A replicator method for the combined determination of minimum inhibitory concentration and minimum bactericidal concentration

Abstract

Minimal bactericidal concentrations (MBCs) of nine antimicrobial agents were determined for clinical isolates by a replica plating method. Membranes were placed on the antibiotic-containing plates and the organisms replicated onto the membranes. After 18 h incubation the minimal inhibitory concentrations (MICs) were determined, the membranes were transferred to antibiotic-free plates and incubated a further 18 h and the MBCs determined. MICs and MBCs were also determined in broth. The reproducibility of the 'membrane' method and the agreement of these results for MIC and MBC with the agar and/or broth methods was satisfactory for most antibiotics, within one two-fold dilution. With sulphamethoxazole, trimethoprim and co-trimoxazole the results were less satisfactory, especially with Gram-negative rods, but agreement within two dilutions could be achieved.

Evaluation of oxacillin tolerance in Staphylococcus aureus by a novel method

“…Again, continued action of oxacillin for 48 h diminished the counts significantly, and the paradoxical effect was barely evident. DISCUSSION Except for a few attempts to use agar dilution replicator methodology (9,23,24), previous investigations largely have used modifications of the BDPC approach for studying the quantitative dynamics of bacterial inhibition and killing. Evidence has gradually accumulated indicating a significant dependency of BDPC results, especially MBCs, on technical factor variations.…”

2d-Qsar Study on Some Novel Dihydropyrimidine-4-Carbonitrile Analogs as an Antifungal Activity

“…Clotrimazole was also shown under the same conditions as an antifungal drug. MIC is explained as the minimum concentration of derivatives that inhibited visible growth [13].…”

Hydrochloric acid-treated Bacillus subtilis ghosts induce IL-1 beta, IL-6, and TNF-alpha in murine macrophage

“…Morphological features of the HCl-induced BSGs and native B. subtilis cells were analyzed via SEM as previously described (Fernandes et al 1985 ). Cells were fixed with 2.0% glutaraldehyde in 0.15 M phosphate buffer (pH 7.0) at 4 °C for 2 h. Subsequently, the cells were washed thrice with the same buffer and post-fixed in 1.1% osmium tetroxide at 4 °C for 2 h. The fixed cells were then dehydrated using increasing ethanol concentrations (10–100%) and dried using liquid carbon dioxide.…”