Microbiology CH 11 - Host-Microbe Interactions Flashcards
(195 cards)
1
Q
Define Symbiosis
A
Sym- Together
-Biosis - Living
2
Q
Does Symbiosis give the information about the nature of the relationship?
A
No
3
Q
What is it called when both species benefit?
A
Mutualism
4
Q
What is it called when one species benefits from an interaction and the other is not affected?
A
Commensalism
5
Q
What is it called when one organism benefits and the other is harmed?
A
Parasitism
6
Q
What is similar to Parasitism?
A
Predation
7
Q
What is it called when one organism is harmed by the actions of another, but the other does not benefit from those actions?
A
Amensalism
8
Q
What are Opportunistic Pathogens?
A
Organisms that are beneficial or harmless can become harmful
9
Q
Can commensal gut bacteria become pathogenic if the opportunity arises?
A
Yes
10
Q
Are Staphylococcus aureus and Clostridium difficile opportunistic pathogens?
A
Yes
11
Q
Where does Staphylococcus aureus reside? What can it cause given the right conditions?
A
- Non-harmful member of skin microbiota
- Severe skin infections
12
Q
Where does Clostridium difficile reside? What can it cause given the right conditions?
A
- Low levels of large intestine
- Normal gut flora is reduced, which leads to excessive growth and a chronic infection
13
Q
Name 3 conditions that provide opportunities:
A
- Compromised immune system
- Malnutrition
- Excessive antibiotic treatment
14
Q
What does it mean when it’s stated that the human body is mostly “non-human”?
A
TLDR; Viruses > Bacterial cells > Human cells
More viruses than bacterial cells; more bacterial cells than human cells
15
Q
How many microbes are on our skin?
A
10^4 to 10^6 CFU/cm^2
16
Q
More than anywhere else, microbes are in our ______________
A
digestive tract
17
Q
How many microbes are in our mouth (saliva)?
A
10^8 to 10^9 CFU/ml
18
Q
How many microbes are in our stomach?
A
10^2 to 10^3 CFU/ml
19
Q
How many microbes are in our small intestine?
A
10^5 to 10^7 CFU/ml
20
Q
How many microbes are in our large intestine?
A
10^9 to 10^12 CFU/ml
21
Q
How many microbes are in our nose?
A
10^4 CFU/nasal swab
22
Q
How many microbes are in our lungs?
A
10^4 CFU/ml
23
Q
How many microbes are in our urogenital tract?
A
10^6 to 10^8 CFU/ml
24
Q
What 7 factors differentiate microbes from one another?
A
- Location on the body
- Age
- Person to person
- Geography
- Dietary Lifestyle
- Antibiotic Use
- Health
25
What organism causes Toxic Shock Syndrome?
Staphylococcus aureus
26
Is Staphylococcus aureus an opportunistic pathogen?
Yes
27
What causes Toxic Shock Syndrome (mechanism)?
Set of toxins produced and enter bloodstream or wounds getting infected from the skin that cause massive immune reaction
28
Can Toxic Shock Syndrome be fatal? If so, what percentage of cases leads to a fatality?
Yes; 5%
29
What are the symptoms of Toxic Shock Syndrome?
Fever, vomiting, rash, rapid blood pressure loss, and loss of skin
30
Staphylococcus aureus causes what disease?
Toxic Shock Syndrome
31
What are the 2 main virulence factors of Staphylococcus aureus and what does each one result in?
1. Beta-lactamase - makes it resistant to penicillin-type antibiotics
2. Toxic Shock Syndrome Toxin - compound that causes immune reaction
32
What 2 factors are needed for treatment of Toxic Shock Syndrome?
1. Treatment of symptoms to prevent organ failure
2. Antibiotics
33
What kind of antibiotics do you want to AVOID when treating Toxic Shock Syndrome?
Antibiotics that aren't Beta-lactams
34
Why is treatment of Toxic Shock Syndrome with antibiotics challenging?
Additional Abx resistance gene
35
What is MRSA and VRSA resistant to respectively? They are becoming more _______, especially in hospitals
1. MRSA - Methicillin
2. VRSA - Vancomycin
3. common
36
Streptococcus pyogenes causes what disease?
Pharyngitis
37
What is another name for Pharyngitis?
Strep throat
38
What are the qualities of Streptococcus pyogenes as a bacterium?
Facultatively anaerobic, hemolytic, and gram-positive
39
Streptococcus pyogenes can lead to what diseases?
