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Flashcards in Test 3 Deck (81):
1

Chemotherapeutic agents that target bacterial cell wall synthesis work only on cells that are metabolically active and

dividing

2

A drug that only kills or inhibits a limited number of pathogens is said to be ___________, whereas those that are effective against many pathogens are _____________.

narrow spectrum, broad spectrum

3

If an antibiotic kills a bacterial pathogen, it is said to be ___________; if it only inhibits the growth of the bacterial pathogen, it is considered to be _____________.

bactericidal, bacteriostatic

4

Lipopolysaccharide, a component of _________________ bacteria cell walls, is release upon call wall destruction and can cause systemic infections in humans

Gram negative

5

____________ are antimicrobial chemicals that are made naturally by certain microorganisms.

Antibiotics

6

Indiscriminate use of antibiotics can lead to the destruction of our resident microbiota and allow overgrowth of non-bacterial microbiota such as __________ ___________.

Candida albicans

7

_______________ is the lowest temperature that will kill all of the cells (sterilize) in a broth culture in 10 minutes.

Thermal death point

8

______ heat is more effective in killing microbes than ____ heat.

moist, dry

9

Formaldehyde gas is commonly used as a 37% solution called __________.

formalin

10

The minimum amount of time required to sterilize a set volume of liquid at a set temperature is known as ______________________.

Thermal death time

11

_____________ is a process in which microbes are quickly frozen then dried.

Lyophilization

12

When all organisms, as well as any endospores have been removed, a specimen is classified as __________.

sterile

13

If an antimicrobial agent is bacteriostatic:

multiplication of microorganisms will resume after removal of the agent

14

Which of the following is an example of sanitization?

A public toilet is treated with disinfectants. A surgeon washes his hands before surgery. Heat is used to kill potential pathogens in apple juice. An autoclave is used to prepare nutrient broth. All of these are examples of sanitization.

A public toilet is treated with disinfectants.

15

Antimicrobial agents that interfere with nucleic acids would also have a direct effect on_________.

protein synthesis

16

Which of he following would have the highest resistance to physical and chemical control?

Bacterial vegetative cells, bacterial endospores, protozoan cysts, fungal sexual spores, or enveloped viruses.

Bacterial endospores

17

Which of the following affects the elimination of bacteria from an object?

Number of bacteria present, host/host material, concentration of the antimicrobial agent, temperature and pH, or all of the above

all of the above

18

Extremely high temperatures exceeding the maximum are ___________, whereas temperatures below the minimum tend to have ____________ effects.

microbicidal, microbistatic

19

In controlling microbial growth, cold temperatures generally

inhibit

20

The temperature-pressure combination for an autoclave is

121 degrees C and 15 psi

21

An effective method for sterilizing heat-sensitive liquids is

filtration

22

The type of antimicrobial drug that would be least toxic to humans is a drug that

inhibits synthesis of the cell wall

23

It is inappropriate to prescribe antibacterial agents to treat cold or flu because

These diseases are cause by viruses.

24

Which of the following is the ultimate means of sterilization?

autoclaving, radiation, incineration, desiccation, or none of these

incineration

25

Which statement is NOT an aim of the use of drugs in antimicrobial chemotherapy?

selective toxicity, active even in high dilution, insoluble in body fluids, microbicidal, all of these are important in antimicrobial therapy

insoluble in body fluids

26

Penicillin and other beta-lactams kill bacteria by affecting

The cell wall

27

Streptomycin and tetracycline kill bacteria by affecting

protein synthesis

28

B-lactam antibiotics have an effect on which of the following type(s) of cells

bacterial cells

29

What is the mode of action of erythromycin?

Inhibit protein synthesis.

30

Erythromycin is particularly effective for treating diseases due to viruses and fungi.

False

31

Antibiotic abuse encourages the development of antibiotic resistant strains such as MRSA.

True

32

Antibiotics can always be taken without risk or worry about side effects on the body.

False

33

A "broad spectrum" antibiotic would be one that attacks many different microbial cell sites.

False

34

Whenever an organism grows in a host, it causes disease

False

35

The number of microorganisms that must be taken into the body for disease to occur is essentially the same for all infectious agents.

False

36

An opportunistic pathogen can invade and cause disease in persons whose host defenses are compromised.

True

37

Autoclaving and pasteurization are two processes that are very effective for sterilization.

False.

38

The best description of the relationship we have with our resident microbiota is

commensalism

39

In a commensal relationship

one benefits, and one is neither harmed nor benefited.

