FA Micro I Flashcards
1
Q
What is the fxn and chemical composition of peptidoglycan
A
gives rigid support, protects against osmotic pressure, sugar backbone with cross linked peptide side chains
2
Q
What is the fxn and chemical composition of cell wall/cell membrane in gram positive bacteria
A
major surface antigen, peptidoglycan for support, teichoic acid induces TNF and IL-1
3
Q
What is the fxn and chemical composition of the outer membrane in gram negative bacteria
A
site of endotoxin (LPS), major surface antigen, lipid A induces TNF and IL-1, polysaccharide is the antigen
4
Q
What is the fxn and chemical composition of the plasma membrance in bacteria
A
side of oxidative transport of enzymes, lipoprotein layer
5
Q
What is the fxn and chemical composition of the bacterial ribosome
A
protein synthesis, 30S and 50S subunits
6
Q
What is the fxn and chemical composition of bacterial periplasm
A
space between cytoplasmic membrane and peptidoglycan wall in gram neg bacteria contains many hydrolytic enzymes, including beta lactamases
7
Q
What is the fxn and chemical composition of the bacterial capsule
A
protects against phagocytosis, polysaccharide (except for B. anthracis which contains D-glutamate)
8
Q
What is the fxn and chemical composition of bacterial pilus/fimbria
A
mediate adherence of bacteria to cell surface;sex pilus forms attachment between 2 bacteria during conjugation, glycoprotein
9
Q
What is the fxn and chemical composition of bacterial flagellum
A
motility, protein
10
Q
What is the fxn and chemical composition of bacterial spore
A
provides resistance to dehydration, heat and chemicals; keratin like coat; dipicolinic acid
11
Q
What is the fxn and chemical composition of plasmid
A
contains a variety genes for antibiotic resistance, enzymes and toxins; DNA
12
Q
What is the fxn and chemical composition of the bacterial glycocalyx
A
mediates adherence to surfaces, especially foreign surfaces like indwelling catheters; polysaccharide
13
Q
What cell wall structures are common to both gram pos and gram neg bacteria
A
flagellum, pilus, capsule, peptidoglycan, cytoplasmic membrane
14
Q
What cell wall structures are found only in gram pos bacteria
A
teichoic acid
15
Q
What cell wall structures are found only in gram neg bacteria
A
endotoxin/LPS, the periplasmic space (location of many beta lactamases)
16
Q
what are the gram pos coccus (genus)
A
streptococcus, staphylococus
17
Q
What are the gram neg coccus (genus)
A
Neisseria
18
Q
What are the gram pos bacilli
A
clostridium, cornybacterium, bacillus, listeria, mycobacterium (acid fast)
19
Q
Of the gram neg bacillus, which are not enterics
A
haemophilus, legionella, bordetella, francisella, brucella, pasteurella, bartonella, garderella
20
Q
Of the gram neg bacillus, which ones are enterics
A
E. coli, shigella, salmonella, yersinia, klebsiella, proteus, enterobacter, serratia, vibrio, campylobacter, helicobacter, pseudomonas, bacteroides
21
Q
Which gram pos bacteria have branching filamentous morphology
A
actinomyces and nocardia (weakly acid fast)
22
Q
Which gram neg bacteria have pleomorphic morphology
A
rickettsiae, chlamydia (Giemsa)
23
Q
Which gram neg bacteria are spiral
A
leptospria, borrelia, treponema
24
Q
Which bacteria have no cell wall
A
mycoplasma - have sterols
25
What makes up the cell membrane of mycobacterium
mycolic acid, high lipid content
26
Which bacteria do not gram stain well because they are intracellular
rickettsia, legionella, chlamydia (lacks muramic acid in cell wall)
27
Which bacteris do not gram stain well because there is no cell wall
mycoplasma
28
Which bacteria don't stain well because they are too thin to be visualized
treponema
29
What bacteria requires acid fast stain to visualize
mycobacterium
30
What stain shows legionella
silver stain
31
What is the technique to visualize treponema
darkfield microscopy and fluoresecent
32
What organisms do Giemsa stain pick up
borrelia, plasmodium, tryapanosomes, chlamydia
33
What organisms stain with PAS
used to diagnose Whipple's disease - tropheryma whippelii
