standard susceptibility zone of compound sulfonamide?

the standard susceptibility zone would depend on the bacterial species being tested, as powerfully as the site of specimen collection. for example, different zone sizes for susceptibility are considered for urine specimens vs. blood culture specimens, as the concentration of the antibiotic needed will depend upon the area of the body one treated, as drug concentrations differ in different areas of the body. also, it would depend on the sulfonamide. generally, i believe the zone size for susceptibility of sulfamethoxazole (sp?) is between 17-21, but can't remember which stock we use in my lab.
I presume that you're conversation about the zone of growth inhibition around a standardized disk of sulfonamides on a Kirby-Bauer sensitivity plate.
Sticks within my craw that sensitivity is a radius of 5 or 10 millimiters, but I have to give an account you, in the hospital environment, sensitivity testin is just about ever done that way anymore. There's an automated dilution technique that give more sensitive results a load more slickly.