OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity | 2022 LATEST UPDATE

OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Chapter 15: Microbial Mechanisms of Pathogenicity * = Correct answer Multiple Choice 1. Which of the following would be considered a symptom? A. blood pressure reading of 150/90 mm Hg B. body ache and chills* C. fever of 39 C D. heart rate of 120 bpm Difficulty: Easy ASM Standard: N/A 2. Which of the following would be considered a sign? A. blurry vision B. body ache and chills C. burning sensation during urination D. gross hematuria (visible presence of blood in urine)* Difficulty: Easy ASM Standard: N/A 3. Which of the following is an example of a nosocomial disease? A. acquiring Giardia while drinking from a stream during a camping trip B. acquiring Listeria after eating at a public restaurant C. acquiring MRSA after touching a locker door handle after an already infected individual did so D. obtaining a Pseudomonas respiratory infection during a recent visit to the hospital* Difficulty: Easy ASM Standard: 23 4. Sickle cell anemia can be classified as which type of disease? A. idiopathic B. infectious, communicable C. infectious, noncommunicable D. noninfectious* Difficulty: Easy ASM Standard: N/A 5. Which of the following is not a zoonotic disease? A. rabies B. Rocky Mountain spotted fever Page 1 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity C. typhoid* D. yellow fever Difficulty: Easy ASM Standard: 23 6. What period of disease describes when the patient begins to feel general signs and symptoms? A. incubation period B. period of convalescence C. period of illness D. prodromal period* Difficulty: Easy ASM Standard: 23 7. During which period of disease is a patient most susceptible to developing a secondary infection? A. incubation period B. period of convalescence C. period of decline* D. prodromal period Difficulty: Moderate ASM Standard: 23 Examine the graph shown below and then answer questions 8 and 9. 8. Examine the graph and determine the approximate ID50 of the virus. A. 10 particles B. 5000 particles C. 13,000 particles* D. cannot be determined from the data collected Difficulty: Moderate ASM Standard: 10, 23, 28b, 29, 36 Page 2 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity 9. Examine the graph and determine the LD50 of the virus. A. 10 particles B. 5000 particles C. 13,000 particles D. cannot be determined from the data collected* Difficulty: Moderate ASM Standard: 23, 28b, 29, 36 10. Identify which pathogen is the least virulent on the basis of ID50. A. pathogen A with an ID50 of 1000 cells* B. pathogen B with an ID50 of 50 cells C. pathogen C with an ID50 of 1 cell D. pathogenicity cannot be determined from ID50 values Difficulty: Moderate ASM Standard: 23 11. Which of the following is the definition of pathogenicity? A. the ability of a microbial agent to cause disease* B. the ability of a microbial agent to cause infection C. the ability of a microbial agent to prevent disease D. the ability of a microbial agent to produce an antimicrobial compound Difficulty: Easy ASM Standard: 23 12. Which pathogen cannot pass the blood–placenta barrier and infect a fetus? A. Herpes simplex virus 1 B. Listeria monocytogenes C. Salmonella typhi* D. Toxoplasma gondii Difficulty: Moderate ASM Standard: 23 13. Which of the following is a common secondary fungal disease? A. giardiasis B. histoplasmosis C. oral thrush* D. syphilis Difficulty: Moderate ASM Standard: 23 14. Which statement properly describes how Salmonella typhi enters host cells? Page 3 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity A. S. typhi binds to receptors on host cells that cause endocytosis. B. S. typhi is not an intracellular pathogen. C. S. typhi secretes effector proteins that cause membrane ruffling.* D. S. typhi specifically invades phagocytic host cells. Difficulty: Difficult ASM Standard: 8, 13, 22, 23 15. Why are Pseudomonas aeruginosa infections difficult to treat? A. Because they are gram-positive bacteria, which are harder to treat. B. Because they form biofilms, which are difficult for antibiotics to penetrate.