chapter 24 & 25: diseases of the respiratory and intestinal tracts Flashcards
(109 cards)
1
Q
diseases of the upper respiratory tract
A
pharyngitis, laryngitis, tonsillitis, sinusitis
2
Q
pharyngitis
A
sore throat, inflammation of mucous membranes of throat
3
Q
laryngitis
A
when larynx is site of infection, affects speech
4
Q
tonsillitis
A
tonsils involved in infection
5
Q
sinusitis
A
sinus cavity infected
6
Q
streptococcal pharyngitis
A
caused by GAS, antibiotic therapy should be started immediately, Beta-lactams effective
7
Q
Streptococcus pyogenes
A
responsible for impetigo, erysipelas, and acute bacterial endocarditis
8
Q
pathogenicity of Streptococcus pyogenes is enhanced by
A
resistance to phagocytosis, presence of polysaccharide capsule, and M protein
9
Q
streptokinase
A
dissolves clots, important virulence trait of Streptococcus pyogenes
10
Q
streptolysins
A
lyses cells, important virulence trait of Streptococcus pyogenes
11
Q
rapid GAS test
A
enzyme immuno assay (EIA) given at clinic to test for the presence of GAS
12
Q
scarlet fever
A
a post-GAS syndrome related to the production of erythrogenic toxin (ET), a phage encoded product
13
Q
only strains that are _____ for the erythrogenic toxin induce scarlet fever
A
lysogenic
14
Q
symptoms of scarlet fever
A
pinkish red rash and spotted tongue having a strawberry-like appearance; upper layer of skin on tongue lost and reddish appearance is quite alarming
15
Q
other than the appearance of scarlet fever, the syndrome is…
A
not dangerous but does signal an acute GAS infection
16
Q
diphtheria is a
A
serious upper respiratory infection caused by Corynebacterium diphtheria
17
Q
corynebacterium diphtheria is _____, but its ____ is very dangerous
A
common, toxin
18
Q
corynebacterium diphtheria is a….. bacteria
A
gram-positive, aerobic, pleomorphic rod
19
Q
diphtheria starts as …
A
sore throat and a fever, followed by malaise and swelling of neck (visible), followed by the appearance of a pseudomembrane clot in the throat made of dead epithelial cells, fibrin, and bacteria that can block the airway
20
Q
death from diphtheria is from
A
asphyxiation due to blocked airway
21
Q
transmission of diphtheria
A
aerosol droplets
22
Q
all symptoms of diphtheria are caused by____
A
diphtheria toxin, DT
23
Q
the DT (diphtheria toxin) blocks…..
A
protein synthesis in eukaryotic cells thus killing them, death of pharyngeal epithelium
24
Q
DT is encoded on a
A
bacteriophage
25
only the _____ strain of diphtheria causes disease
lysogenic
26
treatment of diphtheria
antibiotics and anti-toxin
27
the advent of _____, an effective vaccine, has resulted in the almost disappearance of the disease
DPT (diphtheria, pertussis, tetanus), has a DT toxoid
28
pertussis is known as
whooping cough
29
pertussis caused by bacteria
Bordella pertussis
30
Bordella pertussis is a .... bacteria
small gram-negative, fastidious, obligate aerobic cocc-bacillus
31
____ strains of pertussis are the most virulent
encapsulated
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pertussis is acquired by
aerosol droplets that are inhaled
33
the bacteria of pertussis attach....
to the ciliated epithelial cells of the respiratory airway, unique to this disease
34
after bordella pertussis attached to the ciliated epithelial cells of the airway...
it progressively destroys these cells, negatively affecting the respiratory elevator system for moving mucus
35
pertussis produces several ____ which
toxins, kill cells, esp. ciliated epithelial cells but also neutrophils and other phagocytes
36
pertussis toxin will enter...
the blood stream and this is what causes the systemic symptoms
37
three stages of pertussis
catarrhal stage, paroxysmal stage, convalescence stage
38
catarrhal stage of pertussis
symptoms act like the common cold
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paroxysmal stage of pertussis
characterized by prolonged sieges of coughing with characteristic gasping for air "whooping" sound (destruction of ciliated cells at heart of cough reflex spasms)
40
what causes whooping sounds of pertussis?
host has difficulty expelling air since dying ciliated cells
41
convalescence stage of pertussis
recovery period, may last for months due to intense damage to epithelium
42
deaths from pertussis are from
complications arising after pertussis- meningitis, septicemia, etc.
43
treatment for pertussis
erythromycin and other macrolides, not effective after onset of paroxysmal stage but will reduce spread
44
tuberculosis caused by the bacteria
Mycobacterium tuberculosis
45
Mycobacterium tuberculosis is a .... bacterium
obligate aerobic, slender rod-shaped, acid-fast
46
Tuberculosis: Ziehl-Neelsen stain
requires heat to impregnate waxy, mycolic acid coat of bacterium
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Tuberculosis: Acid-fast stain
carbol-fuchsin stain followed by acid-alcohol decolorization; Tb remains stained, thus "acid-fast"
48
tuberculosis is a ____ growing organism
slow, takes weeks to form colonies
49
tuberculosis is a _______ intracellular bacterium
facultative, lives within macrophages in host, but, can grown on artificial lab media
50
tuberculosis acquired by
inhalation
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if the tuberculosis bacterium reaches the lungs...