34
What organisms stain with Ziehl-Neelson
acid fast organisms
35
What organisms stain with india ink
cryptococcus neoformans
36
What organisms stain with silver stain
fungi (pneumocystis), legionella
37
What does PAS actually stain for
glycogen, mucopolysaccharides
38
what bug grows on chocolate agar with factors V (NAD+) and X (hematin)
h. flu
39
What bug grows on thayer-martin (or VPN) media - what does VPN stand for
N. gonorrhea - vancomycin (inhibits gram pos) polymyxin (inhibits gram neg), nystatin (inhibits fungi)
40
What bug grows on bordet-genou (potato) agar
bordetella pertussis
41
What bug grows on tellurite plate, lofflers media
C. diptheriae
42
What bug grows on lowenstein jensen agar
M. tuberculosis
43
What bug grows on eaton's agar
m. pneumoniae
44
what bug grows pink colonies on MacConkey's agar
lactose fermenting enterics
45
what bug grows blue black colonies on eosin-methylene blue agar with metallic sheen
E. Coli
46
what bug grows on charcoal yeast extract agar buffered with cysteine
legionella
47
What bug grows on sabouraud's agar
fungi
48
What bugs are obligate aerobes
Nocardia, pseudomonas, m. tuberculosis, bacillus - nagging pests must breathe
49
In what clinical scenarios do you see Pseudomonas
burn wounds, nosocomial pneumonia, pneumonias in cystic fibrosis
50
Where does reactivation TB usually go, and what can precipitate reactivation
apices of lung, immune system compromise, or anti-TNF alpha use
51
What are the obligate anaerobes and what do they lack (and hence suscpetible to)
clostridium, bacteroides, actinomyces, lack catalse and superoxide dismutase and susceptible to oxidative damage
52
What are characteristics of obligate anaerobes
foul smelling (short chain fatty acids), difficult to culture, produce gas in tissues (CO2, H2)
53
Which Abx are ineffective against obligate anaerobes and why - where are anaerobes nl found
aminoglycosides, require O2 to enter bacterial cell - nl found in GI tract
54
What bugs are obligate intracellulars and why
rickettsia and chlamydia - can't make out ATP
55
What bugs are the facultative intracellular
salmonella, neisseria, brucella, mycobacterium, listeria, francisella, legionella
56
What does the quellung reaction test for and what does a positive result indicate
encapsulated or not - positive if encapsulated bug is present; capsule swells when specific anticapsular antisera are added
57
What organisms are encapsulated
strep pneumo, klebesiella, H flu type b, N. meningititides, salmonella, group B strep
58
How do bacterial capsules function
antiphagocytic virulence factor
59
What is a capsule conjugated with a protein
antigen in vaccines
60
Why is the polysaccharide capsule conjugated to a protein
promote T cell activation and subsequent class switching - alone only IgM antibodies would be produced
61
What is in pneumovax
H. flu type B, meningococcal vaccines
62
What bugs are urease pos
proteus, klebsiella, H. pylori, ureaplasma - particular kinds have urease
63
What bugs produce yellow sulfur granules composed of a mass of filaments and formed in pus
actinomyces isreallii
64
What bug produces a yellow pigment
S. aureus
65
What bug produces a blue-green pigment
pseudemonas aeruginosa
66
What bug produces a red pigment
serratia
67
What virulence factor binds Fc region of Ig, prevents opsonization and phagocytosis and what bug has it
Protein A - S. aureus
68
What bugs can colonize the respiratory mucosa and why
S. pneumo, H. flu type b, Neisseira- SHiN - IgA protease cleaves IgA
69
What does M protein do, who has it
prevents phagocytosis - group A strep
70
This substance binds directly to MHC II and T cell receptor simultaneously, activating large numbers of T cells to stimulate release of IFN gamma and IL-2
superantigen
71
What is toxic shock syndrome, what bug secretes what substance to cause it
fever, rash, shock - S aureas, TSST-1
72
What toxins does S. aureus secrete
enterotoxins, TSST-1, exfoliatin which causes scalded skin syndrome
73
What bug secretes scarlet fever erythrogenic toxin and what does it cause
