A sample of drug susceptible Pseudomonas organisms were
placed on top of a monolayer of tissue culture cells and
incubated for 30 minutes at 37°C before gentamicin was added
(50 µ/ml). After incubating for an hour, the cells were removed
from the monolayer, washed, and then diluted. Then 500 cells
were inoculated onto a blood agar plate and incubated. The
next day, 40 Pseudomonas colonies were found on the plate.
Which of the following best explains these findings?
A. The colonies are gentamicin resistant mutants
B. These bacteria are contaminants
C. Gentamicin was mainly bacteriostatic
D. These bacteria are intracellular
(this multiple choice question has been scrambled)