The susceptibilities of 20 clinical isolates of Mycobacterium intracellulare to rifampin, MDL 473, and ansamycin were determined by broth and agar dilution methods. Ansamycin was more active than MDL 473, which in turn was usually more active than rifampin by either method. The MICs for 90% of the strains tested by agar dilution were 1, 2, and 4 micrograms of ansamycin, MDL 473, and rifampin pe...

E-test, Vitek 2, MicroScan, agar dilution, and disk diffusion were compared for detection of decreased linezolid susceptibility due to 23S rRNA gene G2576T mutation among 32 clinical Enterococcus strains initially reported as intermediate or resistant by E-test alone or Vitek 2 confirmed by E-test. Agar and broth dilution methods were in concordance with PCR detection of the mutation, and disk ...

A total of 97 anaerobic bacteria were tested for susceptibility to ampicillin, ampicillin-sulbactam, and amoxicillin-clavulanic acid by broth microdilution and disk elution methods, the results of which were compared with those of the reference agar dilution method. With the broth microdilution method, approximately 95% of MICs were within 1 dilution of those of the reference agar method, with ...

Tests with 10-micrograms amdinocillin disks were performed in parallel with agar dilution tests and three different ranges of inoculum density. A resistance breakpoint of less than or equal to 13 mm and an intermediate category of 14 to 16 mm are recommended. Susceptible strains provided zones greater than or equal to 17 mm in diameter, but many appeared to be resistant by the agar dilution met...

Forty-seven Bordetella pertussis isolates recovered from January 1985 to June 1997 at Primary Children's Medical Center were tested for erythromycin resistance. Agar dilution MICs were determined on Regan-Lowe agar. Forty-six isolates were found to be erythromycin susceptible (all MICs were less than or equal to 0.12 microg/ml). One isolate was found to be erythromycin resistant (MIC, 32 microg...

The in vitro activity of ciprofloxacin, ofloxacin, amifloxacin, and norfloxacin against 22 clinical isolates of Mycobacterium tuberculosis was evaluated by agar dilution. The MICs for 90% of the isolates of ciprofloxacin and ofloxacin were 0.5 and 1 microgram/ml, respectively. Amifloxacin and norfloxacin were less active. The MICs for 90% of the isolates of ciprofloxacin and ofloxacin against 2...

The antibacterial effects of six inorganic antibacterial agents were assessed using broth dilution and agar dilution tests on six pathogenic bacteria associated with oral infectious diseases: Streptococcus mutans (ATCC 25175), S. mutans (Ingbritt), Actinomyces viscosus (ATCC 15987), Lactobacillus casei (ATCC 393), Staphylococcus aureus (ATCC 29213) and Candida albicans (ATCC 90028). The results...

In this study, we determined the accuracy of phenotypic tests (cefoxitin agar dilution, 30 microg-cefoxitin and 1 microg-oxacillin disks) to detect the oxacillin resistance/mecA gene among coagulase-negative staphylococci (CoNS) isolates. The presence of the mecA gene was detected by PCR technique (gold standard). A total of 176 CoNS isolates from blood of hospitalized patients were evaluated. ...

OBJECTIVES To evaluate the usefulness of cefoxitin when used as a surrogate marker for the detection of methicillin resistance. PATIENTS AND METHODS Eight hundred and seventy-one strains of Staphylococcus aureus, collected from eight tertiary referral centres serving diverse socio-economic populations, were included in the study using NCCLS disc diffusion and the agar dilution methods. RESU...

E test was evaluated as an alternative rapid and simple method of MIC estimation for nutritionally variant streptococci. E test with various media was compared with conventional broth and plate dilution techniques supplemented with 0.001% (wt/vol) pyridoxal hydrochloride (vitamin B6). Of the 14 strains tested with E test, isosensitest agar supplemented with 5% defibrinated horse blood and 0.001...