S. pyogenes, toxic shock-like syndrome
74
What do ADP-ribosylating A-B toxins do
interfere with host cell function, binding component binds to a receptor on surface of host cell enabling endocytosis - active portion attaches an ADP-ribosyl to a shost cell protein altering protein function
75
What kind of exotoxin does corneybacterium have and what does it do
ADP-R AB toxin - inactivates EF-2; causes pharyngitis and pseudomembrane in the throat (similar to pseudomonas exotoxin A)
76
What kind of exotoxin does V. cholerae have and what does it do
ADP ribosylation of G protein stimulates adenylyl cyclase, inc Cl- secretion into gut and dec Na absorption, H20 into gut lumen, voluminous rice water diarrhea
77
What kind of exotoxin does E. coli have and what does it work
ADP-R AB toxin: heat labile, stimulates adenylate cylcase, heat stable toxin stimulates guanylate cyclase - both cause watery diarrhea
78
What kind of exotoxin does bordetella pertussis have and what does it do
ADP-R AB toxin: inc cAMP by inhibiting Galpha1, causes whooping cough, inhibits chemokine receptor, causing lymphocytosis
79
What toxin does clostridium perfringens have and what does it do
alpha toxin, a lecithinase that acta s a phospholipase to cleave cell membranes and causes a gas gangrene
80
What do you see on blood agar with C. perfringens
double zone of hemolysis
81
What kind of exotoxin does C. tetani have and what does it do
tetanus toxin blocks the release of inhibitory GABA and glycine, causes lockjaw
82
What kind does exotoxin from C. botulinum do
blocks the release of ACH, causes anticholinergic symptoms, CNS paralysis, especially cranial nerves
83
Where are spores of C. botulinum found
canned food, honey (causing floppy baby)
84
What kind of exotoxin does b. anthracis have
edema factor, part of the toxin complex, is an adenylate cyclase
85
What does shiga toxin do and what bugs produce it
cleaves host cell rRNA (inactivates 60S ribosome), also enhances cytokine release causing HUS - shigella and E. Coli 0157:H7
86
What organism secretes streptolysin O and what is it used for
S. pyogenes, hemolysin antigen for ASO antibody which is used in the dx of rheumatic fever
87
What does vibrio cholerae do to Gs
toxin permanently activates causing rice water diarrhea via induction of cAMP - turns the on on
88
What does pertusses toxin do to Gi
permanently disables causing whooping cough via induction of cAMP - turns the off off
89
What toxin from E. Coli induces cAMP
heat labile toxin
90
What is the difference in mechanism between cholera, pertussis and E. coli with anthrax
the first 3 act via ADP ribosylation causing permenately activating adenylate cyclase, while anthrax edema factor is itself an adenylate cyclase causing an inc in cAMP
91
What is endotoxin
A lipopolysaccharide found in the outer membrance of gram neg bacteria
92
What 3 pathways does endotoxin activate
macrophages, complement pathway and hageman factor
93
What happens when macrophages activate macrophages
IL-1 - lever, TNF - fever/hemorrhagic tissue necrosis, NO - hypotension
94
What happens when endotoxin activates the complement pathway
C3a - hypotension, edema and C5a - neutrophil chemotaxis
95
What happens when endotoxin activates hagemans factor
coagulation cascade - DIC
96
In the bacterial growth curve, what happens in the lag phase
metabolic activity without division
97
In the bacterial growth curve, what happens in the log phase
rapid cell division
98
In the bacterial growth curve, what happens in the stationary phase
nutrient depletion slows growth, spore formation in some bacteria
99
In the bacterial growth curve, what happens in the death phase
prolonged nutrient depletion and buildup of waste products leads to death
100
What is the ability to take up DNA from evironment in bacteria
transformation or competence
101
What bacteria in particular have the ability to transform
SHiN - strep pneumo, h flu, neisseria
102
What is the difference between F+ x F- and Hfr x F- conjugation
