Micro Exam 3 Flashcards
(150 cards)
1
Q
3 major factors leading to the significant decrease of infectious disease during the 20th century.
A
- greatly improved methods of sanitation/water treatment
- the discovery and use of vaccines
- the development and use of antimicrobial drugs and
antibiotics
2
Q
antimicrobial drug
A
-Destroy the disease-causing organism without harming
the host cell
3
Q
antibiotic
A
- natural product made by 1 microbe that inhibits or kills another microbe
4
Q
Define what is meant by the term ‘spectrum of activity
A
- (specifity) specific group of organisms that agent is effective against
5
Q
Narrow Spectrum:
A
-target very specific group
6
Q
Broad Spectrum:
A
- target more than one group
7
Q
Classify how ethambutol and isoniazid work
A
- Highly selective for Mycobacterium tuberculosis
- Inhibit the production and incorporation of mycolic acid
into the cell wall of Mycobacterium
Inhibition of the Cell Wall
8
Q
Inhibition of cell wall synthesis
A
- penicillians
- cephelosporin
- bacitracin
- vancomycin
-isoniazid/ethambutol
9
Q
Inhibition of protein synthesis
A
-aminoglycosides
-tetracycline
-erythromycin
-clindamycin
-chloramphenicol
10
Q
Disruption of nucleic acid
A
-quinolones
-rifampin
11
Q
Disruption of the plasma membrane
A
-polymyxins
-daptomycin
12
Q
Inhibition of folic acid synthesis
A
-sulfonamides
-trimethoprim
13
Q
Inhibition of fungal infections
A
- polyenes
-imidazoles
-echinocandins
-griseofulvin
14
Q
Inhibition of protozoan infections
A
-synthesized quinolines
-metronidazole
15
Q
Antihelminth drugs
A
-helminths: parasitic works
- flukes, tapeworms, roundworms
16
Q
Antiviral drugs (modes of action)
A
- stop the penetration of the virus into the host cell
- stop the replication, transcription, and translation of viral genetic information
- stop the normal maturation of viral particles
17
Q
Anti viral drugs that treat the flu
A
- Amantadine and rimantidine
- relenza and tamiflu
18
Q
Anti viral drugs that treat herpes
A
-cyclovir drugs
19
Q
Antiviral drugs that treat HIV a
A
-inhibit the entry of the virus
-inhibit conversion
-inhibit HIV protein processing, assembly, and release
20
Q
Antibiotic resistance
A
Microbes no longer respond to antimicrobial drugs/antibiotics
21
Q
Describe the 5 mechanisms by which an organism can become resistant to a drug/antibiotic.
A
- drug inactivation
- decreased permeability
- activation of drug pumps
4.change in drug binding site - use of alternate metabolic pathway
22
Q
What are 3 major factors that play a role in the development of resistance?
A
- hospitals
- drug in animal feeds
- global transport
23
Q
Identify possible interactions between the drug/antibiotic and the host.
Toxicity
A
-Liver/kidney: damage
-intestines: diarrhea
-heart: irregular heartbeat
-decreased blood count
-brain: seizures, dizzy, deaf, motor/sensory
-skin:photodermatitis
-teeth: discoloration
24
Q
Identify possible interactions between the drug/antibiotic and the host.
Allergic reaction
A
-skin rash
-respitory inflammation
-anaphylaxis (rare)
25
Identify possible interactions between the drug/antibiotic and the host.
supression of the normal flora
-super infection
-diarrhea, fever, abdominal pain
26
Explain what the Kirby Bauer test is used for
- extremely standardized disk diffusion assay
- used to test susceptibility of pathogenic bacteria and fungi
27
how to do the kirby baur test in the lab.
1. bacterial suspension in broth is made
2. Mueller-Hilton agar swabbed
3. antibiotic disk pressed onto surface of agar
4. plat incubated overnight at 37 degrees
5. Zones of inhibition: measured in mm
6. sensitivity or resistance (standard table)
7. results interpreted: sensitive, intermediate, resistant
28
Explain what the MIC test is used for
-tube dilution assay
-which antibiotic is most effective
29
how to do the MIC test in the lab.
