The following fungal strains were tested for the production of the mycotoxin ochratoxin A: Aspergillus melleus (CCM F 802), Aspergillus ochraceus (CCM 8002) and Aspergillus ochraceus (CCM F 803). The strain Aspergillus melleus (CCM F 802) proved to be very suitable for the laboratory preparation of ochratoxin A. The mould was multiplied on a natural substrate for 14 days at the temperature of 28 degrees C and at 100% relative humidity. Ochratoxin A was extracted into organic solvents (chloroform + acetic acid), purified with aqueous alkaline solutions and by preparative thin-layer chromatography. The isolated mycotoxin was identified by physico-chemical methods. The amount of pure ochratoxin A isolated from 600 g of substrate was 305 mg.

• MeSH
• Aspergillus metabolismus   MeSH
• ochratoxiny biosyntéza   izolace a purifikace   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

Indirect, enzymoimmunological assays of the mycotoxin ochratoxin A were developed. In this technique a polyclonal (rabbit) antibody to ochratoxin A was used, along with the other, peroxidase-labelled (pig anti rabbit) antibody. The sensitivity of this method ranged around 75 pg of ochratoxin A per pit. The range of calibration curve was from 10 to 1000 pg per pit. The cross reactions with other ochratoxins made 1.4% (ochratoxin C). The ELISA test of ochratoxin A can be used as an expeditious screening method for a preliminary examination of the greater number of samples.

• MeSH
• ELISA MeSH
• ochratoxiny analýza   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

A new radioimmunological method was developed for the determination of the mycotoxin ochratoxin A. The specific antibodies used in this method had been prepared by the immunization of rabbits by means of administration of ochratoxin A conjugate with bovine serum albumin. Their effective affinity constant was Ka = 5.1 X 10(-9) l. Mol-1. The substance used as radioligand was 125I-ochratoxin with a high specific radioactivity (Czechoslovak patent PV 6136, 1986). The average sensitivity of determination (ED 85%) was 10 to 15 picograms per 0.1 ml of sample. The range of the calibration curve was mostly from 5 to 360 picograms.

• MeSH
• králíci MeSH
• ochratoxiny analýza   imunologie   MeSH
• radioimunoanalýza metody   MeSH
• specificita protilátek MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

Trials were conducted to verify a simple procedure of preparing food and feed samples of plant origin for the radioimmunological assay of ochratoxin A. All 27 food samples subjected to testing met the general hygienic regulations for foods (NPK - ochratoxin A 20 micrograms.kg-1), and so did all 23 samples of the tested feeds. The proposed method of sample preparation is not suitable for the examination of animal-origin foods because some proteins (albumin) might interfere.

• MeSH
• jedlá semena analýza   MeSH
• kontaminace potravin analýza   MeSH
• krmivo pro zvířata analýza   MeSH
• ochratoxiny analýza   MeSH
• radioimunoanalýza metody   MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

According to the EU legislation, ochratoxin A contamination is controlled in wines. Tokaj wine is a special type of sweet wine produced from botrytized grapes infected by "noble rot" Botrytis cinerea. Although a high contamination was reported in sweet wines and noble rot grapes could be susceptible to coinfection with other fungi, including ochratoxigenic species, no screening of Tokaj wines for mycotoxin contamination has been carried out so far. Therefore, we developed an analytical method for the determination of ochratoxin A (OTA) and ochratoxin B (OTB) involving online SPE coupled to HPLC-FD using column switching to achieve the fast and sensitive control of mycotoxin contamination. The method was validated with recoveries ranging from 91.6% to 99.1% with an RSD less than 2%. The limits of quantification were 0.1 and 0.2 µg L-1 for OTA and OTB, respectively. The total analysis time of the online SPE-HPLC-FD method was a mere 6 min. This high throughput enables routine analysis. Finally, we carried out an extensive investigation of the ochratoxin contamination in 59 Slovak Tokaj wines of 1959-2017 vintage. Only a few positives were detected. The OTA content in most of the checked wines did not exceed the EU maximum tolerable limit of 2 µg L-1, indicating a good quality of winegrowing and storing.

