clinical bacteriology Flashcards
1
Q
How are GP first differentiated
A
By morphology
- cocci
- bacillus
- branching
2
Q
how are GP cocci split first?
A
catalase +
catalase -
3
Q
catalase + organisms
A
staphylococci
4
Q
catalase - organisms
A
streptococci direction
5
Q
how are GP cocci catalase + organisms split?
A
coagulase +
coagulase -
6
Q
GP; cocci; catalase +; coagulase + organism
A
staph aureus
7
Q
GP; cocci; catalase +; coagulase - organism split based on what?
A
Novobiocin sensitivty/resistance
8
Q
novobiocin resistant
A
staph saprophyticus
9
Q
novobiocin sensitive
A
staph epidermidis
10
Q
how are GP; cocci; catalase - organisms split?
A
based on ability to undergo hemolysis
11
Q
classes of hemolysis
A
alpha
beta
gamma
12
Q
alpha hemolysis
- extent of hemolysis
- differentiated by what
- what color
A
- partial
- capsule / optochin sensitivity / bile solubility
- green
13
Q
examples of alpha-hemolytic organisms and their differentiating characteristics (2)
A
- strep pneumo: capsule / optochin sensitive / bile soluble
- viridans strep: no capsule / optochin resistant / bile insoluble
14
Q
beta hemolysis
- extent of hemolysis
- differentiated by what
- color
A
- complete hemolysis
- bacitracin resistance
- clear
15
Q
examples of beta hemolytic organisms and their differentiating charateristics (4)
A
- GAS (strep pyogenes) : bacitracin sensitive
- GBS (strep agalactiae): bacitracin resistant
- staph aureus (catalase and coagulase +)
- Listeria monocytogenes
16
Q
gamma hemolysis
- extent of hemolysis
- differentiated by what
A
- no hemolysis
- grown in bile and 6.5% NaCl
17
Q
examples of gamma hemolytic organisms and their differentiating characteristics (2)
A
- GDS (enterococcus): grows in both bile and NaCl
2. Nonenterococcus: grows only in bile
18
Q
staph aureus
- types of infections
- virulence factor and mechanism
A
- skin
- organ abscesses
- PNA (superimposed)
- endocarditis
- osteomyelitis
- Protein A: binds to IgG to prevent complement and phagocytosis
19
Q
MRSA is resistant to? (2)
A
methicillin
nafcillin
20
Q
Types of toxins that staph aureus has (3)
A
- TSST-1
- enterotoxin (heat stable)
- exfoliative toxin
21
Q
Special enzymes for algortihm
A
GP / cocci / catalase + / coagulase +
therefore, can form firbin clot around itself and create a abscess
22
Q
what’s the one that infects prosthetic devices and IV catheters?
A
staph epidermidis
23
Q
staph epidemidis algorithm
A
GP / cocci / catalase + / coagulase - / novobiocin sensitive
24
Q
second most common cause of uncomplicated UTI in young women?
A
staph saprophyticus (after e.coli)
25
staph saprophyticus algorithm
GP / cocci / catalase + / coagulase - / novobiocin resistant
26
strep pneumo is most common cause of what infections (4)
- virulence factor? mechanism?
1. meningitis
2. otitis media in children
3. PNA
4. sinusitis
capsule - protection
IgA protease to protect from IgA
27
strep pneumo algorithm
GP / cocci / catalase - / alpha-hemolysis / optochin sensitive and bile soluble
28
viridans strep algorithm
GP / cocci / catalase - / alpha-hemolysis / optochin resis and bile insoluble
29
viridans strep normal flora of where? therefore common cause of what?
