URIs Flashcards
1
Q
What are the components of the upper respiratory system?
A
Conjunctiva Nasolacrima ducts Epiglottis Middle ear Sinuses and nasal cavity Pharynx Larynx The nose
2
Q
What does surfactant contain that provides protection from pathogens?
A
IgA
Fibronectin
Surfactant
macrophages
3
Q
What is the consequence of EtOH, smoke, and narcotis on the cilia of the upper respiratory tract?
A
Inhibits them
4
Q
What parts of the UR system are not colonized by bacteria? (7)
A
mastoid air cells middle ear sinuses trachea bronchi bronchioles alveoli
5
Q
True or false: Most healthy individuals have no bacteria in their conjunctiva
A
True
6
Q
What keeps the conjunctiva usually sterile?
A
Lysozyme and eyelid blinking
7
Q
What are the normal nose flora? (3)
A
Staphlococcus epidermidis
Staphylcococcus aureus
Corynebacterium spp (diptheroids)
8
Q
What is the gram stain and morphology of staph?
A
Gram + cocci
9
Q
What is the gram stain and morphology of strep?
A
Gram + cocci
10
Q
What is the gram stain and morphology of corynebacterium?
A
Gram + rod
11
Q
What are the four strep bacteria that are found in the nasopharynx (from the viridans group)? Are these usually pathogenic?
A
S. mutans
S. mitis
S. milleri
S. salivarius
These are not usually pathogenic
12
Q
What are the three major groups of bacteria that are in the nasopharynx?
A
Strep
Moraxella catarrhalis
Bacteroides
13
Q
Are strep bacteria aerotolerant?
A
Yes
14
Q
What is the gram stain and morphology is moraella catarrhalis? Aerobic or anerobic?
A
Gram negative coccobacillus
Aerobic
15
Q
What does staph aureus look like in tissue?
A
Bunches of grapes
16
Q
What are the four common pathogens in the nasopharynx, especially in the winter months?
A
Strep penumoniae
Haemophilus influenze
Moraxella catarrhalis
17
Q
Are strep bacteria catalase negative or positive?
A
Negative
18
Q
Are staph bacteria catalase negative or positive?
A
Positive
19
Q
What is group A strep?
A
S. pyogenes
20
Q
What is group B strep?
A
S. agalactiae
21
Q
What is group D strep?
A
S. bovis or Enterococcus faecalis
22
Q
What is the one alpha hemolytic group of strep?
A
Strep Pneumoniae
23
Q
What is the causative agent of strep throat?
A
Strep pyogenes (group A)
24
Q
What is the hemolytic result of strep pyogenes?
A
beta
25
What is the target of a rapid strep test?
Cell wall antigen
26
What does alpha hemolytic mean?
Partial hemolysis of blood (green coloration)
27
What does beta hemolysis mean?
Complete hemolysis around colonies (clear zone around colonies)
28
What does gamma hemolysis mean?
No hemolysis
29
What is the M protein that is on Strep pyogenes?
Antiphagocytic essential for virulence (there are 80 serotypes). This degrades C3b
30
What is the importance of the capsule that some strep pyogenes have?
Inhibits phagocytosis and is a virulence factor
31
Why can someone get infected with strep mutiple times a year?
There are 80 serotypes of the virulence factor
32
What are the superantigens of strep pyogenes?
SPE A, B etc, that are the cause of toxic shock syndrome, fever, rash
33
What is the F protein that strep pyogenes has?
Mediates attachment to host cell
34
Only what disease that S pyogenes causes that is preceeded by a strep throat?
Scarlet fever
35
What is the function of streptolysin O that S. Pyogenes produces? What is this useful for?
cytotoxin responsible for beta hemolysis, lyse red and white cells.
Antibodies against streptolysin O useful for diagnosis
36
What is the function of streptokinase that S.Pyogenes produces?
lyses blood clots and facilitates dissemination of bacteria
37
What is the function of C5a peptidase that Strep Pyogenes produces?
enzyme that degrade C5a component of complement, inhibits attraction of phagocytes
38
Why do we treat strep throat with abx if it would resolve in 7 days anyway?
Scarlet fever and rheumatic fever
39
Why have vaccines been ineffective against Strep throat?
80 different serotypes
40
What is scarlet fever? What is caused by?
Redness of skin, and white coating on the tongue
Caused by erytherogenic toxin release
41
What is acute rheumatic fever? What is it caused by?
A cross reaction of our immune response to S. Pyogenes and our own tissues. This causes heart arrhythmias, arthralgias.
42
What is the treatment for rheumatic fever?
Immunosuppressants
43
Will you have a S. pyogenes infection with rheumatic fever?
No, just immune response gone out of whack.
44
What happens when someone had rheumatic fever, and is reexposed to Strep pyogenes?
Results in a severe autoimmune reaction
45
What group of strep causes Streptococcal Toxic Shock Syndrome (STSS)? Symptoms?
Any group A
nausea, vomiting, diarrhea, hypotension shock and organ failure
46
What causes acute glomerulonephritis after a strep infection? Symptoms?
Antibody complexes
Edema, HTN, Hematuria and proteinuria
47
What is the antigen that S. Pyogenes produces, that causes scarlet fever?
Erytherotoxin
48
A culture of S.pyogenes will show what type of result on a blood agar (alpha, beta, or gamma)?
Beta
49
What are the antibodies that are detected in a strep throat infection?
Antistreptolysin-O
50
What is the causative agent of diptheria?
Corynebacterium diptheriae
51
What are the symptoms of diptheria?
