Microbiology: Bacterial Flashcards
(241 cards)
1
Q
Two toxins produced by C. difficile:
What kind of toxin? What is its function?
A
Toxin A = enterotoxin = exotoxin, binds brush border.
Toxin B = cytotoxin = destroys enterocyte cytoskeleton -> pseudomembranous colitis.
2
Q
Two antibiotics especially associated with C. diff:
A
Clinda
Amp
3
Q
Treatment for C. diff:
A
Metronidazole
ORAL vanc
4
Q
Dx of C. diff:
A
Toxin in stool
5
Q
Most common E. coli strain causing bloody diarrhea:
A
Enteroinvasive
6
Q
Treatment for dysentery caused by E. coli:
A
Fluoroquinolones, TMP-SMX
7
Q
Two toxins produced by enterotoxigenic E. coli:
Second messenger inside the cell for action of each?
A
Heat labile = cAMP increase = watery diarrhea like cholera
Heat stable = cGMP increase
8
Q
Cause of traveler’s diarrhea (“Montezuma’s revenge”):
A
Enterotoxigenic E. coli
9
Q
E. coli strain causing diarrhea in daycare:
A
EPEC
10
Q
Causes HUS:
A
Enterohemorrhagic E. coli
Usually 0157:H7
11
Q
Triad of HUS:
Explain how this happens:
A
Anemia
Thrombocytopenia
Acute renal failure
Shiga-like toxin from EHEC 0157:H7 damages endothelium, which swells, cuts off blood flow to the kidney. Narrow vessels shear RBC -> mechanical hemolysis. Damaged endothelium consumes the platelets -> thrombocytopenia.
12
Q
Most E. coli ferment this sugar:
Which one does not?
A
Sorbitol
EHEC does not ferment sorbitol
13
Q
Tx for HUS:
A
Supportive only.
Do not give abx.
14
Q
Two E. coli strains causing dysentery:
A
Enteroinvasive
Enterohemorrhagic
15
Q
E. coli strain causing watery diarrhea:
A
Enterotoxigenic
16
Q
How would you distinguish EHEC from other forms of E. coli on culture?
A
It does not ferment sorbitol. The others do.
17
Q
Organism responsible for causing staghorn calculi:
A
Proteus
18
Q
Urease-positive, ammonium-Mg-phosphate stones:
A
Proteus
19
Q
Common cause of osteomyelitis in sickle cell patients:
A
Salmonella
20
Q
Four A’s of Klebsiella:
A
Aspiration pneumonia
Alcoholics
Abscesses in lungs and liver
di-A-betics
21
Q
Mucoid colonies, lobar pneumonia in a diabetic:
A
Klebsiella
22
Q
Flagellated organism, hematogenous dissemination, produces H2S:
A
Salmonella
23
Q
Very virulent organism, frequently causes bloody diarrhea, human and primate but not pet reservoirs:
A
Shigella
24
Q
Associated with Reiter syndrome:
A
Shigella
25
Rose spots on abdomen:
Salmonella typhi
26
Carried in the gallbladder, found only in humans:
Salmonella typhi
27
Which organism ferments lactose: Salmonella or Shigella?
Trick question.
| Neither.
28
Which organism produces H2S: Salmonella or shigella?
Salmonella
29
Which organism produces a monocytic response: Salmonella or Shigella? A PMN response?
```
Monocytes = Salmonella
PMNs = Shigella
```
30
Leading cause of bloody diarrhea in the US:
Campylobacter
31
Common antecedent to Guillain-Barre:
Campylobacter
32
Fecal-oral transmission through poultry, meat, milk, grows at 42C:
Campylobacter
33
Oxidase (+), grows in alkaline media:
Vibrio cholerae
34
Mesenteric adenitis that can look like Chron's, pet feces:
Yersinia enterocolitica
35
Egg salad -> delayed diarrhea:
Salmonella
36
Egg salad -> instant diarrhea / vomiting:
S. aureus
37
Permanently activates Gs, toxin is heat-stable:
Vibrio cholerae
38
Food poisoning from contaminated seafood:
Vibrio sp.
