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The sensitivity against 5 antimycotics was examined with 353 yeast strains of 13 species from clinical material. The tests were carried out by means of the disc diffusion test on Bacto yeast morphology agar under standardized conditions. 33 (6.3%) of the isolates were resistant against 5-fluorocytosine, 11 (2.1%) strains showed no sensitivity against the imidazolyl antimycotics clotrimazole or miconazole. The resistant strains belonged to the species Candida albicans and Candida tropicalis. All of the isolates were sensitive to the polyene antimycotics nystatin and pimaricin (natamycin).

The prior condition for the application of pimaricin is its heat stability (up to 80 degrees C) and the low penetration (around 2.6 mm), so that it is available for the effect on the cheese surface for a long period. With 13 different aflatoxin forming moulds, the inhibition on the mycel development and thereby on the aflatoxin formation was tested; the different strains were inhibited to various degrees. The effect on cheese was not definite, because the native cheese surface remained free of mould for 8 weeks after pimaricin treatment, whereas cheese slices dipped into pimaricin solution were covered with moulds very soon. The aflatoxin formation itself is only inhibited, if the growth of the moulds is inhibited. Therefore the cheeses have to be treated very early before strong growth of the moulds has started. The aflatoxin formation, however only starts at a certain growth period of the moulds, but at a not completed inhibition, a reduced aflatoxin formation has to be taken into consideration.