Microbiology #3

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  1. Essentials of Virology
    • 1. Genomes
    • 2. Structure
    • 3. Replication
    • 4. Bacterial Viruses: Lytic vs. Lysogenic
    • 5. Animal Viruses: Retroviridae
    • 6. Viral Classification
  2. Viruses of eukaryotic cells are called
  3. Viruses of prokaryotic cells are usually called
    Phages (bacteriophages)
  4. Small extracellular infectious form of viruses and phages is also called a
    Virion (=complete virus particle”)
  5. Q- HIV exhibits _______________ for cells that display a CD4 receptors on their surface.
    A- tropism
  6. Enterics
    Gram negatives in GI tract (normal flora and pathogens)
  7. Enterogenic-
    • No epithelial cell invasion
    • Watery Diarrhea
  8. Enteroinvasive 5 items:
    • 1. Invasion of intestinal cells
    • 2. WBC Infiltration-immune response
    • 3. Blood, WBC in diarrhea
    • 4. Painful
    • 5. Salmonella, Shigella
  9. Circulatory and lymph system invasion of Enterics
  10. Enteric Bugs (11)
    • 1. Escherica Coli-prototype
    • 2. Salmonella-facultative intracellular, usually from animal feces
    • 3. Shigella-similar to enterinvasive E. coli
    • 4. Vibrio-curved with polar flagella.
    • 5. Cholera-death from dehydration/fluid loss
    • 6. Helicobacter-2nd leading cause of duodenal ulcers –acid loving (first cause of ulcers is ASA and chronic gastritis
    • 7. Klebsiella
    • 8. Proteus
    • 9. Enterobacter
    • 10. Yersinia enterocolitica-closely related to Y. pestis (plague)
    • 11. Campylobacter
  11. McConkey agar
    Uses bile salts, turns pink when lactose ferments.
  12. MSA (Mannitol Salt Agar)
    Image Upload 1-

    • selective for: gram-positive Staphylococci bacteria
    • o 7% salt in the medium inhibits the growth of most gram-positive and gram-negative bacteria
    • - differential for: mannitol fermentation
    • o phenol red pH indicator turns yellow in the presence of acid by-products of mannitol fermentation
    • o Staphylococcus aureus ferments mannitol
    • o S. aureus changes the color of the medium from pink to yellow due to acid by-products of mannitol fermentation
    • o Staphylococcus epidermidis grows on MSA, but does not ferment mannitol (media remains light pink in color & colonies are colorless
  13. Selective Medium: culture medium that allows the growth of certain types of organisms, while inhibiting the growth of other organisms
    - dyes in the medium (e.g.: methylene blue in EMB & crystal violet in MacConkey's) or high salt concentration in the medium (e.g.: 7% salt in MSA) inhibit the growth of unwanted microorganisms
  14. Differential Medium: culture medium that allows one to distinguish between or among different microorganisms based on a difference in colony appearance (color, shape, or growth pattern) on the medium.
    - dyes in the medium (e.g.: eosin/methylene blue in EMB) or pH indicators change the color of the medium as sugars in the medium (e.g.: lactose in EMB & MacConkey's and mannitol in MSA) are fermented to produce acid products
  15. EMB (Eosin Methylene Blue) Agar
    Image Upload 2-

    • selective for: gram-negative bacteria
    • o growth of gram-positive bacteria (e.g.: Staphylococcus aureus in the image below) is inhibited by the eosin & methylene blue dyes in the media
    • - differential for: lactose fermentation
    • o gram-negative Enterobacteria Escherichia coli and Enterobacter aerogenes ferment lactose
    • o E. coli produces colonies with a characteristic green metallic sheen on EMB agar
    • o E. aerogenes produces pink colonies often with a central dark purple dot (fish eye colonies) on EMB agar
    • o gram-negative bacteria Proteus vulgaris and Salmonella typhimurium grow on EMB agar, but do not ferment lactose
  16. Hemolysis with Blood Agar
    • - agar contains 5% sheep's blood
    • - differential for: hemolysis...particularly in streptococci
    • - based on the ability to break down hemoglobin or red blood cells, 3 groups of microorganisms can be described
    • o alpha-hemolysis: a green to light-brown halo is seen around the colonies; bacteria partially break down hemoglobin leaving a green pigment (biliverdin)
    • o beta-hemolysis: a clearing is seen around the colonies; bacteria produce a "beta-hemolysin" (streptolysin O or S), which lyses red blood cells in the medium
    • o gamma-hemolysis (no hemolysis): no hemolysis is observed; bacteria do not produce a hemolysin
    • Image Upload 3
  17. Ixodes Tick (5 items)
    • 1. Transmits Lyme Borrellia
    • 2. Bloodmeals preferred source-rodents and small mammals
    • 3. Duration of meal 5-7 days
    • 4. Time between meals-months to years
    • 5. Tick species-scapularis, pacificus
  18. Borrelia species (3)
    • Burgdorferi
    • Afselii
    • Garinii
  19. Pathology of Lyme Disease
    • Bulls eye rash
    • Arthritis
    • Bells Palsy
  20. LYMErix (6 items)
    • 1. Located on 54kb linear plasmid (B. bergdorferi has 12 linear and 9 circular plasmids) ospA and ospB are co-transcribed.