39
Food poisoning from reheated rice:
Bacillus cereus
40
Preformed toxin, food poisoning from custard:
S. aureus
41
Food poisoning from reheated meat:
Clostridium perfringens
42
Undercooked meat, bloody diarrhea:
E. coli 0157:H7
43
Infection with these three organisms can mimic appendicitis:
Yersinia enterocolitica
Salmonella
Campylobacter
44
Most common cause of mesenteric adenitis:
Yersinia
45
Food poisoning as a result of mayonnaise sitting out:
S. aureus
46
Diarrhea caused by a gram (-) non-motile non-lactose fermenting organism:
Shigella
47
Rice-water stools (2):
V. cholera
| ETEC
48
Diarrhea caused by an S-shaped organism:
Campylobacter
| Remember, campy=twisted, it's more of a corkscrew than a comma, but they might say "S-shaped"
49
Diarrhea caused by a non-lactose fermenting Gram (-) motile organism:
Salmonella
50
Diarrhea caused by a Gram (-) lactose fermenting bacterium:
| A non-lactose-fermenting bacterium:
E. coli
| Salmonella or Shigella
51
Cause of Chagas disease?
| Cause of African sleeping sickness?
Trypanosoma cruzii
| Trypanosoma brucei, gambiense, or rhodesiense
52
This form of the malaria parasite looks like a diamond ring inside an RBC:
Trophozoite
53
This form of the malaria parasite is the one that ruptures the RBC:
Merozoite
54
This form of the malaria parasite replicates inside RBCs:
Schizont
55
This is the form of the malaria parasite injected by the Anopheles mosquito:
Sporozoite
56
This form of the malaria parasite is banana-shaped:
Gametocyte
57
Describe how Shigella gains access to the intestinal mucosa:
Via M cells in Peyer's patches, through endocytosis. It spreads laterally from M cells to other epithelial cells.
58
The _________ is where you will find b-lactamase.
Periplasm
| This is in Gram (-)s
59
This bacterial structure protects against phagocytosis:
Capsule
60
This bacterium is encapsulated, but its capsule is not polysaccharide like the others. What is it, and what is its capsule made of?
Bacillus
| Capsule contains D-glutamate
61
What is the test for whether a bacterium is encapsulated or not?
Quellung reaction
62
This structure mediates adherence to surfaces:
| This structure mediates adherence to cells:
Glycocalyx makes biofilms
| Pilus is a glycoprotein projection that mediates cell-cell interactions
63
```
Feature of Gram (+) bacterial cell walls not shared with Gram (-)s:
What cytokines (2) does this cell wall component prompt release of?
```
Lipoteichoic acid
| This induces IL-1 and TNF-a production
64
Two structural features of Gram (-) bacteria not shared with Gram (+)s:
Endotoxin / LPS outer membrane
| Periplasmic space
65
What is unusual about Mycoplasma's cell wall and membrane?
1. It has no cell wall
| 2. Membrane contains a lot of sterols
66
What is unusual about the cell walls of the Mycobacteria?
They contain mycolic acid and a ton of lipids.
67
These six organisms do not take Gram stain well:
| Briefly think of why.
These Rascals May Microscopically Lack Color:
Treponema (too thin)
Rickettsia (intracellular)
Mycobacteria (high lipid content, need carbolfuschin)
Mycoplasma (no cell wall)
Legionella (mostly intracellular)
Chlamydia (intracellular)
68
How do you visualize Chlamydia?
Giemsa stain
69
When would you use the Ziehl-Neelsen carbol fuschin stain (2)?
