In vitro leishmanicidal activity of aurones.

A series of aurones with drug-potential for Leishmania infections was identified in vitro using both a direct cytotoxicity assay against extracellular promastigotes of Leishmania donovani, L. infantum, L. enriettii, and L. major, and a test against intracellular amastigote forms of L. donovani residing within murine macrophages. The most active aurone (6-hydroxy-2-[phenylmethylene]-3(2H)-benzofuranone) had an EC50 of 0.45 microgram/ml in the extra-, and an EC50 of 1.40 micrograms/ml in the intracellular assay. Other aurones were active between 0.06-12.50 micrograms/ml and 0.04-7.81 micrograms/ml, respectively. When tested against murine bone marrow-derived macrophages as a mammalian host cell control, the compounds showed only moderate cytotoxicity (EC50 2.32 to > 25.0 micrograms/ml). This is the first report on aurones as a new class of natural products with leishmanicidal activity.

Serodiagnostic value of culture filtrate antigens from aspergilli with septate phialides.

Culture filtrate antigens from 6 typical isolates of Aspergillus fumigatus, 6 isolates with septate phialides, and isolates of A. fumigatus var. ellipticus, A. fishceri, A. flavus and A. niger were studied in tests with 2,100 samples of serum originating from 1,452 patients suffering from miscellaneous diseases, including 60 cases of aspergillosis, 850 samples of serum from apparently healthy blood donors and 522 sera referred to us as positive for C-reactive protein. The culture filtrate antigen prepared from a septate-phialide-strain proved to be most useful in detecting precipitating antibodies in the sera of patients suffering from aspergillosis caused by A. fumigatus. The antigen from this strain not only gave sharper and a larger number of precipitin bands than others but also proved to be an invaluable tool in the serodiagnosis of 5 to 56 (8.9%) A. fumigatus cases in which all other antigens repeatedly failed to give a positive result. The serological data also suggest that the septate-phialide strains are mutants of A. fumigatus and should not be classified as a separate species.

Serotypes of Cryptococcus neoformans strains isolated in Germany.

An examination of 21 strains of Cryptococcus neoformans isolated from environmental and clinical sources in Germany revealed only serotypes A, D, and AD. Of these, 13 isolates were serotype A, 5 isolates were serotype D, and 3 isolates were identified as serotype AD. The absence of serotypes B or C confirms earlier reports from other European countries.

Pathogenic yeast-like fungi in meat products.

100 samples of sausage and ham (cut in fine slices) were examined to find out whether meat products can harbour yeast-like fungi pathogenic for man. Pieces of the test material were placed in a sterile Petri dish containing 1 ml distilled water and incubated at 26 degrees C for 2 days. The colonies grown on the material were identified by international standard methods, tested for extracellular proteolytic activity and serotypes. Experimentally infected meat products were studied culturally and histologically (PAS stain). 14 out of the 100 samples examined were found to contain Candida parapsilosis and 1 C. tropicalis. In vitro, extracellular proteolytic activity was found in 54.5% of the C. parapsilosis isolates. By serotyping, 2 of the isolates wree found to be related with serotype A and 8 with serotype B of C. albicans. The strains isolated from the blood of 27 patients, in part of them, identity of serotype and proteolysing activity was established. In the experimentally infected meat products, C. albicans showed a scarce growth preferably in the pseudomycelium form. C. tropicalis grew very well on the boiled sausage of salami type but mostly in the pseudomycelium form. C. parapsilosis on the other hand, showed a strong growth preferably as round blastospores on all 3 meat products and Cryptococcus neoformans a moderate growth as round blastospores in all the 3 meat products (Bologna type sausage, boiled sausage of salami type and smoke ham). The findings are discussed with a view of their implications for Medical Mycology, epidemiology and the practice of food control.

A comparative study of antigens of Aspergillus fumigatus isolates from patients and soil of ornamental plants in the immunodiffusion test.

The strikingly frequent and constant presence of Aspergillus fimigatus in the soil of potted ornamental plants kept in private houses and hospitals has been the reason for studying the antigens of the strains found from the diagnostic and epidemiological angles. Culture-filtrate antigens of A. fumigatus strains isolated from the soil of 4 different ornamental plants, epiphyllum (Epiphyllum truncatum), orange tree (Citrus sinensis), Alpine rose (Azalea indica) and Christmas flower (Euphorbia pulcherrima), were compared, in the immunodiffusion test, with antigens of A. fumigatus strains from aspergillosis patients prepared in an identical way. When tested against 8 different sera from different aspergillosis patients there was a good coincidence of results. Control sera from patients suffering from diseases other than aspergillosis, no false-positive reactions could be observed. The findings are discussed in respect of diagnosis and epidemiology.