MICs and minimum fungicidal concentrations of amphotericin B, miconazole, itraconazole, ketoconazole, fluconazole, and flucytosine against 17 isolates of Scopulariopsis spp. were determined by a broth microdilution method. All the isolates were resistant to itraconazole, fluconazole, and flucytosine, and amphotericin B, miconazole, and ketoconazole MICs were low for only a few.

Linezolid was tested by broth microdilution against 140 clinical Nocardia isolates belonging to seven species. The MIC at which 50% of the strains are inhibited (MIC50) and MIC90 for all species other than Nocardia farcinica were 2 and 4 microg/ml. Linezolid is the first antimicrobial agent demonstrated to be active against all Nocardia species.

Broth microdilution was used to determine the MICs of AR-709 and comparator antimicrobial agents for 224 invasive multidrug-resistant isolates of Streptococcus pneumoniae. AR-709 was highly active, with a MIC 50 of 0.25 microg/ml, a MIC 90 of 0.5 microg/ml, and a range of <or=0.008 microg/ml to 1 microg/ml.

The Vitek 2 yeast susceptibility test was evaluated by testing 122 Candida isolates against fluconazole and voriconazole. Excellent categorical agreement with the CLSI broth microdilution method was observed (97.5% for both the azoles). Moreover, the Vitek 2 system was able to identify all but 2 of 59 investigated fluconazole-resistant organisms.

Multiple morphotypes of Pseudomonas aeruginosa isolated from 50 respiratory specimens of cystic fibrosis patients were tested for correlation of broth microdilution susceptibility results of a mixed-morphotype inoculum with a predicted antibiogram of the individual isolates. The overall correlation was 96.0%, with only 1.6% very major or major errors.

The effect of the two antibiotics ceftazidime and meropenem on a collection of 46 Burkholderia pseudomallei isolates representing clinical and environmental sources across northern Australia was investigated by using a series of in vitro test methods. The susceptibility testing methods used included Kirby-Bauer disk diffusion, Etest MIC, broth microdilution MIC, and a modification of the microd...

We evaluated a new microtiter assay for antifungal susceptibility testing based on a colorimetric reaction to monitor fungal substrate utilization. This new method (rapid susceptibility assay [RSA]) provides quantitative endpoint readings in less than 8 h compared with visual determination of MIC by the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method, whi...

Clinical "superbug" isolates of Pseudomonas aeruginosa were previously observed to be resistant to several antibiotics, including polymyxin B, and/or to have a distinct, reproducible adaptive polymyxin resistance phenotype, identified by observing "skipped" wells (appearance of extra turbid wells) during broth microdilution testing. Here we report the complete assembled draft genome sequences o...

Zone diameters for anidulafungin by disk diffusion for 139 isolates of C. parapsilosis were compared with MICs by NCCLS M27-A2 broth microdilution. The comparison was poor unless the disks were prepared by dissolving anidulafungin in 1% dimethyl sulfoxide plus 0.1% Tween 80 and testing on Mueller-Hinton agar flooded with glucose and methylene blue.

Broth microdilution MICs were determined for 258 clinical isolates of Mycobacterium fortuitum (3 biovariants) and M. chelonae (2 subspecies) with amikacin, tobramycin, cefoxitin, doxycycline, erythromycin, and sulfamethoxazole-trimethoprim and with several new beta-lactams and aminoglycosides and ciprofloxacin. Variations in susceptibility by and within species subgroups confirm the need for su...