Microbiology Exam 3

  1. What is Epidemiology?
    the study of where and when diseases occur and how they are transmitted
  2. What are epidemiologists particularly interested in?
    changes in disease date like if diseases are occuring, spreading, and if control methods are working
  3. What is Infection?
    the penetration of the host defenses and colonization by a pathogen
  4. What is Disease?
    a state of unhealth, the loss of homeostasis, or the presence of signs and symptoms
  5. What is an example of a disease NOT caused by a microorganism?
  6. What is Incubation Period?
    the period of time between the initial infection and disease and when symptoms first appear
  7. What is happening to microorganisms during the incubation period?
    pathogens are adjusting metabolism, reproducing, attempting to evade the immune system, and producing toxins
  8. What do Incidence and Prevalence discribe?
    the number of cases of disease that occur
  9. What is Incidence?
    the number of new cases reported during a period of time
  10. What is Prevalence?
    the total number of cases during a period of time (includes new cases and old cases from an older period of time)
  11. How are Incidence and Prevalence usually reported? Why?
    number of cases per 100,000 - this allows for comparison of areas with different populations
  12. Why are Incidence and Prevalence important to epidemiologists?
    they allow authorities to track where and when diseases occur, the changes can tell if control measures are working or if they require intervention
  13. What are some words to describe how common or widespread a disease is?
    sporadic, endemic, epidemic, and pandemic
  14. What is Sporadic?
    disease occurs infrequently
  15. What is Endemic?
    the disease is constantly present
  16. What is Epidemic?
    a sudden increase in the incidence of a disease over the normally expected amount of time
  17. What is Pandemic?
    epidemic on more than one continent
  18. 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
  19. What is a Reservoir?
    where the microbe normally lives
  20. What can a reservoir be for a disease?
    a continuous source of the pathogen or infection
  21. Where are most reservoirs for human pathogens?
    the human
  22. What are some other pathogen reservoirs?
    animals, soil, water, enviromental
  23. How can transmission happen from person-to-person?
    direct, indirect, or aerosols
  24. 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
  25. What are objects that transfer pathogens called? What are some examples?
    fomites - door knobs, phone buttons, tissues, clothing, bedding, food, dishes, money
  26. 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
  27. What are vectors?
    arthropods that transport pathogens from one host to another
  28. What are some common biting vectors?
    fleas, ticks, mosquitoes
  29. What are some regular vectors and how do they transmit?
    Flies and Roaches - spread them as they crawl around carrying pathogens on their surface
  30. What are diseases called that occur primarily in animals but can be transmitted to humans?
    zoonotic diseases
  31. How does one acquire a nosocomial infection?
    hospital visit
  32. What percent of all visitors to hospitals develop nosocomial infections?
  33. 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
  34. 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
  35. How do compromised hosts work in hospitals?
    people often have immune systems that are compromised due to drugs or disease, and medical procedures often bypass the body's defenses
  36. How is the chain of transmission attributed to nosocomial infections at hospitals?
    medical personnel and instruments move microbes from person to person, and ventilation systems move air and microbes around
  37. How do hospitals take infection control precautions?
    they have an epidemiologist or infection control officer on staff
  38. What are most nosocomial infections due to?
    bypassing a normally intact defense
  39. What is the most common type of nosocomial infection? What is the second most common?
    urinary tract infection - surgical site infection
  40. 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
  41. How do surgical incisions cause nosocomial infections?
    expose normally protected tissues to microbes in the environment
  42. What are the most common causes of nosocomial infections?
    gram-positive cocci, gram-negative rods
  43. What gram-positive cocci causes nosocomial infections?
  44. What gram-negative rods cause nosocomial infections?
    E. coli, Psuedomonas
  45. What causes intestinal infections?
    Clostridium difficile
  46. When does Clostridium difficile cause intestinal infections?
    following antibiotic therapy (when competing microbes in the intestinal tract are eliminated)
  47. When does Clostridium difficile cause intestinal infections?
    following antibiotic therapy (when competing microbes in the intestinal tract are eliminated)
  48. When does Clostridium difficile cause intestinal infections?
    following antibiotic therapy (when competing microbes in the intestinal tract are eliminated)
  49. What are some symptoms of an intestinal infection?
    diarrhea to death
  50. 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)
  51. What is an example of a fungal infection? Caused by what?
    yeast infection - Candida albicans
  52. What are the four steps used to prove the cause of an infectious disease caused?
    Koch's Postulates
  53. What is Koch's Postulates?
    • 1) The organism you suspect must be present in every instance of the disease.