    • 2. OspA and OspB are lipoproteins
    • 3. OspA and OspB homologous to each other (53% overall sequence identity)
    • 4. Neither share significant homology with any other available sequence.
    • 5. Recombinant OspA is the immunogen of the Lymbe disease vaccine
    • 6. FDA approval 1998-discontinued 2001.
  21. Is OspA/OspB a midgut adhesin?( 5 quotes)
    • They are the major outer surface proteins expressed by Lyme borrelia in the Ixodes midgut
    • OspA synthesis in the tick is down-regulated duringthe bloodmeal.
    • Mammals infected by tick bite do not seroconvert to OspA.
    • OspA is a transmission-blocking Lyme disease vaccine.
    • Crystal structure predicts a bind pocket in C-terminal domain.
  22. 1. Cellular morphologies of bacteria are described as coccoid (round) and bacilliform (rod). Virus particles (virion) also have common shapes, two of which are;
    A. Orthogonal and enveloped
    B. Helical and Icosohedral
    C. Orthogonal and Icosohedral
    D. Enveloped and amorphous
    B. Helical and Icosohedral
    (this multiple choice question has been scrambled)
  23. 2. The nucleocapsid is best described as;
    A. The envelope plus the capsid
    B. Binding site for nucleotides on the capsid
    C. Capsid and Genome
    D. Lipid bilayer nucleus
    C. Capsid and genome
    (this multiple choice question has been scrambled)
  24. 3. Which best describes the virion size and nucleic acid content of picornaviruses?
    A. RNA genome, large
    B. DNA genome, large
    C. DNA genome, very small
    D. RNA genome, very small
    D. RNA, very small (pico-rna)
    (this multiple choice question has been scrambled)
  25. 4. Hepadnaviridae are a group of viruses that have a ________________________ genome and are associated with infection of the________________________.
    A. DNA, heart
    B. RNA, gut
    C. DNA, liver
    D. RNA, liver
    C. DNA, liver (hepa dna)
    (this multiple choice question has been scrambled)
  26. 5. From a single cell, bacteria multiply (binary fission) resulting in a population of clones on the surface of an agar plate termed a ‘colony’. Analogously, a single virion can infect a single host cell on the surface of a culture plate containing living tissue or cells. Subsequent infection and lysis of neighboring cells results in a clearing termed a ______________________.
    A. lysozone  B. virolony  C. plaque  D. hemozone
    C. Plaque I think
  27. 6. The ___________________________ assay is a method used to quantify the number of virion in a particular sample, wherein serial dilutions of the sample are mixed with RBC’s in microtiter plates, and ‘button’ results are visible by eye.
    A. precipitation
    B. hemagglutination
    C. hemadsorption
    D. adherence
    B. hemagglutination--find out for sure!
    (this multiple choice question has been scrambled)
  28. 7. _____________________ is the term used to describe the process where enveloped virion are released from the host cell.
    A. virolease
    B. budding
    C. germination
    D. exocytosis
    B. Budding
    (this multiple choice question has been scrambled)
  29. 8. Presence of virion in the _________________ is termed viremia.\
    A. blood
    B. urine
    C. brain
    D. lymph
    A. Blood
    (this multiple choice question has been scrambled)
  30. 9. Reverse transcriptase is an enzyme that converts ____________ into ____________ , a necessity for the retroviridae such as HIV.
    A. RNA, protein\
    B. Protein, RNA
    C. RNA, DNA
    D. DNA, RNA
    C. RNA to DNA
    (this multiple choice question has been scrambled)
  31. 10. Positive-strand RNA viruses possess a genome that is just like eukaryotic ______________, enabling instantaneous synthesis of proteins required for self replication.
    A. rRNA
    B. mRNA
    C. tRNA
    D. gDNA
    I think it's mRNA
  32. 12. The acquired immune response plays a mayor role in viral infections. true or false
  33. 12. Initial binding of virus particle to host cell is most commonly referred to as ______________________.
    A. adsorption
    B. accumulation
    C. adherence
    D. contact
    C. Adherence
    (this multiple choice question has been scrambled)
  34. 14. Quantification of virus can be achieved by hemagglutination, plaque formation, and real time PCR. True or False
  35. 14. The 3 terms used to describe outcomes of a viral infection are acute, chronic, and _____________.