For acid-fast organisms (2):
Mycobacteria
Nocardia
70
Six organisms you would stain with Giemsa:
```
Certain Bugs Really TRY His Patience
Chlamydia
Borrelia
Rickettsiae
Trypanosomes
Histoplasma
Plasmodium
```
71
Four cases in which you would use silver stain:
Fungi
Legionella
Pneumocystis
H. pylori
72
What does PAS stain for?
Glycogen
73
Stain you would use to diagnose Whipple's disease:
PAS
74
Stain you would use to diagnose Cryptococcus:
India ink
75
Stain you would use to diagnose Nocardia:
Carbol fuschin (Ziehl-Neelsen)
76
Stain you would use to diagnose Borrelia:
Giemsa
77
Stain you would use to diagnose Legionella:
Silver
78
Stain you would use to diagnose Histoplasma:
Giemsa
79
Stain you would use to diagnose Pneumocystis:
Silver
80
Stain you would use to diagnose Chlamydia:
Giemsa
81
Gram (+) organisms stain ____.
| Gram (-) organisms stain ____.
Blue
| Pink
82
These four organisms are obligate aerobes:
```
Nagging Pests Must Breathe:
Nocardia
Pseudomonas AERuginosa (think aerate)
Mycobacterium tuberculosis
Bacillus
```
83
Obligate aerobe seen in burn wounds, causes pneumonia in patients with CF:
Pseudomonas aeruginosa
84
These three bugs are obligate anaerobes:
| Why?
```
Can't Breathe Air:
Clostridium
Bacteroides
Actinomycetes
They do not have catalase or SOD, cannot deal with oxygen.
```
85
Treatment for infection with obligate anaerobes:
Metronidazole
| Clindamycin
86
This class of antibiotics requires oxygen to enter a cell:
AminOglycosides
87
These two bugs are obligate intracellular creatures, they cannot make ATP:
Rickettsiae
| Chlamydia
88
These bugs are facultative intracellular pests (7):
```
Some Nasty Bugs May Live FacultativeLY:
Salmonella
Neisseria
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersinia pestis
```
89
These bacteria are encapsulated (8):
```
Even Some Pretty Nasty Killers Have Shiny Bodies:
E. coli
Strep pneumo
Pseudomonas
Neisseria
Klebsiella
H. influ
Salmonella typhi
gB Strep
```
90
Asplenics are at risk for infection with these bacteria (8):
```
Even Some Pretty Nasty Killers Have Shiny Bodies:
E. coli
Strep pneumo
Pseudomonas
Neisseria
Klebsiella
H. influenzae
Salmonella typhi
group B Strep
```
91
These organisms make catalase (7):
```
You need PLACESS for CATs.
Pseudomonas
Listeria
Aspergillus
Candida
E. coli
S. aureus
Serratia
```
92
Organisms you may be susceptible to infection with if you have NADPH oxidase deficiency:
```
These organisms readily break down the limited amount of H2O2 people with this def. have. They are:
PLACESS for CATs:
Pseudomonas
Listeria
Aspergillus
Candida
E. coli
Serratia
Staph. aureus
```
93
Yellow-pigmented colonies (2):
Staph aureus
| Actinomyces israelii
94
Blue-green pigmented organism:
Pseudomonas aeruginosa
95
Red-pigmented organism:
Serratia marcescens
96
These organisms are urease-positive (8):
```
CHuck norris hates PUNKSS:
Cryptococcus
H. pylori
Proteus
Ureaplasma
Nocardia
Klebsiella
S. epidermidis
S. saprophyticus
```
97
What is the function of bacterial protein A?
| Which organism makes this?
This binds Fc of Ig and prevents host immune cells from phagocytosing the bacterium. S. aureus makes this.
98
Which bugs make IgA protease?
These are all respiratory pathogens:
S. pneumo
H. iB
Neisseria
99
What is M protein, and which bacteria make this?
M protein inhibits phagocytosis:
Don't Munch me, I will give you GAS:
Group A Strep
100
Where is the genetic material coding for exotoxin production located?