    • 2) The organism must then be isolated and grown in pure culture.
    • 3) The organism you isoled must cause the disease when it's inoculated into healthy individuals.
    • 4) The organism must be present in newly infected individuals.
  54. Who discovered Koch's Postulates? What theory did he prove? What year?
    Robert Koch - germ theory of disease - 1876
  55. What microbe causing what disease did Koch use to prove his theory?
    Bacillus anthracis - anthrax
  56. What is the germ theory of disease?
    many diseases are caused by microbes
  57. 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
  58. What are risk factors?
    traits of a ohst that increase the risk of developing a disease
  59. How is virulence measured?
    the severity of the disease the pathogen causes
  60. What are virulence factors?
    traits of a pathogen that contribute to its ability to cause disease
  61. What are some virulence factors?
    Attachment, Toxins, Evading immune system
  62. 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
  63. 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
  64. What is ID50?
    infectious dose for 50% of the population
  65. Highly pathogenic species have what kind of ID50?
    low (low numbers of cells)
  66. How are respiratory illnesses contracted?
    through airborne transmission (the air we breathe)
  67. The route a pathogen uses to enter the body.
    portal of entry
  68. What is the most common portal of entry? The second most common?
    respiratory tract - gastrointestinal tract
  69. What are some portals of entry?
    Mucous membranes, Skin, Parenteral route
  70. What are some mucous membranes that provide a portal of entry for pathogens?
    respiratory tract, gastrointestinal tract, genitourinary tract, conjunctiva (inside of eye and white)
  71. How is skin considered a portal of entry?
    only if the microbe can penetrate the skin, which few can, but they can penetrate damaged skin
  72. When skin is damaged, the portal of entry is called what?
    Parenteral route
  73. What are some examples of disease by Parenteral route?
    injections (iv's), animal bites (insect bites), surgery, and injuries (scrapes, tacks, nails, silvers)
  74. What are commonly used to attach to surfaces, including host cells?
    fimbriae and capsules
  75. What are biofilms formed?
    if cells produce enough capsule slime
  76. What is biofilm?
    a thick layer of slime inhabited by numerous slime-producing and non-slime-producing cells
  77. What is an example of a biofilm?
    slime on spoiled food or slime that develops on dirty dishes soaking in the sink
  78. What is dental plaque considered?
  79. What do biofilms do for cells?
    has a protective effect on cells
  80. What are exotoxins?
    toxins that are released from the cell - always proteins
  81. What are the genes that code for exotoxins?
    on plasmids
  82. 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
  83. What is the biologically active component of LPS?
    lipid A
  84. What do endotoxins caused in low amounts? High amounts?
    fever and chills - shock and death
  85. How does LPS cause fever?
    • 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
  86. How do aspirin, acetaminophen, and inbuprofen reduce fever?
    block the production of prostaglandins
  87. What is shock?
    life-threatening drop in blood pressure
  88. 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
  89. What is septic shock caused by?
    the presence of bacteria in the blood and the complex toxic condition that occurs as a result
  90. What is the term for having bacteria in the blood?
  91. What is the complex toxic condition that can result from having bacteria in the blood?
  92. What are the symptoms of sepsis cause of?
    chemicals our immune system produce during the fight against the bacteria in the blood
  93. How does LPS cause septic shock?
    • 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
  94. How can you raise blood pressure?
    fluid replacement and epinephrine
  95. How does epinephrine raise blood pressure?
    causes blood vessels to constrict
  96. What two major branches can the immune system be divided into?
    the innate immune system and the adaptive immune system
  97. When are the components of the innate immun system functional?
    at birth or soon after
  98. When are the components of the adaptive immune system functional?
    as we are exposed to more microbes throughout our lives
  99. What are some physical microbe barriers?
    skin, mucous membranes, ciliary escalator, peristalsis, fluid flow in various locations