Scarlet Fever, Rheumatic Fever, Pharyngitis
40
What organism causes Pharyngitis?
Streptococcus pyogenes
41
What are the symptoms of strep throat?
Swollen lymph nodes, inflammation of back of pharynx, and pus-filled abscesses covering the tonsils
42
What are the 2 main important virulence factors for Streptococcus pyogenes?
1. Capsules that contain Hyaluronic Acid
2. M-Protein
43
Where is Hyaluronic Acid found? What is its function in Streptococcus pyogenes?
1. Normal cells in the body
2. Acts as camouflage against immune system
44
What is M-Protein?
Membrane protein that protects the bacterial cell from being targeted by immune cells (if recognized)
45
What is needed for treatment of Streptococcus pyogenes?
Long-term antibiotics
46
For other Streptococcus pyogenes diseases that are NOT pharyngitis, what other drugs may be used?
Anti-inflammatories
47
What are the qualities of Clostridium botulinum as a bacterium? Where is it found and in what form?
Rod-shaped, gram-positive, spore forming obligate anaerobe
Found in soil (usually spore form)
48
Clostridium botulinum causes what disease?
Botulism
49
What causes Botulism (mechanism)?
Toxin that acts as a muscle relaxant, leading to paralysis
50
What are the symptoms of Botulism?
Blurred vision, dizziness, dry mouth, progressive paralysis, and death
51
What is an alternative way Botulism can be contracted in adults? What about in infants?
HINT: This is why you don't give babies honey
1. Ingestion of toxin (rather than live cells)
2. Ingestion of spores
52
What is Botulism's virulence factor?
Botulinum toxin
53
Botulism is caused by what bacteria?
Clostridium botulinum
54
Describe Botulinum Toxin and how it functions
1. World's most toxic proteins
2. Toxic protein binds to ends of muscle-controlling neurons
3. Binding stops neuron from transmitting its message to muscle, leading to paralysis
55
Are small doses of Botulinum Toxin toxic or dangerous if directly injected into specific muscles?
No
56
What are the 2 'steps' to treating Botulism? What is the alternative treatment for infants?
1. Repeated washing of intestinal tract to remove Clostridium
2. Antibodies to neutralize toxin
3. Antibiotics in infant infections
57
How long do symptoms of Botulism last?
Years or are permanent
58
What are the qualities of Clostridium difficile as a bacterium?
Anaerobic gram-positive spore-forming rods
59
What disease does Clostridium difficile lead to (include alternative name)?
Pseudomembranous Colitis (C-Diff)
60
Where is Clostridium difficile found? When AND why does it become pathogenic?
1. Common member of GI tract
2. Becomes pathogen after broad-spectrum antibiotics treatment
3. As normal gut microbiome dies off, C. difficile survive and reproduce rapidly
61
What are the symptoms of Colitis? The more lethal symptoms are found especially in __________ patients
Inflammation, possible necrosis (death) of colon walls, internal bleeding, and death
Elderly
62
What are the 2 main virulence factors of Clostridium difficile? What are these factors functions/result in?
1. Production of toxins and enzymes, leading to hemorrhagic death of intestinal walls and actual symptoms
2. Spores that are resistant to antibiotics (Cephalosporin and Penicillin), so it can survive while being hard to get rid of
63
What are the 2 treatment methods for Clostridium difficile? What does each one do?
1. Stronger antibiotics such as vancomycin or metronidazole to kill vegetative cells
2. Repopulation of GI tract with healthy community of microbes
64
___________ from healthy colons are incredibly effective against recurring infection
Fecal transplants
65
Pseudomembranous Colitis is caused by what organism?
Clostridium difficile
66
What are the qualities of Mycobacterium tuberculosis as a bacterium?
Gram-positive, acid-fast aerobic bacillus
67
Mycobacterium tuberculosis causes what disease?
Tuberculosis
68
Can people be carriers for Mycobacterium tuberculosis?
Yes
69
The rate of tuberculosis is relatively ________, due to its ______________
low; low virulence
70
What are the symptoms of Tuberculosis?
Persistent productive cough, frequently with blood in sputum, fever, and weakness (more symptoms can arise)
71
In Tuberculosis, what part(s) of the body are infected?
Lungs, BUT more organs can be infected
72
Tuberculosis is caused by what organism?
Mycobacterium tuberculosis
73
What is Mycobacterium tuberculosis' virulence factor?
Mycolic Acid
74
What are the 2 functions of mycolic acid?
