Kirby-Bauer Technique

Question 1

the larger the zone size, the more ___ the bacterium is to that microbial agent

Answer 1

susceptible

Question 2

results of Kirby-Bauer test can help how with patients

Answer 2

provide info on which antibiotic agents work best against pathogen infecting a patient

Question 3

is gram + or - more susceptible and why

Answer 3

g+ more susceptible bc thick peptidoglycan wall; g- have porins, which act as a defense, and LPS… making g- usually more resistant

Question 4

kirby-bauer method

Answer 4

transfer paper disks with each antibiotic to plate w microbe
incubate and measure zone of inhibition; test resistance-susceptibility

Question 5

kirby-bauer methods vs filter paper test IMPORTANT

Answer 5

kirby-bauer tests for sensitivity to antibiotics
filter paper test test for antimicrobial sensitivity

Question 6

antiseptics (4) and their functions

Answer 6

alcohols: dehydrate g+ cell wall and destroy g- outer mem
iodine: affects proteins
chlorhexidine (skin cleansers): interferes w proteins
boric acid: changes pH; affects proteins
hydrogen peroxide: produces free radicals; strongest bc free radicals and oxidizes cell, breaking cell walls

Question 7

disinfectants (5) and their functions

Answer 7

alcohols
aldehydes (formaldehyde): affects proteins
oxidizing agents: produces free radicals (H2O2)
phenols: damage proteins
quaternary ammonium compounds (soaps): damage proteins

Question 8

filter paper disk method

Answer 8

inoculate bacteria onto nutrient agar plate, close streaks (2 different plates; staphylococcus and pseudomonas fluorescens)
add disc to center of plate
incubate and measure zone of inhibition