  100. 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
  101. 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
  102. 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
  103. How is peristalsis a physical barrier?
    rhythmic contractions that move materials along the digestive tract
  104. 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
  105. What are some chemical microbe barriers?
    low pH, lysozyme, digestive enzymes, and transferrins
  106. 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
  107. Why is the pH of our skin so low?
    due to fatty acids in sebum as well as acids produced by bacteria on our skin
  108. Why is the pH of the vagina so low?
    acids produced by a species of Lactobacillus
  109. 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
  110. 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
  111. 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
  112. 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
  113. 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
  114. Where is the vast majority of our normal microbiota?
    in the colon
  115. What do our normal microbiota contribute to?
    innate immune system
  116. How do our normal microbiota contribute to our innate immune system?
    crowd out pathogens and produce acids
  117. What is a common microorganism in the colon?
  118. Where is E. coli commonly found?
  119. What is the most common microbiota of the skin?
    Staphylococcus epidermidis
  120. What are other common microbiota of the skin?
    • Propionibacterium acnes
    • Brevibacterium linens
  121. What is Propionibacterium acnes?
    major contributor to the acidity of the skin
  122. What is Brevibacterium linens?
    major contributor to foot and body oder due to sulfer compounds it produces (methanethiol)
  123. What are probiotics?
    live microbes consumed for a benficial effect
  124. What are some microbiota that are considered probiotics?
    lactobacillus (Lactobacillus acidophilus or Bifidobacterium - colon)
  125. What does consuming probiotics ensure?
    a good population of normal microbiota will always be present in the intestinal tract
  126. What do leukocytes include?
    neutrophils, basophils, eosinophils, monocytes, natural killer cells, B cells, and T cells
  127. What is the most common leukocyte?
  128. What are the major functions of neutrophils?
    phagocytic, first responder
  129. What do basophils contain?
  130. What do basophils play a role in?
    allergic and inflammatory responses
  131. What do eosinophils defend against?
  132. What do monocytes differentiate into?
    macrophages (which are phagocytic)
  133. What do natural killer cells do?
    attack infected cells
  134. What are neutrophils also known as?
    PMNs (polymorphonuclear leukocytes)
  135. 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)
  136. Where are mast cells located?
    they live under skin and mucous membranes
  137. 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
  138. Are mast cells leukocytes? Why?
    No, they don't live in the blood
  139. How do eosinophils kill helminths?
    releasing toxins and reactive oxygen species (like peroxide)
  140. Monocytes are inactive, but how do they work?
    they leave the circulatory system when stimulated and mature into macrophages
  141. What do monocytes do at sites of infection?
    they come second (after neutrophils) and act as clean up crew
  142. Where do wandering macrophages exist?
    they wander through our tissues and respond to infection where they find it
  143. Where do fixed macrophages exist? What is an example of a fixed macrophage?
    a specific organ - Kupffer cells, microglial cells, and alveolar macrophages
  144. What are Kupffer cells?
    macrophages found in blood vessels of the liver where they kill bacteria that flow by
  145. What are microglial cells?
    macrophages found in the central nervous system (spinal cord, brain) where they migrate around and kill bacteria they find
  146. Where are alveolar macrophages found?
    passageways and alveoli of the lungs where they digest bacteria or particles that enter
  147. 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
  148. What is cell suicide called scientifically?
  149. 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
  150. Any chemical that stimulates or regulates immune cells.
  151. How does most communication in the cell occur?
    chemicals (cytokines)
  152. The ingestion of microbes or particles by an immune cell.
  153. What are the three steps to killing microbes by phagocytosis?
    phagocytosis, fusion of the vesicle with a lysozome, and digestion
  154. Describe the step of phagocytosis.
    initial ingestion of an invader, after the microbe is contained in a vesicle inside the cell
  155. Describe the step of fusion.
    the vesicle merges with a lysozome (another vesicle filled with digestive enzymes)
  156. 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
  157. 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
  158. What are the interferons alpha-INF and beta-INF produced by?
    virus-infected cells
  159. 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
  160. How are interferons used medically?
    therapeutically in combination with other drugs to treat chronic viral infections and some types of cancer
  161. What is complement?
    a set of proteins found in the blood, when damage or inflammation occur they enter the affected area and activate
  162. How do complement proteins work?
    form pores in the cell membrane of invading cells, resulting of the death of the invader
  163. 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
  164. What is the increase in prostaglandins usually caused by?
  165. What does higher body temp do to us?
    increases our metabolism and effectiveness of immune cells (the high temp does not kill pathogens)
