[The effectiveness of an (Aspergillus) differential medium in the course of the mycological examination of foods]. / Zur Effektivität eines Aspergillus-Differentialmediums bei mykologischen Lebensmitteluntersuchungen.

The effectiveness of Aspergillus differential medium (ADM) for the identification of Aspergillus strains was tested. The bright yellow-orange pigment was produced by 205 (88,7%) of 231 strains and resp. 97 (61,3%) of 158 strains, which during routine mycologic diagnostic as A.flavus and A.oryzae, respectively. Strains of the groups A.clavatus (76), A.glacus (100), A.fumigatus-(9), A.niger-(6), A.candidus-(3), A.wentii-(1), A.versicolor (23), A.nidulans (6), A.ustus (1) and A.terreus (1) gave negative results. Positive results were shown by 9 strains of the A.ochraceus group. It was shown that for the mycological examination of certain foods the ADM medium can make an important contribution to the identification of potential aflatoxin producers. However it is better not to use the ADM medium only alone but also together with other customary mycological nutrient media.

[Problems of the presence of potential mycotoxin producers in milk powders for babies (author's transl)]. / Zur Problematik der potentiellen Mykotoxinproduzenten in Milchpulvern für Kleinstkinder.

Because of the finding of aflatoxin B1 in the liver of deceased children and in some samples of milk powder, commercial samples of domestic and foreign milk powder intended for babies were examined. From 4950 g of milk powder 11 119 colonies of 29 genera of mould were isolated, averaging 1,9 colonies for the domestic and 0,1 colonies/g for the foreign milk powders. The moulds were uniformly dispersed through the powder, but in one sample the greatest number of colonies was isolated from the surface layer of the powder in the original package. The results of the investigation must lead to a revision of views on the microbiological standards and the production and packaging technologies for baby foods.

Collaborative study of the effectiveness of the screening test on APA medium for aflatoxin producing aspergilli.

In 252 strains or Aspergillus flavus the ability of producing a blue fluorescenting substance in the APA medium (Hara et al., Appl. Microbiol. 27 (1974) 118) and the ability to produce aflatoxin B1 (AF) on Karlsbad biscuits have been investigated. In 92% of strains the three working places agreed in the characteristics of the observed properties of strains, but 20 (8,0%) strains producing AF on biscuits were evaluated on APA as negative. In 3 strains of 13 the working places B and C, which determined the AF production on buscuits, did not agree in their results. The authors discussed about the causes, but came to the conclusion that the screening method for the searching of AF producing of A. flavus by aid of the APA medium can be suitable at the investigation of big amounts of strains in routine laboratories, even when there exists a risk that some producers will be overlooked.

Potential producers of aflatoxin in working environment.

It has been investigated the amount of the viable germs of A. flavus in the environment of the food-stuff establishment, where peanuts and hazel nuts, almonds, crushed coconuts, tea and other food-stuffs, imported from tropical and subtropical countries, were processed and packed. In the air of the store-hall have occurred the most 3.73 x 10(2) and in the air of the working-halls, where they were manipulating with food-stuffs - the most 6.2 x 10(3) germs of A. flavus/m3. From the samples of the sedimented dust were isolated at least 0.4 x 10(1), the most 1.3 x 10(4) colonies of A. flavus/g. From 57 investigated strains produced aflatoxin B1 64.9%. The authors are discussing about a professional risk for the workers of some establishments during the manipulation with food-stuffs or feeds, which are contaminated with germs of toxinogenic moulds and with mycotoxins.