Hospital Acquired Infections

Question 1

3 factors causing HAI?

Answer 1

Concentration
Dissemination
Intervention

Question 2

List the ESCAPE pathogens

Answer 2

E - enterococcus faecium 
S - staph aureus 
C - Clostridium difficile 
A - Acinetobacter baumanii
P - pseudomonas aeruginosa 
Enterobacteriaceae

Question 3

Which of the ESCAPE pathogens are gram positive?

Answer 3

ESC

Question 4

Which of the ESCAPE pathogens are gram negative?

Answer 4

APE

Question 5

What is enterococcus faecium resistant to?

Answer 5

Vancomycin

Question 6

When do C.diff infections occur?

Answer 6

Usually after a previous course of antibiotics

Question 7

The APE pathogens are problematic because?

Answer 7

They are multi drug resistance

Question 8

Give example of three enterobacteriaceae

Answer 8

Pathogenic E.coli
Klebsiella penumoniae
Enterobacter species

Question 9

What is the most frequent cause of bacteraemia by a gram negative bacterium?

Answer 9

Pathogenic e.coli

Question 10

E.coli is the most frequent cause of what?

Answer 10

Community and hospital acquired UTI!

Question 11

Name one class of antibiotics that E.coli is resistant to, and its mode of resistance

Answer 11

Cephalosporins - by expressing extended spectrum beta lactamases (ESBL)

Question 12

Which drug class is pathogenic E.coli still sensitive to?

Answer 12

Carbapenems

Question 13

What class of antibiotics do cephalosporins fall into?

Answer 13

Beta lactam antibiotics

Question 14

Describe the mechanism of action of cephalosporins

Answer 14

Inhibit peptidoglycan synthesis by inhibited the activity of penicillin binding proteins (PBP)

Question 15

What is the target of cephalosporins?

Answer 15

Penicillin binding proteins such as transpeptidase enzyme

Question 16

How do ESBL work?

Answer 16

They hydrolyse the C-N bond of the beta lactam ring

Question 17

What are ESBLs encoded on?

Answer 17

A plasmid

Question 18

Name two other beta lactam antibiotics

Answer 18

Penicillin

Carbapenems

Question 19

How do bacteria resistant carbapenems?

Answer 19

Carbapenemase enzyme

Question 20

What is carbapenemase encoded on?

Answer 20

A transposon

Question 21

Name another important cause of UTI and respiratory tract infections

Answer 21

Klebsiella pneumoniae

Question 22

Who is at particularly high risk of acquiring Klebsiella pneumoniae?

Answer 22

Immunocompromised people

Question 23

Which antibiotics are ineffective against Klebsiella due to resistance?

Answer 23

3rd generation cephalosporins
Fluroquinolones
Aminoglycosides

Question 24

Which carbapenem resistant enterobacteriae is most commonly encountered in the US?

Answer 24

Carbapenem resistant klebsiella pneumoniae (CRKP)

Question 25

Name an antibiotic against which Pseudomonas aeruginosa are resistant

Answer 25

Carbapenems

Question 26

How does MRSA block methicillin from working?

Answer 26

MRSA produces PBP2A which has a lower affinity for methicillin and therefore can still synthesise peptidoglycan in the presence of methicillin

Question 27

What is the third most frequently identified cause of nosocomial blood stream infections BSI in the US?

Answer 27

VRE: vancomycin resistant enterococcus faecium

Question 28

How does vancomycin work?

Answer 28

Binds to peptidoglycan precursor and inhibits the synthesis

Question 29

How is enterococcus faecium resistant to vancomycin?

Answer 29

It produces a different peptidoglycan precursor

Question 30

How are the vancomycin resistant genes encoded?

Answer 30

On plasmids or transposons via multiple genes