Crisamicin A, a new antibiotic from Micromonospora. I. Taxonomy of the producing strain, fermentation, isolation, physico-chemical characterization and antimicrobial properties.

A microorganism, designated as RV-79-9-101 and now identified as Micromonospora purpureochromogenes subsp. halotolerans, isolated from a mud sample in the Philippines, has been shown to produce a complex of antibiotics called crisamicins. Thin-layer chromatography and bioautography, employing solvent extracts of whole fermentation broths, revealed a minimum of five antimicrobial components. The major biologically-active component of the antibiotic complex, crisamicin A, was obtained in pure form after preparative silica gel column chromatography followed by crystallization. Based on physico-chemical data crisamicin A has been identified as a novel member of the isochromanequinone group of antibiotics. It exhibits excellent in vitro activity against Gram-positive bacteria but little or no activity towards Gram-negative bacteria or fungi.

Laboratory mill for pulverizing and homogenizing nail specimens as an aid to microscopy and culture confirmation of onychomycosis.

A small mill has been developed for reducing nail clippings to a convenient size for microscopy and inoculation onto isolation media. The milling process acts to pulverize and homogenize the specimen. The use of a homogeneous sample in microscopy increases the opportunity for the discovery of fungal hyphae in a specimen. The use of a pulverized specimen increases the possibility of culture isolation by permitting greater numbers of potentially viable fungal cells to come into direct contact with the isolation medium.

Geodermatophilus, a new genus of the Dermatophilaceae (Actinomycetales).

Organisms having a complex life cycle similar to the animal pathogen Dermatophilus congolensis have been isolated from soils of the United States. The soil isolates grow readily on agar media producing a black, friable, or sooty colony; in broth, the isolates produce a thick sediment with a clear supernatant fluid and occasionally a black surface pellicle. The generic taxon Geodermatophilus is proposed for these soil isolates. Geodermatophilus differs morphologically from Dermatophilus in thallus shape, ensheathment, and branching, and physiologically in respect to blood hemolysis, casein hydrolysis, carbohydrate utilization, acid production, and media requirements. The type species proposed is G. obscurus. Three subspecies are recognized.