Day 3.3 Micro Flashcards Preview

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Flashcards in Day 3.3 Micro Deck (90):
1

What do penicillins (and cephalosporins) do?

Disrupt the cell wall (so good for gram+, also some gram-)

2

What is a penicillinase?

Aka Beta-lactamase
Substance md by some bacteria that breaks down penicillin

3

Sometimes abx can be combined with a penicillinase (beta-lactamase) inhibitor to give them a wider spectrum. What are the inhibitors?

Clavulanic acid
Tazobactam
Sulbactam

Amoxicillin + clavulinic acid = augmenten, used for ear infections in kids
Ampicillin + sulbactam - unacyn
IV med used for surgical infections

4

What is the toxicity for Ampicillin and amoxicillin (the aminopenicillins)?

HPS rxn
Ampicillin rash in mono pts (EBV)
Pseudomembranous colitis (C. diff)

5

What are the clinical uses of penicillin?

Gram+:
S. pneumonia, S. pyogenes, Acintomyces, Gp B strep (esp moms in labor)
Gram+ rods: Clostridium, Bacilus, Listeria
Spirochetes: Syphilis (drug of choice)
Gram-neg cocci: Neisseria

6

How do gram-neg organisms cause resistance to penicillins?

Hydrolysis of Beta-lactam ring by bacterial penicillinases (beta-lactamases) in the periplasmic space. (Can use beta-lactamase inhibitors- clavulanic acid- to prevent this)

7

How do gram+ organisms cause resistance to penicillins?

They alter the B-lactam targets. (Alter PBPs- penicillin binding proteins)
S. pneumonia and S. aureus especially.

8

Augmenten

Amoxicillin + clavulanic acid
Used for ear infections in kids

9

Unasyn

Ampicillin + sulbactam
Used in surgery

10

Timentin

Ticarciliin + clavulanic acid

11

Zosyn

Piperacillin + tazobactam

12

Which drugs cause a disulfiram-like reaction?

Anatabuse (disulfiram)
Certain cephalosporins
Metronidazole
1st gen sulfonureas
Procarbazine (chemo for Hodgkin's)

13

Treatment for Proteus, E. coli, K. Pnuemonia (UTI bugs)

1st gen cephalosporins- esp cephalexin

14

When are 1st gen cephalosporins used w/ aminopenicillins?

Prophylaxis is against Viridans in dental procedures

15

3rd gen cephalosporins provide less gram+ coverage- but can still be used for which gram+ organism?

S. pneumonia

16

What kind of drug is gentamycin?

Aminoglycoside.
Cephalosporins increase the nephrotoxicity of aminoglycosides like gentamycin.

17

If a pt has a bad infection and you don't know what it is, what is a good antimicrobial to use?

Imipenem/cilastin; meropenem.
V broad spectrum, v powerful, beta-lactamase resistant.
Doesn't work for MRSA tho.

18

Clinical use for vancomycin

serious gram+ multi-drug resistant organisms- S. aureus (MRSA) and C. diff (pseudomembranous colitis). Can use oral vanc for C. diff bc only need it to go to gut, not systemic.
Also Coagulase-negative endocarditis caused by S. epidermidis (IV drug users)

19

Which cephalosporin lasts the longest?

Longest half-life = ceftriaxone (3rd gen)
give 1x/day IV or IM

20

Disulfiram-like rxn

Disulfiram inhibits aldehyde dehydrogenase, so ethanol is not fully metabolized. Aldehyde accumulates and causes flushing, sweating, nausea/vom, headache

21

Rx for Pseudomonas (Gram-neg rod, aerobic, likes moist env and hospitals)

3rd gen- ceftazidime
4th gen- cefepime
aztreonam
ticarcillin, carbenicillin, piperacillin (ant-pseudomonals)

22

Aminoglycoside pretender

aztreonam

23

Clinical use for aztreonam

Klebsiella, E coli, Pseudomonas, Serratia.
For pts who are allergic to penicillin, pts with renal insufficiency who can't tolerate aminoglycosides

24

Red man syndrome

Diffuse whole-body flushing caused by vancomycin.
Prophylaxis: anti-histamines, slow infusion of vanc

25

If otitis media is resistant to amoxicillin, what should you give?