1. serial dilutions of a particular antibiotic are made in microtiter plates: low concentration to high
2. each well inoculated with bacterial suspension
3. plate incubated at 37 degrees
4. MIC determined: lowest concentration of antibiotic that inhibitis growth
30
Normal Flora
- microorganism normally found in a given habitat on our body consistenly
31
transient microorgansims
- organisms found on the body only for a brief period of time (hands/arms)
32
Define pathogen
organism capable of causing disease
33
infection
the invasion or colonization of the body by pathogenic organsims
34
invasiveness
the pathogens ability to penetrate a host and establish itself in the tissue
35
infectious disease
altered state of health caused by invasion of a pathogenic microorganism
36
sign vs symptom
- a sign is changes in the patient you can see and measure as a result (rash, swelling)
- a symptom is a change felt only by the patient as a result (pain, nausea)
37
Describe Mutualistic symbionts
Microbes and host both benefit
38
commensals
microbes benefit, host not affected
39
opportunist
microbes benefit, host is harmed
40
3 major interacting factors determining potential pathogen to infectious disease
- virulence of the organism
-number of organisms
-strength of the host immune response
41
6 major virulence factors:
- Body site
- adherence factors
-escape from body immune response
-direct invasion of the host cell
-siderophores
-toxin production
42
6 major virulence factors:
Body site
- All growth requirements must be met
-examples: nutrient availbility, pH, temp, oxygen requirements
43
6 major virulence factors:
Adherence Factors
1. cell wall components
2. fimbriae
3. extracellular secretion
44
6 major virulence factors:
Escape from the bodys immune response
1. antiphagocytic structures
2. genetic changes
45
6 major virulence factors:
direct invasion
invades, multiplies, kill
46
6 major virulence factors:
Siderophores
aid organism to remain in host and be invasive (iron)
47
6 major virulence factos:
Toxin
1. exotoxins
2. endotoxins
48
Exotoxins
-secreted proteins
-cause disease-specific sign and symptom
-gene frequently located on a plasmid or a prophage
-antibodies are produced in response to exotoxins
- we immunize against exotoxins by using toxoid
-produced mainly by gram (+) bacteria, algae, fungi
49
endotoxins
- lipopolysaccharides
-released when the organism is destroyed
-produced the same signs and symptoms in the host
-antibodies are not produced in response to endotoxins
- we do not immunize against endotoxins
-produced only by gram (-) bacteria
50
Pathology
the study of disease
51
3 major concerns of pathology
- etiology (what is causing the disease)
-pathogenesis (development of disease)
-the effects of the disease on the whole body
52
Identify the reservoirs of infectious disease
continual source of the infectious agent.
53
Identify the transmission routes for infectious disease
how the pathogen is spread
54
List the 5 major portals of entry into the body
1. Respiratory tract
2. Gastrointestinal tract
3. Genitourinary Test
4. Skin and Mucous Membranes
5. Blood
55
Explain the 4 phases of infectious disease development
-incubation
-prodromal
-illness
-convalescence
56
incubation
- time interval between infection and appearance of first sign and symptoms
- length: organism, virulence, #s, immune resistance
57
prodromal period
short period of mild signs/symptoms
58
illness period
most acute: full blown disease; overt signs
59
convalescence period
recovery time: signs/symptoms subside
60
Categorization of infectious disease
-acute vs chronic
-local vs systemic
-primary vs secondary vs inapparent
61
acute vs chronic
acute:
disease develops rapidly
short duration
fever involved
chronic:
disease develops slow
long lasting symptoms
62
Local vs systemic infection
Local: infection limited to one area of the body
systemic: infection spread throughout the body (spread through blood)
63
Primary vs secondary vs inapparent
Primary: long term or permanent damage
secondary: opportunistic only after primary infection
inapparent: signs/symptoms absent
64
Define occurence of infectious disease: endemic
disease constantly present within a geographical area
65
Define occurence of infectious disease:
epidemic
sharp increase in the # of cases of a disease during a particular period of time
66
Define occurence of infectious disease:
sporadic
disease occurs occasionally in a random, unpredictable way
67
Define occurence of infectious disease:
prevalence
percentage of the population having a specific disease at any time
68
Define occurence of infectious disease:
incidence
percentage of the population that contracts a particular disease during a particular time
69
What is ‘epidemiology’?
study of...
