MYCOMON -nine years the study duration (1999-2007)
Toxigenic microfungi are microorganisms capable of producing mycotoxins. They are important factors that may have a potentially negative effect on human health. The most important toxigenic microfungi are the producers of aflatoxins and ochratoxin A. Foodstuffs are suitable substrates for the contamination, growth and propagation of toxigenic microfungi and for the production of mycotoxins. A study „MYCOMON” of the occurrence of toxigenic microfungi, producers of aflatoxins and ochratoxin A, in selected commodities of a consumer food basket was prepared. Investigations in this study were incorporated into the National Environment Health Monitoring Programme in the Czech Republic. Its objective was to obtain information on the degree of the immediate contamination of foodstuffs with toxigenic microfungi which could serve as the basis for the evaluation of the dietary exposure and health risk assesment of afla- and ochra- toxigenic microfungi in the Czech foodstuffs.
Materials and Methods:
Twenty-five commodities were purchased from retail at 12 places in 4 terms (March, May, September, November) during the years 1999–2007. It presents 2196 foodstuffs samples in all. Aflatoxigenic microfungi Aspergillus Section Flavi (e.g. Aspergillus flavus, Aspergillus parasiticus) and ochratoxigenic microfungi (Aspergillus ochraceus, Aspergillus Section Nigri, Penicillium verrucosum, Penicillium nordicum) were monitored in foodstuffs. CSN ISO 7954 norm and classical mycological methods were used. Chromogenic media (AFPA medium, ADMB medium, DRYES agar and PRYES agar) were used for identification of toxigenic microfungi. Chemotaxonomy, HPTLC determination of aflatoxins and cyclopiazonic acid in YES medium was carried out.
Results and Conclusions:
Frequency data about the quantitative incidence of microfungi, qualitative and quantitative incidence of toxigenic microfungi for these commodities were obtained. CFU/g and the mycological profile of selected toxigenic microfungi were assessed. 115 (63% toxigenic) strains of Aspergillus flavus were isolated from foodstuffs (black tea, fruit tea, caraway seeds, fine semolina, fine flour, granular flour, semi-granular flour, sweet red pepper, black pepper, raisins, rice, pasta, oat flakes), 26 (46% toxigenic) strains of Aspergillus tamarii were isolated from foodstuffs (black tea, black pepper, sweet red pepper) and 254 strains of Aspergillus Section Nigri were isolated from foodstuffs (black tea, fruit tea, caraway seeds, peanuts, fine flour, sweet red pepper, black pepper, raisins, rice, fine flour, fine semolina). A. parasiticus, A. nomius A. ochraceus, Penicillium verrucosum, Penicillium nordicum were not isolated from the tested foodstuffs. The toxigenic microfungi are stored in 30 % solution of glycerol in deep-freezer box by – 71 oC for further research.
This study was supported by the Czech National Environment and Health Monitoring Programme
Full-textDOI: · Available from: Vladimir Ostry, Jun 30, 2015
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ABSTRACT: Ochratoxin A (OA) production of 92 isolates belonging to the A. niger aggregate was tested. All these isolates were grouped into the two proposed species A. niger and A. tubingensis, according to their ITS-5.8S rDNA RFLP patterns. The distribution of the isolates into the two species was very similar since 52.2% were classified as pattern T (corresponding to A. tubingensis), and 47.8% were classified as pattern N (corresponding to A. niger). Six out of the 92 isolates studied produced OA. All the OA producing strains were classified as pattern N while none of the isolates classified as pattern T produced OA.Antonie van Leeuwenhoek 10/2001; 79(3-4):365-70. DOI:10.1023/A:1012003813985
Conference Paper: Raisins, ochratoxin A and human health[Show abstract] [Hide abstract]