    A. ingressive
    B. latent
    C. innate
    D. terminal
    B. Latent
    (this multiple choice question has been scrambled)
  36. 16. The most effective cellular immune response to viral infection is accomplished by;
    A. Natural Killer cells
    B. Dendritic cells
    C. Macrophages
    D. PMN’s
    I think it's A. Natural Kill
  37. What is Epidemiology?
    the study of where and when diseases occur and how they are transmitted
  38. What is Infection?
    the penetration of the host defenses and colonization by a pathogen
  39. What is Disease?
    a state of unhealth, the loss of homeostasis, or the presence of signs and symptoms
  40. What is an example of a disease NOT caused by a microorganism?
  41. What are some words to describe how common or widespread a disease is?
    sporadic, endemic, epidemic, and pandemic
  42. What is Sporadic?
    disease occurs infrequently
  43. What is Endemic?
    the disease is constantly present
  44. What is Epidemic?
    a sudden increase in the incidence of a disease over the normally expected amount of time
  45. What is Pandemic?
    epidemic on more than one continent
  46. What's the difference in an outbreak and an epidemic?
    They are the same to an epidemiologist, they both indicate a sudden increase in number of cases
  47. What is a Reservoir?
    where the microbe normally lives
  48. What can a reservoir be for a disease?
    a continuous source of the pathogen or infection
  49. Where are most reservoirs for human pathogens?
    the human
  50. What are some other pathogen reservoirs?
    animals, soil, water, enviromental
  51. How can transmission happen from person-to-person?
    direct, indirect, or aerosols
  52. How does Indirect Transmission occur?
    when a pathogen is temporarily transferred to an object by one person and picked up by a second person when they handle the same object
  53. What are objects that transfer pathogens called? What are some examples?
    fomites - door knobs, phone buttons, tissues, clothing, bedding, food, dishes, money
  54. What is Aerosol Transmission? What are some examples?
    when pathogens travel on tiny droplets (aerosols) of fluid from person to person - when we talk, cough, or sneeze
  55. What are vectors?
    arthropods that transport pathogens from one host to another
  56. What are some common biting vectors?
    fleas, ticks, mosquitoes
  57. What are some regular vectors and how do they transmit?
    Flies and Roaches - spread them as they crawl around carrying pathogens on their surface
  58. What are diseases called that occur primarily in animals but can be transmitted to humans?
    zoonotic diseases
  59. What three factors attribute the high risk of contracting infections during hospital visits?
    pathogens in the hospital environment, presence of compromised hosts, and a chain on transmission
  60. What are some ways pathogens work their way into hospitals?
    people often come to the hospital carrying pathogens, and sanitation efforts leave behind resistant microbes with little competition
  61. What is the most common type of nosocomial infection? What is the second most common?
    urinary tract infection - surgical site infection
  62. What usually causes urinary tract infections? How?
    use of catheters - they carry microbes into the urinary tract if it's contaminated or it prevents normal flush of urine and microbes in tract multiply
  63. How do surgical incisions cause nosocomial infections?
    expose normally protected tissues to microbes in the environment
  64. What are the most common causes of nosocomial infections?
    gram-positive cocci, gram-negative rods
  65. What gram-positive cocci causes nosocomial infections?
  66. What gram-negative rods cause nosocomial infections?
    E. coli, Psuedomonas
  67. What causes intestinal infections?
    Clostridium difficile
  68. What are some symptoms of an intestinal infection?
    diarrhea to death
  69. When are fungal infections caused?
    after antibiotic theraphy (when antibiotics kill bacteria and leave fungi without any competition for nutrients, which result in overgrowth of fungi)
  70. What is the germ theory of disease?
    many diseases are caused by microbes
  71. In order to cause disease a microbe must follow what steps?
    must be capable of causing disease, must be transmitted to the host and have a route of entry, host must be susceptible
  72. How is virulence measured?
    the severity of the disease the pathogen causes
  73. What are virulence factors?
    traits of a pathogen that contribute to its ability to cause disease
  74. What are some virulence factors?
    Attachment, Toxins, Evading immune system
  75. What is an example of Attachment when talking about Virulence Factors?
    E. Coli and Neisseria gonorrhoeae require fimbriae to attach to the cell of the urinary tract, Streptococcus pnuemoniae requires a capsule to stick to cells of the respiratory tract
  76. What is an example of evading the immune system when talking about virulence factors?
    flagella allows cells to move away from immune cells - the mycolic acid in the cell walls of mycobacteria is resistant to many chemicals immune defenses
  77. What is ID50?
    infectious dose for 50% of the population
  78. Highly pathogenic species have what kind of ID50?
    low (low numbers of cells)
  79. How are respiratory illnesses contracted?
    through airborne transmission (the air we breathe)
