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R Kano

Publications and source records attributed to R Kano.

95 records · Page 6Linked to original sources

Identification of clinical isolates of Microsporum canis and M. gypseum by random amplification of polymorphic DNA (RAPD) and Southern hybridization analyses.

Clinical isolates of Microsporum canis and M. gypseum from humans, dogs and cats were examined by random amplification of polymorphic DNA (RAPD) and Southern hybridization analyses. The RAPD band patterns of six clinical isolates of M. canis were identical to those of standard strains of Arthroderma otae. Of nine clinical isolates of M. gypseum seven and two isolates showed RAPD patterns identical to those of standard strains of A. gypseum and A. incurvatum respectively. Southern blot analysis using a probe (C3) obtained from A. otae DNA revealed that six clinical isolates of M. canis showed specific bands identical to those detected in the standard strains of A. otae. Of nine clinical isolates of M. gypseum, seven and two isolates showed bands hybridized by the C3 probe identical to those detected in A. gypseum and A. incurvatum respectively. Furthermore, the results from mating experiments on these nine clinical isolates of M. gypseum showed complete agreement with the results from RAPD and Southern hybridization analyses. These findings clearly indicate that RAPD and Southern hybridization analyses are very useful in the identification of clinical isolates of M. canis and M. gypseum.

Animals↗

Enhanced activity of antifungal drugs by lysozyme against Cryptococcus neoformans.

The in vitro susceptibility of 16 isolates of Cryptococcus neoformans to three antifungal drugs and lysozyme in combination was determined using an urea broth microdilution method. The antifungal activities of each drug alone against 16 isolates of Cr. neoformans were determined as mean minimal inhibitory concentrations (MICs). MICs of fluconazole, itraconazole and terbinafine were 2.0 micrograms ml-1, 0.004 microgram ml-1 and 0.25 microgram ml-1, respectively. Lysozyme alone inhibited the growth of Cr. neoformans in a dose-dependent manner, although the lysozyme was unable to kill the cells of Cr. neoformans at the highest concentration of 20 micrograms ml-1. The mean MICs of fluconazole, itraconazole and terbinafine in combination with lysozyme were 0.13 microgram ml-1, 0.004 microgram ml-1 and 0.03 microgram ml-1 respectively. The antifungal activity of fluconazole and terbinafine in combination with lysozyme against Cr. neoformans was greatly enhanced compared with that of each drug alone. Itraconazole was unable to enhance the antifungal activity, as it demonstrated higher activity against Cr. neoformans when alone rather than in combination. Lysozyme was confirmed to enhance the antifungal activity of fluconazole and terbinafine in vitro.

Antifungal Agents↗

Differentiation of Microsporum species by random amplification of polymorphic DNA (RAPD) and southern hybridization analyses.

Molecular characterization of 18 species belonging to the genus Microsporum isolated from human and animal dermatophytosis was carried out by random amplification of polymorphic DNA (RAPD) and Southern hybridization analyses. All of these 18 Microsporum species showed different band patterns specific to each species in RAPD analysis. Southern hybridization analysis using C3 probe derived from a RAPD band from Arthroderma otae, teleomorph of M. canis, revealed distinct bands in 14 of the 18 Microsporum species but not in the other four species. The sizes of the hybridized bands of the 14 species were specific to each species, except three species (A. otae, M. equinum and M. ferrugineum) showing bands of the same size. These findings indicate that the RAPD and the Southern hybridization analyses could be effective to differentiate the species of Microsporum.

Animals↗

Isolates of Cryptococcus neoformans serotype A and D developed on canavanine-glycine-bromthymol blue medium.

Two isolates of Cryptococcus neoformans serotype A and one isolate of serotype D from pigeon droppings were found to grow on canavanine-glycine-bromthymol blue (CGB) medium, when the Japanese isolates of Cr. neoformans were examined for their serotype and biochemical characteristics. The susceptibility to canavanine and the activity in assimilation of glycine were analysed on these three isolates. They were resistant to canavanine at the high concentration of 3.6 mmol l-1 and developed by assimilating the glycine even at a concentration of 7 mmol l-1. These isolates were proved to develop well on CGB medium, which contains 0.1 mmol l-1 of canavanine and 133 mmol l-1 of glycine. Three isolates of Cr. neoformans developed on CGB medium were also confirmed to be serotype A or D by the molecular analysis.

Animals↗

Susceptibility testing of Cryptococcus neoformans using the urea broth microdilution method.

An urea broth microdilution method to assay the susceptibility of Cryptococcus neoformans to antifungal drugs was newly developed. Using this method, urease activity of the fungus was measured instead of the viability by checking colony development. The urease activities were indicated by colour changes in optical density at 545 nm. The end point in this assay was considered as 99% inhibitory concentration. When we measured antifungal activities of the three drugs against 16 isolates of Cr. neoformans using this assay method, mean minimum-inhibitory concentrations (MICs) of fluconazole, itraconazole and terbinafine were 2.0 micrograms ml-1, 0.008 microgram ml-1 and 0.25 microgram ml-1 respectively. This assay method resulted in higher sensitivity in MICs of the three antifungal drugs than the broth microdilution method recommended by the Committee for Laboratory Standards of the Japanese Society for Medical Mycology. The results obtained using this assay method support the more effective evaluation of antifungal substances in susceptibility testing of Cr. neoformans.

Antifungal Agents↗