Lecture Exam 3 Flashcards
1
Q
Antibiotics
A
Antimicrobial agent that kills and interferes with the growth of microbes
2
Q
Synthetic antibiotic
A
Not natural: made in the lab
3
Q
Semi synthetic antibiotics
A
Natural product that is modified in the lab
4
Q
Why was cantaloupe used to produce penicillin
A
It is cheep and easy to grow
- makes lots
5
Q
Broad spectrum
A
Antibiotic works against many types of bacteria
6
Q
Narrow spectrum
A
Antibiotic works only on a certain bacteria
Specific!!
7
Q
Superinfection
A
Bacterial overgrowth
8
Q
What causes a superinfection?
A
Disruption of a community
- overgrowth of a certain microbe
9
Q
Magic bullet idea
A
Kill the bacteria w/o harking host cells
10
Q
What is the technical term for “magic bullet”
A
Selective toxicity
11
Q
Antimicrobial drugs
A
Kill or interfere with growth of microbes
12
Q
Bacteriostatic
A
Reversibly stops bacteria from growing
- “static” like the tv is stuck
13
Q
Bactericidal
A
Kills bacteria
- like suicide - kill oneself
14
Q
What are the 5 mechanisms of action for Antimicrobial drugs ( inhibit what)
A
- Inhibit cell wall synthesis
- Inhibit protein synthesis (ribosome)
- Inhibit dna replication
- Injury the plasma membrane
- Inhibit metabolism
15
Q
Transpeptidase
A
Enzyme that joins cross bridges on the cell wall
16
Q
Penicillin
A
beta lactam ring = consistent part
Side chain = what makes them different (variable)
17
Q
Competitive inhibitor
A
It competes w/ substrate to bind to active site
- able to bind to active site making it still a functional enzyme
18
Q
Non competitive inhibitor
A
Binds outside of substrate- substrate still able to bind to active site
- makes it nonfunctional due to changing shape
19
Q
Penicillin is a _______ inhibitor
A
Competitive
20
Q
How does penicillin inhibit cell wall synthesis?
A
It inactivated transpeptidase, weakening the cell wall - resulting in the cell lyses (die)
21
Q
What type of solution would the cell lyse in the presence of penicillin?
A
Hypotonic
22
Q
Penicillinase
A
Breaks the beta-lactam ring of penicillin making the antibiotic not functional
23
Q
What are the beta lactams we looked at?
A
- natural penicillin
Methicillin
Amoxicillin
24
Q
Penicillin is most effective against
A
Gram positive : due to having difficult time getting through outer membrane of gram negative
25
Penicillin is a _______ spectrum
Narrow - work against gram positive only
26
Two semisynthetic penicillin
Methicillin & amoxicillin
27
Methicillin
Beta lactamase resistant - resistant against penicillinase
28
Amoxicillin
Fits through porins of gram negatives - can work against normal g+ / g-
29
Clavulanic acid
Non competitive penicillinase inhibitor
30
Amoxicillin with clavulanic acid
Allows it to inhibit cell wall synthesis of normal g+/g- and G+/G- w/ penicillinase present
31
Inhibitors of cell wall synthesis best kill
Only cells that are growing
32
Vancomycin
inhibits cell wall by binding to peptide chains & blocking transpeptidase activity
33
Vancomycin is _____ spectrum
Narrow
34
Mechanisms of inhibiting the ribosome
- blocks tRNA attachment
- Blocks the ability to form a peptide bond
- blocks translocation
- inhibits small & large subunits from interacting
- change shape of ribosome = change of function
35
Ribosome
Has large subunit - 50s
Small subunit - 30s w/ e site, p site, a site
36
What antibiotics target the ribosome
Chloramphenicol
Doxycycline
Streptomycin
Tobramycin
Azithromyosin
Linezolid
37
Doxyclycline
Long retention in the body
38
Streptomycin
Sometimes used for tuberculosis
39
Tobramycin is used for
Cystic fibrosis
40
Azithromycin is sometimes used for
Chlamydia
41
Linezolid is sometimes used against
MRSA
42
Antibiotics that target the ribosome are typically broad or narrow spectrum
Broad
43
What Antimicrobial drug inhibits rna synthesis
Rifampin
44
Rifampin is used to treat
Tuberculosis
45
Rifamycins antibiotic group
Inhibit mRNA synthesis by acting on bacterial rna polymerase
46
Rifampin directly inhibits…..