it is ingested by a macrophage and survives and multiplies here
52
tubercule
granuloma, is formed where organism is walled off within alveoli as a hard nodule
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most tuberculosis infections result in
asymptomatic, latent infection, about 1/10 latent infections progress to active diseases - if left untreated, kills more than 50% of victims
54
____ and TB go hand in hand
HIV
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____ during lung phase of TB spreads the disease
coughing, once latent disease is not infectious
56
Lesions from TB are detected by
X-ray or CT
57
TB: if body defenses fail or immuno-compromised by some other pathology, ____ ____ are released into...
virulent bacilli, lung, cardiovascular and lymphatic systems
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disseminated infection of TB
called miliary tuberculosis, due to many small tubercules formed in various tissues (look like seeds), this is an indicator for systemic TB
59
consumption
another name for systemic TB
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TB: after miliary tuberculosis, body's remaining defenses become overwhelmed....
patient loses weight and vigor and may die
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diagnosis of TB
Tuberculin skin test, is possible for people to develop a robust cell-mediated immunity to Tb (intracellular residence of Tb); an intra-dermal injection of TB antigen results in local delayed hypersensitivity reaction to antigen in "+" test
62
BCG = Bacillus - Calmette - Guerin is
the product of TB strain that was thought to be an effective vaccine, didn't work and gives + skin test results
63
positive skin tests for TB are usually followed by
X-ray or CT since tubercles are visible here, this is to distinguish between active and latent cases, X-ray cannot tell but CT can
64
treatment combination of TB
Isoniazid, Rifampin (rifampicin), Ethanbutol
65
active infection of TB is determined by
observation of acid-fast bacillus in sputa and culture
66
Legionellosis comes from bacteria
Legionella pneumophila, a newly described microbial species common to freshwater environments
67
Legionella pneumophila is a .... bacteria
aerobic, gram-negative rod, facultative intracellular parasite
68
L. pneumophila is a parasite of
protozoa
69
we become accidentally infected with Legionellosis by
inhaling aerosolized organisms, usually from faulty air conditioning or plumbing systems
70
medium of choice for legionellosis
buffered charcoal yeast extract medium
71
symptoms of Legionnaire's disease
fever, nonproductive cough, general lobar pneumonia symptoms (one lobe of lung infected); difficult to diagnose unless looking for it
72
later stages of pneumonia include
neurological symptoms such as delirium, confusion, etc.
73
L. pneumophila _____ and ____ within..
survives and multiplies, macrophages, often complicating disease and treatment
74
L. pneumophila is resistant to
penicillin due to intracellular residence
75
Treatment for Legionnaire's
erythromycin and other macrolides
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all intestinal pathogens enter through
the oral cavity (fecal oral route)
77
staphylococcal food poisoning caused by
ingesting an enterotoxin produced by Staph aureus
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staphylococcal food poisoning leading cause of
gastroenteritis
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staphylococcal food poisoning is resistant to
heat and high osmotic pressures allowing growth in some cured foods, salt tolerant
80
staphylococcal food poisoning : organisms allowed to grow in food produces
enterotoxin
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toxin in staphylococcal food poisoning can withstand ____ for several minutes so...
boiling. can withstand reheating
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toxin in staphylococcal food poisoning leads to
acute illness hours after ingestion, characterized by intense vomiting and diarrhea
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Staph enterotoxin A is the ______ prevalent, has a _____ effect
most, neurotoxin
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______ in staphylococcal food poisoning triggers a massive inappropriate immunologic response
superantigen
85
shigellosis is also known as
bacillary dysentery
86
symptoms of shigellosis
severe diarrhea, about 20 bms per day, severe cramping, fever
87
shigellosis causes ___ cells to...
M, ingest the bacteria, leads to abcess formation because of lateral movement of the infection; avoids immune responses this way as well
88
shigellosis is caused by
members of the genus Shigella, S. sonnei, S. dysenteriae, S. flexneri, S. boydii; gram negative facultative rods
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shigella is closely related to
E. coli
90
shigella rarely enters
the blood stream
91
shigella treatment
rehydration and antibiotic therapy
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Salmonella is a _____ bacteria
gram neg facultative rod, member of enterobacteriae
93
salmonella inhabit
the human intestine
94
salmonella is split into 2 groups
typhoidal and non, non= salmonellosis (gastroenteritis)
95
salmonella is caused by the bacteria
S. enterica subspecies Typhimurium
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chain of events with salmonella
ingestion of contaminated food, organisms enter small intestine and divide rapidly within intestinal epithelium and macrophages; invade intestinal wall and enter lymphatic/circulatory systems (can enter blood!)
97
symptoms of salmonella
moderate fever, nausea, abdominal pain, cramps, diarrhea
98
treatment for salmonella
oral rehydration
99
salmonella caused by organisms in
eggs or contaminated meat products (chicken)
100
diagnosis of salmonella
isolation of organism from patient's stool
101
cholera is caused by
vibrio cholerae, ingestion of the organism and growth in small intestine and produces a potent endotoxin (Cholera toxin) induces fluid and electrolyte excretion
102
vibrio cholerae
slightly curved, gram neg, rod, single polar flagellum
103
cholera can cause blood to be _____, resulting in
viscous, organ failure
104
cholera symptoms
watery diarrhea, (rich water stool) vomiting, infection often gathered from contaminated water
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cholera is ____ to stomach acid
sensitive, consequently requires large inocula
106
treatment for cholera
doxycycline and intravenous hydration
107
vaccine for cholera
has never really been very effective
108
traveler's diarrhea
enterotoxigenic E. coli (ETEC)
109
E. COLI O157:H7
most commonly associated with under cooked meat--man made disease--selected for at feed lots and is specifically from those cattle--acid tolerant