* C. Because they have a special endotoxin that degrades many antibiotics. D. Because we do not have any antibiotics that target P. aeruginosa. Difficulty: Easy ASM Standard: 13, 21, 22, 23 16. Which describes the condition in which blood contains actively dividing bacteria? A. bacteremia B. septicemia* C. toxemia D. viremia Difficulty: Easy ASM Standard: 13, 23 17. Molecular Koch’s postulates are used to identify which characteristic of pathogens? A. an effective treatment B. the ID50 C. the LD50 D. virulence factor genes* Difficulty: Moderate ASM Standard: 8, 23, 36 18. Hyaluronidase is which type of exoenzyme? A. glycohydrolase* B. nuclease C. phospholipase D. protease Difficulty: Easy ASM Standard: 22, 23 19. Intracellular pathogens, like Listeria and Rickettsia, produce which type of exoenzyme to aid in escaping the phagosome? Page 4 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity A. glycohydrolases B. nucleases C. phospholipases* D. proteases Difficulty: Moderate ASM Standard: 13, 22, 23 20. Which virulence factor, produced by Staphylococcus aureus, allows the bacterium to be coated in fibrin that protects it from phagocytes? A. catalase B. coagulase* C. collagenase D. oxidase Difficulty: Moderate ASM Standard: 13, 22, 23 21. What is the toxic component of endotoxin? A. lipid A* B. the core oligosaccharide C. the O-antigen D. the peptidoglycan subunits Difficulty: Easy ASM Standard: 8 22. You are working in a hospital and have been asked to perform the LAL test (Limulus amebocyte lysate). After adding the amebocytes from the horseshoe crab to the serum, coagulation is not observed. What conclusion can you draw from this? A. The patient’s serum contains endotoxin.* B. The patient’s serum contains exotoxin. C. The patient’s serum does not contain endotoxin. D. No conclusion can be reached because the LAL test is not used for detection of toxins. Difficulty: Difficult ASM Standard: 28b, 36, 38 23. In the A-B toxin, which subunit is necessary for making the initial attachment to the host cell? A. the A subunit B. the B subunit* C. Depending on the toxin, it could be either the A or B subunit. D. Neither, because A-B toxins do not function this way. Difficulty: Easy Page 5 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity ASM Standard: 23 24. An enterotoxin targets which type of cell? A. cardiac cells B. hepatic cells C. intestinal cells* D. respiratory cells Difficulty: Easy ASM Standard: 23 25. Which toxin inhibits the release of glycine and GABA at the neuromuscular junction, thus preventing the relaxation of muscles? A. anthrax B. botulinum C. diphtheria D. tetanus* Difficulty: Moderate ASM Standard: 23 26. Which is the target for the diphtheria toxin? A. charged tRNA molecules B. elongation factor 2* C. mRNA molecules D. the eukaryotic ribosome Difficulty: Difficult ASM Standard: 23 27. Which are the attachment sites for hemagglutinin spike proteins of influenza virus? A. CD4 receptors B. CD8 receptors C. heparan sulfate D. sialic acid* Difficulty: Easy ASM Standard: 10, 23 28. Which is the name of the toxin produced by species of Aspergillus that can cause liver cancer? A. aflatoxin* B. citrinin C. ochratoxin D. patulin Page 6 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Difficulty: Moderate ASM Standard: 9, 23 29. The Panton-Valentine leukocidin from Staphylococcus aureus targets which cell type? A. intestinal epithelial cells B. neurons C. red blood cells D. white blood cells* Difficulty: Easy ASM Standard: 13, 22, 23 30. Which surface molecules do helminths commonly express that protect them from the host immune system? A. fibrins B. glycans* C. hemagglutinins D. proteases Difficulty: Easy ASM Standard: 9, 13, 23 True/False 31. The prodromal period is when the maximum number of pathogen particles or organisms are present in an infected host. Answer: False Difficulty: Easy ASM Standard: 23 32. All pathogens satisfy Koch’s postulates. Answer: False Difficulty: Moderate ASM Standard: 23 33. Facultative intracellular pathogens can reproduce both inside and outside host cells. Answer: True Difficulty: Easy ASM Standard: 13, 22, 23 34. The severity of disease depends only on the activity of the pathogen. Answer: False Page 7 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Difficulty: Easy ASM Standard: 23 35. The normal flora and microbiota of an individual can cause disease. Answer: True Difficulty: Moderate ASM Standard: 23 36. All contacts with a pathogen will result in infection. Answer: False Difficulty: Difficult ASM Standard: 22, 23 37. Extracellular DNA from lysed host cells can function as a means of preventing the spread of a pathogen in a host. Answer: True Difficulty: Moderate