Exam 4 Flashcards Preview

Microbiology > Exam 4 > Flashcards

Flashcards in Exam 4 Deck (131):
1

Define Pathology.

Study of disease

2

Define Pathogen.

Disease causing agent

3

Define Etiology.

Cause of disease

4

Define Pathogenesis.

Manner in which the disease develops

5

Define Infection

Invasion of body by pathogens

6

Define Disease.

Infection causes a change in state of health (abnormal state)

7

When does normal microbiota initially develop?

Formed at birth

8

Where and how are normal microbiota initially introduced into the body?

As the baby leaves the birth canal, as the baby eats and breathes

9

Define Normal Microbiota.

Microbes that colonize the body without causing disease

10

Where does normal microbiota get nutrients?

Secretory products of cells, body fluids, dead cells, food in gastrointestinal tract

11

Name 3 physical and chemical factors that affect normal microbiota.

pH
temperature
oxygen

12

List 5 factors that alter the number and types of normal microbiota from one person to another.

a. age
b. Diet (nutrients)
c. Living conditions
d. occupation
e. Personal hygiene

13

Define Symbiosis.

Relationship between normal microbiota and host

14

Define Commensalism and give 1 example.

One organism benefits and the other is unaffectedEx. Corynebacterium inhabits the eye and lives on dead cells

15

Define Mutualism and give 1 example.

Both organisms benefit
Ex. E.coli in large intestine synthesize vitamin K

16

Define Parasitism and give 1 example.

One organism benefits and the other is harmed
Ex. any virus

17

Define Opportunistic pathogen and give 1 example.

Pathogen that can cause disease if conditions change
Ex. E.coli can become harmful if it is in bladder, lungs, spinal cord

18

List Koch’s Postulates

a. The same pathogen must be present in every case of the disease.
b. The pathogen must be isolated from the diseased host and grown in pure culture.
c. The pathogen from the pure culture must cause disease when it is inoculated into a healthy, susceptible laboratory animal.
d. The pathogen must be isolated from the inoculated animal and must be shown to be the original microbe.Classifying Infectious Diseases

19

Define Symptoms.

Changes in body function
2 Examples:
Pain and malaise

20

Define Signs.

Can be observed and measure
4 Examples:
Lesions, swelling, fever, paralysis

21

Define Communicable disease.

Disease that spreads quickly from one host directly or indirectly

5 Examples:
Chickenpox, measles, genital herpes, typhoid fever, tuberculosis

22

Define Contagious disease.

Easily spread from one person to another
2 Examples:
Chickenpox and measles

23

Define Noncommunicable disease.

Not spread from one person to another
1 Example:
Tetanus

24

Define Endemic disease.

Disease constantly present
1 Example:
Common cold

25

Define Epidemic disease.

Many people in a given area acquire a disease in a short period of time
1 Example:
influenza

26

Define Pandemic disease.

Epidemic that is worldwide
2 Examples:
Influenza, AIDS

27

Define Acute disease.

Develops rapidly but lasts a short period of time
1 Example:
influenza

28

Define Chronic disease

Develops slowly but is recurrent or lasts a long time
3 Examples:
Mononucleosis, tuberculosis, hepatitis B

29

Define Latent disease.

Microbe remains inactive but later becomes active to produce symptoms

1 Example:
Shingles—varicella zoster (virus)

30

Define Local Infection.

Invading microbes are limited to a small area
2 Examples:
Boils and abscesses

31

Define Systemic infection.

Microbes spread throughout the body
Example:
Measles

32

List 4 predisposing factors that would make the body more susceptible to
disease.

a. gender
b. Genetic background
c. Inadequate nutrients
d. age

33

Define reservoir of infection.

Source that provides a pathogen with adequate conditions for survival and multiplication

34

List 3 reservoirs of infection.

a. human
b. animal
b. nonliving soil and water

35

Define carriers.

Person that harbors pathogen (without showing signs of illness) and can transmit them to other

36

List 3 diseases that human carriers spread.

a. AIDS
b. gonorrhea
c. typhoid fever

37

List 2 diseases transmitted by animals.

a. rabies
b. lyme disease

38

List the two major nonliving reservoirs of infection.

a. soil
b. water

39

Name 2 microbes that from nonliving reservoirs that can cause infections.

a. Clostridium tetani
b. Clostridium botulinum

40

Define Contact Transmission.

Spread of agent of disease by direct, indirect, droplet

41

Give 3 examples of direct contact (person to person) transmission.

Touch, kissing, sexual intercourse

42

Give 3 examples of illnesses causes by direct contact transmission.

Common cold, hepatitis A, STD, measles

43

Define Indirect contact transmission.

Nonliving objects

44

Define Fomite.

Nonliving objects

3 Examples of fomites:
Needles,tissues, bedding

45

Give 3 examples of illnesses caused by fomites.