  166. What are the four classic symptoms of inflammation? What is a fifth that may occur?
    • heat
    • redness
    • swelling
    • pus
    • pain
  167. 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
  168. What is vasodilation?
    expansion of the blood vessels
  169. What does vasodilation do?
    increases blood flow to the area which results in heat and redness
  170. 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
  171. How is pus formed?
    phagocytes flowing in the bloodstream sense histamine and other cytokines and they migrate to the damaged area
  172. Macrophages phagocytize bacteria just like neutrophils, but they're big enough to also do what?
    phagocytize dead neutrophils and damaged host cells
  173. Aspiring, ibuprofen, etc reduce pain by blocking the production of prostaglandins. Why?
    prostaglandins sensitize pain nerves
  174. How does the adaptive immune system differ from the innate immune system?
    the adaptive immune system improves throughout the life as each person is exposed to more microorganisms
  175. What are B and T cells called? Why?
    lymphocytes - they spend most of their time in the lymph system and the lymphoid tissues (but are also considered leukocytes because they spend part of their time in the blood)
  176. What do the vessels of the lymph system do?
    collect fluids that leave the circulatory system and return them to the circulatory system near the heart
  177. Where do lymphocytes congregate?
    near lymphoid tissues
  178. What are some lymphoid tissues?
    lymph nodes, tonsils, Peyer's patches, spleen
  179. What are lymph nodes?
    enlarged pockets that occur along the vessel of the lymph system
  180. What do lymph nodes contain?
    numerous lymphocytes that detect invaders that flow by in the lymph fluid
  181. How do lymph nodes become swollen?
    they fill up with large numbers of reproducing lymphocytes during infection
  182. What do cells on surface of the tonsils and peyer's patches do?
    constantly sample materials on the surface and present the material to the immune cells under the surface which allows immune cells to respond to pathogens before they have time to penetrate the body
  183. Where are peyer's patches located?
    the small intestine
  184. What is one function of the spleen?
    trap and destroy damaged red blood cells
  185. What are Helper T Cells called?
    CD4 cells
  186. What is CD4?
    a molecule on the surface of helper t cell's that is important to their function
  187. What are Helper T Cell's?
    ringleaders of the immune system, they stimulate and regulate oher immune cells with the cytokines they release
  188. 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
  189. What are every B cell coated with?
    antibodies - each are identical and grab the same antigen
  190. What are events are required for the stimulation of B cells?
    initial stimulation by an antigen and then stimulation by a helper t cell
  191. What do most B cells turn into? What do the rest turn into?
    plasma cells, memory cells
  192. What do plasma cells do?
    release large quantities of antibodies, all of which are identical and bind to the antigen that stimulated its production
  193. 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
  194. The first time we are exposed to an antigen, how long does it take to produce antibodies?
  195. What is the first type of antibody produced during an infection? What does large amounts of this antibody indicate?
    IgM - first stages of infection
  196. What is produced after IgM?
  197. When a second exposure occurs what are IgM and IgG amounts in the body?
    they are both produced but IgG are much higher
  198. 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
  199. What are antibodies?
    proteins produced by plasma cells in response to an antigen and able to bind to the antigen