Transcription
47
What Antimicrobial drug inhibits dna synthesis
Fluoroquinolones
48
Fluoroquinolones antibiotic group
Inhibits bacterial DNA gyrase which can ultimately cause DNA breakage ( relieving tension in dna when dna is unwound during dna replication)
49
What 2 Antimicrobial drugs injure the plasma membrane
Polymyxin B
Daptomycin
50
Polymyxin
Inserts into membrane causing increased permeability (leaky cell)
- target more electronegative membranes
-
51
Polymyxin is effective against
Gram negatives only
52
Daptomycin
Insert into the membrane creating pores leading to leakiness
53
Daptomycin is effective against
Gram positive only
54
Antimicrobial drugs that inhibit metabolism
Sulfonamide
Trimethoprim
55
Sulfonamides (sulfa drugs)
Inhibits one step of folic acid synthesis
56
Trimethoprim
Inhibits another step of folic acid synthesis
57
Synergism
Effectiveness of 2 drugs is greater than one
58
Sulfonamides & trimethoprim are ______ inhibitors
Competitive
59
What are the 4 mechanisms of bacteria resistance to antibiotics
1. Blocking entry
2. Inactivating enzyme
3. Altering molecule
4. Efflux (kicking out) antibiotic
60
Superbug
Multi drug resistant bacteria
61
Example of a superbug
MRSA
62
What can staphylococcus aureus cause
Pimples
Pneumonia
Food poisoning
63
Infections caused by staphylococcus aureus
Skin and soft tissue
Breast implant infection
Endocarditis
64
Mutations that provide antibiotic resistance occur
Spontaneously
65
Natural selection
Passing down genetics
- surviving and reproducing
66
Mutations that allow an organism to survive/ reproduce are selected under certain selective pressure
True or False
True
67
Directional selection
Bacteria that are antibiotic resistance are able to survive and reproduce if treatment was stopped early
68
Advantageous mutations in bacteria can be passed how
Vertically and horizontally
69
What are the 3 ways horizontal gene transfer can occur
Transformation
Conjugation
Transduction
70
What are the 2 ways antibiotic resistant bacteria strains come about?
- overuse of antibiotics
- misuse of antibiotics
71
Overuse of antibiotics cases the high resistance bacteria to survive
True or False
True: ⬆️ antibiotic use = ⬆️ exposure of bacteria to antibiotic = ⬆️ likelihood antibiotic resistant bacteria will survive/ reproduce
72
What are some ways a person can misuse antibiotics
- used inappropriately (taking for their infections)
- treatment is not long enough
Treatment is too low of a dose
73
HAI - Hospital acquired infection
Infection patient gets while in the hospital
74
Hospital acquired infection is also known as
Nosocomial infection
75
CAI - community acquired infection
Infection acquired outside a healthcare facility
76
What three things should you consider with a hAI
Compromised hosts
Chain of transmission
Microbes present in healthcare - antibiotic resistant ones
77
Compromised hosts
Resistance to infection is impaired by disease, therapy or burns
- have suppressed immune system
78
What are some routes of transmission
Direct contact
Indirect contact
79
What a re some ways to prevent antibiotic resistant bacteria from spreading ?
- complete entire antibiotic dose
- do not use left over medication to treat other illness
- try to use narrow spectrum when possible
- don’t take it if it is not necessary
80
Pathology
The study of a disease and its…
81
Etiology
Cause of the disease ( the source)
82
Pathogenesis
How a disease develops ( structurally and functionally)
83
Epidemiology
Study of when and where diseases occur and how diseases are treated
- on population level
84
Infection
Body gets invaded by pathogen
85
Disease
Body (or parts of it)re in a abnormal state where it is incapable of preforming its normal function
86
Can you have an infection without it causing disease?
Yes!!
87
Symptoms
Changes that a patient feels or experiences
Ex. Dizziness or nausea
88
Signs
Changes a physician can physically see/ measure
Ex. Temperature, color,rash
89
Predisposing factors
A factor that makes an individual more susceptible to the disease and may change the diseases progression
90
What are the two disease classifications
Incidence & prevalence
91
Incidence
Number of people in a population that develop a disease during a specific time
- indicates spread of disease (only new cases)
92
Prevalence
Number of people in a population who have a disease at a specific time
- new/old cases
93
Sporadic disease
Occurs spontaneously
94
Endemic disease
Constantly present in a population
Ex, common cold
95
Epidemic disease
Many people in one area contract the disease in a short period of time
96
Pandemic disease
Epidemic disease that occurs worldwide
97
What are the 3 main themes of duration of a disease?