Add clavulanic acid (Augmentin)
or use 3rd gen cefidinir

26

What increases the nephrotoxicity of aminoglycosides?

Cephalosporins

27

Rx for syphilis

Penicillin

28

Rx for gonorrhea

Single dose ceftriaxone

29

Rx for C. diff

Oral vanc or metronidazole

30

1st gen cephalosporins

cephalexin
cefazolin
for PEcK

31

2nd gen ceph

cefprozil
for HEN PEcKS

32

3rd gen ceph

cefdinir
ceftrixone

33

4th gen ceph

cefipime

34

Epiglottitis mgmt

mk pt comfortable and don't do anything
avoid upsetting child and losing airway
want ability to rapidly intubate

35

Epiglottitis px

Cherry red
Omega sign
Lean fwd to straighten airway
Drooling bc can't swallow spit
Thumb sign on xray d/t edema

36

Fitz-Hugh-Curtis syndrome

PID (from neisseria gonorrhea) that starts in lower genital tract but ascends to upper tract, ultimately affecting the liver capsule

37

Waterhouse-Friedrichson syndrome

Adrenal hemorrhage d/t meningiococcemia.
Bleeding causes adrenal insufficiency- hypotension, electrolyte imbalance, DIC

38

How do you prophylax close contacts of Neisseria meningococci?

Rifampin

39

What kind of proteases does Neisseria produce?

IgA proteases

40

Cause of epiglottitis

H. influenzae (Gram-neg cocco-baciliary rod)

41

What kind of protease does H. influenzae produce?

IgA protease

42

Hemophilus ducreyi

Painful genital ulcer- chancroid

43

Atypical pneumonia

Diffuse, lighter (NOT lobar like regular pneumonia). More interstitial areas.
Caused by Legionella, Chlamydia, Mycoplasma.

44

Rx for atypical pneumonia

Macrolides-
Erythromycin
Azithomycin
Zithromax

45

Pneumonia in cystic fibrosis is caused by which organism?

Pseudomonas aeruginosa

46

Drug use leading to endocarditis- which bacteria?

Gram-pos S. epidermidis
Gram-neg Pseudomonas aeruginosa

47

Bilateral Bell's Palsy (facial nerve paralysis)- 2 causes

Lyme dz
Guillan-Barre syndrome

48

Most common cause of Gram-neg sepsis?

E.coli
2nd- Klebsiella

49

Septic arthritis in young adult

Neisseria gonorrhea

50

Cat scratch

Bartonella henselae

51

Dog/cat bite

Pasturella multocida

52

Cat feces

Toxoplasmosis
(avoid if prego)

53

Puppy feces

Yersinia enterocolitica

54

Animal urine

Leptospira

55

Rat bites

Spirillum minus

56

Proteus (mirabilis, vulgaris)

Motile, no distinct colonies can be grown.
Common cause of UTI
Carries urease:
urea --> NH3 + CO2 --> ammonium/magnesium/phosphate stones --> staghorn caliculi

57

Osteomyelitis in sickle cell pts

Salmonella

58

Neisseria gonorrhea

urethritis, cervicitis, PID, epididymitis (same as chylamydia)
Most common cause of septic arthritis in young sex-active pts
Opthalmia neonatorum-vertical txmsn, sticky eye discharge, may cause blindness

59

How is opthalmia neonatorum prevented?

Erythomycin eye drops- give to everyone.
(prevents n. gonorrhea vertical txmsn)

60

Pseudomonas aeruginosa causes...

pneumonia (CF, immunocompromised)
burn, wound infections
corneal infections (contact lens)
osteomyelitis in DM, IV drug abusers
sepsis (v high mortality)
extermal otitis (elderly, DM)
hot tub folliculitis,
endocarditis (IV-DA)
UTI (foley)

61

What are the enterobacteraiceae?

Family of gram-neg rods:
E. coli
Salmonella
Shigella
Klebsiella
Enterobacter
Serratia
Proteus

All have O (somatic) Ag
K (capsular) Ag is related to virulance
H (flagellar) Ag is on motile species
All ferment glucose
All are oxidase negative.

