7. Micro Flashcards Preview

Step 1 DIT > 7. Micro > Flashcards

Flashcards in 7. Micro Deck (124):
1

What bacterial structure mediates adherence of bacteria to the surface of a cell?

fimbria

2

What bacterial structure protects against phagocytosis

capsule

3

What bacterial structure provides rigid support to bacterial cell and protects against osmotic pressure

peptidoglycan

4

What bacterial structure is the space b/w the inner and outer cellular membranes in gram negative bacteria?

periplasmic space

5

What bacterial structure allows motility?

flagella

6

What is the bacterial form which provides resistance to dehydration, heat, and chemicals?

spore

7

what forms attachment b/w two bacteria during transfer of DNA material (aka conjucation)

pilus

8

What is the name of independent pieces of genetic material within bacteria that may contain genes for abx resistance?

plasmid

9

What stain is required to see Cryptococcus neoformans?

india ink

10

What stain is required to see PCP?

silver stain

11

What stain is required to see Chlamydia?

Giemsa stain

12

Which organisms are not well visualized with Gram stain? (4)

- treponema
- legionella
- mycoplasma (b/c no cell wall)
- mycobacteria (b/c of high lipid content)

13

Which bacteria are encapsulated?

- Strep pneumo
- H. influenzae type B
- Neisseria meningitidis
- E. coli
- Salmonella
- Klebsiella pneumoniae
- GBS

14

By what method are plasmids exchanged b/w bacteria?

conjugation (via pilus)

15

What exotoxin matches each of the following characteristics?

- inhibits ACh release --> flaccid paralysis

botulinum toxin (clostridium botulinum)

16

What exotoxin matches each of the following characteristics?

- phospholipase that causes gas gangrene

alpha toxin (clostridium perfringens)

17

What exotoxin matches each of the following characteristics?

- inhibits the inhibitor of adenylate cyclase --> increased cAMP --> impairing phagocytosis; whooping cough

Pertussis toxin (Bordetella pertussis)

18

What exotoxin matches each of the following characteristics? (2)

- stimulates adenylate cyclase --> increasing Cl and water secretion into gut --> diarrhea

Heat-labile ETEC toxin
Cholera toxin (Vibrio cholerae)

19

What exotoxin matches each of the following characteristics? (2)

- destroys leukocytes

1. gamma-hemolysin (S. aureus)
2. Panton-Valentine leukocidin (tissue destruction with MRSA)

20

What exotoxin matches each of the following characteristics?

- composed of edema factor, lethal factor, and protective antigen

Anthrax toxin (Bacillus anthracis)

21

What exotoxin matches each of the following characteristics?

- enterotoxin causing rice-water diarrhea

Cholera toxin

22

What exotoxin matches each of the following characteristics?

- causes Scarlet fever

pyogenic/exotoxin A (GAS)

23

What exotoxin matches each of the following characteristics?

- causes toxic shock syndrome

TSST-1 (S. aureus)

24

What exotoxin matches each of the following characteristics?

- inactivates EF-2 --> pseudomembranous pharyngitis

Diphtheria toxin (Corynebacterium diphtheriae)

25

What exotoxin matches each of the following characteristics?

- blocks release of inhibitory neurotransmitter (GABA and glycine)

tetanospasmin (Clostridium tetani)

26

What 6 bacteria secrete enterotoxins (exotoxins that causes water and electrolyte imbalances of intestinal epithelium resulting in diarrhea)?

1. Vibrio cholerae
2. ETEC
3. S. aureus
4. Shigella
5. Yersinia
6. C. diff

27

What is the function of catalase?

Hydrogen peroxide --> water + o2

28

One hour after eating potato salad at a picnic, an entire family began to vomit. After 10 hrs, they were better. What is the organism?

S. aureus

29

What very common aerobic skin colonizer is responsible for many indwelling foreign device infections?

S. epidermidis

30

What types of disease processes are caused by Strep pyogenes? (3)

1. Pyogenic (pharyngitis, cellulitis, impetigo, erysipelas)
2. Toxin-mediated (scarlet fever, toxic shock-like syndrome, necrotizing fasciitis)
3. Immune mediated (rheumatic fever, glomerulonephritis)

31

Which gram positive organism causes scalded skin syndrome?

S. aureus (exfoliative toxin)

32

Which gram positive organism cause gray-white membrane in the posterior pharynx of an unvaccinated child?

Corynebacterium diphtheriae

33

Which gram positive organism cause pharyngitis resulting in glomerulonephritis

GAS

34

Which gram positive organism is the most common cause of meningitis?

Strep. pneumo

35

Which gram positive organism is the most common cause of osteomyelitis?

S. aureus

36

Which gram positive organism cause serious newborn infections

GBS, listeria, E.coli

37

Which gram positive organism cause infants with poor muscle tone?