1. Protects cell from immune system
2. Protects cell from dehydration - allows survival outside the body for months
75
Can mycolic acid cell be swallowed by immune cells?
Yes
76
What happens when mycolic acid cell is swallowed by immune cells?
Won't be digested in lysosome
77
What makes the cells of Mycobacterium tuberculosis acid-fast?
Mycolic Acid
78
What is the treatment for Tuberculosis?
Long-term antibiotic treatment
79
What are the qualities of Bordetella pertussis as a bacterium?
Non-motile, aerobic, gram-negative coccobacillus
80
Bordetella pertussis causes what disease (include alternative name)?
Whooping Cough (Pertussis)
81
In what group does infection of Bordetella pertussis primarily occur in?
Infants
82
What are the symptoms of Whooping Cough?
Cold-like symptoms, deep coughing, whooping sound between coughs
83
How many coughing spells occur every day?
40-50
84
What are the consequences of the coughing spells?
Difficulty breathing, broken ribs, exhaustion, and vomiting
85
Whooping Cough is caused by what organism?
Bordetella pertussis
86
Half of the infected infants of Bordetella pertussis require hospitalization. True or False?
True
87
What is the main virulence factor of Bordetella pertussis and what does it function in?
2 toxins that increase mucus production in tracheal cells, creating more sticky stuff to attach to
88
What are the 2 toxins and what are their functions respectively?
1. Pertussis Toxin - Adhesion, helping attach to host cell (like viral attachment proteins)
2. Tracheal Cytotoxin - Prevents cilia from moving, so that the mucus stays in place and bacteria can replicate
89
What is the treatment for Whooping Cough?
Individual symptoms are treated, so immune system can kill bacteria
90
How do you prevent Whooping Cough?
Vaccination
91
What are the qualities of Treponema pallidum as a bacterium?
Thin, gram-negative spirochete, obligate parasite
92
Treponema pallidum causes what disease?
Syphilis
93
Define what Syphilis is
Sexually-transmitted infection that has 3 major stages
94
What is it called when Syphilis-infected individuals who become pregnant transmits it to their embryos?
Congenital Syphilis
95
Much of what we know about Syphilis comes from ethical studies. True or False?
False
96
Syphilis is caused by what organism?
Treponema pallidum
97
What are the 3 stages of Syphilis?
1. Primary syphilis
2. Secondary syphilis
3. Tertiary syphilis
98
What is a chancre?
Type of ulcer
99
In primary syphilis, where does a chancre form? What is it like when the chancre forms? When does the chancre go away?
1. Site of infection
2. Frequently painless, may not be noticed
3. Goes away on its own in 3-6 weeks, even if infection is ongoing
100
What is the timeline for secondary syphilis?
3 weeks - 6 months
101
What is the main symptom in secondary syphilis? What are other symptoms that may occur?
Primary Symptom: Whole-body rash
Secondary Symptoms: Fever, headaches, sore throat
102
Many of the skin symptoms go away on their own in secondary syphilis. True or False?
True
103
After secondary syphilis, what percentage of infections enter a latency that lasts for years or decades?
30%
104
Where do complications occur in secondary syphilis?
Bones, joints, liver, eyes, and brain
105
In tertiary syphilis, gummas can form in __________. What type of ____________ do gummas form in (be specific)?
NOTE: Both blanks are the same word
1. Tissue
2. Liver, skin, bone, and cartilage
105
What does latency mean in secondary syphilis?
Person is still infected and can still transmit it, but does not have any symptoms
106
What are gummas?
Benign tumors
107
What do gummas feel like? What do they cause?
1. Painful, but not fatal
2. Can still impair function
108
Neurosyphilis is part of what syphilis stage? It's an infection of what system?
1. Tertiary syphilis
2. Nervous system
109
What part(s) of the body does neurosyphilis frequently occur in?
Blood vessels in brain, cranial nerves, and dorsal roots of spinal cord
110
Symptoms of neurosyphilis are variable, thus depending on the location of the disease. True or False?
True
111
What are the variable symptoms of neurosyphilis?
1. Severe headaches
2. Convulsions
3. Blindness - Argyll-Robertson pupil
4. Dementia
112
Treponema pallidum is very easy to grow in lab. True or False?
False
113
What causes Syphilis (mechanism)?
Spiral shape includes adhesion at the tip, helps attach to epithelial cells
114
After Treponema pallidum is attached to an epithelial cell, what occurs? How many (general amount) tissue types are potential hosts for Treponema pallidum?