  200. What is another term for antibody?
  201. What is an antigen?
    any molecule that stimulates the production of antibodies
  202. What are antigens usually?
    proteins or polysaccharides on the surface of a pathogen
  203. What is the shape of an antibody?
  204. What are the three antibodies we need to know?
    IgG, IgM, IgA
  205. What does Ig stand for?
  206. What is IgG?
    a monomer
  207. What is the most common antibody in the blood?
  208. What is the most abundant antibody produced during an infection?
  209. What does IgG do during pregnancy?
    crosses the placenta and protects the fetus
  210. What is IgM?
    a pentamer
  211. What is the first antibody produced during infection?
  212. What is IgM especially good at?
  213. What is IgA?
    a dimer
  214. What antibody is secreted into fluids like mucus, saliva, tears, and breast milk?
  215. What antibody protects our moist surfaces?
  216. This provides protection for breast-fed infants.
  217. What are three ways antibodies increase the effectiveness of the immune system?
    • agglutination
    • enhanced immune cell grip
    • complement activation
  218. What is agglutination?
    antibody binding causes clumps of the pathogen to form
  219. How does agglutination destroy pathogens?
    immobilizes them until immune cells can destroy them
  220. Cytotoxic T Cells are also called what?
    CD8 cells
  221. What is CD8?
    molecule of the surface of cytotoxic t cell's that is important to their function
  222. What do cytotoxic t cells kill?
    infected cells
  223. The adaptive immune system can be divided into what two parts?
    humoral immunity and cell-mediated immunity
  224. What is humoral immunity?
    immunity provided by antibodies
  225. What is humoral immunity active against?
    extracellular pathogens
  226. What is cell-mediated immunity?
    immunity provided by cytotoxic t cells
  227. What is cell-mediated immunity active against?
    intracellular pathogens
  228. What is immunology?
    the study of the immune system
  229. What are vaccines?
    preparations designed to induce adaptie immunity
  230. What are three types of vaccines?
    • whole agent vaccines
    • subunit vaccines
    • toxoids
  231. What do whole-agent vaccines contain?
    whole cells or whole virions, but these may be weakened or killed
  232. What do subunit vaccines contain?
    antigenic pieces of a pathogen, usually proteins or polysaccharides rom a cell membrane or viral capsid
  233. What are subunit vaccines usually safer?
    they only contain necessary cell parts, so they're less likely to cause disease or have side effects
  234. What do toxoid vaccines contain?
    inactivated toxins
  235. Why do attenuated whole-agent vaccines provide the longest-lasting immunity?
    they reproduce in the host and mimic an actual infection
  236. 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
  237. What is herd immunity usually reached?
    85-90% of population becomes vaccinated
  238. What do antitoxins contain?
    antibodies against a toxin
  239. Antitoxins are used when?
    after exposure to a toxin (like a snake bite) in order to provide immediate relief by neutralizing the toxin
  240. What are some antitoxins available for bacterial toxins?
    toxins that cause botulism or tetanus
  241. Tests that use antibodies to determine the results.
    Serological tests
  242. What are serological tests useful for?
    indentifying bacteria or diagnosing disease
  243. What are some examples of serological tests?
    agglutination and immunofluorescence
  244. What indicates a positive result during an agglutination test?
  245. What can be used in agglutination tests?
    microscopic latex beads - they can be coated with antibodies - latex agglutination
  246. When clumping involves red blood cells, what is it called?
  247. What is an example of hemagglutination?
    blood typing
  248. Immunofluorescence uses antibodies that have been treated how?
    bonded with fluorescent dye
  249. What type of microbe that causes infection would you use an immunofluorescence test on?
    Mycobacterium tuberculosis and Treponema pallidum (causes syphillus)
  250. What is an immunodeficiency?
    an inability to produce a normal immune response
  251. What is an example of an immunodeficiency?
    AIDS (acquired immunodeficiency), SCID (severe combined immunodeficiency syndrome)
  252. What is HIV?
    an enveloped retrovirus
  253. What does HIV mostly infect?
    CD4 cells - a protein in the envelope called gp120 attaches to the CD4 cells
  254. 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
  255. What are some common indications of a failing immune system?
    persistent yeast infections (oral in males, vaginal in females)
  256. What is the normal tH cell count?
  257. What is the average period of time from initial infection to the development of AIDS
    10 years
  258. 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)
  259. What region has the most HIV-infected persons in the world?
    sub-saharan africa
  260. How was HIV probably first transmitted?
    contact with the blood of monkeys killed or food
  261. What are the most common drugs used to fight HIV infection?
    reverse transcriptase inhibitors, usually in combination with other drugs
  262. Substances produced by one microorganism that inhibits or kill another microorganism.
  263. What was the first antibiotic?
  264. Who discovered the first antibiotic and when?
    Alexander Fleming - 1928
  265. When was the first widespread use of antibiotics?
    World War II
  266. What are half of the antibiotics used in the US each year used for?
    in animal feeds to encourage weight gain
  267. What are half of all antibiotics produced by?
    species of Streptomyces
  268. What are other antibiotics produced by?
    molds or species of Bacillus
  269. What do the species that produce antibiotics all have in common?
    they are soil microbes, and their antibiotics are useful in eliminating competition in the crowded soil environment
