Question

The Kirby Bauer antibiotic disk test is run repeatedly on many strains of the same organism. All suscpetable strains will have a zone of inhibition with a diameter greater than the ____.

		bactericidal breakpoint
		resistance breakpoint
		bacteriostatic breakpoint
		susceptibility breakpoint
		Inhibition breakpoint

Answer 1

The correct answer is :-

(d) Susceptibility breakpoint.

Susceptibility breakpoint is a zone of diameter which if greater than or equal to a zone of inhibition of a bacterial stain implies that the strain is susceptible to that antibiotic.

Only the susceptible breakpoint determines whether the bacterial stain is susceptible, intermediate or resistance to an antibiotic.

Other options are incorrect since there is no such breakpoint present and cannot be used to determine the susceptibility of that stain.

So the correct answer is (d) All Susceptibile strain have a zone of inhibition greater than susceptibility breakpoint.