  80. What is the most common portal of entry? The second most common?
    respiratory tract - gastrointestinal tract
  81. What are some portals of entry?
    Mucous membranes, Skin, Parenteral route
  82. When skin is damaged, the portal of entry is called what?
    Parenteral route
  83. What are some examples of disease by Parenteral route?
    injections (iv's), animal bites (insect bites), surgery, and injuries (scrapes, tacks, nails, silvers)
  84. What are commonly used to attach to surfaces, including host cells?
    fimbriae and capsules
  85. What are biofilms formed?
    if cells produce enough capsule slime
  86. What is biofilm?
    a thick layer of slime inhabited by numerous slime-producing and non-slime-producing cells
  87. What is an example of a biofilm?
    slime on spoiled food or slime that develops on dirty dishes soaking in the sink
  88. What do biofilms do for cells?
    has a protective effect on cells
  89. What are exotoxins?
    toxins that are released from the cell - always proteins
  90. What are the genes that code for exotoxins?
    on plasmids
  91. What are endotoxins? Example?
    held in or on the cell and are released only when the cell dies or breaks apart - lipopolysaccharide in the outer membrane of gram-negative bacteria
  92. What is the biologically active component of LPS?
    lipid A
  93. What do endotoxins caused in low amounts? High amounts?
    fever and chills - shock and death
  94. How does LPS cause fever? 6 items
    • 1) phagocytes engulf and digest gram-negative cells
    • 2) digestion breaks the cells apart which releases the LPS
    • 3) LPS stimulates the phagocyte to produce IL-1 (interleukin-1)
    • 4) IL-1 travels through the bloodstream and stimulates the hypothalamus to produce prostaglandins
    • 5) prostoglandins stimulate the hypothalamus to re-set the body temperature to a higher level
    • 6) fever develops and continues as lonas as the level of prostaglandins remains high in the hypothalamus
  95. How do aspirin, acetaminophen, and inbuprofen reduce fever?
    block the production of prostaglandins
  96. What is shock?
    life-threatening drop in blood pressure
  97. What happens if blood pressure drops too low?
    blood flow to various organs decreases or even stops, which results in organ failure followed by death if the condition isn't corrected
  98. What is septic shock caused by?
    the presence of bacteria in the blood and the complex toxic condition that occurs as a result
  99. What is the complex toxic condition that can result from having bacteria in the blood?
  100. What are the symptoms of sepsis cause of?
    chemicals our immune system produce during the fight against the bacteria in the blood
  101. How does LPS cause septic shock? 6 items
    • 1) phagocytes engulf and digest the gram-negative bacteria
    • 2) digestion breaks the cells apart which releases the LPS
    • 3) LPS stimulates the phagocyte to produce TNF (tumor necrosis factor)
    • 4) a series of events initiated by TNF results in damage to capillaries
    • 5) the damaged capillaries leak excessive fluid from the circulatory ystem
    • 6) the loss of fluid caues blood pressure to drop
  102. How can you raise blood pressure?
    fluid replacement and epinephrine
  103. How does epinephrine raise blood pressure?
    causes blood vessels to constrict
  104. What two major branches can the immune system be divided into?
    the innate immune system and the adaptive immune system
  105. When are the components of the innate immun system functional?
    at birth or soon after
  106. When are the components of the adaptive immune system functional?
    as we are exposed to more microbes throughout our lives
  107. What are some physical microbe barriers?
    skin, mucous membranes, ciliary escalator, peristalsis, fluid flow in various locations
  108. What is skin a physical barrier?
    the major protein of skin is keratin, few microbes produce enzymes that can break down keratin so as long as the skin is not damaged microbes can't go through it
  109. How are mucous membranes physical barriers?
    they line the respiratory, digestive, and genitourinary tracts, the membranes trap invading cells and prevent contact with host cells
  110. How is the ciliary escalator a physical barrier?
    the cilia on the cells in the respiratory tract move mucus (and microbes trapped in it) out of the lungs and into the throat
  111. How is peristalsis a physical barrier?
    rhythmic contractions that move materials along the digestive tract
  112. How is fluid flow a physical barrier?
    fluids flowing across the surfaces of the mouth (saliva), urinary tract (urine), and eyes (tears) rinse away microbes
  113. What are some chemical microbe barriers?
    low pH, lysozyme, digestive enzymes, and transferrins
  114. How is low pH a chemical barrier?
    the pH of the skin is often around 3-5, which is low enough to inhibit microorganisms, the pH of the stomach is about 2, and the pH of the vagina is very low
  115. How is lysozyme a chemical barrier?
    an enzyme produced in tears, sweat, and saliva that breaks down peptidoglycan and ruining that peptidoglycan layer make the cell vulnerable to damage and death
  116. How are digestive enzymes chemical barriers?
    enzymes in our saliva, stomach, small intestine, and pancreas break down the carbohydrates, proteins, and lipids in bacterial cells as easily as the food we eat
  117. How are transferrins chemical barriers?
    iron-binding proteins in the blood, saliva, milk, and tears work by preventing iron from floating free in our fluids which prevent nutrients for microbes
  118. If transferrins take away iron in body fluids, how do some microbes get nutrients in our body?
    they produce their own iron-binding proteis called siderophores that help them grab available iron
  119. What are included in transient microbiota?
    bacteria we pick up and drop off during the day when we come into contact with dust and other things
