EXAM III: Chapter 10 - Host-Microbe Interactions and Pathogenesis

13. Toxemia is a condition A) where a toxin is acting on tissues locally. B) where a toxin has entered the bloodstream resulting in systemic effects. C) that may describe both localized and systemic effects. D) where a vaccine is used to protect against a toxin. E) where a toxin acts as a superantigen.

B) where a toxin has entered the bloodstream resulting in systemic effects.

19. Which biosafety level is incorrectly matched with its description? A) BSL-1: non-pathogens or those that rarely cause disease in healthy people B) BSL- 2: known pathogens but the disease is treatable or preventable C) BSL-2+: known animal pathogens which do not infect humans D) BSL-3: serious, lethal pathogens though some diseases may be treatable E) BSL-4: dangerous, lethal pathogens with no cures or treatments

C) BSL-2+: known animal pathogens which do not infect humans

22. Droplet and airborne precautions A) both require the use of a procedural mask. B) both involve transmission through fine aerosols which require close contact for transmission. C) both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route. D) both require isolation in a specially-ventilated room (AIIR). E) both require use of an N95 respirator.

C) both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route.

16. Which portal of exit will a bloodborne pathogen likely use? A) ocular B) GI mucosa C) parenteral D) respiratory mucosa E) skin

C) parenteral

23. The role of healthcare workers in the management of disease outbreaks A) is only important in BSL-3 or higher facilities. B) can be approached casually. C) should be addressed through periodic training and re-training. D) is limited to properly using personal protective equipment. E) is not critical in U.S. healthcare facilities.

C) should be addressed through periodic training and re-training.

18. Pathogens can obtain iron from the body using A) lipases. B) proteases. C) siderophores. D) transferrin. E) siderophores or transferrin.

C) siderophores.

9. ID50 describes A) the number of cells or virions which will kill 50 individuals. B) the number of cells or virions which will kill 50% of exposed hosts. C) the number of cells or virions needed to establish an infection in 50 percent of exposed hosts. D) the amount of toxin lethal to a 50-pound human or other animal. E) the percentage of individuals which will develop an infection after exposure to 50 cells or virions.

C) the number of cells or virions needed to establish an infection in 50 percent of exposed hosts.

17. Which type of invasin allows a pathogen to break down a blood clot that the body has generated to trap their spread? A) coagulase B) collagenase C) flagella D) kinase E) neuraminidase

D) kinase

2. Examples of healthy host-microbe interactions with our normal microbiota include all except A) immune system maturation. B) vitamin manufacture. C) competition with pathogens. D) microbiota disruption. E) moderation of immune attack against microbiota species while in their normal tissues.

D) microbiota disruption.

12. Exotoxins are A) secreted. B) only made by Gram-positive bacteria. C) the targets of some childhood vaccines. D) secreted and only made by Gram-positive bacteria. E) secreted and the targets of some childhood vaccines.

D) secreted and only made by Gram-positive bacteria.

4. The preference of a pathogen for a specific host is A) dysbiosis. B) opportunism. C) pathogenicity. D) tropism. E) virulence.

D) tropism.

21. Which mode of transmission is not addressed by transmission precautions? A) direct contact B) airborne C) droplet D) vector E) airborne and droplet

D) vector

20. Which statement is true about standard precautions? A) They are used only when the patient is known to be infected with a BSL-2 or higher pathogen. B) They are used in student labs that only handle BSL-1 pathogens C) They are in force only for bloodborne pathogens. D) They require full face shields, gloves, and barrier gowns for all patient contact situations. E) They apply to all healthcare providers working with all patients.

E) They apply to all healthcare providers working with all patients.

