Microdilution methods

The microdilution method was employed for antibacterial and antifungal activity tests. Media were placed into each well of the 96 well-microplate. Extract solutions at 1,024 pg/ml were added into first raw of microplates and twofold dilutions of the compounds (512-0.25 pg/ml) were made by dispensing the solutions to the remaining wells. Ten microliters of culture suspensions were inoculated into all the wells. The sealed microplates were incubated at 35°C for 24 and 48 h in humid chamber. The lowest concentration of the extracts that completely inhibit macroscopic growth was determined and minimum inhibitory concentrations (MICs) were... 

A rapid semiautomated microdilution method for the microbiological assay of the chloroquine has been developed by Desgardins (26). Antimalarial activity of chloroquine may be studied against cultured Plasmodium falciparum, microplates are used to prepare serial dilution of the drug. Parasites obtained from continuous stock cultures are subcultured in the micro-plates for 42 h. Inhibition of uptake of a radio labeled nucleic acid precursor by parasites serves as the indicator of antimicrobial activity. 

In one of our recent studies, we examined antimicrobial and antiviral activities of four flavonoid derivatives, namely, scandenone (5), tiliro-side (6), quercetin-3,7-O-a-L-dirhamnoside (7), and kaempferol 3,7-O-a-L-dirhamnoside (8) as shown in Fig. 2. These were tested against E. coli, P. aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter bau-mannii, S. aureus, B. subtilis, and Enterococcus faecalis, as well as the fungus Candida albicans by the microdilution method [26]. In addition, both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of the compounds using Madin-Darby bovine kidney (MDBK) and Vero cell lines. 

The MIC value ( ig/ml) was determined for each compound by a broth microdilution method using H. pylori (ATCC43504) [26,27], Each 69 and 70 each equivalent mixture of DL (R, S). 

A sensitive and simple chemiluminescent (CL) method for measuring antioxidant activity was developed. The determination of TEAC (Trolox equivalent antioxidant capacity) is based on the inhibition of CL intensity of luminol by an antioxidant. Antimicrobial activity was tested as a minimal inhibitory concentration (MIC) by broth microdilution method on gram-positive Enterococcus faecalis. Staphylococcus aureus) and gram-negative Pseudomonas aeruginosa, Escherichia coli) bacterial strains. 

In a recent study, with S. multicaulis, four of the new compounds (29-32) showed structural resemblence to tanshinone-type compounds. Therefore, they and the other new compounds (33-34 ) isolated from the same plant, were tested against bacterial strains (Table 28). All the compounds from this plant were also tested in Mycobacterium tuberculosis H37Rv test system. Their antituberculous activity was established according to broth microdilution method . When the MIC results were... 

In order to assess the bacterial susceptibility profile, the MIC for different drugs was established using the broth microdilution method [135]. The surface hydrophobicity of the bacterial strains was determined using the microbial adhesion to hydrocarbon... 

Antibacterial activity testing. Determined using the broth microdilution method. Incubations were performed for 18 h using an Ominolog automated incubator (Biolog Inc. 21124 Cabot Boulevard, Hayward, CA 94545, USA). 

Liao, R. S. Rennie, R. P. Talbot, J. A. Comparative evaluation of a new fluoreseent carboxyfluoies-cein diacetate-modified microdilution method for antifungal susceptibility testing of Candida albicans isolates. Antimicrob. Agents Chemother. 2002, 46, 3236-3242. 

Minimal inhibitory concentrations (MIC, mg/ml) were determined by a broth microdilution method adapted from the tentative reference method (document MJ7-T) recommended hy the Committee on Antifungal Susceptibility Testing (36). Antibiotic medium 3 was used rather than RPMI 1640 medium. The MIC is defined as the lowest concentration of compound chat completely snhihited growth when tested with LY303366, cilofungin, or amphotericin B. 

Weseler, A., H.K. Geiss, R. Sailer et al., 2005. A novel colorimetric broth microdilution method to determine the minimum inhibitory concentration (MIC) of antibiotics and essential oils against Helicobacter pylori. Pharmazie, 60 498-502. 

In contrast, agar dilution and broth microdilution methods are able to overcome some of the limitations of the disk diffusion method. Not only are they more convenient for routine antimicrobial susceptibihty testing of bacteria in clinical laboratories, they are capable of drawing quantitative conclusions by determining the MIC values for antimicrobials, as opposed to qualitative data generated by the disk diffusion method (Kim and Kim 2007). 

Several honeybee products including RJ have been evaluated for their ability to inhibit the growth of 40 yeast strains of Candida albicans, Candida glabrata, Candida krusei, and Trichosporon spp. using the broth microdilution method. MIC values for RJ and fluconazole (used as standard) were 0.06-1 and 0.02-96 pg/mL, respectively, demonstrating that RJ could potentially control some fluconazole-resistant fungal strains [44]. lO-hydroxy-2-decenoic acid (10-HDA), main component of RJ, is well known for its antimicrobial... 

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