ABSTRACT: Raisins are original candy - natural candy. They are one of the most nutritious dried fruits in the world. Raisins are cholesterol-free, low in sodium and totally fat-free. They provide many necessary vitamins and minerals, including iron, potassium, calcium and certain B vitamins. Raisins are a good source of fiber and rich in antioxidants. Raisins are 70% pure fructose which is easily digested for quick energy. The process of drying fruit in the warm sunshine has been attributed to the Persians, and the first description of how black grapes could be dried in the sun to make raisins was written more than 2,000 years ago. Ochratoxin A (OTA) is naturally occurring secondary metabolite produced by several toxigenic micromycetes (especially Aspergillus ochraceus and Penicillium verrucosum) on a variety of crops, especially cereal grains and further foodstuffs including raisins. OTA can enter raisins by contamination resulting from the growth of toxigenic fungi during drying (short-term humid weather). Investigations of the determination OTA in raisins were incorporated in the project of monitoring exposure to chemical substances from foodstuffs in the system of Environment Health Monitoring in the Czech Republic. Raisins were purchased from retail in 12 places of the Czech Republic (the samples came from Prague, Brno, Ostrava, Plzen, Hradec Kralove, Usti nad Labem, Ceske Budejovice, Zdar nad Sazavou, Znojmo, Jablonec, Benesov and Sumperk) during the years 1999 - 2002. An HPTLC method for quantification of OTA was used. The combination of immunoaffinity chromatography (OchraTest, VICAM, USA) and HPTLC has increased the selectivity and sensitivity of the method used. Validation of the method was performed according to the principles of ICH Guideline. Method was accredited by CSN EN 45000. The results of the determination of OTA in raisins are shown in the following Table. Sampling places 1999 2000 2001 2002 OTA /ng.g-1/ 01 < 1 9.3 < 1 8.0 02 < 1 3.0 4.7 < 1 03 < 1 < 1 5.1 6.5 04 1.9 < 1 < 1 < 1 05 < 1 < 1 < 1 < 1 06 < 1 < 1 1.6 < 1 07 < 1 2.4 3.1 < 1 08 < 1 < 1 6.1 < 1 09 12.0 < 1 < 1 < 1 10 < 1 < 1 < 1 < 1 11 2.0 3.2 63.6 17.5 12 52.5 < 1 5.2 < 1 Mean 6 1.8 7.7 3.0 Median 0.5 0.5 2.4 0.5 90% percentile 11 3.2 6 7.9 The estimation of dietary exposure dose of OTA from raisins for the Czech population (adult, infant) is presented in the lecture. The results of dietary exposure dose of OTA are compared with PTDI (EU SCF 1998) = 5 ng/kg body weight/day. For example: PTDI for infant, weight 25 kg is 125 ng/person/day. The consumption of 16 g raisins contaminated with OTA 7.7 ng.g-1 = 100% PTDI for infant.23. Mycotoxin Workshop, Berlin, Germany; 06/2002
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ABSTRACT: Skarkova, J., Ostry, V., Ruprich, J., Kubátová, A.: Chemotaxonomy of aflatoxigenic species of Aspergillus section Flavi. Czech Mycol., 55 (1-2), 2003, s. 145-146. Abstract from colloquium "Fungi as Model Organisms in Research and Biotechnology - 11" Olomouc, Czech Republic, September 5th-6th, 2002 The colloquium was a continuation of a previous scientific meeting that took place in Olomouc in 1999 (Czech Mycology 52: 139-178, 2000). It was organised by the joint Commission for Experimental Mycology of the Czechoslovak Microbiological Society and the Czech Scientific Society for Mycology together with the Institute of Biology, Faculty of Medicine of Palackf University, Olomouc. The purpose of the colloquium was to provide a platform for a broad discussion on the use of fungi as model organisms in both basic and applied research. The programme of the colloquium was divided into four parts dealing with the following topics: biochemistry, biotechnology and genetics of fungi; phytopathogenic fungi; fungi pathogenic to humans and animals; and mycology of food and mycotoxins. Each topic was opened with a plenary lecture (30 min.), followed by short communications (10 min.) and accompanied by poster presentations. Besides five plenary lectures, 20 short communications and 24 posters were presented. In total 42 researchers took part in the colloquium and discussed various topics important for the further direction of experimental mycology. Abstracts of the contributions are given below.