ASM Standard: N/A 38. Endotoxin is produced only by gram-negative bacteria. Answer: True Difficulty: Easy ASM Standard: 8 39. Giardia lamblia invades the intestinal mucosa, causing them to shrink and limiting their absorption of nutrients. Answer: False Difficulty: Moderate ASM Standard: 9, 23 40. Bacteria, fungi, and protozoa often use similar virulence factors and mechanisms of pathogenicity. Answer: True Difficulty: Moderate ASM Standard: 8, 9, 23 Matching 41. Match the disease nomenclature to its meaning. A. –derma i. cell destruction Page 8 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity B. –emia ii. thickened skin C. –itis iii. tumor formation D. –lysis iv. inflammation E. –oma v. blood Answers: A. ii., B. v., C. iv., D. i., E. iii. Difficulty: Easy ASM Standard: N/A 42. Match the type of infection to its proper description. A. focal i. The pathogen goes from one location to a second location. B. local ii. A second infection emerges due to killing of protective flora during antibiotic treatment. C. secondary iii. The pathogen spreads throughout the host. D. superinfection iv. The pathogen remains in one location. E. systemic v. Another disease-causing pathogen emerges after an initial infection. Answers: A. i., B. iv., C. v., D. ii., E. iii. Difficulty: Easy ASM Standard: 23 43. Match the bacterial toxin to its mechanism of action. A. botulinum i. inhibits host cell protein synthesis B. cholera ii. activates adenylate cyclase, resulting in higher levels of cAMP and loss of electrolytes leading to diarrhea C. diphtheria iii. inhibits glycine release to inhibit muscle relaxation D. tetanus iv. inhibits release of acetylcholine to inhibit muscle contraction. Answers: A. iv., B. ii., C. i., D. iii. Difficulty: Moderate ASM Standard: 23 44. Match the bacterial toxin to its mechanism of action. A. Clostridium perfringens α toxin i. inhibits host cell protein synthesis B. pneumolysin ii. overactivates immune system, leading to inflammation and toxic shock syndrome C. Shiga toxin iii. assembles into membrane pores, resulting in cell rupturing D. Streptococcus pyogenes mitogenic exotoxin iv. degrades membrane phospholipids Answers: A. iv., B. iii., C. i., D. ii. Difficulty: Difficult ASM Standard: 23 Fill in the Blank Page 9 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity 45. ________ pathogens always cause disease. Answer: Primary (alternative answers: True, Frank) Difficulty: Easy ASM Standard: 23 46. ________ pathogens can cause disease when the host is immunocompromised. Answer: Opportunistic Difficulty: Easy ASM Standard: 23 47. ________ permit pathogens to cause disease. Answer: Virulence factors Difficulty: Easy ASM Standard: 8, 22, 23 48. ________ are molecules, receptors, or surface structures necessary for attachment to a host cell. Answer: Adhesins Difficulty: Moderate ASM Standard: 8, 23 49. ________ are anatomic locations where pathogens can pass into host tissue. Answer: Portals of entry Difficulty: Easy ASM Standard: 23 50. A(n) ________ is a biological poison produced by certain pathogens. Answer: toxin Difficulty: Easy ASM Standard: 23 51. ________ are exotoxins that can trigger a cytokine storm. Answer: Superantigens Difficulty: Easy ASM Standard: 23 52. ________ is a yellowing of the skin and eyes due to the lysis of erythrocytes resulting from infection with either hepatitis B virus or Plasmodium falciparum. Page 10 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Answer: Jaundice Difficulty: Easy ASM Standard: 23 53. ________ are extracellular structures in bacteria that are involved in conjugation and can be used as adhesins. Answer: Pili Difficulty: Easy ASM Standard: 8, 23 54. A(n) ________ is when an influenza virus acquires a new hemagglutinin neuraminidase spike protein from another influenza virus coinfecting the same host cell. Answer: antigenic shift Difficulty: Moderate ASM Standard: 10, 18, 23 Short Answer 55. Explain the similarity and difference between iatrogenic and nosocomial diseases. Sample Answer: Both could occur in the hospital setting. However, iatrogenic diseases are the direct result of a medical procedure, whereas nosocomial diseases are simply acquired in a hospital setting. Difficulty: Easy ASM Standard: 23 56. Why are not all communicable diseases contagious? Sample Answer: Communicable diseases can be transmitted from person to person. How contagious it is depends upon how