It has no activity againstPseudomonas species. Antagonism has been demonstrated in vitro between nitrofurantoin and quinolone antimicrobial agents. The clinical significance of this finding is unknown. Quantitative methods that require measurement of zone diameters give the most precise estimate of the susceptibility of bacteria to antimicrobial agents. This category provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretations.
Standardized procedures require the use of laboratory control organisms.
128 Resistant As with standard diffusion techniques, dilution methods require the use of laboratory control organisms.