  120. Where is the vast majority of our normal microbiota?
    in the colon
  121. What do our normal microbiota contribute to?
    innate immune system
  122. How do our normal microbiota contribute to our innate immune system?
    crowd out pathogens and produce acids
  123. Where is E. coli commonly found?
  124. What is the most common microbiota of the skin?
    Staphylococcus epidermidis
  125. What are other common microbiota of the skin?
    • Propionibacterium acnes
    • Brevibacterium linens
  126. What is Propionibacterium acnes?
    major contributor to the acidity of the skin
  127. What is Brevibacterium linens?
    major contributor to foot and body oder due to sulfer compounds it produces (methanethiol)
  128. What are probiotics?
    live microbes consumed for a benficial effect
  129. What are some microbiota that are considered probiotics?
    lactobacillus (Lactobacillus acidophilus or Bifidobacterium - colon)
  130. What does consuming probiotics ensure?
    a good population of normal microbiota will always be present in the intestinal tract
  131. What do leukocytes include?
    neutrophils, basophils, eosinophils, monocytes, natural killer cells, B cells, and T cells
  132. What is the most common leukocyte?
  133. What are the major functions of neutrophils?
    phagocytic, first responder
  134. What do basophils contain?
  135. What do basophils play a role in?
    allergic and inflammatory responses
  136. What do eosinophils defend against?
  137. What do monocytes differentiate into?
    macrophages (which are phagocytic)
  138. What do natural killer cells do?
    attack infected cells
  139. What are neutrophils also known as?
    PMNs (polymorphonuclear leukocytes)
  140. Basophils are important in what? Why?
    anaphylactic shock - they histamine they release when stimulated cause capillaries to expand and become leaky all over the body - the loss of fluid from the blood is shock (anaphylactic bc of the things that enter the blood)
  141. Where are mast cells located?
    they live under skin and mucous membranes
  142. What do mast cells contain? What do mast cells cause?
    vesicles of histamine - basic allergic reactions that affect they eyes and respiratory passages where their histamine cause a more local reaction that involves redness and swelling
  143. Are mast cells leukocytes? Why?
    No, they don't live in the blood
  144. How do eosinophils kill helminths?
    releasing toxins and reactive oxygen species (like peroxide)
  145. Monocytes are inactive, but how do they work?
    they leave the circulatory system when stimulated and mature into macrophages
  146. What do monocytes do at sites of infection?
    they come second (after neutrophils) and act as clean up crew
  147. Where do wandering macrophages exist?
    they wander through our tissues and respond to infection where they find it
  148. What are Kupffer cells?
    macrophages found in blood vessels of the liver where they kill bacteria that flow by
  149. What are microglial cells?
    macrophages found in the central nervous system (spinal cord, brain) where they migrate around and kill bacteria they find
  150. Where are alveolar macrophages found?
    passageways and alveoli of the lungs where they digest bacteria or particles that enter
  151. How do natural killer cells kill the cells?
    they release perforin and granzymes - the perforin creates pores in the cell membrane which allows granzymes to enter then stimulate cell suicide
  152. What is cell suicide called scientifically?
  153. Natural killer cells do not kill microbes inside the host cell, but instead do what?
    kill the host cell and then phagocytes (neutrophils and macrophages) kill any bacteria/viruses released
  154. Any chemical that stimulates or regulates immune cells.
  155. How does most communication in the cell occur?
    chemicals (cytokines)
  156. The ingestion of microbes or particles by an immune cell.
  157. What are the three steps to killing microbes by phagocytosis?
    phagocytosis, fusion of the vesicle with a lysozome, and digestion
  158. Describe the step of phagocytosis.
    initial ingestion of an invader, after the microbe is contained in a vesicle inside the cell
  159. Describe the step of fusion.
    the vesicle merges with a lysozome (another vesicle filled with digestive enzymes)
  160. Describe the step of digestion.
    various digestive enzymes begin breaking down all parts of the microbe (proteins, lipids, DNA, carbs) and other enzymes produce acids, hypochlorite, and an oxidative burst
  161. What is an oxidative burst?
    the sudden production of various toxic forms of oxygen (ROS) - cause numerous undesirable reactions and interfere with all cell functions
  162. What are the interferons alpha-INF and beta-INF produced by?
    virus-infected cells
  163. How do interferons work to prevent infection?
    the stimulate neighboring cells antiviral proteins (hopefully before it becomes infected), these proteins prevent viral biosynthesis and limit the spread of infection
  164. How are interferons used medically?
    therapeutically in combination with other drugs to treat chronic viral infections and some types of cancer
  165. What is complement?
    a set of proteins found in the blood, when damage or inflammation occur they enter the affected area and activate
  166. How do complement proteins work?
    form pores in the cell membrane of invading cells, resulting of the death of the invader
  167. When does fever occur?
    when the level of prostaglandins increase in the hypothalamus, which causes the hypothalamus to reset the body temp to a higher temp
