Chapter 24 - Microbial Diseases of the Respiratory System Flashcards
1
Q
What are the diseases of the upper respiratory tract?
A
-strep throat
-scarlet fever
-otitis media
-diphtheria
2
Q
What is the scientific name for “strep throat”?
A
streptococcal pharyngitis
3
Q
Which pathogen causes strep throat?
A
GAS (group A streptococci pyogenes)
4
Q
Why is GAS so pathogenic?
A
have M proteins that resist phagocytosis
5
Q
What are the two enzymes produced by GAS?
A
streptokinases and streptolysins
6
Q
Streptokinases
A
lyse fibrin clots
7
Q
Streptolysins
A
are cytotoxic to tissue cells, RBCs and leukocytes
8
Q
What are the symptoms of strep throat?
A
-redness
-inflammation
-tonsilitis
-enlarged lymph nodes
9
Q
How is strep throat diagnosed?
A
throat swab cultured on blood agar
10
Q
Exudate
A
fluid that leaks out of blood vessels into nearby tissues made of cells and proteins
11
Q
What antibiotic is used to treat strep throat?
A
penicillin
12
Q
What is the sequel to strep throat?
A
scarlet fever
13
Q
What is the toxin produced by S. pyogenes that results in scarlet fever?
A
erythrogenic toxin
14
Q
Is erythrogenic toxin an endotoxin or exotoxin?
A
exotoxin
15
Q
The strain that produced scarlet fever has bee lysogenized meaning…
A
the genetic information of a bacteriophage has been incorporated into the chromosomes of the bacteria, altering them
16
Q
What are the symptoms of scarlet fever?
A
-red skin rash
-high fever
-swollen, strawberry red tongue
-red cheeks
17
Q
What can scarlet fever develop into left untreated?
A
Rheumatic fever
18
Q
S_______ P_______ E________
A
strep pyrogenic exotoxin
19
Q
What organism is responsible for diphtheria?
A
Corynebacterium diphtheriae
20
Q
Corynebacterium diphtheriae
A
-gram-positive
-rod
-pleomorphic
21
Q
Diphtheria is a p__________ disease.
A
progressive
22
Q
What kind of exotoxin does diphtheria produce?
A
A-B exotoxin
23
Q
What does the diphtheria exotoxin do?
A
circulate in blood and damage heart and kidneys
24
Q
Diphtheria Phase I Symptoms
A
-mild fever
-sore throat
-fatigue
-swelling of the neck
25
What is used to treat phase I diphtheria?
erythromycin
26
Diphtheria Phase II Symptoms
-fluid oozes out that thickens and coats the respiratory tract
-resulting in a PSEUDOMEMBRANE
27
How is a pseudomembrane removed?
surgical removal
28
Diphtheria Phase III Symptoms
-pseudomembrane covers respiratory tract and occludes airways
-leads to possible suffocation or death
29
How is diphtheria phase III treated?
-tracheostomy tube
30
What does the D in ''DTaP'' stand for?
-diphtheria toxoid, an inactivated toxin
-produced antibodies against diphtheria toxin
31
What is cutaneous diphtheria?
-ulcer or skin lesion
-covered with a grey membrane
32
What circulatory symptom sets in with cutaneous diphtheria?
septicemia
33
What do antibiotics need to be mixed with when treating diphtheria? Why?
-antitoxin
-antibiotics don't neutralize diphtheria toxin
34
What is a common complication of respiratory tract infections?
otitis media
35
What is otitis media?
middle infection ear
36
Otitis media affects ___% of children before age 3.
85%
37
What forms that puts pressure on the ear drum and causes pain?
pus
38
What is used to treat otitis media?
semi-synthetic penicillin aka amoxicillin
39
What are some of the bacteria that cause otitis media?
-S. pneumoniae
-H. influenzae
-Moraxella sp.
-S. pyogenes
-viruses (RSV)
40
What is the most common cause of otitis media?