Clostridium botulinum

38

Which gram positive organism cause resp distress in a postal worker?

Bacillus anthracis

39

Which gram positive organism cause otitis media in children

strep. pneumo

40

Which gram positive organism cause cellulitis? (2)

s. aureus, GAS

41

Which pts are susceptible to Listeria monocytogenes?

old, young, pregnant, immunocompromised

42

Which bacteria are spore formers? (3)

Bacillus, clostridium, coxiella burnetti

43

A culture reveals gram negative, oxidase positive diplococci. What is the likely organism? (3)

1. Moraxella catarrhalis (COPD)
2. Neisseria gonorrhoeae (urethral discharge from college student)
3. N. meningitidis (CSF)

44

A 50 yo male smoker presents with a new cough and flu-like symptoms. Gram stain of the sputum shows no organisms but silver stain shows rods. What is the diagnosis?

legionella pneumophila

45

What gram-negative organism cause sepsis, DIC, adrenal hemorrhage?

N. meningitidis (Waterhouse-Friderichsen syndrome)

46

What gram-negative organism cause 5 yo with pharyngitis, drooling, and x-ray revealing thumb sign?

H. influenzae type B

47

What gram-negative organism cause burn wound infection?

pseudomonas

48

What gram-negative organism cause life-threatening meningitis + purpura?

N. meningitidis

49

What gram-negative organism cause septic arthritis in young, sexually active patients?

N. gonorrhoeae

50

Which form of E.coli causes HUS?

EHEC (0157:H7)

51

What infectious agent cause diarrhea caused by gram-negative, non-motile organism that does NOT ferment lactose?

Shigella

52

What infectious agent cause rice-water stools (2)

Vibrio cholerae, ETEC

53

What infectious agent cause diarrhea caused by S-shaped organism?

Campylobacter

54

What infectious agent cause diarrhea transmitted from household pet?

Yersinia (pet feces)

55

What infectious agent cause diarrhea caused by gram-negative motile organism that does not ferment lactose

Salmonella

56

Most common cause of traveler's diarrhea

ETEC

57

What infectious agent cause bloody diarrhea after eating undercooked hamburger meat?

EHEC (O157:H7)

58

What infectious agent cause diarrhea and RLQ pain mimicking appendicitis?

Yersinia

59

What infectious agent cause diarrhea after consuming eggs or handling raw chicken? (2)

Salmonella, campylobacter

60

What infectious agent cause osteo in sickle cell patient?

Salmonella

61

What organism cause LAD with new kitten?

Bartonella

62

What organism is associated with dog bite?

Pasturella

63

What organism is associated with ixodes tick?

Borrelia burgdorferi

64

What organism is associated with rabbit hunter?

Francisella tularensis

65

What organism is associated with pet prairie dog?

Yersenia pestis

66

What is the treatment for latent TB?

Isoniazid alone for 9 months (+B6)

67

What ist he treatment for active TB?

RIPE for first 2 months
Just rifampin+isoniazid for next 4 months

68

What abx is used for ppx of MAC in AIDS patients? When should this begin?

Azithromycin
when CD4+

69

What is the distinction b/w Ghon complex and Ghon focus? Are these seen in primary or reactivated TB?

Ghon focus: lung lesion from primary TB

Ghon complex: Ghon focus + hilar LAD

70

What is the Rickettsial triad of symptoms?

1. HA
2. Fever
3. Rash

71

25 yo with mycoplasma atypical pneumonia exhibits ANEMIA due to cold agglutinins. What type of immunoglobulins is responsible for the anemia?

IgM antibodies

note: cold agglutinins are non-specific IgM ab to erythrocytes. can agglutinate (lyse) RBCs in cold environments

72

Which abx should be used to treat mycoplasma pneumoniae?

tetracycline or macrolide (azithromycin)

73

Which abx should be used to treat rocky mountain spotted fever

doxy

74

Which abx should be used to treat bacterial vaginosis?

metronidazole

75

Which penicillin drug would you use given the following infection?
- syphilis

penicillin G (IV)

76

Which penicillin drug would you use given the following infection?
- UTI

aminopenicillins, like amoxicillin (better gram (-) coverage)

77

Which penicillin drug would you use given the following infection? (3)
- pseudomonas

- ticarcillin
- carbenicillin
- piperacillin

78

What extended coverage do ampicillin or amoxicillin have? (7)

HEELPSS
- H. influenzae
- E coli
- Enterococci
- Listeria
- Proteus mirabilis
- Salmonella
- Shigella

79

What are the 2 diff. mechanisms of resistance bacteria use against penicillin agents?