the pathogen is transmitted. For example, a sexually transmitted disease is contagious only between sexually active individuals. However, someone who is not sexually active would most likely not acquire the disease. Difficulty: Moderate ASM Standard: 23 57. Name three different types or classes of noninfectious diseases. Sample Answer: Any of the following are noninfectious diseases: inherited, congenital, degenerative, nutritional deficiency, endocrine, neoplastic, and idiopathic. Difficulty: Moderate ASM Standard: 23 Page 11 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity 58. On the axes below, sketch and identify the five periods of disease progression, and show the severity of symptoms at each stage. Sample Answer: See below: Difficulty: Moderate ASM Standard: 23 59. (a) Which part of the body does Helicobacter pylori colonize? (b) What is the virulence factor produced by H. pylori that allows it to survive in that location? Page 12 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Sample Answer: H. pylori persists in the stomach by producing urease, which raises the pH of the stomach. Difficulty: Moderate ASM Standard: 13, 22, 23 60. Explain the similarity and difference between chronic and latent infections. Sample Answer: A chronic disease lasts for months or years. Latent diseases last for years, but are distinguished from chronic diseases by a lack of active replication during extended dormant periods. Difficulty: Moderate ASM Standard: 23 61. What is the parenteral route? Sample Answer: The parenteral route refers to any way into the body bypassing the skin and mucous membranes. Thus, it refers to routes into the body other than through the respiratory tract, gastrointestinal tract, or genitourinary tract. It typically it refers to entry into the host through breaks in the skin due to wounds, insect bites, animal bites, and needle pricks. Difficulty: Moderate ASM Standard: 23 62. (a) Explain what a capsule is and how it functions as a virulence factor. (b) Besides bacteria, do any pathogenic eukaryotic microorganisms produce a capsule? Sample Answer: The capsule is a type of glycocalyx. The glycocalyx is a coating of molecules external to the bacterial cell wall, typically made of sugars and/or proteins. The capsule is a highly organized type of glycocalyx. It acts as a virulence factor because it assists attachment of pathogens to a host and protects the pathogen against phagocytosis. Fungi and protozoa also produce capsules. Some helminths produce extracellular polysaccharide glycans that allow them to evade the immune system, functioning in that way like the capsules produced by other pathogenic microbes. Difficulty: Difficult ASM Standard: 8, 9, 13, 23 63. What are the four steps of pathogenesis? Sample Answer: exposure (contact), adhesion (colonization), invasion, infection Difficulty: Easy ASM Standard: 23 64. Describe two ways bacterial pathogens can initiate endocytosis into a nonphagocytic host cell. Page 13 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Sample Answer: Pathogens can secrete effector molecules to trigger entry (membrane ruffling1 ). Alternatively, pathogens can exhibit surface molecules that bind to host cell receptors, allowing the pathogens to enter.2 Difficulty: Moderate ASM Standard: 8, 22, 23 65. How do hyaluronidase and collagenase promote invasion? Sample Answer: Hyaluronan is a sugar polymer found in the epidermis; it connects adjacent cells in connective tissue. Collagen is an important protein found in connective tissue. These two enzymes promote pathogenic invasion of the host by enabling the pathogen to degrade host cell connective tissue, which, in turn, allows the pathogen to penetrate and spread.. Difficulty: Easy ASM Standard: 22, 23 66. In A-B toxins, how does the A subunit separate from the B subunit inside the host cell? Sample Answer: The A-B toxin binds to a specific receptor on the host cell via the B subunit. The toxin is then endocytosed. While in the vacuole, the acidity within the vacuole causes the separation of the two subunits, allowing the A subunit (the activity subunit) to enter the host cell cytoplasm and locate its particular target. Difficulty: Moderate ASM Standard: 23 67. Explain the similarities and differences between the mechanisms of the botulinum and tetanus toxins. Sample Answer: Both toxins are A-B neurotoxins. The botulinum toxin inhibits