cardio relation
oropharynx
dental caries
can cause endocarditis at damaged leaflets
30
strep pyogenes (GAS) algorithm
GP / cocci / catalase - / beta-hemolysis / bacitracin sensitive
31
strep pyogenes (GAS) infections (8)
1. pharyngitis
2. cellulitis
3. impetigo
4. scarlet fever
5. toxic-shock-like syndrome
6. necrotizing fasciitis
7. rheumatic fever
8. acute glomerulonephritis
32
strep pyogenes virulence factor... how does this play role in infection too even with protection
M protein
cross reactivity of M protein with heart leaflets --> rheumatic fever
33
what titers detects strep pyogenes infection
ASO titer
34
what commonly precedes post-strep glomerulonephritis?
impetigo > pharyngitis
35
Scarlet fever?
scarlet rash with sandpaper texture
strawberry tongue
circumoral pallor
36
strep agalactiae (GBS) algorithm
GP / cocci / catalse - / beta-hemolysis / bacitracin resistant
37
common infections of GBS
1. PNA
2. meningitis
3. sepsis mainly in babies
38
GBS is common bacteria of what area? therefore...
vagina... therefore pregnancy screen at 35-37 weeks ... if positive PCN ppx
39
enterococci (GDS) algorithm
GP / cocci / catalase - / gamma-hemolysis / grows in bile and NaCl
40
enterococci common infections
1. UTI
2. biliary tract infections
3. subacute endocarditis (following GU/GI procedures)
41
GDS is normal flora where?
colon, GI
42
what's REALLY special about enterococci?
they are very resistant
| VRE - vanco resistant enterococci ... nosocomial infections
43
strep bovis ...
- what group strep is it
- where is it colonized
- what does it cause
- GDS
- gut
- bacteremia and subacute endocarditis in colon cancer pts
44
what encodes diphtheria toxin?
beta-prophage
45
presentation of diphtheria toxin infection
1. pseudomembranous pharyngitis (gray-white MB)
2. LAD
3. myocarditis
4. arrhythmias
46
corynebacterium diphtheria algorithm
GP with metachromatic (blue/red) granules and Elek text for toxin
47
examples of spore producing GP found in soil
bacillus anthracis
clostridium perfringens
clostridium tetani
48
other spore formers: (3)
1. b cereus
2. c botulinum
3. coxiella burnetti
49
clostridia with exotons (4)
1. tetani
2. botulinum
3. perfringens
4. difficile
50
c. tetani
- what exotoxin does it produce
- what does it do
- what does it cause
- tetanospasmin
- protease that cleaves SNAREs and prevents release of GABA and glycine
- spastic paralysis, trismus (lockjaw), and risus sardonicus
51
c. botulinum
- where can it be found
- what does it cause
- properties of toxin
- honey
- flaccid paralysis
- preformed, heat-labile toxin that inhibits release of Ach
52
c. perfringens
- what exotoxin
- what does it cause
- alpha toxin (lecithinase)
- myonecrosis (gas gangrene) and hemolysis
"perfringnes "perf"orates the leg"
53
c. difficile
- what toxins
- what do they do
- how diagnosed
- 1. Toxin A (enteroxin)
2. Toxin B
- Toxin A binds to brush border
- Toxin B disrupts actin depolymerization
- detection of one or both toxins in stool
54
anthrax by what organism
bacillus anthracis
55
bacillus anthracis algorithm
GP, spore-forming rod
56
what's particular about bacillus anthracis
only bacterium with polypeptide capsule that contains D-glutamate
57
two types of anthrax
1. cutaneous
| 2. respiratory
58
properties of cutaneous anthrax
| - bacteremia?
boil-like lesion that causes ulcer with black eschar
- painless and necrotic
- rarely to bacteremia and death
59
properties of pulmonary anthrax
| -
2/2 inhaled spores
| - flu-like to fever, pulmonary hemorrhage, mediatstinitis, shock
60
Woolsorter's disease
inhalation of spores from contamined wool
61
bacillus cereus
- what does it cause
- properties of toxin
- what's toxin called
- what syndrome does it cause?
- food poisoning
- spores survive cooking
- cereulide
- Reheated rice syndrome
62
Reheated rice syndrome?