Chronic, substrate, acute
98
Acute means
It develops quickly
- lasts for a short period of time
99
Chronic means
It develops slowly
- likely to recur
100
Subacute means
It’s b/ chronic and acute
101
Latent disease
Causative agent remains dormant but then becomes active
Ex, chicken pox
102
What are some reservoirs of disease?
Humans, animals, water soil
103
Reservoir of infection
A continual source of infection
104
What are two common non living reservoirs?
Soil & water
105
Asymptomatic carriers
Harbor pathogen w/o showing signs of illness
106
Zoonotic disease
Vertebrate animal reservoirs
107
What are ways a person can contract a zoonotic disease?
By handling in Al waste, eating animal products or animal fur
108
What is the goal of. Pathogen when it infects a host?
Survive, reproduce and spread to more individuals
109
What are the 3 main mechanisms of transmission
Contact, vehicle & vector
110
What a re the 3 ways of contact transmission?
Direct, indirect and droplet
111
Direct contact
Physical contact b/w a source and susceptible host
112
Indirect contact
An agent is susceptible host indirectly such as a non living object
113
Fomite
Non living object that spreads infection
114
Droplet contact
Pathogen spreads via mucus droplets (droplet nuclei)
115
How far can pathogen droplets travel?
Less then 1 meter
116
Vehicle transmission
Transmission of disease agents by a medium
- what we need to survive!!!
117
What are some vehicle transmissions (think of essential things to live)
Food, water, air
118
How far can airborne disease travel?
More than 1 meter
119
What helps determine the distance a pathogen will travel?
Pathogen size/ shape
120
Vector transmission
Pathogen is carried in vectors usually by an arthropod
121
Vector
An organism that carries a pathogen from one host to another
122
What are the two types of vector transmission?
Mechanical & biological
123
Vector via mechanical transmission
Arthropod carries pathogen accidentally on feet
Ex. Houseflies
124
Vector biological transmission
Pathogen reproduces in vector and is passed via bitting
Ex. Mosquito
125
When a MRSA is transmitted on a stethoscope from one patient to the next this is an example of what type of transmission?
Indirect contact transmission
126
When salmonella is ingested by eating contaminated food, this is an example of what type of transmission?
Vehicle transmission
127
When plasmodium is transmitted to a human host from a mosquito bite this is an example of what type of transmission?
Vector biological transmission
128
What’s a diseases impact on a community?
- it impacts the community and the community impacts the spread of a disease, how it develops
129
Why was it/ is difficult to study a virus?
- they are really small
- they require a host in order to survive
130
Viruses structure (what they include)
Nuclei acid
DNA/RNA
Protein coat (capsid)
Sometimes: Few proteins
Lipid bilayer - Envelope
131
Virion
Single, mature, infective final particle
132
Capsid
Protein coat that surrounds nuclei acid
133
Capsomere
Protein subunit that makes up capsid
- maybe one/ multiple protein types
134
What a re the different capsid types
Helical
Polyhedral
Complex
135
Helical capsid
Hollow rods
-flexible/ rigid
136
Polyhedral capsid
(Found in animals)
- has many sides
137
Complex capsid
(Looks like spaceship)
Can have multiple capsids
- variable shape
138
An envelope
Lipid layer that covers capsids
- can contain proteins/carbohydrates
139
Glycoprotein spikes purpose
Help attach to host cells
140
Viruses without a envelope are called
Non enveloped viruses
141
What are the two main cycle sin bacteriophage replication?
Lyric cycle
Lysogenic cycle
142
Lyric cycle
Culminates in host cell death
143
What are the 5 steps of the lyric cycle?