release of acetylcholine, thus inhibiting muscle contraction. The tetanus toxin inhibits glycine release, which, in turn, inhibits muscle relaxation. Difficulty: Moderate ASM Standard: 23 68. Why must the flu vaccine (flu shot) be given every year? Sample Answer: The rate of antigenic variation, due to antigenic drift or point mutations, and antigenic shift [change in spike proteins due to gene reassortment in a host coinfected with two different influenza viruses]) is high. The immune system may not recognize a new strain of flu from a previous year’s vaccination. Difficulty: Moderate ASM Standard: 10, 23 69. What are four ways that helminths protect themselves from the host immune system? 1Other references may refer to this as the trigger mechanism. 2Other references may refer to this as the zipper mechanism. Page 14 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Sample Answer: For some helminths, their large size alone is enough to protect them from a host immune response. Others produce a tough outer cuticle. Yet others use glycan mimicry, whereby they produce surface glycan molecules that resemble the glycan molecules found on host cells, thereby “disguising” themselves as host cells. Yet others produce proteases that target host cell antibodies. Others suppress the immune system in other ways, including releasing large amounts of material that may either overload the immune system or cause it to act inappropriately. Difficulty: Moderate ASM Standard: 9, 23 Brief Essay Essay Question Rubric RATING Failing Below Average Competent Advanced Criteria for evaluati on Answer does not provide an argument. Answer contains inaccuracies. Writing is poor and contains numerous grammatical mistakes and misspellings. Answer fails to provide examples to support an argument. Writing is poor and grammatical errors are common. Answer is somewhat incoherent. Answer provides an argument with one or two examples that support it. Writing is acceptable for the college level but may contain one or two grammatical mistakes or misspellings. Answer clearly provides an argument with two or more excellent examples that support it; student makes the argument clearly and eloquently. Answer is well organized and free of grammatical errors and misspellings. POINT VALUE 0 1 2 3 Assume rating/grading scale for the question ranges from 0 to 3 points. Questions 70 and 71 involve the following scenario: You are working in a hospital and have discovered what you believe to be a new bacterial pathogen that infects both humans and mice. The pathogen causes a nosocomial disease of conjunctivitis. You now wish to characterize this pathogen. 70. You take a conjunctival swab of an infected patient and culture it for any bacteria. You isolate a bacterial pathogen and grow it in pure culture. Using microscopy and a negative stain, you observe the following: Page 15 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity (credit: American Society for Microbiology) (a) What shape do these cells have? (b) What is the structure surrounding these cells? (c) How could you use Koch’s postulates to determine if this bacterium is the causative agent of the conjunctivitis? (d) How could you use molecular Koch’s postulates to see if the structure surrounding each cell is necessary for the pathogen’s virulence? Answer: Student responses may vary but should include the following. (a) The cells are rod or bacilli shaped. (b) There is a capsule surrounding each cell, which is resistant to stain and appears as a clear halo in this negative stain. Capsule is a type of glycocalyx. The glycocalyx is a coating of molecules external to the cell wall, typically made of sugars and/or proteins. Capsule is a highly organized type of glycocalyx. (c) To determine if the pathogen is causing the conjunctivitis, first, swabs should be taken from both healthy and diseased individuals. The pathogen should only be present in diseased individuals. Second, the suspected pathogen should be grown in pure culture (which the question states can be done). Third, healthy individuals (or mice) should be infected with the suspected pathogen. The same disease (i.e., conjunctivitis) should occur. Fourth, the suspected pathogen should again be isolated, grown in pure culture, and match the pathogen that was observed in the second step. (d) To determine if the capsule is a virulence factor, you can use molecular Koch’s