S. pneumoniae
41
What is another name for pertussis?
whooping cough
42
Pertussis is an infection of the _________ respiratory tract.
lower
43
What pathogen causes pertussis?
Bordetella pertussis
44
Bordetella pertussis
-obligate aerobe
-gram-negative
-coccobacilli
-has a capsule
45
How and where does pertussis attach?
-by a capsule
-to ciliated cells in the trachea
46
What does the aP in "DTaP" stand for?
acellular pertussis
47
What are the toxins produced by pertussis?
-tracheal cytotoxin
-pertussis toxin
48
What do the pertussis toxins produce?
-damage to ciliated cells
-mucus
49
Does pertussis produce an endotoxin?
yes
50
Stage I Pertussis: Catarrhal Stage
-resembles common cold: fever (endotoxin) and runny nose
51
Stage II Pertussis: Paroxysmal Stage
-violent coughing bouts that can cause broken ribs, bloodshot eyes, and even a small brain hemorrhage
52
Stage III Pertussis: Convalescence Stage
-lasts weeks/moths of coughing
53
What antibiotic commonly treats pertussis?
erythromycin
54
What bacteria causes tuberculosis?
Mycobacterium tuberculosis
55
Mycobacterium tuberculosis
-rod
-obligate aerobe
-acid-fast
56
How does TB affect healthy individuals?
-hardly at all
-innate immunity by macrophages arrest the disease
57
TB Partial Immunity Failure
-symptoms may appear
-tubercule forms with calcified lesions
58
What are GHON complexes?
-healed calcified lesions that are seen on X-ray films
59
TB Total Immunity Failure
-tubercule breaks and bacilli spread into the circulatory and lymphatic systems
60
Miliary Tuberculosis
-TB consumes the patient
-defenses are overwhelmed
61
What are the symptoms of miliary TB?
-loss of weigh and rigour
-productive, bloody cough
62
What is the tuberculin skin test?
-protein mycobacterium derivative injected into forearm
-if a reaction occurs, progression of TB is measured
63
How long does TB treatment take?
~9 months
64
Why is multiple-drug therapy needed for TB?
minimize emergence of resistant strains
65
First-line TB Drugs
1. Isoniazid
2. Ethambutol
3. Rifampin
4. Pyrazinamide
66
What does the first-line do?
suppress cell wall synthesis
67
Second-line TB Drugs
1. Aminoglycosides
2. Fluoroquinolones
3. Streptomycin
4. Para-aminosalicylic acid
68
Multi-Drug-Resistant (MDR) TB Strains
-resist first line drugs rifampin and isoniazid
69
Extensively Drug-Resistant (XDR) TB Strains
-resist second line
-virtually untreatable
70
Is there a TB vaccine?
-yes, Bacilli Calmette Guérin (BCG) Vaccine
71
What is pneumonia?
-pulmonary (lung) infection
-inflammation
-alveoli fill with fluid
72
Pneumonia is a common _________ infection.
nosocomial (HAI)
73
What is the most common pathogenic cause of pneumonia?
Streptococcus pneumoniae
74
What causes typical pneumonia?
Streptococcus pneumoniae
75
Streptococcus pneumoniae
-has a capsule
-gram-positive
76
What is another name for typical pneumonia?
Pneumococcal pneumonia
77
How many strains of S. pneumoniae exist? How many have a vaccine?
90 exist, 20 have a vaccine
78
What are the symptoms of pneumococcal pneumonia?
-high fever
-difficulty breathing
-chest pain
-rust coloured sputum (blood containing) is coughed up
79
Does pneumococcal pneumonia have a toxin?
no
80
What are some susceptible populations to pneumococcal pneumonia?
-COPD patients
-diabetics
-kidney disease patients
-people who smoke/drink
-HIV patients
81
Where does pneumococcal pneumonia first invade? (Hint: circulatory)
bloodstream
82
Where does pneumococcal pneumonia invade second? (Hint: lungs)
pleural cavity surrounding the lungs
83
What can pneumococcal pneumonia invade and cause disease in some cases?
meninges, causing meningitis
84
What are some other causes of Streptococcus pneumoniae?