  168. What is the increase in prostaglandins usually caused by?
  169. What does higher body temp do to us?
    increases our metabolism and effectiveness of immune cells (the high temp does not kill pathogens)
  170. What are the four classic symptoms of inflammation? What is a fifth that may occur?
    • heat
    • redness
    • swelling
    • pus
    • pain
  171. What is the inflammatory response?
    • injury causes mast cells to release histamine, prostaglandins, and other materials
    • histamine increases vasodilation, vascular permeability, and phagocyte chemtaxis
    • damage, sweeling, and prostaglandins all stimulate pain nerves
  172. What is vasodilation?
    expansion of the blood vessels
  173. What does vasodilation do?
    increases blood flow to the area which results in heat and redness
  174. What does increased permeability do for blood vessels during inflammation?
    allows fluids, phagocytes, complement, and antibodies to escape from capillaries - the accumulation of these fluids causes swelling
  175. How is pus formed?
    phagocytes flowing in the bloodstream sense histamine and other cytokines and they migrate to the damaged area
  176. What do lymph nodes contain?
    numerous lymphocytes that detect invaders that flow by in the lymph fluid
  177. How do lymph nodes become swollen?
    they fill up with large numbers of reproducing lymphocytes during infection
  178. What are Helper T Cells called?
    CD4 cells
  179. What is CD4?
    a molecule on the surface of helper t cell's that is important to their function
  180. What are Helper T Cell's?
    ringleaders of the immune system, they stimulate and regulate oher immune cells with the cytokines they release
  181. What are helper t cell's activited by?
    antigens displayed on the surface of other immune cells, once stimulated they release cytokines that stimulate the immune cell
  182. What are every B cell coated with?
    antibodies - each are identical and grab the same antigen
  183. What are events are required for the stimulation of B cells?
    initial stimulation by an antigen and then stimulation by a helper t cell
  184. What do most B cells turn into? What do the rest turn into?
    plasma cells, memory cells
  185. What do plasma cells do?
    release large quantities of antibodies, all of which are identical and bind to the antigen that stimulated its production
  186. What do memory cells do?
    they wait and multipy and release antibodies when we become infected again with the same pathogen, these cells help us react more quickly the second time
  187. The first time we are exposed to an antigen, how long does it take to produce antibodies?
  188. What is the first type of antibody produced during an infection? What does large amounts of this antibody indicate?
    IgM - first stages of infection
  189. What is produced after IgM?
  190. When a second exposure occurs what are IgM and IgG amounts in the body?
    they are both produced but IgG are much higher
  191. What is the purpose of vaccinating individuals?
    to mimic the initial infection of a pathogen and stimulate the adaptive immune response (without causing sickness) so that the immune system can respond faster and stronger when exposed to the actual pathogen
  192. What are antibodies?
    proteins produced by plasma cells in response to an antigen and able to bind to the antigen