postulates. First, check that the capsule is produced in virulent strains of this bacterium and not in nonpathogenic strains. Generate a mutation in the genome of the pathogen such that it no longer produces a capsule, and then infect a healthy individual (or mouse) to see if the virulence of the pathogen decreases. Finally, restore the capsule production in that mutant and observe if virulence is restored. If it is, then the capsule is a virulence factor. Difficulty: Moderate ASM Standard: 6, 8, 23, 32, 36, 38 71. You take various amounts of the pathogen and infect a group of mice. After a week, you record the number of mice that are alive and dead. The data are shown below. Pathogen Concentration (No. of Cells) Live Mice Dead Mice Page 16 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity 101 10 0 102 7 3 103 4 6 104 2 8 105 1 9 106 0 10 (a) Prepare a graph of percent mortality versus concentration of pathogen. (b) Using the graph, calculate the LD50. (c) You wish to compare the LD50 of this pathogen to Pseudomonas aeruginosa, another known bacterial pathogen that causes nosocomial diseases. If the LD50 of P. aeruginosa for mice is 104 , would you say that your new pathogen is more or less virulent than P. aeruginosa? Be sure to explain your answer. Answer: Student responses may vary but should include the following. (a) Graph is shown below. (a) The LD50 will be between 102 and 103 cells (5 × 102 cells) (b) The unknown pathogen is more virulent. The lower the LD50, the more virulent it is (i.e., less pathogen is necessary to cause death). Difficulty: Difficult ASM Standard: 23, 28b, 29, 36, 38 72. Compare and contrast endotoxins and exotoxins. Specifically address their source, composition, effect on the host, and heat stability. Also, compare their LD50s. Answer: Student response should include the following answers (taken from the textbook table). Page 17 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity Difficulty: Moderate ASM Standard: 23 73. Answer the following questions regarding the cholera toxin: (a) What organism produces this toxin? Briefly identify the shape and cell envelope of this organism. (b) In which class of toxin is the cholera toxin? (c) What results from ingestion of the cholera toxin? Be sure to describe in detail the mechanism of action. Answer: Student responses may vary but should include the following. (a) Vibrio cholerae produces the cholera toxin. V. cholerae is a gram-negative bacterium with a curved rod shape. (b) The cholera toxin is an A-B enterotoxin. (c) The B subunit binds to intestinal epithelial cells and the A subunit enters the intestinal cell and binds to Gs (a G protein). This results in increased adenylate cyclase activity, converting ATP into cAMP. The increased cAMP activates a chloride ion channel in the cell, resulting in the release of chloride ions into the intestinal lumen. Due to osmotic pressure, water also leaves the cells and enters the lumen, resulting in “rice-water stool,” a watery diarrhea. Difficulty: Moderate ASM Standard: 12, 13, 22, 23 74. Explain how Candida albicans, a fungus that is part of the normal flora/microbiota, is an opportunistic pathogen and can cause disease. What diseases can it cause? Answer: Student responses may vary but should include the following. Candida albicans is part of the microbiota of the skin, mouth, intestine, and vagina. Normally, its growth is kept in check by other members of the microbiota or by the environmental conditions of the body. C. albicans is an opportunistic fungal pathogen and can cause disease when overgrowth occurs. Overgrowth can occur due to the following factors:  the use of antimicrobials  decrease in the efficacy of the immune system (i.e., being immunocompromised)  untreated diabetes in which there is a high sugar content in saliva that allows the fungus to grow Page 18 of 19 OpenStax Microbiology Test Bank Chapter 15: Microbial Mechanisms of Pathogenicity  vaginal pH changes  decreases in estrogen during menstruation or menopause C. albicans is the causative agent of oral thrush, vaginal yeast infections, and cutaneous candidiasis. The virulence factors of candida include surface glycoproteins that act as adhesins, proteases to degrade keratin, and phospholipases to facilitate entry. Difficulty: Moderate ASM Standard: 12, 13, 22, 23 This file is copyright 2017, Rice University. All rights reserved. Page 19 of 19