transfer of just plasmid in F+ and transfer of plasmid plus some flanking genes in Hfr x F-
103
How is Hfr made
F+ plasmid can become incorportated into bacterial chromosome DNA
104
Segment of DNA that can jump from one location to another, can transfer genes from plasmid to chromosome and vice versa
transposition - some flanking genes can be gained and lost, and transferred in conjugation
105
Lytic phage infects bacterium, cleavage of bacterial DNA and synthesis of viral proteins, parts of bacterial chromosome may become packaged in viral capsid
generalized transduction - a packaging event
106
lysogenic phage infects bacterium, viral DNA incorporated into bacterial chromosome, when phage DNA is excised can bring portions of bacterial chromosome into capside
specialized transduction - an excision event
107
Genes for which 5 bacterial toxins are encoded in a lysogenic phage
shiga like toxin, botulinum toxin, cholera toxin, diptheria toxin, erythrogenic toxin of s. pyogenes
108
With staph grown on novobiocin, which is resistant and which is sensitive
saprohyticus resistant, epidermidis is sensitive - NO StRES
109
With strep grown on optichin, which are sensitive and which are resistant
Viridans is resistant and pneumo is sensitive - OVRPS (overpass)
110
With strep grown on bacitracin, which are sensitive and which are resistant
group B are resistant, group A are sensitive - B-BRAS
111
Which bacteria are alpha hemolytic
strep pneumo and viridans
112
Which bacteria are beta hemolytic
S. aureus, Strep pyogenes, group B strep, listeria monocytogenes
113
What associations go with listeria monocytogenes
tumbling motility, meningitis in newborns, unpasteurized milk
114
What does catalase do
degrades H2O2 before it can be converted to micorbicidal products by the enzyme myeloperoxidase
115
Which bacteria make catalase and which do not
staph make it, strep don't
116
Which staph make coagulase, and which don't
aureus does, epidermidis and group B do not
117
What kind of microbes cause recurrent infections in patients with chronic granulomatous disease and why
catalase pos organisms - remove H2O2 leading to infection - staph
118
What bacteria has protein A and what does it do
s. aureus, virulence factor, binds Fc-IgG, inhibiting complement fixation and phagocytosis
119
What does inflammatory diseases do staph aureus cause
skin infections, organ abscesses, pneumonia
120
What toxin mediated diseases does staph aureas cause
toxic shock syndrome (TSST-1), scalded skin syndrome (exfoliative toxin), rapid onste fod poisoning (enterotoxin
121
What s. aureus infection is an imporant cause of serious nosocomial and community-acquired infections
MRSA - resistant to beta lactams due to altered penicillen binding protein
122
How does TSST work
superantigen that binds MHCH II and T cell receptor resulting in poly colonal T cell activation
123
What is S. aureus food poisoning due to
ingestion of preformed toxin
124
What specific infections are likely to be staph aureus
acute bacterial endocarditis and osteomyelitis
125
Infects prosthetic devices and intravenous catheters by producing adherent biofilms - what bacteria and where do you normally find it
staph epi - normal skin flora, contaminates blood cultures
126
What does MOPS stand for with s pneumo
meningitis, otitis media, pneumonia, sinusitis OR - Most Optichin Sensitive
127
What color sputum, and sepsis in which patients is associated with pneumococcus,
rusty sputum, sepsis in sickle cell after splenectomy
128
What shape are s pneumo, do they have a capsule and what protease do they have
lancet shaped, encapsulate, IgA protease
129
Where are strep viridans normal flora and what do they cause
nl flora in oropharynx, cause dental carries (mutans), subacute bacterial endocarditis (sanguis)
130
What pyogenic infections does s pyogenes cause
pharyngitis, cellulitis, impetigo
131
What toxigenic infections does s pyogenes cause
scarlet fever, toxic shock-like syndrome
132
What immunolgic infections does s pyogenes cause
rheumatic fever, acute glomerulonephritis