For endotoxin?
Exotoxin DNA is stored in plasmids or bacteriophages.
| Endotoxin DNA resides in the bacterial chromosome.
101
Where is endotoxin found?
On Gram (-)s, their outer membrane.
102
Which kind of toxin is destroyed quickly by heat?
| Which is more stable to high temps?
Exotoxin is easily destroyed by heat.
| Endotoxin you can cook.
103
Six main toxins made by Staph aureus, two words about what they do:
1. a-toxin -> hemolysis
2. b-toxin -> sphingomyelinase
3. leukocidin
4. enterotoxins (A-E) -> food poisoning
5. TSST-1 -> toxic shock syndrome
6. Exfoliative / epidermolytic toxin -> scalded skin
104
Three main toxins made by Strep pyogenes, two words about what they do:
1. Streptolysin O (O2 Labile) &
2. Streptolysin S (O2 Stable) -> hemolysis
3. Erythrogenic pyrogenic toxins -> rash / fever, cause scarlet fever
105
These two toxins inhibit EF-2:
| Which bacteria make them?
```
Diphtheria toxin
Exotoxin A (made by Pseudomonas)
```
106
These two toxins remove a residue from our rRNA coding for our 60S ribosomal subunit:
Which bacteria make them?
```
Shiga toxin (made by Shigella)
Shiga-like toxin (made by enterohemorrhagic E. coli)
```
107
This toxin mediates hemolytic uremic syndrome:
| What was the triad again?
Shiga or shiga-like toxin
1. Anemia
2. Thrombocytopenia
3. Acute renal failure
108
T/F: Enterohemorrhagic E. coli invades host cells:
F. Shigella does this, but E. coli does not.
109
This organism produces a toxin that behaves like cholera toxin. What is it, and how does the toxin work?
Enterotoxigenic E. coli makes a heat labile toxin, increases cAMP and Cl- secretion into the gut.
(The heat stable toxin increases cGMP and decreases NaCl resorption.)
110
A strain of E. coli makes a toxin that remains when the bacterium is heated and killed. What does this toxin do?
Another organism makes a similar toxin, which one?
This is heat stable toxin
Increases cGMP, slows NaCl and thus water resorption in the gut -> watery diarrhea
Yersinia enterocolitica does something similar
111
Four toxins that act to increase cAMP. Which organisms make them, what is their effect?
cGMP increase with:
E. coli heat-labile toxin, watery diarrhea
Cholera toxin, rice-water stools
(Both of these are high Cl- secretion mechs)
Bacillus anthracis makes edema factor
Pertussis toxin disables Gi, effect is impaired phagocytosis
112
Two toxins that cleave SNARE proteins:
| What type of paralysis results from each?
```
Tetanospasmin (prevents inhibitory neurotransmitter release -> spastic paralysis)
Botulinum toxin (prevents ACh release -> flaccid paralysis)
```
113
Mechanism of action of pertussis toxin:
Breaks Gi
| Increases cAMP
114
Mechanism of action of alpha toxin made by Clostridium:
Phospholipase, breaks down tissues and cell membranes, causes necrosis
115
This Strep. pyogenes toxin degrades cell membranes:
Streptolysin O
This is the toxin that LYSES cell membranes
This is also the SO of ASO, eg Ab titers for RF
116
These two superantigens cause shock:
| Which organism makes them?
```
TSST-1 (made by Staph aureus)
Exotoxin A (made by Strep. pyogenes)
```
117
S. pneumo, H. influenzae, and Neisseria are able to undergo transformation. What does this mean?
Can take up naked DNA from their environment.
118
How is plasmid DNA transferred from bacterium to bacterium?
During conjugation, F+ x F- meet
119
What is a Hfr cell? What kind of genetic material is transferred when Hfr x F- during conjugation?
Hfr = an F+ plasmid (plasmid with the pilus instructions) incorporated into chromosomal DNA.