• Klíčová slova
• Tokaj wine, chromatography, column switching, food control, mycotoxin, ochratoxin A, ochratoxin B, online extraction,
• MeSH
• analýza potravin metody   MeSH
• chromatografie kapalinová MeSH
• extrakce na pevné fázi MeSH
• kontaminace potravin analýza   MeSH
• ochratoxiny analýza   MeSH
• řízení kvality MeSH
• senzitivita a specificita MeSH
• víno analýza   MeSH
• Vitis chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxin B MeSH Prohlížeč
• ochratoxiny MeSH

A feeding trial was performed with chick broilers (cockerels). The feed with an addition of 850 micrograms ochratoxin A (OA) per kg was administered for six weeks. The feeding of the chicks stopped twelve hours before slaughter (in keeping with slaughter technology for chicks). Blood, liver and kidney samples were taken. At the end of trial the level of OA residues in the samples did not exceed 5 micrograms per kg. In other trials the dynamics of OA residues in the blood plasma of chicks was investigated after i.v. implantation at an amount of 2 and 20 micrograms per chick (1.5 kg lw.). An open two-compartment model was used to estimate toxicokinetic parameters. The half-time of elimination (t1/2(beta)) was about 3.3 hours. The high total clearance (CL) of 34.2 ml/min/kg lw. and apparent distribution volume (Vd(area)) of 9.8 l/kg lw. demonstrate rapid distribution to the tissues and rapid OA elimination. The results document that neither at a long-term intake of feed contaminated to the level of 850 micrograms OA per kg will the present hygienic limits of residues for foods be exceeded (5 and 20 micrograms per kg) if the principles of correct slaughter technology are observed. The blood of chicks used as feed is not an important source of OA in this case.

• MeSH
• krmivo pro zvířata analýza   MeSH
• kur domácí MeSH
• maso analýza   MeSH
• ochratoxiny aplikace a dávkování   analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• anglický abstrakt MeSH
• časopisecké články MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

The aims of the study were to obtain information about the occurrence of ochratoxin A (OTA) and citrinin (CIT) in cereals harvested in the Czech Republic and to compare two analytical procedures for detecting OTA. A total of 34 cereal samples, including two matrix reference materials (R-Biopharm, Germany), were analysed. The results were compared with the limit for raw cereal grains used as a foodstuff according to Commission Regulation No. 1881/2006, which allows a maximum OTA level of 5 µg kg(-1). Compared were two methods based on the high-performance liquid chromatography principle, one using the immunoaffinity columns OchraTest (VICAM) and the second based on solvent partition (PART), both followed by fluorescence detection. The highest OTA contents were found in two barley samples. According to the method employed, the results for the first sample (malting barley) were VICAM = 31.43 µg kg(-1) and PART = 44.74 µg kg(-1). For the second sample (feeding barley) they were VICAM = 48.63 µg kg(-1) and PART = 34.40 µg kg(-1). Two samples of bread wheat had an OTA content approaching the legal limit (VICAM = 4.71 µg kg(-1) and PART = 6.03 µg kg(-1); VICAM = 4.12 µg kg(-1) and PART = 3.95 µg kg(-1)). CIT was analysed using the PART method only, and its highest content (93.64 µg kg(-1)) was found for the malting barley sample with high OTA content (44.74 µg kg(-1) as analysed using PART).

• MeSH
• citrinin analýza   MeSH
• ječmen (rod) chemie   normy   MeSH
• jedlá semena chemie   normy   MeSH
• kontaminace potravin * MeSH
• kontrola potravin metody   MeSH
• limita detekce MeSH
• metody pro přípravu analytických vzorků MeSH
• ochratoxiny analýza   normy   MeSH
• reprodukovatelnost výsledků MeSH
• semena rostlinná chemie   MeSH
• voda analýza   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• citrinin MeSH
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH
• voda MeSH

Ochratoxin A (OTA) is a very important mycotoxin, and its research is focused right now on the new findings of OTA, like being a complete carcinogen, information about OTA producers and new exposure sources of OTA. Citrinin (CIT) is another important mycotoxin, too, and its research turns towards nephrotoxicity. Both additive and synergistic effects have been described in combination with OTA. OTA is produced in foodstuffs by Aspergillus Section Circumdati (Aspergillus ochraceus, A. westerdijkiae, A. steynii) and Aspergillus Section Nigri (Aspergillus carbonarius, A. foetidus, A. lacticoffeatus, A. niger, A. sclerotioniger, A. tubingensis), mostly in subtropical and tropical areas. OTA is produced in foodstuffs by Penicillium verrucosum and P. nordicum, notably in temperate and colder zones. CIT is produced in foodstuffs by Monascus species (Monascus purpureus, M. ruber) and Penicillium species (Penicillium citrinum, P. expansum, P. radicicola, P. verrucosum). OTA was frequently found in foodstuffs of both plant origin (e.g., cereal products, coffee, vegetable, liquorice, raisins, wine) and animal origin (e.g., pork/poultry). CIT was also found in foodstuffs of vegetable origin (e.g., cereals, pomaceous fruits, black olive, roasted nuts, spices), food supplements based on rice fermented with red microfungi Monascus purpureus and in foodstuffs of animal origin (e.g., cheese).