133
What laboratory test distinguishes strep pyogenes from group B strep, and what causes the immunologic response
bacitracin sensitive, antibodies to M protein enhance host defenses, but can give rise to rheumatic fever
134
What titer can detect recent s pyogenes infection
ASO titer
135
What is the clinical picture of rheumatic fever
subcutenous plaques, polyarthritis, erythema marginatum, chorea, carditis - no "rheum" for SPECCulation
136
How do group B strep respond to bacitracin
resistant
137
How do group B strep grow on blood agar
beta hemolytic
138
Where does group B strep colonize
vagina
139
What does group B strep cause
pneumonia, meningitis, sepsis in babies
140
What does group B strep produce and what does it cause
CAMP factor enlarges area of hemolysis formed by S. aureus
141
When do you screen pregnant women and what do you treat them with if they are are pos
35 to 37 weeks, intrapartum pen prophylaxis
142
What bacteria are considered enterococci, where are they found, and what do they cause
enterococci (E. faecalis, E. faecium) nl colonic flora, pen G resistant, cause UTI and subacute endocarditis
143
What are VRE and what do they cause
vanc resis enterococci and are important cause of nosocomial infection
144
How can you distinguish enterococci from nonenterococcal group D
grow in 6.5% NaCl and bile
145
Which bacteria is an important cause of subacute endocarditis and bacteremia in colon cancer patients
strep bovis, also group D
146
What is diptheria exotoxin coded by and what does it do
coded by beta prophage, inhibits synthesis via ADP ribosylation of EF-2
147
What are the symptoms of diptheria
pseudomembranous (grey-white membrane) pharyngitis with lymphadenopathy
148
What is the lab diagnosis of C. dipetheria
gram pos rods with metachromatic (blue and red) granules
149
What vaccine can prevent diptheria
toxoid vaccine
150
What C. diptheria grow on
tellurite agar
151
When do gram pos rods form spores
when nutriets are limited
152
What are spores highly resistant to, and what can be done to overcome it
resistant to destruction by heat or chemicals, need to autoclave to kill by steaming at 121C for 15 minutes
153
What acid is in the spore core
dipicolinic acid
154
What gram pos rods form spores in soil
b anthracis, c. perfringens, c tetani (b cereus and c botulinum also form spores
155
gram pos, spore forming, obligate anaerobes
clostridia
156
produces tetanospas an exotoxin causing tetanus
c tetani
157
How does tetanus toxin cause tetanus
blocka glycine and GABA release - inhibitory NTs from Renshaw cells in spinal cord
158
What kind of paralysis does tetanus toxin produce
spastic, trismus (lockjaw and risus sardonicus)
159
What does botulinum toxin do and what is it characterized by
heat labile toxin that inhibits ACH release from NMJ causing a flaccid paralysis
160
What is the difference in route of infection of botulism in adults vs babies
adults - preformed toxin, babies - ingestion of spores in honey
161
What does c perfringens produce and what does it do
alpha toxin (lecithinase) that can cause myonecrosis (gas gangrene) and hemolysis
162
What two toxins does C. diff produce andw what do they do
Toxin A - enterotoxin binds to brush border of the gut, Toxin B - cytotoxin, destroys the cytoskeletal structure of enterocytes, causing pseudomembranous colitis
163
What often causes infection with C. diff and how is it dx
often secondary to Abx use - diagnosed by detection of one or both toxins in the stool
164
usage of which Abx can lead to c diff
clindamycin or ampicillin
165
What is the treatment for c. diff infection
metronidazole
166
What is the only bacterium with a polypeptide capsule and and what does it cause
b anthracis - anthrax -cutaneous is black eschar ulcer (painless) can progress to bacteremia or death, pulmonary anthrax is inhalation of spores producing flu-like sx that rapidly progress to fever pulmonary hemorrhage, mediastinitis and shock
167
What are the black skin lesions in anthrax caused by