Conjugation -> transfer of plasmid and chromosomal information that just happened to be near the plasmid insertion point.
120
What is transduction?
Infection with a bacteriophage, can go two ways.
1. Phage carries some bacterial DNA with it when it lyses (vanilla)
2. Phage inserts itself into bacterial DNA, when it lyses it carries flanking genes with it.
121
These five toxins are carried by lysogenic phages:
```
ABCDE:
ShigA-like toxin
Botulinum toxin
Cholera toxin
Diphtheria toxin
Erythrogenic toxin (Strep pyo.)
```
122
Gram (+) cocci in clusters:
| Gram (+) cocci in chains:
Staph
| Strep
123
5 Gram (+) rods:
```
Clostridium
Corynebacterium
Listeria
Bacillus
Mycobacteria
```
124
```
Two Gram (+) branching filaments:
Which is an aerobe?
```
Actinomyces
Nocardia
Nocardia is the aerobe
125
What is alpha hemolysis?
| Which Strep. sp are a-hemolytic?
Partial hemolysis = a-hemolysis
Strep pneumo
Viridans strep
126
What is beta hemolysis?
| Which Strep. sp are b-hemolytic?
```
b-hemolysis = complete hemolysis
Strep pyogenes (= GAS)
Strep agalactiae (= GBS)
```
127
What is the difference in antibiotic sensitivity between group A and B Strep?
```
GAS = pyogenes = bacitracin-sensitive
GBS = agalactiae = bacitracin-resistant
```
128
What is gamma hemolysis?
| Which Strep. sp are g-hemolytic?
g-hemolysis = no hemolysis at all
Enterococci
Non-enterococci (Strep. bovis)
129
How do you tell between Strep pneumoniae and viridans group strep?
1. S. pneumo has a capsule, Quellung will be (+). It is Optochin sensitive.
2. Viridans strep. have no capsule (Quellung negative) and are Optochin resistant. Remember the viridans Strep. are mouth bacteria, they are OFF the CHIN resistant.
130
Which bacteria are beta-hemolytic, how will you tell them apart (4)?
```
Staph aureua (coag and cat +)
Strep pyogenes (GAS) (cat neg, optochin sensitive)
Strep agalactiae (GBS) (cat neg, optochin resistant)
Listeria monocytogenes (tumbling motility)
```
131
Mechanism by which MRSA are b-lactamase resistant:
Altered PCN binding proteins.
132
This Staph. sp is known for infecting prosthetic devices and IV catheters:
Staph. epidermidis
133
Most common cause of meningitis:
Strep pneumoniae
134
Gram (+) diplococcus associated with sepsis in sickle cell anemia:
Strep pneumoniae
135
This normal member of our oral flora causes dental caries:
Strep. mutans
136
Which of the a-hemolytic Strep. groups is optochin-sensitive?
Which is optochin-resistant?
Strep. pneumoniae = optochin sensitive
| Strep. viridans = optochin resistant
137
These three organisms make an IgA protease:
HiB
Neisseria meningitidis
S. pneumoniae
138
Cause of rheumatic fever:
Strep pyogenes (GAS)
139
Jones criteria:
Joints
| s chorea
140
Which Strep pyogenes infection is most likely to precede glomerulonephritis?
Impetigo > pharyngitis.
141
Three organisms particularly deadly to babies:
GBS
E. coli
Listeria
142
Which is the more burly organism: Enterococcus or non-enterococcus group D?
Enterococci. You can grow them in bile AND salt.
143
This b-hemolytic Strep. is bacitracin-resistant as a rule:
Strep agalactiae (GBS) is bacitracin-resistant.
144
This titer detects recent infection with S. pyogenes:
ASO
145
Strep. sp associated with colon cancer:
Streptococcus bovis
146
Mechanism of action of diphtheria toxin:
EF-2 inhibitor
| just like Pseudomonas
147
Gram (+) club-shaped rods with metachormatic red-blue granules:
Corynebacterium diphtheriae
148
Black colonies on cystine-tellurite agar:
Corynebacterium diphtheriae
149
Treatment for diphtheria:
Penicillin or erythromycin.