-pneumonia
-meningitis
-otitis media
-sepsis
85
What was typical pneumonia treated with before resistance was developed?
cephalosporin
86
How is pneumococcal pneumonia diagnosed?
presence of capsular antigen in urine
87
Does pneumococcal pneumonia have a vaccine?
yes, conjugated pneumococcal vaccine
88
What is typical pneumonia now usually treated with?
macrolides
89
What are the possible causes of Atypical pneumonia?
-fungi
-protozoa
-viruses
-other bacteria
90
What is the symptom difference for atypical pneumonia rather than typical?
-Atypical has slower onset, less fever and chest pain
91
What are some bacteria that cause atypical pneumonia?
-Haemophilus influenzae
-Mycoplasma pneumoniae
-Legionella pneumophila
-Coxiella burnetti
92
What is the primary atypical pneumonia cause?
mycoplasma pneumoniae
93
Haemophilus influenzae
-gram-negative
-coccobacillus
94
How is H. influenzae pneumonia diagnosed?
-chocolate agar media culture
-recall X and V factors
95
What is used to treat H. influenzae pneumonia?
cephalosporins
96
What is the drug of choice for H. influenzae pneumonia?
3rd gen cephalosporins
97
What is the HiB vaccine used for?
H. influenzae
98
Mycoplasmas do not have ____ _____
cell walls
99
What is walking pneumonia?
mycoplasmal pneumonia
100
What is the drug of choice for mycoplasmal pneumonia?
tetracycline
101
Legionella pneumophila
-gram-negative
-aerobic
-rod
-replicates in macrophages
102
Is person-to-person transmission possible with L. pneumophila?
no
103
What is L. pneumophila also responsible for?
pontiac fever
104
What does coxiella burnetti cause?
Q fever
105
Coxiella burnetti is the only gram-______ that has ________
gram-negative; endospores
106
Acute Q Fever Symptoms
-high fever
-muscle aches
-headache
-coughing
107
Chronic Q Fever Symptoms
endocarditis (may occur years later)
108
How is Q fever transmitted?
inhalation of aerosols from animals and unpasteurized milk
109
What is used to treat Q fever?
-doxycycline
-tetracycline
110
What is a virus that commonly causes viral pneumonia?
Respiratory Syncytial Virus (RSV)
111
What ages groups does RSV usually affect?
infants and elderly
112
Syncytium
-formed by RSV
-fusion of cells to create giant cells in the lungs
113
Why was RSV called 'Houdini Virus'?
it escaped the immune system
114
RSV Symptoms
-persistent coughing and wheezing
-fever only with bacterial complications
-bronchiolitis
115
RSV Treatment
-prophylaxis
-palivizumab
116
What are influenza symptoms?
-chills
-fever
-headache
-muscular-aches
-coldlike symptoms post fever
117
Is "stomach-flu" really the flu?
-no, influenza has no GI symptoms
-it is probably gastroenteritis
118
What kind of spikes does influenza have?
hemagglutination (HA) and neuraminidase (NA) spikes
119
What do HA spikes do?
allow virus to recognize and attach to body cells
120
What do NA spikes do?
-use enzymes to help virus separate from infected cell after reproduction
121
Spikes account for the ___________ changes that makes influenza have many ___________
antigenic; variations
122
Antigenic Drift
-minor change in genome spikes
123
Antigenic Shift
-major change in genome
-evades most immunity
124
Influenza vaccines are usually m_____valent
multivalent
125
Multivalent
-directed at 3 or 4 most important strains currently circulating
126
What are some disadvantages to the multivalent vaccine for influenza?
-hard to produce
-no long-term immunity
127
What is influenza treated with?
-zanamivir
-oseltamivir
128
What is the goal of antivirals on influenza?
inhibit neuraminidase
