hospital acquired infection and antibiotic resistance

Question 1

4 mechanisms of antibiotic resistance

Answer 1

altered target site, inactivation of antibiotic, altered metabolism, decreased drug accumulation

Question 2

explain altered target site

Answer 2

acquire alternative gene, or one that encodes a target-modifying enzyme

Question 3

explain inactivation of antibiotic

Answer 3

enzymatic degradation or alteration; can also be enzyme-independent

Question 4

explain altered metabolism

Answer 4

increase production of enzyme substrate so outcompete antibiotic inhibitor; switch to other metabolic pathways, reducing enzyme requirement

Question 5

explain decreased drug accumulation

Answer 5

reduce penetration (influx) of antibiotic into cell or increase efflux out of cell

Question 6

3 sources of antibiotic resistance genes

Answer 6

plasmids (carry multiple antibiotic resistance genes; swapped by conjugation or bacteriophage), transposons (integrate into chromosomal DNA), naked DNA (from environment)

Question 7

5 non-genetic mechanisms of resistance or treatment failure

Answer 7

biofilm, IC location, slow growth, spores, persisters

Question 8

important gram +ve multidrug resistant bacterial pathogens

Answer 8

P. aeruginosa, E. coli, Salmonella spp., A. baumanii

Question 9

important gram -ve multidrug resistant bacterial pathogens

Answer 9

S. aureus, S. pneumoniae, C. difficile, Enterococcus spp.

Question 10

when does resistance emerge

Answer 10

soon after arrival of new antibiotic

Question 11

what is the minimal inhibitory concentration

Answer 11

lowest concentration of antibiotic required to inhibit growth

Question 12

what is antibiotic resistance associated with in hospitals

Answer 12

increased morbidity, mortality, length of hospital stay, cost