  193. What is another term for antibody?
  194. What is an antigen?
    any molecule that stimulates the production of antibodies
  195. What are antigens usually?
    proteins or polysaccharides on the surface of a pathogen
  196. What is the shape of an antibody?
  197. What are the three antibodies we need to know?
    IgG, IgM, IgA
  198. What does Ig stand for?
  199. What is IgG?
    a monomer
  200. What is the most common antibody in the blood?
  201. What is the most abundant antibody produced during an infection?
  202. What does IgG do during pregnancy?
    crosses the placenta and protects the fetus
  203. What is IgM?
    a pentamer
  204. What is the first antibody produced during infection?
  205. What is IgM especially good at?
  206. What is IgA?
    a dimer
  207. What antibody is secreted into fluids like mucus, saliva, tears, and breast milk?
  208. What antibody protects our moist surfaces?
  209. This provides protection for breast-fed infants.
  210. What are three ways antibodies increase the effectiveness of the immune system?
    • agglutination
    • enhanced immune cell grip
    • complement activation
  211. What is agglutination?
    antibody binding causes clumps of the pathogen to form
  212. How does agglutination destroy pathogens?
    immobilizes them until immune cells can destroy them
  213. Cytotoxic T Cells are also called what?
    CD8 cells
  214. What is CD8?
    molecule of the surface of cytotoxic t cell's that is important to their function
  215. What do cytotoxic t cells kill?
    infected cells
  216. The adaptive immune system can be divided into what two parts?
    humoral immunity and cell-mediated immunity
  217. What is humoral immunity?
    immunity provided by antibodies
  218. What is humoral immunity active against?
    extracellular pathogens
  219. What is cell-mediated immunity?
    immunity provided by cytotoxic t cells
  220. What is cell-mediated immunity active against?
    intracellular pathogens
  221. What are three types of vaccines?
    • whole agent vaccines
    • subunit vaccines
    • toxoids
  222. What do whole-agent vaccines contain?
    whole cells or whole virions, but these may be weakened or killed
  223. What do subunit vaccines contain?
    antigenic pieces of a pathogen, usually proteins or polysaccharides rom a cell membrane or viral capsid
  224. What are subunit vaccines usually safer?
    they only contain necessary cell parts, so they're less likely to cause disease or have side effects
  225. What do toxoid vaccines contain?
    inactivated toxins
  226. Why do attenuated whole-agent vaccines provide the longest-lasting immunity?
    they reproduce in the host and mimic an actual infection
  227. What is the goal of immunizing a community?
    establish herd immunity and prevent outbreaks - if a large enough population is immune the risk is reduced because the chances of susceptible people coming into contact with someone infected is decreased
  228. What is herd immunity usually reached?
    85-90% of population becomes vaccinated
  229. What do antitoxins contain?
    antibodies against a toxin
  230. Antitoxins are used when?
    after exposure to a toxin (like a snake bite) in order to provide immediate relief by neutralizing the toxin
  231. What are some antitoxins available for bacterial toxins?
    toxins that cause botulism or tetanus
  232. What are some examples of serological tests?
    agglutination and immunofluorescence
  233. What indicates a positive result during an agglutination test?
  234. What can be used in agglutination tests?
    microscopic latex beads - they can be coated with antibodies - latex agglutination
  235. When clumping involves red blood cells, what is it called?
  236. What is an example of hemagglutination?
    blood typing
  237. Immunofluorescence uses antibodies that have been treated how?
    bonded with fluorescent dye
  238. What type of microbe that causes infection would you use an immunofluorescence test on?
    Mycobacterium tuberculosis and Treponema pallidum (causes syphillus)
  239. What is an immunodeficiency?
    an inability to produce a normal immune response
  240. What is an example of an immunodeficiency?
    AIDS (acquired immunodeficiency), SCID (severe combined immunodeficiency syndrome)
  241. What is HIV?
    an enveloped retrovirus
  242. What does HIV mostly infect?
    CD4 cells - a protein in the envelope called gp120 attaches to the CD4 cells
  243. How can the progression of HIV be described?
    • the first stage is usually asymptomatic
    • as infection progresses, cell numbers drop, and susceptibility increases
    • when tH cell count reaches 200/mm3 the CDC diagnoses AIDS
  244. What are some common indications of a failing immune system?
    persistent yeast infections (oral in males, vaginal in females)
  245. What is the average period of time from initial infection to the development of AIDS
    10 years
  246. What are some diseases associated with AIDS?
    Candida albicans (yeast infections that can spread to esophagus and lungs), Pneumocystis jiroveci (yeast that causes severe pnuemonia), and humans herpesvirus (causes Kaposi's sarcoma, a skin cancer)
  247. What region has the most HIV-infected persons in the world?
    sub-saharan africa
  248. How was HIV probably first transmitted?
    contact with the blood of monkeys killed or food
  249. What are the most common drugs used to fight HIV infection?
    reverse transcriptase inhibitors, usually in combination with other drugs
  250. What are half of the antibiotics used in the US each year used for?
    in animal feeds to encourage weight gain
  251. What is tetracycline effective against?
    gram-postive, gram-negative, and obligate intracellular bacteria
  252. What is an example of a narrow spectrum antibiotic?
  253. What is penicillin effective against?
    only gram-positive bacteria
  254. The ability to inhibit a microbe without harming the host.
    selective toxicity
  255. Finding selective toxicity agents is easiest for what pathogens? Harder for who? Hardest for who?
    bacterial pathogens - eukaryotic pathogens - viruses
  256. Why is it so easy to find selective toxicity agents for bacterial pathogens?
    prokaryotic cells have numerous differences from our cells that can be taken advantage of
  257. What is it more difficult to find selective toxicity agents for eukaryotic pathogens?
    human cells are eukaryotic and have many similarities to the cells of eukaryotic pathogens (fungi, protozoa, helminths)
  258. What is it the most difficult to find selective toxicity agents for viruses?
    viruses use host cells to reproduce, which makes it hard to inhibit viral production without inhibiting normal cell function
