Pathogen-Infection-Antibiotic Matching Considering Resistance

Question 1

Steps in a diagnosis

Answer 1

1. Look at patient symptoms and think of initial potential diagnosis
2. likelihood of those diagnoses being the problem – pre-test probability
3. Update the probabilities through tests
4. Take systemic history and examination
5. Post-test probability – how likely are each differential is now that you’ve done a history and examination

Question 2

Diagnostic iteration

Answer 2

Procedure in which repetition of a sequence of tests yields results successively closer to a desired result

Question 3

MRSA resistance

Answer 3

• producing a cell membrane molecule that beta-lactam antibiotics can’t bind to, making the antibiotics ineffective
• MRSA is resistant to most beta-lactam antibiotics

Question 4

ESBL (extended spectrum beta-lactamases) resistance

Answer 4

• Resistant to most beta lactams

- Some beta-lactam antibiotics are “stable” (not broken down) in the presence of ESBLs

Question 5

CPEs (carbapenememase producing enterobacteriaceae)

Answer 5

Bacteria able to produce an enzyme which breaks down many beta-lactam antibiotics including carbapenems

Question 6

CPEs (carbapenememase producing enterobacteriaceae) resistance

Answer 6

• CPEs are often coded for by a plasmid

- Plasmids often carry multiple antibiotic resistance genes, so CPEs are often resistant to many other antibiotics

Question 7

Antimicrobial stewardship =

Answer 7

working to improve the prescribing of antibiotics to reduce resistance