Usual + MASSIVE neck swelling, whitish gray membrane over tonsils, throat, and nasal cavity
52
What is the gram stain and morphology of corynebacterium diphtheriae?
gram positive rod
53
What does corynebacterium diphtheriae look like histologically?
Chinese letters
54
What is the main virulence factor of diptheria?
Diptheria toxin
55
What must happen to diptheria to become pathologic?
Has to be lysogenized by a bacteriophage
56
What is the pathogenesis of diptheria?
Not invasive, does not enter blood or tissue. The released toxin is absorbed by the bloodstream.
57
What is the gray-white membrane in the throat of diptheria made of?
Epithelial cells
58
What explains the targeted virulence of diptheria toxin?
B protein receptor are only on heart, kidneys, nerve cells
59
True or false: the diptheia toxin is released in an inactive form
True
60
What type of toxin is diptheria toxin?
AB exotoxin
61
What is the MOA of diptheria toxin?
Binds EF-2 and stops ribosomal action
62
Why is the diptheria toxin so potent?
True enzyme that can continue to catalyze after one rxn
63
How can you differentiate between bacterial and viral causes of conjunctivitis?
more pus = probably bacteria
64
What are the three main causative agents of conjunctivitis?
Haemophilus influenzae
Streptococcus pneumoniae
Moraxella lacunata
65
What is the gram stain and morphology of Haemophilus influenzae?
Gram - rod
66
What does haemophilus look like under the microscope?
Small, hard to see gram - rods
67
What allows the causative agents of conjunctivits to live in the eye?
Destruction of lysozyme
68
What is the treatment for conjunctivitis?
Cipro, gentomycin, or eye drops
69
What is the MOA of gentomycin?
binds to 30s subunit
70
What are the three main causative agents of OM?
Haemophilus influenze
Strep penumoniae
Moraxella catarhallis
71
What is the one strep group that has alpha hemoylsis?
Strep pneumoniae
72
What is the cause of the pain of OM?
Presse on the stapedius and greater petrosal nerves
73
What causes the transient hearing loss of OM?
Fluid behind the ear imparing movement
74
What is the mechanical cause of OM?
Movement of bacteria from pharynx to inner ear via eustachian tube
75
What are the three main causative agents of sinusitis?
Strep pneumo
Haemophilus influ
Moraxella catarrhalis
76
True or false: Decongestants and antihistamines are generally effective for OM and sinusitis
False- can be harmful
77
What does chlamydia cause?
trachomatis
78
What is the family of bacteria that are obligate intracellular parasites?
Chlamydia
79
What are the elementary bodies of chlamydia?
metabolically inactive but infectious forms
80
What are the reticulate bodies of chlamydia?
Metabolically active and non infectious form
81
What is the pathogenesis of chlamydia?
direct destruction of host cells during replication, and the hos immune response
82
How does chlamydia gain access to the body?
Skin abrasions
83
What is the treatment for diptheria?
Antiserum for the toxin, erytheromycin and penicillin for the bacteria
84
What is the effect of pacifiers on OM?
Increases chances if used beyond age 2
85
What are common complications of OM?
Mastoiditis
86
What are the gram staining, morphology, and anerobic/aerobic qualities of H. influenzae?
Facultative Gram negative rods
87
Encapsulated H. influenzae causes what diseases?
Meningitis
Epitglottis
Cellulits
88
What is the major virulence factor in H. influenzae?
Antiphagocytic capsule
89
Why do patients with systemic H. influenzae infection require prompt antimicrobial therapy?
because the mortality of patients with untreated meningitis or epiglottitis is 100%
90
What is the treatment of choice for H influenzae?
cephalosporins
91
What is the primary prevention approach to treating H. influenzae?
Immunization (3 doses before 6 mo)
92
What are the two genera of chlamydia?
Chlamydia and Chlamydophila
93
What is the mechanism of infection of chlamydia?
Elementary bodies infect phagocytic cells, then turn into reticulate bodies
94
What is the organism that is responsible to trachoma, adult inclusion conjunctivitis, neonatal conjunctivitis, infant pneumonia, and UG infection?
Chlamydia trachomatis
95
What type of chlamydia causes adult inclsion conjunctivitis? Symptoms?
Same as the sexy ones.
Characterized by mucopurulent discharge, keratitis, corneal infiltrates and some vascularization
96
What is neonatal conjunctivitis caused by? Symptoms?
C. trachomatis at birth
Symptoms = eyelid swelling 5-12 days after birth. Causes conjunctival scarring and vascularization (blindness)
97
What is infant pneumonia caused by?
Chlamydia serotype
Symptoms = cough and rhinitis 2-3 week post birth
98
What are the three ways C. trachomatis can be diagnosed?
1) cytologic, serologic or culture findings,
2) direct detection of C. trachomatis antigen in clinical specimens and
3) C. trachomatis through the use of molecular probes.
99
What is the organism that causes TWAR?
Chlamydophila pneumoniae
100
What is the disease caused by chlamydophila pneumoniae?
Pneumonia
101
What is the treatment for C. Pneumoniae infection?
Macrolides
102
What is the causative agent of psittacosis (parrot fever)? Where is this bacteria usually found?
Chlamydia Psittaci--usually found in parrots/other birds
103
What are the symptoms of psittacosis?
Edema, thickening of the alveolar wall, infiltration of macrophages, and necrosis
104
What is the treatment for chlamydia trachomatis?
azithromycin or doxycycline
105
What is the treatment for chlamydia psitti?
Macrolide and tetracycline