May want to give diphtheria antitoxin.
Vaccinate (again) too.
150
Spore-forming bacteria:
```
Bacillus anthracis
Bacillus cereus
Clostridium botulinum
Clostridium perfringens
Clostridium tetani
Coxiella burnetii (rickettsial, causes Q-fever)
```
151
The two toxins produced by Clostridium dificile and their MOA:
1. Toxin A = enterotoxin, binds to enterocytes
| 2. Toxin B = cytotoxin, destroys cytoskeleton of enterocytes
152
This bacterium has a polypeptide capsule containing D-glutamate:
Bacillus anthracis
| Remember, it has a weird ENVELOPE. You would not want it at the post office.
153
Some nice wool-comber develops pulmonary anthrax. What do you expect will happen to them?
Look like they have the flu.
Suddenly they have a fever, shock.
Pulmonary hemorrhage and mediastinitis.
154
Nausea and vomiting in 1-5 hours after eating reheated rice:
| What is the toxin responsible?
Bacillus cereus
| Cereulide
155
Unpasteurized milk / dairy / vaginal transmission of an organism with tumbling motility:
What does this little guy look like on Gram stain?
Listeria
| Gram (+) rod
156
Treatment for Listeria:
Ampicillin
157
Oral / facial abscess, yellow sulfur-granule appearance. How do you treat it?
This is Actinomyces.
| Tx is penicillin.
158
Gram (+) filamentous branching aerobe. Treatment?
Nocardia, treatment is sulfonamides.
159
Why might someone be PPD (-) (3 reasons)?
No infection
Anergy (steroids, malnutrition, immunocompromised)
*Sarcoidosis*
160
What is a Ghon complex?
A Ghon focus + hilar LAD, seen in primary TB.
161
What is the recommended prophylactic treatment for MAC?
Azithromycin
162
Treatment for leprosy:
Dapsone
Clofazimine
Rifampin
163
This form of leprosy is communicable. What T cell response will you characteristically see?
Lepromatous, TH2 dominant response. Diffuse presentation over the skin.
164
Second most common cause of Gram (-) sepsis:
Klebsiella
165
Mesenteric adenitis that might look a lot like Chron's:
Yersinia enterocolitica
166
Three symptoms of leptospirosis:
| Who gets this disease and from where?
Jaundice
Photophobia
Conjunctivitis
Surfers in the tropics, it's found in water contaminated with animal urine.
167
What is Weil's disease?
Severe leptospirosis:
Jaundice
Liver / kidney dysfx, azotemia
Hemorrhage / anemia
168
Question mark shaped organism, flu-like symptoms:
Leptospira interrogans
169
Treatment for Lyme disease:
Doxycycline
| Ceftriaxone
170
Natural reservoir for Borrelia burgdorferi:
| Vector:
Mouse
| Carried by Ixodes tick
171
Characterizes primary syphilis:
Single painless chancre
172
Rash on palms and soles, 3 possibilities:
Syphilis (secondary)
RMSF
Coxsackie A virus
173
Alopecia areata, rash on palms and soles:
Secondary syphilis
174
What is a Charcot joint?
Damage done to joints because they are insensate. Usually in DM, can be seen in tertiary syphilis.
175
This is an early sign of congenital syphilis:
The snuffles.
(Cute. Or not.)
Blood-tinged nasal secretions.
176
Tertiary syphilis can do this to an aorta:
Destruction of the vaso vasorum that feed the aorta itself, causes "tree-barking"
177
What is an Argyll-Robertson pupil?
A pupil that constricts with accomodation but fails to react to light. AKA the prostitute's pupil. Seen in tertiary syphilis.
178
What are some common scenarios where you might see false positives with VDRL testing?