1. Cell multiplies rapidly and penetrates into capillaries
2. Many tissue types are potential hosts
115
How is Syphilis treated? Specifically, what kind is used?
1. Antibiotics are extremely effective
2. Ciprofloxacin commonly used
116
Historically, what was used to treat Syphilis? Name 2
Mercury and arsenic
117
How can Syphilis be prevented?
Contact avoidance (condoms) and treatment of the infected before sexual contact
118
What are the qualities of Neisseria gonorrhea as a bacterium?
Gram-negative, aerobic diplococcus
119
Neisseria gonorrhea causes what disease?
Gonorrhea
120
Gonorrhea is a sexually-transmitted disease with different symptoms in men and women. True or False?
True
121
What are the symptoms of gonorrhea in men?
Painful urination, pus, infertility (rare)
122
50% of women mistake gonorrhea for what disease?
Bladder infection
123
What percentage of women are asymptomatic when it comes to gonorrhea?
50%
124
Gonorrhea is caused by what organism?
Neisseria gonorrhea
125
Can Neisseria gonorrhea attach to vaginal cells?
No
126
Where does Neisseria gonorrhea attach to in women?
Cells further up in genital tract (cervix, uterus, fallopian tube)
127
What disease can Neisseria gonorrhea cause in WOMEN?
Pelvic Inflammatory Disease
128
What are the 4 virulence factors of Neisseria gonorrhea? What are their functions?
1. Fimbriae - Attach to host cell (cell specific)
2. Capsule
3. Enzymes - Destroy host antibodies
4. Constantly changing surface proteins - So host doesn't develop long term immunity
129
How is Gonorrhea treated? What specific one is used?
Antibiotics; cephalosporins
130
What is the challenge in treating Gonorrhea?
Resistant strains are arising
131
Enteric bacteria include what organisms? List 3
1. Escherichia Coli
2. Salmonella
3. Yersinia
132
What is the name of a sub-group of Enteric bacteria called?
Coliforms
133
What are the characteristics of Enteric bacteria? What are they frequently associated with?
1. Facultatively anaerobic, gram-negative rods that don’t form endospores and can ferment lactose
2. Frequently associated with fecal contamination
134
What are the 4 virulence factors of Enteric bacteria?
1. Capsules and fimbriae
2. Toxins (that often lead to diarrhea)
3. Hemolysins
4. Type-3 secretion systems (T3SS)
135
What organism causes Bubonic Plague?
Yersinia pestis
136
What kind of bacterium is Yersinia pestis?
Enteric bacterium
137
Do different strains of Yersinia pestis have different severities?
Yes
138
What are the symptoms of Bubonic Plague?
High fever, Buboes (very swollen lymph nodes), bacteremia (bacteria in the blood), necrosis of tissue, and death
139
How is Yersinia transmitted?
Fleas on rodents (rats and squirrels)
140
What is another name for the Bubonic Plague? How much of Europe did it kill?
1. Black death
2. 1/3 of Europe
141
Yersinia pestis causes what disease?
Bubonic Plague
142
What are the 2 key virulence factors of Bubonic Plague? Describe each one
1. Type-3 Secretion System (S3SS) - creates link between bacterium and host phagocyte (immune cell)
2. Toxin it injects - Induces apoptosis in immune cell, so it doesn’t attack Yersinia pestis cell
143
What is apoptosis?
Programmed cell death
144
How is Yersinia pestis treated?
Antibiotics, with easier treatment with early detection
145
How is Yersinia pestis prevented?
Control of rodent populations
146
What is Hepatitis?
Inflammatory condition of the liver
147
What are the 3 main functions of the liver?
1. Sugar storage and regulation in the blood
2. Production of clotting agents
3. Removal of toxins in the body
148
What is Jaundice?
Accumulation of bilirubin (metabolic waste product) in the blood
149
What are the 4 main symptoms of Hepatitis?
1. Jaundice
2. Abdominal distress
3. Bleeding into skin and internal organs
4. Chronic inflammation leading to cirrhosis
150
What is the genome of Hepatitis B? What is the function?
1. Partially dsDNA, partially ssDNA
2. Replicates with an RNA intermediate
151
What does Hepatitis B do?
HINT: 2 parts
1. Infects liver cells, then is released by exocytosis
2. Cell doesn’t die and continues to make more virions (billions of virions per mL of blood)
152
What can happen in the Hepatitis B process?