  259. The lowest concentration that's still effective at killing or inhibiting growth.
    MIC - minimum inhibitory concentration
  260. Why is the MIC an important concept?
    you have to reach the MIC in the body for the antibiotic to be effective at treatment but if the levels get too high the risk of side effects is high
  261. Why is peptidoglycan important to a cell?
    provides protection against physical damage and osmotic pressure
  262. Why are proteins important in a cell?
    they are required for nearly all active functions of a cells
  263. Why are nucleic acids important to a cell?
    cells can't reproduce or make proteins if they can't make nucleic acids
  264. Why are ribosomes important to a cell?
    they make proteins and proteins are needed for all cell function
  265. What's an example of a microorganism that inhibit protein synthesis?
    tetracycline (all of the -cyclines), neomycin, and erythromycin
  266. What does blocking DNA replication prevent? RNA?
    prevents cell from dividing - prevents transcription and protein production
  267. What causes antibiotic resistance?
    mutations or genetic recombination
  268. What are three bacterial diseases of the skin?
    TSS (toxic shock syndrome), Necrotizing fasciitis, and Inflammatory acne
  269. What are five viruses of the skin?
    Warts, Cold Sores, Genital Herpes, Chickenpox/Shingles, and Kaposi's sarcoma
  270. What are three fungal diseases of the skin?
    tinea, candidiasis, and dandruff
  271. What is a helminth of the skin?
  272. What is an arthropod of the skin?
  273. What are two bacterial diseases of the eyes?
    neonatal conjunctivitis and trachoma
  274. What causes TSS?
    staphylococcus aureus (usually)
  275. What causes Necrotizing fasciitis?
    streptococcus pyogenes (usually)
  276. What causes Inflammatory acne?
    propionibacterium acnes
  277. What causes warts?
  278. What causes cold sores?
    herpes simplex virus 1
  279. What causes genital herpes?
    herpes simplex virus 2
  280. What causes chickenpox and shingles?
    vericella zoster virus
  281. What causes Kaposi's sarcoma?
    human herpesvirus 8 (HHV-8)
  282. What causes pediculosis?
    pediculus humanus (lice)
  283. What causes neonatal conjunctivitis?
    neisseria gonorrhoeae or chlamydia trachomatis
  284. What is toxic shock syndrome toxin?
  285. What does TSS cause in immune response?
    fever, vomiting, rash, fatigue, and shock
  286. What dose necrotizing fasciitis produce?
    exotoxin A-a superantigen
  287. What does the immune response for necrotizing fasciitis cause?
    destruction of local tissues
  288. What does inflammatory acne release?
    digestion of sebum oils releases fatty acids
  289. How do warts spread?
    virus stimulates cell division
  290. Where do chickenpox/shingles usually remain latent?
    nervous, reactivation causes shingles
  291. What are Kaposi's sarcoma?
    raised dark red lesions on the skin
  292. What does tinea produce?
    keratinases (and other proteases) which permits infection of skin, hair, and nails
  293. What are candidiasis?
    whitish patches on surface
  294. What is dandruff?
    disgestion of sebum lipids releases fatty acids that irritate the skin
  295. What does irritation on scalp cause?
    increase in cell division (flaking)
  296. What is dracunculiasis?
    an emerging worm causes a blister and burning sensation
  297. What is pediculosis?
    lice feed on blood, skin is sensitized to louse saliva, causes itching
  298. What is neonatal conjunctivitis?
    infection of the conjuctiva, eventual damage to cornea leads to blindness
  299. What is trachoma?
    infection of conjunctiva, long term inflammation leads to scarring under eyelid, scards abrade the cornea
  300. Inflammatory acne is a major contributor to what? Happens mainly in who?
    skin acidity, adolescents (produce more sebum)
  301. Some HPV's cause what?
    skin or cervical cancer
  302. What is chickenpox/shingles also known as? How is it transmitted?
    HHV-3, direct contact or respiratory route
  303. Kaposi's sarcoma is almost always an indicator of what?
  304. Tinea includes what things?
    jock itch, athlete's foot, ringworm, and nail infections
  305. What causes jock itch?
    tenea cruris
  306. What causes athlete's foot?
    tinea pedis
  307. What causes ringworm?
    tinea capitis, if on the head - tinea corporis, if on the body
  308. What causes nail infections?
    tinea unguium
  309. An increase in yeast infections is often the first sign of what?
    failing immune system in an HIV infection (decrease in number of helper t cells)
  310. Pediculosis includes what? Does NOT include what?
    head/body lice, not pubic lice (crabs)
  311. What are "crabs"?
    pubic lice - Phthirus pubis
  312. What prevents neonatal conjunctivitis?
    erythromycin (US) - iodine solutions (rest of world)
  313. Trachoma is transmitted by what?
    same species that causes STD chlamydia, but non-sexually (touching, fomites, vectors)
  314. What is the leading infectious cause of blindness?
  315. What are Chlamydia?
    obligate intracellular parasites
Card Set:
Microbiology #3
2012-07-25 02:30:34

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