Attachment
Penetration
Biosynthesis
Maturation
Release
144
Attachment of lytic cycle
Tail fibers help virus to attach to host cell
145
Penetration of lytic cycle
Drives core through allowing sheath to inject genetic info
146
Biosynthesis of lytic cycle
DNA replication
RNA created via transcription/ translation
- host dna degraded = virus uses host to replicate
147
Maturation lytic cycle
DNA & proteins self assemble creating virions
- build up new viruses
148
Release lytic cycle
Host cell lyses and new viruses released
149
Lysogenic cycle
Host cell survives
- viral dna being integrated into host
150
Prophage
Page dna inserted in to genome
151
What happens during the Lysogenic cycle
Virus attaches releasing dna letting it get integrated (prophage) into host enzyme allowing it to reproduce creating more
152
Transduction
-type of horizontal gene transfer
Bacterial dna is packaged/ integrated into the virus instead of viral dna
153
Animal virus replication steps
1. Attachment
2. Entry
3. Uncoating
4. Biosynthesis
5. Maturation
6. Release
154
Animal virus replication : attachment
Complementary receptor attachment
- host range driven by protein = receptor interacting
155
Animal virus replication: entry
2 ways ; receptor mediated endocytosis & fusion
156
Entry via receptor mediated endocytosis
Virus bound to protein on plasma membrane and brought in by membrane folding
157
Entry via fusion
Viral envelope fuses plasma membrane and releases the capsid into the cells cytoplasm
158
Animal viruses replication: uncoating
Viral nuclei acid separated from protein coat
159
Animal viruses replication: biosynthesis
Synthesis of nucleic acids/ proteins
- creates more phage dna using host machinery
160
Animal virus replication: maturation
Capsid is assembled around genetic info
161
Animal virus replication: release
Can be either via budding or rupture
162
Rupture release
Host plasma membrane is broken apart as virus releases
- host cell usually killed
163
Budding release
Host plasma membrane surrounds virus and pinches off forming an envelope
164
Plaques means
A clearing in a bacterial lawn resulting from lysis by phages
165
What are the different phases of disease?
1. Incubation period
2. Prodromal period
3. Period of illness
4. Period of decline
5. Period of convalescence
166
Incubation period
Time b/w infection and signs/symptoms
167
Prodromal period
Mild, general symptoms (1st few days)
Hard to distinguish b/w common cold & other diseases
168
Period of illness
Most severe signs/symptoms
Where immune system is actively fighting off pathogen
169
Period of decline
Immune system is ‘wining”
- signs/symptoms decreasing
(Pathogen present = declining)
170
Period of convalescence
Recovery time, where individual is regaining strength
- body returns to normal
171
True or False
You can be contagious during all phases of disease
True
172
Pathogenicity
Ability of a microorganism to cause disease by overcoming the defenses of the host
173
Virulence
The degree of pathogenicity of a microb
174
Virulence factor
Specific proteins that help a microbe establish disease
175
What are some portals of entry for a microorganisms?
Mucus membranes
Skin
Parental route
176
Why do bacteria have a preferred portal of entry?
Depending on certain entry will either cause disease or no disease
177
More microbes that invade makes it harder for the immune system to fight
True or False
True
178
ID50
Infectious dose
- needs to infect 50% of population
179
LD50
Lethal dose
- needs to kill 50% of the population
180
Measurements ID50 & LD50 describe
- virulence of bacteria or specific strain
- preferred portal of entry
- # of invading microbes needed to establish disease
181
Adherence
Microbe attaching to plasma membrane
182
Are adherence be pathogenic or non pathogenic
Both!
183
Adhesion (ligand)
Microbial factor that promotes attachment to receptor
184
What are ways bacteria can hide from the immune system?
Capsule
Extracellular enzyme
- coagulase / igA proteais
Antigenic variation
Type 2 secretion system
185
A capsule is best described as a _____ glycocalyx
Organized
186
Capsules
Prevent phagocytic cells from engulfing and killing bacteria
187
Extracellular enzymes
(Exoenzymes) enzymes that work outside the cell
188
Coagulase
Converts fibrinogen into fibrin
- binding fibrin making it resist phagocytosis
189
IgA proteasis
Destroying igA antibodies
- goes in a cuts them
190
Antigenic variation
Alters surface of an antigen
- LIKE A DISGUISE !
Pathogen changes antigen to be unrecognizable
191
How are antigens recognized?
Antigens = surface marker on microbe
Antibody = made from host, who recognizes antigen
192
Influenza virus can have antigenic variation
True or False
True: varies each year
193
Type two secretion system
(Protein “syringes” found in gram- )
- inject effectors into host to make it easier to infect
194
Two ways t cause damage to host cells
Siderophores & toxins
195
Siderophores
Proteins that bind iron (often taken from host)
196
Toxins
Poisonous substances made by certain microorganisms
197
What are the 2 types of toxins?
Endotoxin
Exotoxin
198
Exotoxin
Produced inside bacteria and then released
199
3 types of an exotoxin
A-b
Membrane disturbing
Superantigen
200
Endotoxin
Part of pathogen (the cell wall of g-)
201
Endotoxin a means
Active - effects cells function
202
Endotoxin B means
Binding part - binds to host receptor allowing toxin into host
203
Endotoxin membrane disturbing
Disrupts cell membrane & cell lysis occurs
Ex. Lipids
204
What a re some portals of exit for microbes?
Mucus membranes
Skin
Blood
205
Convolution
The influence of closely associated species on each other in their evaluation