- production of beta-lactamase
- alteration of penicillin-binding protein (ex. MRSA)

80

What are the beta-lactamase inhibitors? (3)

- clavulanic acid
- sulbactam
- tazobactam

81

Which generation of cephalosporin would you choose to use for each of the following infections?

- UTI prevention

1st

82

Which generation of cephalosporin would you choose to use for each of the following infections?

- Serratia UTI

2nd (remember, HENS PEcK)

83

Which generation of cephalosporin would you choose to use for each of the following infections?

- N. meningitidis

3rd

84

Which generation of cephalosporin would you choose to use for each of the following infections?

- Pseudomonas

4th (cefepime)

or ceftazidime (3rd)

85

Which generation of cephalosporin would you choose to use for each of the following infections?

- resistant otitis media

cefdinir (oral 3rd gen)

86

What side effect would you be concerned about if a patient is receiving both ceftriaxone and gentamicin?

nephrotoxicity

87

Classify the following cephalosporins in their generation: cefepime

4th

88

Classify the following cephalosporins in their generation: cephalexin

1st

89

Classify the following cephalosporins in their generation: cefuroxime

2nd

90

Classify the following cephalosporins in their generation: ceftazidime

3rd

91

Classify the following cephalosporins in their generation: ceftaroline

5th

92

What is the MoA of cephalosporins?

Binds to penicillin-binding protein --> inhibition of synthesis and cross-linking of peptidoglycans

93

What cell wall inhibitor matches each of the following statements?

- aminoglycoside pretender

Aztreonam (monobactam)

94

What cell wall inhibitor matches each of the following statements?

- broad-spec coverage for appendicitis

imipenem + cilastin OR
meropenem

95

How does an organism develop resistance to vancomycin?

amino acid modification; D-ala D-ala --> D-ala D-lac

96

A patient is receiving an IV infusion of an abx and the nurse calls you when his face becomes flushed 15 min after the infusion started. What is the treatment for this patient?

- stop vanco
- antihistamines
- restart @ slower infusion

97

What are the side effects of aminoglycosides?

NOT
- nephrotoxicity
- ototoxicity
- teratogenic

98

What drugs have photosensitivity reactions?

SAT for photo
- Sulfonamides
- amiodarone
- tetracyclines

99

What causes gray baby syndrome? Gray man syndrome? Red man syndrome?

a. Chloramphenicol
b. amiodarone
c. vanco

100

What are the clinical uses for macrolides?

PUS
- pneumonia (atypical)
- URI
- STD: chlamydia, gonorrhea

101

What agent is used for ppx of gonorrhea

ceftriaxone

102

What agent is used for ppx of syphilis

penicillin G

103

What agent is used for ppx of recurrent UTIs (3)

- TMP-SMX or
- nitrofurantoin or
- cephalexin

104

What agent is used for ppx of PCP pneumonia

TMP-SMX

105

What agent is used for ppx of exposure to H. influenzae type B meningitis

rifampin

106

What agent is used for ppx of endocarditis prevention in pt with turbulent flow heart disease?

amoxicillin

107

What are the major side effects of the IV polymyxins? (2)

- neurotoxicity
- nephrotoxicity

108

What is the MoA of sulfamethoxazole (SMX)?

inhibits dihydropteroate synthase

109

What is the MoA of trimethoprim?

inhibits dihydrofolate reductase

110

What is the MoA of levofloxacin?

inhibits DNA gyrase (topoisomerase III)

111

What is the MoA of nitrofurantoin

inhibits bacterial ribosomes (only effective in urine)

112

What is the MoA of metronidazole

forms toxic free radicals that damage DNA

113

What is the MoA of polymyxin B?

cation detergent

114

What 2 organisms are important causes of pneumonia and meningitis in neonates?

GBS
e. coli

115

A group of picnic goers develop vomiting 2 hrs after eating. What is the most likely cause?

S. aureus

116

What infection matches each of the following descriptions?

- green frothy vaginal discharge with flagellated cells on wet prep

Trichomonas vaginalis

117

What infection matches each of the following descriptions?

- koilocytes on biopsy of lesion

HPV

118

What infection matches each of the following descriptions?

- multiple tender vesicles which becomes shallow ulcers

Herpes simplex virus

119

What infection matches each of the following descriptions?

- painless genital ulcer followed by rash on palms and soles

syphilis

120

What infection matches each of the following descriptions?

- mucopurulent cervical discharge with cervical motion tenderness

PID

121

Which TORCHeS infections is the most likely cause?

chorioretinitis, hydrocephalus, intracranial calcifications

toxo

122

Which TORCHeS infections is the most likely cause?

hydrops fetalis

parvo virus B19

123

Which TORCHeS infections is the most likely cause?

PDA, cataracts, deafness

rubella

124

Which TORCHeS infections is the most likely cause?

saddle nose, snuffles, Hutchinson teeth, saber shins

syphilis