40

The human body typically begins to be colonized by its normal microbiota

during and immediately after birth

41

The body site with resident microbiota that produces beneficial body products including vitamin K and other vitamins is the

large intestine

42

Infection occurs when

Pathogens enter and multiply in body tissues

43

Normal microbiota may be found in all the following environments except:

The stomach, the pharynx, the vagina, the upper respiratory tract, or the large intestine

The stomach

44

The relationship between the body and its normal microbiota

is an example of symbiosis

45

Fungi and yeasts are not members of the normal microbiota.

False

46

The predominant organisms of our normal microbiota in lung alveoli are viridans streptococci.

False

47

Symptoms are:

subjective characteristics of a disease that can only be felt by the patient

48

Growth of Lactobacillus on the surface of teeth is an example of __________.

normal microbiota becoming opportunistic pathogens

49

A toxin able to induce septic shock, fever, and pain due to cell wall degradation of the gram negative Pseudomonas aeruginosa in the blood is

endotoxin

50

what is the correct sequence of events in infectious disease?

incubation, prodromal period, illness, decline, convalescence

51

Virulence factors include all of the following except:

capsules, exoenzymes, endotoxins, ribosomes, or exotoxins

ribosomes

52

Microbial hyaluronidase, coagulase, and streptokinase are examples of

exoenzymes

53

Exotoxins are

proteins

54

According to the CDC, what would be classified as a Class 4 microorganism?

Ebola virus

55

The total number of deaths in a population due to a disease is the

mortality rate

56

Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are

biological vectors

57

An example of a fomite is

a contaminated utensil

58

After walking through a field, your feet have picked up fungal spores and pathogenic bacteria. Your feet are

mechanical vectors.

59

Hospital acquired infections are called

nosocomial infections

60

Lipopolysaccharide consists of lipid A and O antigen and, as a component of Gr - bacterial cell walls, is released upon cell lysis and causes systemic infections in humans. This component is classified as a(n)

endotoxin

61

A positive antibody test for HIV would be a ________ of infection.

sign

62

Endemic

Present more or less continuously in a particular location

63

Sporadic

Occurs occasionally or in scattered incidences

64

epidemic

attacks many people at same time in same place

65

Pandemic

spread of an epidemic across continents

66

Infection

Condition in which pathogenic microbes penetrate and multiply in the tissues of a host

67

Mixed infection

several agents establish at the same site at same time

68

Systemic infection

Condition which spreads to several body sites and tissue fluids

69

Focal infection

condition in which agent leaves local site and moves to another tissue

70

Local infection

condition which remains confined to a specific tissue

71

Chronic infection

progress slowly, persist of long periods of time

72

Acute infection

rapid onset, severe effects, short duration

73

Secondary infection

cause by normal microbiota; typically follows an infection by a true pathogen

74

Urine specimen

Yes, it would indicate infection because there are no normal microbiota that should live in the urinary tract except for in the urethra.

75

Lung biopsy

Yes, it would indicate infection because there should be no microbiota living in the lower respiratory tract.

76

Cerebrospinal fluid

Yes, it would indicate infection because there should not be anything in the CSF. It should be a sterile environment.

77

Throat Swab

No it does not indicate infection because there are normal microbiota that can be found in the throat that are not causing an infection.

78

Feces

No, because there are normal microbiota that are found in the large intestine and can be seen in stool.

79

Blood

Yes, because there should not be any bacteria found in the blood. Blood is supposed to be sterile, and any bacterial growth would indicate infection.

80

A new bacterium has been secretly engineered and released by aerosol into the population of a large metropolitan city as part of a terrorist scheme. This bacterium produces a lethal neurotoxin, several horrific enzymes, grows rapidly, and has a capsule. After several days, no unusual illnesses have been reported and the terrorists scheme has failed. What factors could the terrorist bioengineers have overlooked?

1. Dehydration of the bacterium due to the aerosol release causing dry capsules and easier digestion by lysosomes.
2. Too high or low optimum growth temperature
3. Neurotoxins may not bind to human cell receptor sites

81

Compare and contrast endotoxins and exotoxins describing toxicity, effects on the body, chemical composition, how they are released from organism and typical sources (types of bacteria that produce them).

Endotoxins are fairly toxic chemicals released by Gram negative bacteria. They are caused by the production and release of lipid A when the bacterial cell lyses. It can cause serious illness in the host. Exotoxins are the most toxic of toxins known to man. They can be caused by Gram positive or gram negative cells. These toxins are released outside of the cell as a product of the exoenzymes that the cell produces naturally to live. These toxins can cause systemic infection, shock, and even death in the host.