chapter 10 hostpital acquired gram negatives

Question 1

the 4 Ws

-these are the main ways that hospital acquired gram negative infections occur

Answer 1

Wind (pneumonia) (endotracheal intubation)
water (UTI)
wound and wires (IV lines)

Question 2

what is the most common family of bacteria that are acquired in hospital acquired infections

-what is significant about them

Answer 2

the enterobacteriacae

E coli, klebsiella, enterobacter

multidrug resistance

Kleb enters back East

Question 3

pseudomonas aeruginosa, 2 important things about it

Answer 3

colonizes and infects sick, immunocompromised hospitalized patients

multidrug resistance

Question 4

how you can tell infection is pseudomonas aeruginosa

Answer 4

lactose fermenter

produces pyoverdin and pyocyanin which gives colonies greenish-blue coloration

produces sweet grape-like scent

Question 5

what is the exotoxin in p aeruginosa

Answer 5

exotoxin A

Question 6

important pseudomonas aeurginosa infections

Answer 6

pneumonia (wind)

• CF pts have lungs colonized by pseudomonas aeruginosa–>chronic pneumonia
• immunocomp pts are highly susceptible to pneumonia caused by p aeurginosa

osteomyelitis (related to wounds)

• diabetic pts have increased risk of infection and developing foot ulcers, this can penetrate into bone
• IV drug users have increased risk too
• children who step on rusty nail

burn-wound infections (wound)

sepsis (wire): high mortality rate

urinary tract infections, pyelonephritis (water)

• debilitated pts in nursing homes and hospitals
• urethral foley catheters

endocarditis: in IV drug users

malignant external otitis: in elderly diabetic pts

corneal infections: in contact lens wearers

Question 7

mnemonic for pseudomonas aeruginosa infections

Answer 7

BE PSEUDO

Burns
Endocarditis
Pneumonia
Sepsis
External malignant otitis media 
UTI
Diabetic Osteomyelitis

Question 8

burkholderia cepacia
-patients at risk
-

Answer 8

oxidase positive, aerobic gram neg bacillus
burn and ventilated patients
people with cystic fibrosis are at greatest risk

Question 9

stenotrophomonas maltophilia

-what can it cause and what is it normally for

Answer 9

normal colonizer and part of normal respiratoery flora,
-can cause disease in hospitalized pts
-pneumonia
line related bacteremia

Question 10

acinetobacter are very similar to

Answer 10

psedudomonas

Question 11

acinetobacter

aerobic or anaerobic?

• main species
• causes what
• hard to ID why

Answer 11

aerobic gram negative bacteria found in soil and water

• mainly acinetobacter baumannii
• can survive for extended periods on environmental surfaces
• frequrent cause of pneumonia, line related bacteremias, foley catheter associated UTIs
• tricky to ID bc they are coccobacillary (may be mistaken for Neisseria) and on solid media they form diplococci like neisseria