```
VDRL!
Viruses (mono and hepatitis)
Drugs
Rheumatic fever
Lupus / Leprosy
```
179
This organism causes the yaws:
| Think of a couple features of the yaws.
Treponema pertenue
| Disease of skin / joints, healing with keloids, disfigurement, face commonly involved.
180
What happens to immunocompromised people who get cat scratch disease?
May develop angiomatosis that looks like Kaposi's sarcoma.
181
Appearance of Gardnerella vaginalis on LM:
Gram-variable
| Pleomorphic
182
Treatment for all the Rickettsial diseases:
Doxycycline
183
How does the rash of RMSF differ from the rash seen in typhus?
RMSF: Rash starts at wRists and moves in.
Typhus: Rash starts on the Trunk and moves out.
184
Epidemic typhus:
Rickettsia prowazekii
| R. typhi is the endemic form
185
Morula-like cytoplasmic inclusion, tick-borne:
Erlichia
186
What is Q fever?
Caused by Coxiella burnetii.
Causes interstitial pneumonia.
No rash.
187
What is unusual about the cell wall of Chlamydia?
It has no muramuic acid
188
Treatment for chlamydial infections:
Azithromycin, single dose
189
Three most common causes of atypical pneumonia:
Mycoplasma
Legionella
Chlamydophila pneumoniae
190
What are the three pathogenic Chlamydial sp?
C. trachomatis
C. pneumoniae
C. psittaci
191
What is lymphogranuloma venereum?
Infection with Chlamydia trachomatis type L1-L3, causes inguinal lymphadenitis with a primary ulcer, may mimic UC and cause rectal disease.
192
Why do we give babies azithromycin eye drops at birth?
Worry for congenital transmission of Chlamydia, which can cause conjunctivitis and neonatal pneumonia.
193
Chalmydia trachomatis serotypes associated with blindness in Africa:
A, B, C
194
T/F: C. trachomatis infection can cause ectopic pregnancy.
T. PID can make the uterus an unfriendly place, embryo might just go find another home.
195
Atypical pneumonia with a high titer of cold agglutinins:
| How would you treat such an infection?
Mycoplasma pneumoniae
| Tx is with fluoroquinolone or macrolide
196
This aminopenicillin is usually given orally.
This one is usually given IV.
What infections do they treat?
```
Ampicillin is usually used IV.
AmOxicillin is better Oral.
Used to HELPSS kill enterococci:
H. influ
E. coli
Listeria
Proteus mirabilis
Salmonella
Shigella
enterococci
```
197
Usual mechanism of resistance to ampicillin / amox:
b-lactamases
198
What is augmentin made of:
Amoxicillin + clavulanic acid = augmentin
199
What is unasyn composed of:
Ampicillin + sulbactam
| Used IV
200
What is zosyn made of:
Piperacillin + tazobactam
201
The three b-lactamase inhibitors:
Clavulanic acid
Sulbactam
Tazobactam
202
Penicillin associated with development of pseudomembranous colitis:
Aminopenicillins, amp and amox
203
Good treatment of choice for neonatal infections with E. coli, Listeria:
Ampicillin
| Add gentamycin just to be safe
204
Treatment for uncomplicated URI with Gram (+) organisms:
Aminopenicillins +/- b-lactamase inhibitors
205
Three anti-pseudomonal penicillins:
Ticarcillin
Piperacillin
Carbenicillin
206
Treats pseudomonas and Gram (-) rods:
Ticarcillin
Piperacillin
Carbenicillin
207
Organisms not covered by cephalosporins:
```
These guys are LAME:
Listeria
Atypicals (Chlamydia, Mycoplasma)
MRSA
Enterococci
```
208
First generation cephalosporins are used to treat these infections:
PEcK:
Proteus
E. coli
Klebsiella
209
The two first-generation cephalosporins:
Cefazolin
| Cephalexin
210
Second-generation cephalosporins cover:
```
HEN PeCKS:
H. influ
Enterobacter
Neisseria
Proteus
E. coli
Klebsiella
Serratia
```
211
Drug of choice for OM due to non-typeable H. flu:
```
Second gen. cephalosporin
Consider Cefdinir (3rd gen) if resistant.
