Showing papers on "Agar diffusion test published in 1990"
TL;DR: It is concluded that, by considering simple growth and biochemical characteristics, SPS susceptibilities, and reactions in RapID-ANA, it is possible for more clinical laboratories to definitively identify this organism H. ducreyi.
Abstract: Haemophilus ducreyi has traditionally been difficult to identify. We have utilized simple test methods to identify 19 fresh isolates obtained during a recent outbreak of chancroid in Houston and six strains of H. ducreyi from other outbreaks. Tests were performed from growth on chocolate agar after 48 h of incubation at 35 degrees C with increased humidity and CO2. All isolates exhibited typical colonial morphology and Gram stain. Isolates were catalase negative and oxidase and nitrate positive (in enriched broth). The RapID NH system failed to identify these strains because of negative reactions with alkaline phosphatase and nitrate reductase. However, by using the RapID-ANA system, all strains were positive for alkaline phosphatase and arginine, glycine, and serine aminopeptidases. Their biochemical profiles were distinct from those obtained with 66 strains representing 13 species similar to H. ducreyi. We also investigated the use of sodium polyanetholesulfonate (SPS) disk susceptibility to identify and differentiate H. ducreyi from other species. All H. ducreyi isolates were susceptible, as evidenced by the presence of a zone of inhibition with an average size of 15 mm around the SPS disk. With the exceptions of Neisseria gonorrhoeae, Gardnerella vaginalis, and Capnocytophaga spp., no other strain showed any evidence of inhibition. The latter three organisms can be easily differentiated from H. ducreyi by various features including reactions in the RapID-ANA. We conclude that, by considering simple growth and biochemical characteristics, SPS susceptibilities, and reactions in RapID-ANA, it is possible for more clinical laboratories to definitively identify this organism.
11 citations
Journal Article•
TL;DR: The data show that Gram(+) bacteria were more sensitive to the antimicrobial compounds in spices than Gram(-).
Abstract: The essential oils were isolated by steam distillation from 13 spices used for curry. Antimicrobial activity of essential oils for two strains of Gram(+) bacteria, Gram(-) bacteria, lactic acid bacteria, yeast and mold were investigated by agar diffusion method. 5 spice essential oils(clove, cumin, nutmeg, oregano, rosemary) having high antimicrobial activity were selected and their minimal inhibitory concentration(MIC) were measured. Very low concentration () of 5 spice essential oils were sufficient to prevent microbial growth. The data show that Gram(+) bacteria were more sensitive to the antimicrobial compounds in spices than Gram(-). But though Gram(+) bacteria, lactic acid bacteria were less sensitive to the compounds than Gram(-).
6 citations
Journal Article•
TL;DR: The antimicrobial efficiency of zinc chloride solution in concentration from 0.1% to 2.0% showed a bacteriostatic effect on the strains of reference only; the application of higher concentrated solutions is not indicated intraorally.
Abstract: The antimicrobial efficiency of zinc chloride solution in concentration from 0.1% to 2.0% and 0.2% chlorhexidine solution has been examined on the strains of reference in a comparative study. Three test methods were applied: the agar diffusion test, the dilution test and the suspension test. As was to be expected the antibacterial effect of the zinc chloride solution was dependent on concentration. Between 0.1% and 2.0% the zinc chloride solution showed a bacteriostatic effect on the strains of reference only; the application of higher concentrated solutions is not indicated intraorally. 0.2% chlorhexidine solution showed a bactericidal effect on the test germs.
2 citations