Mechanisms of Bacterial Resistance

Question 1

There are two mechanisms of B-lactam resistance, what are they?

Answer 1

1) B-latamase production 2) Alteratiom of penicillin binding protein target site

Question 2

What are B-lactamases

Answer 2

bacterial enzymes that cleave the B-lactam ring of the antibiotic and thus render it inactive.

Question 3

hospital strains of Staphylococcus aureus and gram negative baciili produce …………… that makes them resistant to benzylpenicillin

Answer 3

B-lactamase

Question 4

What are the two ways to combat B-lactamase?

Answer 4

1) introduce a second component to the antibiotic which is a B-lactamase inhibitor e.g co-amoxiclav
2) Modify the antibiotic side chain to produce an antibiotic which is resistant to the actions of B-lactamase

Question 5

What is Flucloxacillin?

Answer 5

an antibiotiv resistant to the action of B-lactamase

Question 6

What are Extended spectrum B-lactamases (ESBL)?

Answer 6

B-lactamases that are produced by some gram negative organisms that can break down 3rd generation Cephalosporinis and Penicillins, therefore rendering the organism resistant to all B-lactam antibiotics.

Question 7

what are penicillin binding proteins involved in?

Answer 7

enzymes that are involved in peptidoglycan synthesis which are inhibited by the binding of penicillins and cephalosporins.

Question 8

Vancomycin resistance is unusual in gram positive organisms, however what have recently emerged to change this

Answer 8

Vancomycin resistant enterococci