  270. The range of microbes an antibiotic is effective against.
    Spectrum of Action
  271. What is an example of a broad spectrum antibiotic?
  272. What is tetracycline effective against?
    gram-postive, gram-negative, and obligate intracellular bacteria
  273. What is an example of a narrow spectrum antibiotic?
  274. What is penicillin effective against?
    only gram-positive bacteria
  275. When are broad spectrum antibiotics useful? But, what are they most likely to kill?
    when the agent is unknown - normal microbiota
  276. When are narrow spectrum antibiotics useful?
    when the agent is known so the antibiotic can be targeted against a specific pathogen in the location of infection
  277. The ability to inhibit a microbe without harming the host.
    selective toxicity
  278. Why is selective toxicity important?
    we don't want to harm the host when we're trying to heal them
  279. Finding selective toxicity agents is easiest for what pathogens? Harder for who? Hardest for who?
    bacterial pathogens - eukaryotic pathogens - viruses
  280. 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
  281. 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)
  282. 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
  283. What is the most common method for testing the effectiveness for antibiotics?
    disk-diffusion test
  284. What method is used as a disk diffusion test?
    Kirby-Bauer test
  285. The lowest concentration that's still effective at killing or inhibiting growth.
    MIC - minimum inhibitory concentration
  286. 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
  287. How do we regulate MIC and antibiotics?
    using dose regimens in safe levels (above MIC, under toxic level)
  288. What is the most common mechanisms of action for antibiotics?
    inhibit production of an essential cell component or injure the cell membrane
  289. What four things inhibit synthesis of essential cell components?
    peptidoglycan, proteins, nucleic acids, nutrients
  290. Why is peptidoglycan important to a cell?
    provides protection against physical damage and osmotic pressure
  291. Why are proteins important in a cell?
    they are required for nearly all active functions of a cells
  292. Why are nucleic acids important to a cell?
    cells can't reproduce or make proteins if they can't make nucleic acids
  293. Why are nutrients important in a cell?
    lack of essential nutrients eventually causes death of a cell
  294. What is an example of a cell with no peptidoglycan, susceptible to physical damage and osmotic pressure?
    penicillin (all of the -cillins), bacitracin
  295. Why are ribosomes important to a cell?
    they make proteins and proteins are needed for all cell function
  296. What's an example of a microorganism that inhibit protein synthesis?
    tetracycline (all of the -cyclines), neomycin, and erythromycin
  297. What does blocking DNA replication prevent? RNA?
    prevents cell from dividing - prevents transcription and protein production
  298. What's an example of a microorganism that inhibit nucleic acid synthesis?
    rifampin, chloroquine, acyclovir, and reverse transcriptase inhibitors
  299. What's an example of a microorganism that inhibit nutrient synthesis?
    trimethoprim and sulfamethoxazole (sulfa drugs) inhibit folic acid synthesis
  300. What's an example of a microorganism that injure cell membrane?
    polymyxin B, clotrimazole, and miconazole
  301. What does triple antibiotic ointment contain?
    bacitracin (inhibits peptidoglycan synthesis), neomycin (inhibits protein synthesis), and polymyxin B (injures cell membranes)
  302. What causes antibiotic resistance?
    mutations or genetic recombination
  303. When was the first antibiotic resistance recognized?
    late 1940's
  304. What are the four most common ways microorganisms resist the effect of antibiotics?
    prevent entry of the drug, inactivate the drug, alter the target of the drug, or eject the drug from the cell
  305. How does microorganisms block the entry of a drug?
    using the outer membrane of gram-negative bacteria
  306. How do microorganisms inactivate a drug? What is an example?
    enzymes produced by the cell break down the antibiotic - penicillinase
  307. How do microorganisms alter the target of a drug?
    the cell begins producing an altered version of the antibiotic target, the altered version still accomplishes its task but is resistance to antibiotics
  308. How do microorganisms rapidly eject a drug from the cell?
    pumps in the cell membrane quickly remove an antibioitc and send it to the exterior
  309. What are three bacterial diseases of the skin?
    TSS (toxic shock syndrome), Necrotizing fasciitis, and Inflammatory acne
  310. What are five viruses of the skin?
    Warts, Cold Sores, Genital Herpes, Chickenpox/Shingles, and Kaposi's sarcoma
  311. What are three fungal diseases of the skin?
    tinea, candidiasis, and dandruff
  312. What is a helminth of the skin?
  313. What is an arthropod of the skin?
  314. What are two bacterial diseases of the eyes?
    neonatal conjunctivitis and trachoma
  315. What causes TSS?
    staphylococcus aureus (usually)
  316. What causes Necrotizing fasciitis?
    streptococcus pyogenes (usually)