HIV (needles), tetanus, hepatitis B

46

Define Droplet transmission.

Mucus droplets travel less than one meter
3 Examples:
Cough, sneeze, laugh

47

Give 3 examples of diseases spread by droplet transmission.

Influeza, pneumonia, whooping cough

48

Define Vehicle of transmission.

Transmitted by food, water, air, blood, drugs, body fluids

49

Define Vectors.

Animals that carry pathogens

50

Define Nosocomial Infection.

Hospital-acquired infection

51

Nosocomial infections are the result of 3 factors:

a. Microbes in hospital environment

b. Compromised status of host

c. Chain of transmission in the hospital

52

According to the CDC, handwashing is the single most important

means of preventing the spread of infection.

53

CDC reports that on average, health care workers wash their hands before interacting with patients

40% of the time.

54

Define Epidemiology

Science that studies when and where disease occur and how they are transmitted

55

17. List the 4 mechanisms of which bacteria become resistant to chemotherapeutic agents.



a. destruction or inactivation of drug
b. prevention of penetration of target site
c. alternation of drug target site
d. rapid ejection

56

List reasons why antibiotics are no longer effective (human causes).

Misuse, dose regimen too short, poverty, overprescribed

57

Ciproflaxin (nalidixic acid)

- inhibits DNA synthesis
- used to treat Anthrax, UTI’s, pneumonia

58


Linezolid (Zyvox)

- developed in 2001
- 1st new class of antibiotics in 25 years
- inhibit protein synthesis (50S subunit of ribosome)
- treats gram positive bacteria
- used to combat MRSA

59

Sulfoamides


- also called sulfa drugs
- inhibits the synthesis of metabolites
- first synthetic drugs created
- used to treat UTI

60


Erythromycin

- inhibits protein synthesis
- treats gram positive bacteria
- used to treat pneumonia, strepto and staphylo cocci infections

61

Rifampin

- inhibits nucleic acid synthesis
- used to treat tuberculosis and leprosy

62

Tetracycline

- produced by Streptomyces
- inhibits protein synthesis
- used to treat gram positive and negative bacteria and can penetrate body tissues
- used to treat urinary tract infections (UTI), pneumonia, and chlamydial infections

63

Bacitracin

- derived from Bacillus
- inhibits cell wall synthesis
- used to treat gram positives such as staphylococci and streptococci
- applied topically

64

Cephalosporin

- usually given orally
- inhibits cell wall synthesis
- used to treat gram negative bacteria

65

Semisynthetic penicillin

- chemically modified the mold Penicillium
- broad spectrum of activity
- inhibits cell wall synthesis
- used to treat gram negative and gram positive
- Examples: amoxicillin and ampicillin

66

Natural penicillin

extracted from the mold Penicillium
- narrow spectrum of activity
- inhibits cell wall synthesis
- used to treat staphylococci and streptococci
- shouldn’t be taken with acidic foods because they will decrease its effectiveness
- susceptible to penicillinases

67

Define antimicrobial drugs.

Class of chemotherapeutic agents used to treat infectious disease

68

Define broad-spectrum of activity.

Affect gram positive and gram negative bacteria

69

Define spectrum of activity.

Range microbes that antibiotics affect

70

Why is it difficult to treat viral infections?

The virus is in our cells and we don’t want to harm our cells

71

Why is it difficult to treat fungal or protozoan infections?

They are eukaryotic cells and so are humans

72

Name 3 ways eukaryotic and prokaryotic cells differ.

a. cell wall
b. ribosome
c. metabolic reactions

73

Which is easier to develop drugs against prokaryotic or eukaryotic cells and WHY?

Prokaryotic because we are eukaryotic and we don’t want to damage our cells

74

Which type of bacteria (2) produces most antibiotics, which molds produce most antibiotics?

Streptomyces and Bacillus
Penicillium and Cephalosporium
Spectrum of Antimicrobial Activity

75

Are all antibiotics that are discovered used in treating disease, explain?


No, toxic to humans

76

Where was the organism first isolated from a moldy cantaloupe bought?

Peoria, IL

77

Define antibiotic.

Substance produced by microbes that inhibit growth of another microbe

78

What bacterium was first noticed to be inhibited by Penicillium notatum?

Staphylococcus aureus

79

What is Penicillium notatum?

Mold

80

Who discovered Penicillium notatum?

Alexander Fleming

81

Who coined the term “chemotherapy”?

Paul Ehrlich

82

How do antimicrobial drugs kill microbes?