- what organism
- what toxin
- bacillus cereus
| - cereulide
63
Listeria monocytogenes algorithm
GP / bacillus / facultative intracellular
64
what's special about listeria in terms of GP-ness
only one that forms LPS
65
Listeria acquired by what mechanisms? (4)
1. unpasteurized dairy
2. deli meats
3. trans-placenta
4. vertical transmission
66
Listeria moves how?
| how does it avoid antibody?
tumbling motility
forms "rocket tails" via actin polymerization to swim around cytoplasm
67
Listeria causes what sorts of infections in normal healthy people (1)
- what's treatment
mild gastroenteritis
- self-resolving
68
Listeria causes what sorts of infections in immunocompromised people? (1)
- treatment?
meningitis
- ampicillin
69
Listeria causes what in infants? (2)
- treatment?
1. granulomatosis
2. infantiseptica
- ampicillin
70
Listeria causes what in pregnant women? (3)
1. amnionitis
2. septicemia
3. spontaneous abortion
71
what bacteria form branching filaments like fungi?
1. actinomyces
| 2. nocardia
72
actinomyces found where
oral flora
73
nocardia found where
soil
74
actinomyces causes what sorts of inections? (2)
1. oral abscesses
2. facial abscesses
drains via sinus tracts and forms yellow sulfur granules
75
nocardia causes what sorts of infections? (2)
1. pulmonary infection in ummunocompr
| 2. cutaneous infection after trauma in normal pts
76
treat actinomyces with what
PCN
77
treat nocardia with what
sulfonamides
78
what's a Ghon complex
TB: hilar nodes and lesion in mid zone lung from primary TB
79
what's more specific test for TB than PPD?
interferon-gamma release assay (IGRA)
- fever FP from BCG vaccination
80
Mycobacterium avium
- infects whom
- treatment
- causes disseminated non-TB disease in AIDS
| - ppx azithromycin
81
Mycobacteria leprae
- classification
- what temperature does i like
acid-fast bacillus
likes cold temperature
82
Leprosy causes what disease
Hansen disease
83
Two forms of Hansen disease
1. Lepromatous
| 2. Tuberculoid
84
Lepromatous Hansen disease
- presentation
- communicable?
- immune response
- diffusely over skin
- leonine facies
- communicable
- low cell-mediated immunity
- largely Th1 humoral response
85
Tuberculoid Hansen disease
- presentation
- immune response
- limited to few hypoesthetic, hairless, skin plaques
- high cell immunity
- large Th1 response
86
reservoir for mycobacterium leprosae
armadillos
87
what does mycobacterium leprosae infect?
skin and nerves
| stocking glove neuropathies
88
Treatment for lepromatous Hansen disease
Dapsone
Rifampin
Clofazimine
for 2-5 yrs
89
Treatment for tuberculoid Hansen disease
Dapsone
Rifampin
for 6 months
90
MacConkey agar grows what?
pink colonies of lactose-fermenting enteric bacteria
- KEE
- klebsiella
- e. coli
- enterobacter
91
what about GN makes them PCN G resistant?
outer MB and periplasm that has enzymes that prevent entry of active PCN or vanco
92
differences b/w neisseria gonorrheae and meningitidis
- both ferment glucose, but only meningitidis ferments maltose also
-
93
both neisserias have what virulence factor?
IgA protease
94
prevention for neisseria gonorrhea
condom
| erythromycin for eyes in bab ies
95
prevention for neisseria meningitidis
rifampin
cipro
or
CTX
96
treatment for gonorrhea
CTX (+ azithro for chlamydia)
97
treatment for meningitis
CTX or PCN G
98
which neisseira has capsule
meningitids
99
Fitz hugh curtis syndrome
- what is it
- what causes it
- complication of PID that causes uterine and hepatic capsule adhesions
- neisseria gonorrhea
100
inside what cells are neisseria gonorrhae often found
neutrophils
