1. Prior to birth, in the womb, were you sterile?
2. Where do the microorganisms come from that first colonize a newborn human?
3. What decides which
... [Show More] microorganisms become resident flora for the newborn human?
4. Where does the Escherichia coli come from that colonizes the gastrointestinal tract? Why would a newborn baby in a developing country likely be colonized by E. coli much sooner than a newborn baby in the United States or other developed nation?
5. Do human pathogens colonize a newborn? What prevents them from causing disease? What would allow them to cause disease?
6. Distinguish between infection and disease.
7. Where does infection begin? Where on the human body can you find places like this?
8. What prevents all places and surfaces of the human body from being colonized by microorganisms?
9. Name four places in the human body that are sterile (microbe-free).
10. Where on the skin do microbes colonize? In what ways are these places similar to mucosal surfaces? Why is the surface of the epidermis microbe free except for the occasional transient?
11. What glands are responsible to harboring microbes that cause body odor?
12. List the 4 most commonly found microbial genera resident of the skin. Are these Gram-positive or Gram-negative? Which is the cause of acne?
13. Are the majority of skin microflora resident or transient?
14. What Gram-negative bacterium commonly colonizes the skin?
15. List environmental and human host factors that influence skin microflora composition.
16. Upon entering your mouth perhaps on a piece of food, a bacterium would be exposed to what in your saliva that could destroy the bacterium? How could a microbe survive exposure to the enzymes in your saliva to make it to your stomach?
17. How does the microflora of the mouth differ before and after tooth formation?
18. What are the main microbes to colonize the mouth prior to tooth formation? After tooth formation? Why is there a change in the microflora before and after tooth formation?
19. What are biofilms on the surface of teeth called?
20. Describe how Streptococci form dental plaque and provide for other microbes to join the biofilm.
21. Explain how anaerobic microbes predominant the mouth despite their being a constant influx of oxygen from breathing.
22. How does dental plaque result in dental caries?
23. Upon ingestion of sucrose, describe how Streptococci form dental caries.
24. How can dental caries be prevented? What can be used to clean the surface of teeth? What can be used to clean between teeth and in the gingival crevices?
25. How does fluoride help prevent dental caries?
26. What 2 species of Streptococci primarily colonize teeth?
27. If there were no more toothbrushes or dental floss or fluorine left on Earth, what could Americans do to prevent dental caries?
28. Find 2 things you eat or drink regularly that contain sucrose. (Read the label of your food/drink to determine if it has sucrose or look up the food/drink online.)
29. Would dental caries be considered infectious disease? Why?
30. How does the microflora that colonizes your gastrointestinal tract get there in the first place?
31. What organ is a chemical barrier to microbial growth?
32. What makes the stomach unfriendly to microbes?
33. What is the most common microbe found in the stomach?
34. Besides pH what factor influences the stomach microflora composition? Do beef-eaters and vegetarians have the same microflora?
35. What is the primary difference between the stomach and the end of the small intestine that allows for larger numbers of microbes to be present in the small intestine?
36. What is the oxygen requirement for most microbes living in the small and large intestines?
Are the small and large intestines oxic or anoxic environments?
37. What is another name for the colon that tells you what the microbes are metabolically doing there?
38. How much bacteria per gram of fecal content is in the colon?
39. The symbiotic relationship humans have with some of their intestinal flora is mutualistic. How do each benefit?
40. Name 4 gases produced by microorganisms in the human intestine. Do any of these have an odor?
41. Back in human time before fire, did humans contribute to global warming?
42. What percentage of feces is bacteria? Are the bacteria dead or alive or some of both?
43. Is the large intestine like a batch culture or a chemostat?
44. What is the growth rate of bacteria in the intestine lumen?
45. 10,000,000,000,000 What does this number represent?
46. Describe what antibiotics do to your intestinal microflora.
47. Due to proximity to the exit of the gastrointestinal tract, many microbes that inhabit the gastrointestinal tract find their way to what other area of the body?
48. What part of the urogenital tract is sterile? What part is colonized?
49. What lactic acid bacteria used to make yogurt is resident flora of the human female vagina? How does this microorganism affect the pH of the vagina? During the lifetime of a human female when would Lactobacillus acidophilus expect to be resident of the vagina?
50. Some medications like birth control pills raise the pH of the vagina. What are the microbial consequences?
51. What part of the respiratory tract is sterile?
52. What 2 opportunistic pathogens often colonize the upper respiratory tract? Why do they not cause disease most of the time?
53. What type of cells line the respiratory tract? How do these cells help prevent microbes from reaching the lower respiratory tract?
54. Smoking damages the ciliated epithelium of the respiratory tract. What occurs due to this loss of function? Smokers cough in an attempt to do what? Are smokers more susceptible to microbial infections of the lower respiratory tract?
55. Following exposure to a pathogen, list the events of pathogenesis.
56. List 4 adherence factors and an example of each.
57. Describe invasion.
58. Colonization is also known as microbial ____________. Is microbial colonization dependent on location in the body?
59. What type of virulence factors aresiderophores?
60. Distinguish between localized and systemic bacterial infection. Which would be easier to treat with antibiotics?
61. Is bacteremia a localized or systemic infection?
62. Adherence, invasion, colonization are the steps describing infection. To cause disease what must happen?
63. Define toxicity and give an example of a toxin causing disease.
64. Define invasiveness and give an example of an invasive factor helping a microorganisms cause disease.
65. What is the lethal dose50?
66. How many cells of a virulent human pathogen like Streptococcus pneumoniae are needed to kill?
67. Describe the phenomenon of attenuation. How does a virulent strain become attenuated? Is an attenuated strain still deadly?
68. Viruses and bacteria can be attenuated. Attenuated viruses are given as _______________ of common childhood viruses that are deadly or that cause major harm to the human body.
69. What makes Salmonella such a virulent pathogen?
70. Distinguish between exotoxins, enterotoxins and endotoxins.
71. Describe what a cytolytic exotoxin does to be toxic and give an example of cytolytic toxin.
72. Describe how an AB exotoxin is toxic and give 3 examples of an AB exotoxin.
73. Describe how an enterotoxin is toxic and give 2 examples of enterotoxins. What is the main symptom associated with disease caused by an enterotoxin?
74. Describe how an endotoxin is toxic and give an example of an endotoxin. What group of bacteria produce endotoxins?
75. List 4 risk factors that increase a person’s susceptibility to infection.
76. List 8 barriers that provide natural resistance to infection by pathogens. see fig. 27.26 (fig. 28.25 in 12th edition)
77. Provide an explanation for Clostridium tetani causing tetanus if introduced into a deep puncture wound but not causing any harm if ingested.
78. Provide an explanation for Salmonella causing gastroenteritis if ingested but not causing any harm if introduced in a puncture wound.
79. Salmonella is anaerobic and puncture wounds have oxygProvide an explanation for why a mosquito can transmit malaria but a cockroach cannot.
80. Provide an explanation for why HIV is harmless on your skin but potentially lethal in your blood [Show Less]