Microbiology: Bacterial Flashcards Preview

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Flashcards in Microbiology: Bacterial Deck (241)
1

Two toxins produced by C. difficile:
What kind of toxin? What is its function?

Toxin A = enterotoxin = exotoxin, binds brush border.
Toxin B = cytotoxin = destroys enterocyte cytoskeleton -> pseudomembranous colitis.

2

Two antibiotics especially associated with C. diff:

Clinda
Amp

3

Treatment for C. diff:

Metronidazole
ORAL vanc

4

Dx of C. diff:

Toxin in stool

5

Most common E. coli strain causing bloody diarrhea:

Enteroinvasive

6

Treatment for dysentery caused by E. coli:

Fluoroquinolones, TMP-SMX

7

Two toxins produced by enterotoxigenic E. coli:
Second messenger inside the cell for action of each?

Heat labile = cAMP increase = watery diarrhea like cholera
Heat stable = cGMP increase

8

Cause of traveler's diarrhea ("Montezuma's revenge"):

Enterotoxigenic E. coli

9

E. coli strain causing diarrhea in daycare:

EPEC

10

Causes HUS:

Enterohemorrhagic E. coli
Usually 0157:H7

11

Triad of HUS:
Explain how this happens:

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

Most E. coli ferment this sugar:
Which one does not?

Sorbitol
EHEC does not ferment sorbitol

13

Tx for HUS:

Supportive only.
Do not give abx.

14

Two E. coli strains causing dysentery:

Enteroinvasive
Enterohemorrhagic

15

E. coli strain causing watery diarrhea:

Enterotoxigenic

16

How would you distinguish EHEC from other forms of E. coli on culture?

It does not ferment sorbitol. The others do.

17

Organism responsible for causing staghorn calculi:

Proteus

18

Urease-positive, ammonium-Mg-phosphate stones:

Proteus

19

Common cause of osteomyelitis in sickle cell patients:

Salmonella

20

Four A's of Klebsiella:

Aspiration pneumonia
Alcoholics
Abscesses in lungs and liver
di-A-betics

21

Mucoid colonies, lobar pneumonia in a diabetic:

Klebsiella

22

Flagellated organism, hematogenous dissemination, produces H2S:

Salmonella

23

Very virulent organism, frequently causes bloody diarrhea, human and primate but not pet reservoirs:

Shigella

24

Associated with Reiter syndrome:

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