Poliovirus is asymptomatic in some hosts, whereas it paralyzes others. True False

True

The host-microbe interaction does not always lead to disease and it often has roles in health. True False

True

___________ is a relationship in which one organism benefits and the other is not affected. a. Commensalism b. Mutualism c. Parasitism d. Antagonism

a. Commensalism

__________ damage the kidneys, whereas __________ affect the liver. a. Nephrotoxins; hepatotoxins b. Hepatotoxins; nephrotoxins c. Endotoxins; exotoxins d. Exotoxins; endotoxins

a. Nephrotoxins; hepatotoxins

__________ are taken in addition to standard precautions to prevent direct contact, droplet, and airborne disease transmission. a. Transmission precautions b. Contact precautions c. Droplet precautions d. Airborne precautions

a. Transmission precautions

Under standard precautions, __________. Choose all that apply. a. all patients are treated as potential sources of bloodborne or other infectious agents b. health care personnel should follow proper hand washing before and after each patient contact c. people must apply universal precautions first d. surfaces must be disinfected, and any contaminated laundry or garments must be removed and laundered as soon as possible

a. all patients are treated as potential sources of bloodborne or other infectious agents b. health care personnel should follow proper hand washing before and after each patient contact d. surfaces must be disinfected, and any contaminated laundry or garments must be removed and laundered as soon as possible

Gram-negative bacteria release ________ when their cell walls break apart. a. endotoxins b. exotoxins c. lipopolysaccharides d. peptidoglycans

a. endotoxins

Endotoxins are a. lipids. b. proteins. c. carbohydrates. d. inorganic molecules.

a. lipids.

The yeasts Candida albicans are found among normal microbiota, but these fungi can become ___________ as a result of a disruption in the normal microbiota. a. opportunistic pathogens b. antagonistic pathogens c. emerging pathogens d. probiotic pathogens

a. opportunistic pathogens

The ability of a microbe to cause disease is called a. pathogenicity. b. virulence. c. infection. d. transmission.

a. pathogenicity.

Staphylococcus aureus, herpes simplex viruses, most influenza strains, Clostridium tetani, and Salmonella species are examples of a. BSL-1 pathogens. b. BSL-2 pathogens. c. BSL-3 pathogens. d. BSL-4 pathogens.

b. BSL-2 pathogens.

_________ is a type of symbiotic relationship in which both participants benefit. a. Commensalism b. Mutualism c. Parasitism d. Antagonism

b. Mutualism

Which of the following is a true statement? a. Vaccines against rubella and varicella zoster are not effective in prevention of TORCH syndrome babies. b. The respiratory tract is the most common portal of entry. c. Certain sexually transmitted pathogens invade through the skin. d. Parenteral entry refers to pathogens that cross the placenta to infect the fetus.

b. The respiratory tract is the most common portal of entry.

The more infectious the pathogen is, the ________ the infectious dose-50 (ID50). a. higher b. lower c. more dangerous d. less dangerous

b. lower

Pathogens can bypass the skin (via bites, cuts, injections, and surgical incisions) and directly invade the underlying subcutaneous tissues, muscles, or bloodstream using a. mucous membranes. b. parenteral entry. c. epidermal entry. d. conjunctiva.

b. parenteral entry.

Exotoxins are a. lipids. b. proteins. c. carbohydrates. d. inorganic molecules.

b. proteins.

A protein called __________ binds to iron and shuttles it to tissues for incorporation into different molecules. a. hemoglobin b. transferrin c. siderophore d. invasin

b. transferrin

___________ is any feature on a pathogen that the immune system detects and then mounts an immune response against. a. A toxin b. An antigenic specificity c. An antigen d. An antibody

c. An antigen

Which of the features below is not included in virulence factors? a. ability to invade host tissues b. ability to acquire nutrients c. ability to determine the mode of transmission d. ability to evade the host's immune defenses

c. ability to determine the mode of transmission

__________ pathogens are infectious but weakened; thus, they might not cause disease in an immune-competent host. a. Virulent b. Lethal c. Potential d. Attenuated

d. Attenuated

A patient was placed in an airborne infection isolation room (AIIR) and later in a facility labeled "AFB precautions." This patient was probably infected with a. chickenpox viruses. b. HIV. c. E. coli. d. M. tuberculosis.

d. M. tuberculosis.