Interfere with growth

83

Penicillin

- 50 chemically related antibiotics
- different based on the chemical side chains
- produced naturally or semisynthetically
- inhibit cell wall synthesis

84

what is pathogenicity?

ability to cause disease
depends on ability to invade, multiply, and evade host defenses

85

what is virulence?

degree of pathogenicity

86

pathogen?

disease causing agent

87

host?

where pathogen lives

88

infeciton

growth of the microbes on a host

89

why do micbrobes want in?

animals provide favorable environment
-rich in organic food
-maintain Temp and pH

90

what are portals of entry?

where pathogens enter
ex. mucous membrane

91

types of mucous membrane for POE?

resp. tract
gastrointestinal tract
urogential tract

92

what is things to know about resp. tract POE?

enter by inhalation
most common POE
Ex. common cold, pneumonia, strep throat, TB, influenza, measles, and chicken pox

93

what are things to know about the gastro intestial tract POE?

enter by food or water, contaminated objects
Ex. Hepititis A, typhoid fever, and food poisoning

94

what are thing to know about the urogential tract POE?

transmitted sexually
Ex. HIV, Genital warts, herpes, and gonorrhea

95

what is the skin POE?

prime target for pathogen cant be penetrated unless its injured

96

what is the parental route POE?

when microbes enter injured skin or mucous membrane
Ex. injection, bites,cuts, surgery, and burns

97

what is the perfered POE?

pathogens has to enter body in a certain way in order to cause disease
Ex.Clostridium tetni must enter though punctured skin to cause tetanus

98

what is the number of invading microbes?

more microbes present the greater the chance disses happens
LD50
ID50

99

what is LD50

lethal dose ( dose required to kill 50% of test animals)

100

whaat is ID50

infectious dose (dose required to produce infection in 50% of test animals)

101

what is adhesion?

once pathogens are inside host they attach to tissue

102

how is adhesion accomplished?

ligands or adhesion(fimbrae) which bind to receptors on the host's cell

103

if adhesion or receptors are altered

then infection can be prevented

104

What are examples of adherence

S. mutans (cause cavities) attaches to surface of teeth by glycocalyx

105

what are the pentration of Host defense- capsules

glycocaylx around cell wall prevent phagocytosis
Ex. Streptococcus pneumonia and Bacillus anthraets

106

what are the cell wall componets of penetration of host defense?

m protien
mycolic acid

107

what are M proteins

heat and acidic resistance protein prevents phagocytosis
Ex. Streptococcus pyogens (strep throat)

108

what is mycolic acid

waxy lipid in cell wall prevents phagocytosis
Ex. myobacterium tuberculosis (TB)

109

what are the enzymes in part of pentration of host defenses?

leukocidin
collagenase
coagulase
hyalurondinase
hemolysin

110

what is leukocidin?

destorys leukocytes

111

what is collagenase

destroys collagen

112

what is coagulase?

coagulates fibrinogens
Ex. staphylococcus aureus (staph infection)

113

what is hyaluronidase?

digest hyaluronic acid (host cell together)
Ex. streptococcus pyogenes (Flesh Eating)

114

what is hemolysin

the lyse RBC

115

what are the types of hemolysin?

alpha, beta, and gama

116

what is alpha hemolysin?

partial breakdown of hemoglobin adn produces green color around colonies
Ex. S.Mitis and S. salivarius (normal microbiota)

117

what is beta hemolysin?

complete breakdown of hemoglobin and produce clear zone around colonies
Ex. S.pyogenes (strep throat and scarlet fever)

118

what are gama hemolysin?

no breakdown of hemoglobin
Ex. S. epidermis (normal microbiota)

119

what are the four ways damage to cell wall can occur?

1. use host nutrients
2. direct damage (lyse host cell)
3. toxin (poisouns substance)
4. induce hypersensitivity

120

what is toxigenicity?

ability to produce toxin

121

what is toxemia?

presence of toxin in blood

122

what is some toxin info?

can be transported by blood or lymph
can inhibit protein synthesis, destroy blood cells, damage blood vessels, and disrupt NS function
40&% of all toxin cause damgae to cell membrane of hos

123

what symptoms do toxin cause?

fever. shock, diarrhea, and cardiovascular problem

124

what ate the two types of toxins?

Endotoxin and Exterotoxins

125

whar are exotoxins

toxins relase directly inot the blood system
made of proteins
mainly gram positive
produce specific disease symptoms

126

what are the types of extotoxin?

neurotoixin
enterotoxin
cytotoxin

127

what is neurotoxin

attack nerve cells
Ex. E. clostridium tetani (uncontrolled muscle contrations0

128

what is enterotoxin?

affects gastrointestinal tract
Ex. E. Stapholococcus aureus ( food poisoning)

129

what is cytotoxin?

lyse host cell
Ex. E. closridium perfringens (gas gangrene)

130

what are endotoxin?

toxin produced as part of cell wall and released when cell is damaged
gram negative
in LPS layer
antibiotic can worsen it

131

what do all endotoxin produce as symptoms?

chills, fever, weakness, aches, possible shock
but in varying degrees