  111. Medically important Protozoas: Archaezoa
    • 2+ flagella
    • EX: Giardia
    • Disease: Trophozoites (diarrha)
    • Transmited: fecal-oral
  112. Medically improtant Protozoas: Microspora
    • Obligate intrcellular parasites
    • Cause of chronic diarrhea in AIDS pts
  113. Medically important protozoas: Amoebozoa
    • Pseudopodia
    • EX: Entamoeba histolyitca
    • Disease: Amoebic dysentery
    • Trasmited: Fecal-oral
  114. Medically improtant protozoas: Apicomplexia
    • Non motal
    • EX: Plasmodium causes Mararia
    • EX: Toxoplasma gondi causes toxoplasmosis
    • EX: Cryptospordium causes Diarrhea
    • Transmitted: Insect
  115. Medically improtant protozoas: Cilophoria
    • Motility: Cilia
    • EX: Balantidium coli
    • Disease: dysentery
    • Transmited: fecal-oral
  116. Medically improtant protozoas: Euglenozoa
    • Motility: Flagella
    • EX: Trypanosoma cruzi causes chagas disease
    • EX Tryponosoma brucei causes africal sleeping sickness
    • Transmited: Insect bites
  117. Dioecious Helminthes
    Male and female in seperate oragnisms
  118. Monoecious Helminthes
    Male and female in 1 organism Produce large numbers of eggs that are infectious.
  119. Definitive host
    Host where the organism undergoes sexual reproduction
  120. Intermediate Host
    Host where the organism only reproduces asexually
  121. Characteristics of Helminthes
    multicellular animals free living ot parasitic have organ sysmtems have complex life cycles
  122. Plathelminthes
    • Class: Cestode
    • EX and disease: Flat worms and Taenia solium (pork tape worm) Cysticerosis Cysts in brain and muscles
    • Class: Termatodes
    • EX and Diseases: Flukes and schistosoma- Schitosomiasis
  123. Nematoda
    • EX: pin worm, roud worm, hook worm
    • Diseases: hook worm infection
Card Set
Test 4
micro biology test 4