• MeSH
• Aspergillus metabolismus   MeSH
• citrinin analýza   metabolismus   MeSH
• dieta MeSH
• kontaminace potravin * MeSH
• Monascus metabolismus   MeSH
• ochratoxiny analýza   metabolismus   MeSH
• Penicillium metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• citrinin MeSH
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

Since ochratoxin A (OTA) was discovered, it has been ubiquitous as a natural contaminant of moldy food and feed. The multiple toxic effects of OTA are a real threat for human beings and animal health. For example, OTA can cause porcine nephropathy but can also damage poultries. Humans exposed to OTA can develop (notably by inhalation in the development of acute renal failure within 24 h) a range of chronic disorders such as upper urothelial carcinoma. OTA plays the main role in the pathogenesis of some renal diseases including Balkan endemic nephropathy, kidney tumors occurring in certain endemic regions of the Balkan Peninsula, and chronic interstitial nephropathy occurring in Northern African countries and likely in other parts of the world. OTA leads to DNA adduct formation, which is known for its genotoxicity and carcinogenicity. The present article discusses how renal carcinogenicity and nephrotoxicity cause both oxidative stress and direct genotoxicity. Careful analyses of the data show that OTA carcinogenic effects are due to combined direct and indirect mechanisms (e.g., genotoxicity, oxidative stress, epigenetic factors). Altogether this provides strong evidence that OTA carcinogenicity can also occur in humans.

• Klíčová slova
• Balkan endemic nephropathy, biomarkers, carcinogenicity, feed, food, microfungi, ochratoxin A, toxicity, urothelial cancer,
• MeSH
• balkánská nefropatie chemicky indukované   genetika   dějiny   metabolismus   MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• epigeneze genetická účinky léků   MeSH
• hodnocení rizik MeSH
• ledviny účinky léků   metabolismus   patologie   MeSH
• lidé MeSH
• nádorová transformace buněk chemicky indukované   genetika   metabolismus   MeSH
• nádory ledvin chemicky indukované   genetika   dějiny   metabolismus   MeSH
• ochratoxiny dějiny   metabolismus   toxicita   MeSH
• oxidační stres účinky léků   MeSH
• poškození DNA MeSH
• potravinářská mikrobiologie * dějiny   trendy   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• rizikové faktory MeSH
• toxikologie * dějiny   trendy   MeSH
• zvířata MeSH
• Check Tag
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

The aim of this study was to conduct a survey assessing (a) the ochratoxin A (OTA) content in different samples of Astragalus propinquus root (AR), one of the fundamental herbs in traditional Chinese medicine, and (b) the rate of OTA transfer to AR decoctions that are traditionally used to reduce general weakness and increase overall vitality. A validated method of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) was used to determine OTA concentrations in AR samples and AR decoctions. The limit of quantification was 0.35 ng/g; the recovery of the HPLC method for AR samples was 82%; and the relative standard deviation (SD) of repeatability was 2.6%. All 40 tested AR samples were positive, with a mean value of 451.0 ng/g (range, 28.8-1700.0 ng/g). The transfer rate of OTA to decoctions, from a naturally contaminated and homogenized AR sample (internal reference material) with a concentration of OTA of 288.9 ng/g ± 12.3 (SD), was 83.4% ± 8.5 (SD). We believe it is necessary to continue OTA monitoring in AR and other herbal products, estimate the actual human usual intake, and perform health risk assessment.

• Klíčová slova
• Astragalus propinquus Schischkin, HPLC-FLD, Herbal food supplement, Herbal products, Ochratoxin A, Traditional Chinese medicine,
• MeSH
• Astragalus propinquus MeSH
• fluorometrie metody   MeSH
• kontaminace potravin analýza   MeSH
• léky rostlinné čínské chemie   MeSH
• lidé MeSH
• ochratoxiny analýza   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Huang Qi MeSH Prohlížeč
• léky rostlinné čínské MeSH
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH