Gram negative bacteria

Question 1

Gram negative cocci – Neisseria gonorhoea – ID

Answer 1

gram negative cocci

-grows on chocoalte agar and low O2 * think candlelight

Question 2

Gram negative cocci – Neisseria gonorhoea – epi

Answer 2

STI

@ risk: sexually active, neonates

Question 3

Gram negative cocci – Neisseria gonorhoea – pathogenesis

Answer 3

Endotoxin (LOS)

Question 4

Gram negative cocci – Neisseria gonorhoea – clinical

Answer 4

cervicitis/urethritis
pharyngitis
proctitis
disseminated dz

Question 5

Gram negative cocci – Neisseria gonorhoea – tx

Answer 5

ceftriaxone + Azithromycin

Question 6

Gram negative cocci – Neisseria gonorhoea – prevention

Answer 6

barrier

Question 7

Gram negative cocci – Neisseria meningitidis – ID

Answer 7

gram negative cocci

-grows on chocolate agar and low O2 (think candelight)

Question 8

Gram negative cocci – Neisseria meningitidis – epi

Answer 8

college
military
“meningitis belt” Africa

Question 9

Gram negative cocci – Neisseria meningitidis – pathogenesis

Answer 9

Endotoxin (LOS) –> activates TLR40 –> uncontrolled immune response –> septic shock via vasodilation, hypotension, shock

Question 10

Gram negative cocci – Neisseria meningitidis – clinical

Answer 10

• meningitis

- meningococcemia (DIC and petechiae –> necrosis and purpura)

Question 11

Gram negative cocci – Neisseria meningitidis – tx

Answer 11

ceftriaxone

Question 12

Gram negative cocci – Neisseria meningitidis – prevention

Answer 12

• pre-exposure: vaccine, droplet mask

- post-exposure prophylaxis: ciprofloxacin, rifampin

Question 13

Gram negative rod – E. coli – ID

Answer 13

gram negative rod

ferments lactose and glucose

Question 14

Gram negative rod – E. coli – epi

Answer 14

• lives in gut

- most common diseases: UTI, neonatal sepsis, “traveler’s diarrhea” - ETEC, STEC

Question 15

Gram negative rod – E. coli – pathogenesis

Answer 15

1. UTIs: pili bind urinary tract epithelium –> sticky and invasive
2. systemic infxn –> cell wall LPS (endotoxin) –> fever, hypotension, DIC
3. Enteric infxn –> enterotoxin mediated

Question 16

Gram negative rod – E. coli – clinical

Answer 16

1. UTIs
2. systemic: sepsis, neonatal infxn
3. gut: watery (ETEC)and bloody diarrhea (STEC)

Question 17

Gram negative rod – E. coli – tx

Answer 17

1. UTIs and systemic: antibiotics

2. gut: usually supportive

Question 18

Gram negative rod – E. coli – prevention

Answer 18

1. UTIs – remove catheters, prophylactic abx

2. gut: hand hygiene

Question 19

Gram negative rod – Klebsiella – ID

Answer 19

gram negative rod

ferments lactose

Question 20

Gram negative rod – Klebsiella – epi

Answer 20

• lives in gut – causes infxn when it goes to the wrong place (ie lungs)
• pts usually older, male, EtOH, diabetes, but anyone

Question 21

Gram negative rod – Klebsiella – pathogenesis

Answer 21

• antiphagocytic capsule

- person aspirates bacteria into GI

Question 22

Gram negative rod – Klebsiella – clinical

Answer 22

1. community acquired pneumonia (with productive cough of “red currant jelly”)
2. UTI

Question 23

Gram negative rod – Klebsiella – tx

Answer 23

antibiotics

Question 24

Gram negative rod – Klebsiella – prevention

Answer 24

no vaccine

Question 25

gram negative rod -- proteus mirabilis -- ID

Answer 25

gram negative rod NOT a lactose fermenter -highly motile --> "swarming" overgrowth on blood agar

Question 26

gram negative rod -- proteus mirabilis -- epi

Answer 26

stones leading to recurrent UTIs

Question 27

gram negative rod -- proteus mirabilis -- pathogenesis

Answer 27

urease positive pathogenesis: proteus makes urease to hydrolyze urea into ammonia --> increase pH --> struvite stones "staghorn calculi" produced --> recurrent UTIs

Question 28

gram negatie rod -- proteus mirabilis -- clinical

Answer 28

UTIs

Question 29

gram negatie rod -- proteus mirabilis -- tx

Answer 29

antibiotics

Question 30

gram negatie rod -- proteus mirabilis -- prevention

Answer 30

no vaccine

Question 31

gram negative rod -- pseudomonas aeruginosa -- ID

Answer 31

``` gram negative rod NOT a lactose fermenter Oxidase positive green-blue pigment fruity odor ```

Question 32

gram negative rod -- pseudomonas aeruginosa -- epi

Answer 32

- lives in water (*think blue and green) especially in ICU | - @ risk: hospitalized pts, especially intubated, burn, cystic fibrosis, neutropenic pts

Question 33

gram negative rod -- pseudomonas aeruginosa -- pathogenesis

Answer 33

Endotoxin (LPS) primarily | Exotoxin A for tissue necrosis

Question 34

gram negative rod -- pseudomonas aeruginosa -- clinical

Answer 34

sepsis pneumonia wound infxn in burn patients hot tub folliculitis

Question 35

gram negative rod -- pseudomonas aeruginosa -- tx

Answer 35

antibiotics

Question 36

gram negative rod -- pseudomonas aeruginosa -- prevention

Answer 36

keep WBC > 500, scrupulous care burn pts

Question 37

gram negative rod -- Haemophilus influenzae -- ID

Answer 37

small gram negative rod NOT a lactose fermenter grown on "chocolate agar"

Question 38

gram negative rod -- Haemophilus influenzae -- epi

Answer 38

enters via droplets and lives in respiratory tract | -most @ risk: 6mo-6yo

Question 39

gram negative rod -- Haemophilus influenzae -- pathogenesis

Answer 39

IgA protease degrades IgA Antiphagocytic capsule Endotoxin LPS

Question 40

gram negative rod -- Haemophilus influenzae -- clinical

Answer 40

``` meningitis otitis media pneumonia sinusitis sepsis **serious MOPSS ```

Question 41

gram negative rod -- Haemophilus influenzae -- tx

Answer 41

antibiotics

Question 42

gram negative rod -- Haemophilus influenzae -- prevention

Answer 42

conjugated type b vaccine to reduce meningitis by 90%

Question 43

gram negative rod -- Bortadella pertussis -- ID

Answer 43

gram negative rod | NOT a lactose fermenter

Question 44

gram negative rod -- Bortadella pertussis -- epi

Answer 44

highly contagious, droplet transmission | @rick: infants and young children

Question 45

gram negative rod -- Bortadella pertussis -- pathogenesis

Answer 45

Extoxin: ADP-ribosylation disables Gi protein --> overactivates adenylate cyclase leading to inc cAMP --> respiratory mucosal edema

Question 46

gram negative rod -- Bortadella pertussis -- clinical

Answer 46

- inspiratory "whooping" caused by acute tracheobronchitis in kids, 1-4wks - adults can have 100 day cough w/o whooping

Question 47

gram negative rod -- Bortadella pertussis -- tx

Answer 47

antibiotics, supportive care

Question 48

gram negative rod -- Bortadella pertussis -- prevention

Answer 48

Acellular vaccine containing inactivated pertussin toxin, often combined with diphtheria and tetanus -- DTap

Question 49

gram negative rod -- Legionella -- ID

Answer 49

gram negative rod NOT a lactose fermenter needs charcoal yeast agar

Question 50

gram negative rod -- Legionella -- epi

Answer 50

associated with air conditioners | -typically older, smoker, HIV, transplant IC pt

Question 51

gram negative rod -- Legionella -- pathogenesis

Answer 51

can replicate in free-living amoebas in water --> enters respiratory tract --> endotoxin (LPS)

Question 52

gram negative rod -- Legionella -- clinical

Answer 52

severe pneumonia + diarrhea

Question 53

gram negative rod -- Legionella -- tx

Answer 53

antibiotics

Question 54

gram negative rod -- Legionella -- prevention

Answer 54

no vaccine