  317. What causes Inflammatory acne?
    propionibacterium acnes
  318. What causes warts?
  319. What causes cold sores?
    herpes simplex virus 1
  320. What causes genital herpes?
    herpes simplex virus 2
  321. What causes chickenpox and shingles?
    vericella zoster virus
  322. What causes Kaposi's sarcoma?
    human herpesvirus 8 (HHV-8)
  323. What causes Tinea?
    dermatophytes (usually Trichophyton)
  324. What causes Candidiasis?
    Candida albicans
  325. What causes dandruff?
    malassezia globosa
  326. What causes Dracunculiasis?
    dracunculus medinensis (guinea worm)
  327. What causes pediculosis?
    pediculus humanus (lice)
  328. What causes neonatal conjunctivitis?
    neisseria gonorrhoeae or chlamydia trachomatis
  329. What causes Trachoma?
    chlamydia trachomatis
  330. What is toxic shock syndrome toxin?
  331. What does TSS cause in immune response?
    fever, vomiting, rash, fatigue, and shock
  332. What dose necrotizing fasciitis produce?
    exotoxin A
  333. What is exotoxin A?
  334. What does the immune response for necrotizing fasciitis cause?
    destruction of local tissues
  335. What does inflammatory acne release?
    digestion of sebum oils releases fatty acids
  336. How do warts spread?
    virus stimulates cell division
  337. Where do genital herpes remain latent?
    sacral nerves, reactivation causes eruption on the outer genitalia
  338. Where do cold sores remain latent?
    trigeminal nerves, reactivation causes eruption usually on the edge of the lips
  339. Where do chickenpox/shingles usually remain latent?
    nervous, reactivation causes shingles
  340. What are Kaposi's sarcoma?
    raised dark red lesions on the skin
  341. What does tinea produce?
    keratinases (and other proteases) which permits infection of skin, hair, and nails
  342. What are candidiasis?
    whitish patches on surface
  343. What is dandruff?
    disgestion of sebum lipids releases fatty acids that irritate the skin
  344. What does irritation on scalp cause?
    increase in cell division (flaking)
  345. What is dracunculiasis?
    an emerging worm causes a blister and burning sensation
  346. What is pediculosis?
    lice feed on blood, skin is sensitized to louse saliva, causes itching
  347. What is neonatal conjunctivitis?
    infection of the conjuctiva, eventual damage to cornea leads to blindness
  348. What is trachoma?
    infection of conjunctiva, long term inflammation leads to scarring under eyelid, scards abrade the cornea
  349. What are most cases of TSS?
  350. What causes a minority of TSS cases?
  351. What percent of people are carriers of TSS? Where?
    25%, nose
  352. What is necrotizing fasciitis also known as?
    A strep, beta strep
  353. Why is necrotizing fasciitis known as beta strep?
    the beta-hemolysis it causes on blood agar
  354. What percent of people are carriers of necrotizing fasciitis? Where?
    10%, throat
  355. Inflammatory acne is a major contributor to what? Happens mainly in who?
    skin acidity, adolescents (produce more sebum)
  356. Some HPV's cause what?
    skin or cervical cancer
  357. What percent of US population is infected by cold sores? When is the infection began?
    90%, infancy
  358. What percent of what people are infected by genital herpes?
    25% of US adults over the age of 30
  359. What is chickenpox/shingles also known as? How is it transmitted?
    HHV-3, direct contact or respiratory route
  360. Kaposi's sarcoma is almost always an indicator of what?
  361. Tinea includes what things?
    jock itch, athlete's foot, ringworm, and nail infections
  362. What causes jock itch?
    tenea cruris
  363. What causes athlete's foot?
    tinea pedis
  364. What causes ringworm?
    tinea capitis, if on the head - tinea corporis, if on the body
  365. What causes nail infections?
    tinea unguium
  366. 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)
  367. What does dandruff infect?
    normal microbiota of scalp
  368. Where is dracunculiasis transmitted? Who are the hosts?
    contaminated drinking water, humans only
  369. What may soon be the second disease eradicated by humans?
  370. Pediculosis includes what? Does NOT include what?
    head/body lice, not pubic lice (crabs)
  371. What are "crabs"?
    pubic lice - Phthirus pubis
  372. What prevents neonatal conjunctivitis?
    erythromycin (US) - iodine solutions (rest of world)
  373. Trachoma is transmitted by what?
    same species that causes STD chlamydia, but non-sexually (touching, fomites, vectors)
  374. What is the leading infectious cause of blindness?
  375. What are Chlamydia?
    obligate intracellular parasites
Card Set
Microbiology Exam 3
Exam 3 - Guyer