HINT: 4 parts
1. Viral replication process releases a lot of incomplete viral particles
2. Capsid proteins coated with surface antigens, but no genomes
3. Incomplete viral particles aren’t infectious, but is still recognized by the immune system
4. Viral particles overwhelm immune system
153
How is Hepatitis B transmitted? List 2 ways
1. Any bodily fluids
2. Improperly sterilized needles (or even shared razors or toothbrushes)
154
How infectious is Hepatitis B?
1. Incredibly infectious
2. High viral load in infected individuals
3. Infective dose relatively low
155
Treatment of Hepatitis B is HARDER than prevention. True or False?
True
156
Vaccination is incredibly _______, especially in ____________. What is the efficacy rate?
1. Effective; childhood
2. 95%
157
What is the study of the frequency and distribution of disease and other health-related factors in a population?
Epidemiology
158
What 3 questions are asked in Epidemiology?
1. How frequent are outbreaks?
2. Who is susceptible?
3. Where does the disease come from?
159
Epidemiology is a complex field that combines what other fields?
Biology, psychology, meterology, and climatology
160
What are the 6 stages of a disease?
1. Infection
2. Incubation
3. Prodomal period
4. Illness
5. Decline
6. Convalescence
161
What is the acquisition of a pathogen or its transition into pathogenicity?
Infection
162
What is the time between infection and the arrival of the first symptoms?
Incubation
163
What is when generalized, mild symptoms arise?
Prodomal period
164
What is frequently associated with a gradual immune response, rather than the illness itself?
Prodomal period
165
What is when symptoms are most evident and the disease is usually identified?
Illness
166
What is when treatment and/or the immune system works to combat the disease?
Decline
167
What happens during the Decline phase of a disease? Alternatively, what else can happen?
1. Limits and destroys the pathogen
2. If that doesn’t occur, patient may die
168
What is the phase in which recovery from the disease (no symptoms) takes place?
Convalescence
169
Depending on the disease, a patient may be infectious during ANY stage. True or False?
True
170
What are the 3 main ways disease can spread?
1. Animal Reservoirs
2. Human Carriers
3. Nonliving Reservoirs
171
What are diseases spread by animals called?
Zoonotic diseases
172
What are 4 ways transmission can occur via animal reservoir?
1. Eating an infected animal
2. Contact with animal waste
3. Animal bites
4. Biological vectors
173
What are the 2 main reasons as to why controlling animal reservoirs are challenging?
1. If there are many animals
2. If the animals are wild
174
Human carriers are frequently ______________
Asymptomatic
175
Does transmission via human reservoir require direct contact?
No
176
How may transmission via human reservoir occur?
Contact with contaminated materials
177
What are diseases that arise when a patient is hospitalized for something else? What type of pathogens are these typically?
Nosocomial infections; opportunistic pathogens
178
Name 3 possible nonliving reservoirs
1. Water
2. Food
3. Soil
179
How are nonliving reservoirs contaminated?
Contact with an infected individual
180
What is a parasite that can be found in bodies of water where animals defecate?
Giardia
181
What 2 bacterium’s spores can be found in soil?
Tetanus and Anthrax
182
What is it called when pathogens are spread by people or objects that people touch?
Contact Transmission
183
What kind of transmission is person-to-person?
Direct contact
184
What kind of transmission happens via inanimate objects that transmit the pathogens?
Indirect Contact
185
What kind of transmission occurs if two people are very close when one coughs or sneezes?
Droplet Transmission
186
How far do droplets within droplet transmission travel?
Less than 1 meter
187
What is it when pathogens are spread by some nonliving intermediate?
Vehicle Transmission
188
What is it when droplets travel more than 1 meter? What can propel droplets further?
Airborne Transmission; Air conditioning, wind, sweeping, shaking out clothes
189
What transmission involves contaminated water source? What do organisms frequently rely on?
Waterborne Transmission; rely on fecal-oral route travel
190
What transmission involves contaminated food? What does it rely on?
Foodborne Transmission; fecal-oral route
191
What transmission involves contaminated fluids being handled outside the body? What is an example of this?
Bodily Fluid Transmission; Blood transfusions with contaminated blood
192
What transmission is the spread of a pathogen through an intermediate animal? What kind of animal is it typically and what does it typically do?
Vector Transmission; Insect does not cause the disease, it carries it
193
What is it when the pathogen reproduces within the vector and usually has a step in its life cycle that requires the vector? Give an example
Biological Vector; fleas carrying plaque
194
What is it when the pathogen doesn’t reproduce within the vector, but the vector physically moves the pathogen? Give an example
Mechanical Vector; houseflies land on contaminant, then land on food