-number of cases of a particular disease
-population affected
-when and where diseases occur
-the source and how they are transmitted
-control and prevention methods
70
what is meant by the term ‘emerging infectious disease’.
new or changing diseases that are increasing in the near future
71
what/where is CDC
center for disease control and prevention in Atlanta, GA
72
Nosocomial infection
aquired or developed during a hospital stay
73
Immune system
A multi-level network that provides complete protection against infection.
74
1st line of defense
- physical barriers
-chemical barriers
-genetic barriers
75
State the major factors which make the skin an unsuitable environment for most microbes.
- dry
-salty
-acidic
76
What is the mucous membrane
Epithelial layer which secretes mucus
77
where is the mucous membrane lined
-respiratory
-urinary
-gastrointestinal
-reproductive
78
Chemical barriers:
-sebaceous gland
-meibomian gland
-lysozyme
-sweat
-hydrochloric acid
79
sebaceous gland found in
skin
80
meibomian gland found in
eye lid
81
lysozyme found in
body secretion
82
hydrochloric acid found in
stomach
83
what is meant by a ‘genetic barrier’ and how a genetic barrier can protect a host against a specific pathogen.
Natural barrier created because a given pathogen is specific for a given host
84
2nd line of defense
- phagocytosis
-inflammation
-fever
-interferons
-complement system
85
what is the main WBC involved in second line of defense ?
Phagocyte
86
what is a phagocyte
scavenger WBCs that engulf and destroy particulate matter
87
compare/contrast neutrophils and macrophages
Neutrophils respond first then macrophages (phagocytic cell)
88
Four steps of Phagocytosis
1. chemotaxis
2. adherence
3. ingestion
4. digestion
89
what is chemotaxis
WBC moves toward microbes
90
what is adherence
close contact between WBC and microbe
91
ingestion
microbe is internalized by WBC
92
Digestion
microbes are digested, lysosomes fuse with phagosome membrane
93
what does PAMP and PRR stand for?
PAMP= pathogen associated molecular patterns
PRR= pattern recohnition receptors
94
what do PAMP and PRRs do ?
PRRs: are WBC receptors that binds to PAMPS
PAMPS: signal molecules shared by many microbes
95
what are the four hallmarks of inflammation
-heat
-redness
-swelling
-pain
96
process of inflammation
-tissue damage
-chemicals released
-chemotatic factors
-tissue repair
97
define fever
an abnormally elevated body temperature
98
benefit of fever in immune response
- inhibits multiplication of heat sensitive microbes
- impedes nutrition of bacteria by decreasing the availability of iron
- speeds up production of blood cells
99
what is an interferon
small protein produced naturally by certain white blood cells and tissue cells
100
Describe what the complement cascade is and the end result of this process.
complex system of 26 blood protein which work together to destroy bacteria, viruses, and parasites.
End result: forms membrane attack complex, leading to lysis and destruction of pathogen
101
what are the major cell types in the third line of defense?
- Antigen presenting cells: macrophages and dendritic cells
-Lymphocytes
-Natural killer cell
102
where do B cells originate and what are the cell surface receptors?
originate: bone marrow
cell surface receptors: immunoglobulin molecules
103
where do T cells originate and what are the cell surface receptors?
originate: bone marrow
cell surface receptors: thymus gland
104
define MHC-1
present on all nucleated cells of the body
105
define MHC-II
present on macrophages and B cells
106
What are the two branches of the specific immune response?