62

What does E.coli cause?

diarrhea
UTI
neonatal meningitis/pneumonia/sepsis

63

4 types of E. coli

EIEC - invades intestinal mucosa
EHEC, ETEC, EPEC - do not invade

64

EIEC

enteroinvasive E.coli
invades intestinal wall, so get fever and bloody diarrhea.
has shiga-like toxin (verotoxin) which inhibits 60S ribosome

65

ETEC

traveler's diarrhea
Rx: TMP-SMX or fluroquinolones (cipro)
similar to cholera- rice water diarrhea
no intestinal wall invastion- so no fever, bloody
labile toxin and stabile toxin

66

EHEC

O157:H7
hamburger meat
get HUS
shiga-like toxin.
dysentery- bloody diarrhea
does NOT ferment sorbitol like other E.coli

67

What is HUS

Hemolytic-uremic syndrome.
Triad:
1. Anemia (hemolysis)
2. Renal failure (uremia = high lvl of nitrogen waste in blood)
3. Thrombocytopenia (low plt)

68

EPEC

no toxin
adheres to apical surf and flattens villi, so prevents absorption
Diarrhea usu in daycare kids

69

Salmonella

most common cause of food-assocd diarrhea in developed countries (poultry, eggs, reptiles)
S. enterica, S. enteritidis
Avoid Abx!! bc can prolong the carrier state of salmonella in GI tract infections

70

What causes typhoid fever?

Salmonella typhi

71

Shingella

Bacterial dysentery can be caused by Shigella flexneri, sonnei, dystenteriae

72

Shigella flexneri

Assoc w Reiter's Reactive arthritis (can't see, pee, climb a tree)

73

Campylobacter jejuni

Oxidase+ comma-shaped gram-neg
grows in 42C (hot CAMPfire)
mjr cause of diarrhea in kids
fecal-oral
poultry, meat, unpasterized milk
precursor to Guillan-Barre

74

What gram-neg has aerosol txmsn, not person-person

Legionella pneumophilia

75

What enz to obligate anaerobes lack?

Catalase
Superoxide dismutase
so susceptible to oxidate dmg
Clostridium, Bacteroides, Acintomyces

76

Osteomyelitis in DM

pseudomonas

77

Aspiration pneumonia (alcoholic)

Klebsiella pneumonia

78

Common cause UTI and pneumonia

Klebsiella pneumonia

79

Treatment for gonorrhea?

Single dose ceftriaxone

80

What drugs inhibit protein synth?

30S:
Aminoglycosides
Tetracycline

50S:
Chloramphenicol, Clindamycin
Erythromycin
Lincomycin
Linezolid

81

Discoloration of teeth and inhibition of bone growth in kids

Tetracyclines

82

Drugs with ototoxicity and nephrotoxicity

Aminoglycosides
Vancomycin
Loop duretics
Cisplatin (chemo)

83

Gray baby
Gray man
Red man

Gray baby = chloramphenicol
Gray man = amiodarone (anti-arrhythmia)
Red man = vancomycin

84

What drugs should be avoided in pts with sulfa allergy

Sulfonamides
TMP-SMX
Sulfasalazine
Sulfonylureas
Sumatriptan
Acetazolamide (diurectic- CA inhibitor)
Furosemide
Thiazide
Probenecid (gouty arthritis)
Celecoxib (COX-2 inhibitor)

85

Most common causes of UTI

E.coli #1
Proteus, Klebsiella, Pneumonia

86

Abx that treat UTI

Aminopenicillins
Cephalosporins
Nitrofurantoin
Sulfonamides

87

Drugs w photosensitive rxns

SAT for a photo:
Sulfonamides
Amiodarone (anti-arrhythmic)
Tetracyclines

88

Drugs that cause Stevens-Johnson syndrome

Penecillins
Sulfa Drugs
Seizure Drugs- ethosuxamide, lamtrigine, carbamazepine, phenobarbital, phenytoin
Allopurinol (for gout)

89

Drugs used for Anaerobic infections

Metronidazole
Clindamycin
Imipenem/cilastatin
Meropenem

90

Drugs that are used for Pseudomonas

polymyxins
fluroquinolones
cefepime
aztreonam (aminoglycoside pretender)
aminoglycosides
extended-spectrum penicillins (ticarcillin, carbemicillin, piperacillin)