```
212
Four second-generation cephalosporins:
Cefuroxime
Cefaclor
Cefoxitin
Cefprozil
213
Third-generation cephalosporins add coverage for these two main infections:
Gram (-)s
| Meningitis, gonorrhea, pseudomonas
214
Fourth-generation cephalosporin:
| What is it particularly good at?
```
Cefipime
Killing pseudomonas (and everything else)
```
215
Cephalosporins with a disulfiram-like reaction (3):
Cefotetan
Cefamandole
Cefoperazone
216
Mechanism of action of cephalosporins:
Bactericidal.
| Inhibit cell wall synthesis.
217
Mechanism of action of aztreonam:
Binds PBP3 and prevents cross-linking of peptidoglycans.
218
Consider this drug for someone with a Gram (-) infection, renal insufficiency, and who is PCN-allergic:
Aztreonam
219
These drugs can increase the nephrotoxicity of aminoglycosides:
Cephalosporins
220
These two drugs have a very broad spectrum but their use is limited to life-threatening infections of unknown origin and as last resort due to toxicity:
Imipenam
| Meropenem
221
Drug you give with imipenam:
| Why?
Cilastatin
| Inhibits renal dehydropepdisase I, which inactivates the drug.
222
T/F: Meropenam will cover MRSA.
F. You need to give vanc for that. Typical scenario is sepsis of unknown origin, must give carbapenam + vanc to cover for MRSA.
223
Mechanism of action of vancomycin:
Bactericidal.
| Binds D-ala D-ala on cell wall of bacteria, inhibits peptidoglycan formation.
224
Spectrum of coverage for vancomycin:
Gram (+) only.
| Especially useful for MRSA, enterococci, C. diff.
225
Three primary toxicities of vanc:
Nephrotoxic
Ototoxic
Thrombophlebitis
Also, Red Man syndrome
226
Mechanism of resistance to vancomycin:
D-ala D-ala becomes D-ala D-lac in resistant organisms.
| Remember, D-lac = vancomycin activity LACking.
227
Prophylaxis for M. tb:
Isoniazid
228
Prophylaxis for MAC:
Azithromycin / clarithromycin
| When CD4 count < 50
229
Treatment for M. tb:
```
RIPE:
Rifampin
Isoniazid
Pyrazinamide + pyridoxine (B6)
Ethambutol
The B6 prevents isoniazid toxicity
```
230
Treatment for MAC infections:
Clarithromycin + ethambutol
231
Treatment for M. leprae infection:
Dapsone
Rifampin
Clofazimine
232
Mechanism of action of isoniazid:
Decreases mycolic acid synthesis
233
Administering this vitamin can help prevent isoniazid neurotoxicity:
B6
234
Three main toxicities associated with isoniazid:
Neurotoxicity
Hepatotoxicity
Drug-induced lupus
235
Mechanism of action of rifampin:
Inhibits DNA-dependent RNA-pol.
236
This drug is used for prophylaxis of meningitis and HiB chemoprophylaxis:
Rifampin
237
Drug that causes orange body fluids:
Rifampin
238
Main pharmacokinetic consideration with rifampin:
Increases P-450 enzymes, speeds the metabolism of many drugs.
239
Mechanism of action of pyrazinamide:
| It has a really great advantage for M. tb:
Blocks fatty acid synthesis in mycobacteria.
| It works well at acid pH, ie in lysosomes where M. tb likes to hide.
240
This drug blocks arabinosyltransferase and therefor decreases carb. polymerization in Mycobacteria cell walls:
Ethambutol
241
Main side effect of ethambutol:
Optic neuropathy