Which of the following is false regarding cytopathic effects? a. Cytophatic effects can kill the affected cell. b. While pathogens have direct cytopathic effects, the immune system also inflicts damage on the body as a by-product of tactics used to fight infections. c. Viral pathogens generate cytopathic effects when they hijack cellular machinery and disrupt normal host cell function. d. Only viruses can induce cytopathic effects.

d. Only viruses can induce cytopathic effects.

__________ are chemicals that, in small amounts, generate a range of adverse host effects such as tissue damage and suppressed immune response. a. Poisons b. Antigens c. Vaccines d. Toxins

d. Toxins

Which of the following is not a function of the normal microbiota? a. manufacture vitamins b. compete with potential pathogens c. promote immune system maturation d. produce white blood cells

d. produce white blood cells

Biosafety level (BSL) assignment is based on numerous criteria. Which of the following is not one of these criteria? a. level of infectivity b. mode of transmission c. extent of disease caused and mortality rates d. types of pathogens

d. types of pathogens

14. Septic shock is typically associated with A) Gram-negative infections. B) either Gram-negative or Gram-positive infections. C) exotoxins. D) exotoxins or endotoxin. E) superantigens.

A) Gram-negative infections.

7. What is an example of a virulence factor that is related to immune system evasion? A) capsule B) fimbriae C) flagella D) iron-binding protein E) LPS in Gram-negative cell wall

A) capsule

10. Which type of toxin is pictured A) endotoxin B) type 1 exotoxin C) type 2 exotoxin D) type 3 exotoxin E) either type 1, type 2, or type 3 exotoxins

A) endotoxin

5. Which factor is responsible for many emerging pathogens in humans? A) expanded host or tissue range of the pathogen B) increased use of antibiotics in the past half-century C) improved sanitation and hygiene practices D) availability of vaccines E) longer life spans resulting in a larger elderly population

A) expanded host or tissue range of the pathogen

8. An attenuated pathogen A) has lost virulence factors needed to cause disease in an immune competent host. B) has recently acquired virulence factors allowing it to jump species. C) is part of the normal human microbiome. D) has become antibiotic-resistant. E) produces toxins.

A) has lost virulence factors needed to cause disease in an immune competent host.

1. Host-microbe interactions A) involve a dynamic give-and-take between the microbe and the host. B) are always harmful. C) are generally commensal. D) never result in the normal species of the microbiota causing disease. E) do not involve host factors.

A) involve a dynamic give-and-take between the microbe and the host.

15. Which portal of entry is mismatched to its description? A) parenteral: pathogen is passed from mother to child through the placenta B) otic: pathogen enters via the ear C) gastrointestinal: often involves fecal-to-oral transmission D) urogenital: often associated with sexually-transmitted pathogens E) ocular: via the conjunctiva

A) parenteral: pathogen is passed from mother to child through the placenta

3. Which factors may result in a normal microbiota species causing disease? A) dysbiosis due to antibiotic therapy B) immune system attack on the host's own tissues C) invasion of other tissues by the microbiota species D) dysbiosis due to antibiotic therapy or immune system attack on the host's own tissue E) dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species

E) dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species

11. Which type of bacterial toxin is matched incorrectly with its description? A) type 1 exotoxin: bind to the targeted host cell at a membrane receptor but do not enter the cell B) type 2 exotoxin: disrupt and damage the host cell membrane leading to cell lysis C) type 3 exotoxin: bind to a membrane receptor then enter the cell D) endotoxin: enters the bloodstream during infection with Gram-negative bacteria E) toxemia: a toxin produced during a viral infection

E) toxemia: a toxin produced during a viral infection

6. The degree or extent of disease that a pathogen causes is A) attenuation. B) a host factor. C) pathogenicity. D) toxicity. E) virulence.

E) virulence.

Minimum personal protection equipment (PPE) is required for BSL-1 and BSL-2. True False

False