black necrosis surrounded by edematous ring, caused by letha factor and edema factor
168
Why is anthrax called woolsorters disease
inhalation of spores from contaminated wool
169
How is listeria acquired, what does it form, and how is motility characterized
facultative intracellular microbe, ingestion of unpasteureized milk/cheese and deli meats or by vaginal transmission - forms actin rockets, cell to cell movements and tumbling motility
170
What does listeria infection cause
in pregs - amnionitis, septicemia, spontaneous abortion, granulomatous infantiseptica, neonatal meningitis in neonates, immunoCised - meningitis, healthy people - mild gastroenteritis
171
Which two bacteria are gram pos rods forming long braching filaments resembling fungi
actinomyces and nocardia
172
gram pos anaerobe, causes oral-facial abscesses that may drain through sinus tracts of skin, yellow sulfur granules - nl oral flora
actinomyces israeli
173
gram pos, weakly acid fast aerobe in soil, causing pulmonary infection in immuncompromised patients
nocardia asteroides
174
How do you treat actinomyces or nocardia
SNAP - sulfa for nocardia and actinomyces get pen
175
Which lobe of the lung does primary TB usually occur in
lower lobe
176
What is the Ghon complex
TB granulomas (Ghon focus + lobar and perihilary lymph node involvment) - primary infection or exposure
177
What happens when primary TB heals by fibrosis
immunity and hypersensitivity, tuberculin positive
178
in what instance does primary TB become progressive lung disease and what happens
HIV, malnutrition, death
179
How does miliary TB occur and what happens
severe bacteremia, death
180
How do dormant tubercle bacilli end up in multiple organs, and what happens
preallergic lymphatic or hematogenous dissemination, reactivation in adult life
181
What kind of lesion is characteristic of secondary pulmonary tuberculosis
fibrocaseous cavitary lesion in upper lobe
182
What are the sites for extrapulmonary TB
CNS - parenchmal tuberculoma or meningitis, vertebral body (pott's disease), lymphadenitis, renal, GI
183
What does neg PPD indicated
no infection, anergic (steroids, malnutrition, immunoCised, sarcoidosis)
184
What are the symptoms of TB
ferver, night sweats, weight loss, hemoptysis - can be drug resistant
185
which mycobacterium is also pulmonary with TB-like symptoms and not M. tuberculosis
M. kansasii
186
mycobacterium causing disseminated disease in AIDS, resistant to multiple drugs, cannot be grown in vitro
M. avium intracellulare
187
What prophylactic treatment is given to AIDS pts to prevent M. avium intracellulare
azithromycin
188
Which mycobacterium are acid fast
all of them
189
What kind of temperatures do m. leprae like, what tissues do they infect, and what is the resevoir in the US
cool temps, infects skin and superficial nerves, armadillos
190
What is the TX for leprosy and what is the toxicity of this TX
dapsone - hemolysis and methemoglobinemia or rifampin and combination clofazimine + dapsone
191
What are the two forms of Hansens disease and which patients get which
lepromatous - diffusely over skin and is communicalbe (immunoCised) tuberculoid limited to a few hypoesthetic skin nodules (immunoCtent
192
Which form of Hansens disease is lethal
lepromatous
193
Which bacteria grow pink colonies on MacConkey's agar
lactose fermeting enterics - citrobacter, klebsiella, E. coli, enterobacter, serratia
194
What enzyme breaks down lactose and which bacteria produces it
E. Coli produces beta galactosidase
195
What Abx does the gram neg outer membance inhbit entry of, but which derivatives of that same class might they be sensitive to
pen G and vanc - may be sens to ampicillin
196
What sugars do the various neisseria bacteria ferment and what enzyme do they both produce
MeninGococci - maltose and glucose, Gonococci - only glucose - both produce IgA protease
197
Which neisseria has a polysaccharide capsule
meningococci
198
What neisseria is there a vaccine for
meningococci
199
Why is there no vaccine for gonococci
rapid antigenic variation of pilus proteins
