In vitro activities of 17 antibiotics against 53 clinical strains of Mycobacterium marinum, an atypical mycobacterium responsible for cutaneous infections, were determined using the reference agar dilution method. Rifampin and rifabutin were the most active drugs (MICs at which 90% of the isolates tested were inhibited [MIC(90)s], 0.5 and 0.6 microgram/ml, respectively). MICs of minocycline (MI...

The soft-agar overlay technique was originally developed over 70 years ago and has been widely used in several areas of microbiological research, including work with bacteriophages and bacteriocins, proteinaceous antibacterial agents. This approach is relatively inexpensive, with minimal resource requirements. This technique consists of spotting supernatant from a donor strain (potentially harb...

The MICs for 101 isolates of Neisseria gonorrhoeae obtained by Etest (AB-Biodisk, Solna, Sweden) and the agar dilution method on GC medium base supplemented with 1% Kellog's defined supplement (GCMB) were compared. The overall percent agreement (within 1 log2 dilution) between methods was greater than 97.9. The Pearson's correlation coefficients for penicillin, tetracycline, erythromycin, and c...

Twelve strains of Haemophilus influenzae were tested for susceptibility to gentamicin, ampicillin, chloramphenicol and cephalothin using two methods, agar dilution and microdilution (broth). Although inocula and incubation conditions were standardized, significant differences in the minimal inhibitory concentration (MIC) were seen as a result of growth media. Method dependent differences were a...

The E test was evaluated in comparison with reference agar methods (National Committee for Clinical Laboratory Standards) for the susceptibility testing of 248 Pseudomonas aeruginosa isolates from bladder-catheterized patients against nine antibiotics. The E-test MICs correlated well with those determined by the agar dilution and disk diffusion reference methods (88 and 92.5% within 1 log2 dilu...

To determine appropriate mupirocin susceptibility testing interpretive criteria, 177 staphylococci were tested by agar dilution, disk diffusion, and E test. E test was found to be a reliable method for determining susceptibility of staphylococci to mupirocin. The agar dilution and disk diffusion results were plotted on a scattergram, and error rates were calculated. No errors were found with su...