- Humoral Response
-Cell mediated response
107
what is humoral response
production of antibodies
108
what are the specific cell types
- macrophages
- t helper 2 cells
- B cells
- plasma cells
109
define antigen
Any foreign molecule which can trigger a specific immune response
110
antibody
Glycoprotein produced and secreted by activated WBCs in response to a specific antigen in the body
111
epitope
the tips of the Y, 3d pockets which binds to a very specific site on the antigen
112
hapten
if too small to elicit an immune response
113
what are the five classes of antibodies
-IgM
-IgG
-IgA
-IgD
-IgE
114
IgM
-5 to 10 percent antibodies
-largest Ig
-first Ig to increase in antigen response
-lysis of gram - bacteria
-M: macroglobulin
115
IgG
-primary secondary response
-only class that crosses placental barrier
-eliminates gram - and gram +
-80 percent of total Igs
-neutralization of viruses and toxins
116
IgE
-0.002 %
-responsible for allergic reactions
-Fc portion bound tightly to basophils and mast cells
-desensitization programs
117
IgA
-1st line of defense
-monomer form: serum
-diner form: mucus secretions
-respiratory, genitoruinary, intestinal, and breast milk
-1-15%
118
steps in T cell dependent pathway
-protein based
-APC-TH2 Cells- B cells- plasma cells - antibodies
119
steps in T cell independent pathway
-simple carbs
-B cells-plasma cells-antibodies
120
what is amnestic response
rapid production of antibody following second contact with antigen
121
what cells are responsible for amnesties response
memory cells
122
primary response to antigen
primary response to antigen
a
occurs directly after exposure
IgM responds first then IgG
123
secondary response to antigen
- antigen exposed to body for the second time
- me rory cells produced that allow body to respond quickly and effectively
- IgG primary response and increases significantly
124
6 roles of antibodies
-activation of compliment
-inflammation
-cytotoxicity
-neutralization
-opsonization
-agglutination
125
benefits of live vaccines
- grow in host
-stimulate antibody production for longer period of time
-stimulate numeral and cell mediated response
-induce production of IgA
126
clonal selection theory
when foreign antigen enters body, only lymphocytes having receptors specific for that antigen will be activated to proliferate
127
cell mediated response
- cell-cell contact leading to destruction of infected/abnormal cells
- defends against bacteria, viruses, protozoa, worms, cancer cells
128
Specific cells involved in cell mediated
- Macrophages
-T helper 1 cells
- cyto t cells
-natural killer cells
129
process of cell mediated response
- APC engulf, process, and display antigen fragments in MHC-2
- TH1 cells recognize MHC2/Ag and bind
- in response to cytokines: TH1 cells activated
- Activated TH1 cells produce additional cytokines which activate macrophages and T cytotoxic cells
130
define cytokine
secreted proteins of the immune system that have an affect on other cells
131
process of T cytotoxic cell lysis
- T cells recognize specific antigen in context on MHC1
- granules within cell move to point of contact between 2 cells and fuse with membrane
- potent cytolytic enzymes cause lysis of target cells
- Tc cells released unharmed to seek out another target cell
132
T cytotoxic cells and natural killer cells
- both derived from bone marrow and target and lyse cells
- NKC do not recognize Ag/MHC-1
- important in killing malignant cells and antibody released cells
133
active immunity
- person exposed to antigen, antibody created, memory forms
- long term protection
134
passive immunity
- preformed antibodies
- immediate protection
short term
135
Natural active
immune response produced antibodies
136
artificial active
antigen exposure through vaccine
immune response produces antibodies
137
natural passive
antibodies pass from mother to fetus
138
artificial passive
anti-serum containing preformed antibodies
139
define vaccine
provides active acquired immunity to infectious disease
140
Name the categories of vaccines
- Killed bacteria or viruses
- Living, attenuated bacteria or viruses
- Toxoids/capsular material of bacteria
- Recombinant DNA technology (genetic engineering)
- Conjugated vaccines
141
benefits of live vaccines
- grow in host
- stimulate antibody production for longer period of time
- stimulate numeral and cell mediated response
- induce production of IgA
142
why do some vaccine require boosters
to ensure an effective secondary response
143
What is an ‘adjuvant’, and why do some vaccines require an adjuvant?
compound that enhances the immune response and it retains antigen at the injection site
144
normal flora and role
- organism found on consistent basis in specific body areas
- compete with and control pathogens
145
body parts with normal flora
- skin
- eyes
- nasal cavity, middle ear, auditory tube, pharynx (highly colonized)
- mouth, esophagus (highly colonized)
- large intestines(extreme numbers)
- external urethra
- reproductive tracts
146
sterile body parts
- larynx, trachea, lungs, bronchus
- stomach
- small intestines
- kidneys, ureters, urinary bladder
- blood and tissues
147
things to know about normal flora
- what is normal flora for one person may not be normal flora for another
- what is normal flora on one body part may not be normal flora on another
- gram (+) bacteria
148
What is ‘conjunctivitis’?
inflammation of the conjuctiva "pink eye"
149
what is the ciliary escalator and how does it work
- mucus traps organisms and particles
-the cilia moves them up and out
150
