• Journal of Animal Science and Technology
• /
• v.64 no.5
• /
• pp.842-853
• /
• 2022

Ochratoxin A (OTA) is a well-known mycotoxin that causes disease through the ingestion of contaminated food or feed, for example, in the porcine industry. The intestinal epithelium acts as the first barrier against food contamination. We conducted a study on the exposure of the porcine intestinal epithelium to OTA. We used the intestinal porcine epithelial cell line IPEC-J2 as an in vitro model to evaluate the altered molecular mechanisms following OTA exposure. Gene expression profiling revealed that OTA upregulated 782 genes and downregulated 896, totalling 1678 differentially expressed genes. Furthermore, immunofluorescence, quantitative real-time polymerase chain reaction, and western blotting confirmed that OTA damages the tight junction protein ZO-1. Moreover, OTA activated the expression of inflammatory genes (IL-6, IL-8, IL-10, NF-kB, TLR4, and TNF-α). In summary, this study confirmed that OTA alters various molecular mechanisms and has several adverse effects on IPEC-J2 cells.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.10
• /
• pp.1687-1695
• /
• 2016

Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified as Aspergillus tubingensis M036 and M074 through sequence analysis of the beta-tubulin gene. After culturing both A. tubingensis isolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). Both A. tubingensis strains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by the A. tubingensis strains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest that A. tubingensis isolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.

• Korean Journal of Microbiology
• /
• v.55 no.1
• /
• pp.33-38
• /
• 2019

Ochratoxin A (OTA), one of mycotoxins produced mainly by Aspergillus is a common contaminant of stored grains, posing health hazards to human and livestock. The aim of this study is to explore ability of isolated bacteria Bacillus subtilis AF13 and Streptomyces shenzhenensis YR226 to remove OTA. AF13 and YR226 could remove 94.23 and 97.73% of OTA ($100{\mu}g/L$), respectively during 24 h incubation in NB medium. When cultures of two strains were separated into washed cells and cell-free supernatant, the supernatant of both strains removed more than 90% of $100{\mu}g/L$ OTA, and 98.88% of OTA could be also removed by the washed cells of YR226. OTA removal occurred in a few second by the supernatant of both strains, and treatments of autoclaving, proteinase K and chymotrypsin did not affect the OTA removal by the culture supernatants, which indicate that some thermostable and non-proteinaceous substances secreted by these bacteria may be involved in OTA removal in these two bacteria. These results suggest that AF13 and YR226 can be used to remove OTA from OTA-contaminated grains and feeds, and therefore decrease economic damage in agriculture and feed industry.

• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.353-358
• /
• 2007

Contamination of ochratoxin A (OTA) was studied in 194 compound feeds and 59 feed ingredients samples distributed in South KOREA in 2006 and 2007. The degree of OTA contamination in feed ingredients was 27%, and its detected levels were ranged from 0.27 to 3.39 ppb. Seventy six percent of compound feeds were contaminated with OTA at concentration between 0.21 and 13.64 ppb. The highest degree of OTA contamination was observed in compound feeds for dairy cattle (96%) followed by for poultry (85%) and swine (79%). Beef cattle exhibited the highest level of OTA contamination (2.2 ppb). Compound feeds for dairy cattle and feed ingredients for vegetable proteins showed relative lower level of contamination at 1.6 and 1.2 ppb, respectively.

• YAKHAK HOEJI
• /
• v.42 no.3
• /
• pp.336-344
• /
• 1998

Effects of ochratoxin A (OTA) on embryo development were studied in cultured whole embryos from 9.5 day gestation rat for 48 h. OTA (more than $0.5{\mu}g/ml$) induced microcephaly in the cultured rat whole embryos. Protein and DNA content, and DNA synthesis were significantly inhibited by OTA. We next examined whether the microcephaly seen in cultured whole embryo partially results from inhibition of differentiation of embryonic midbrain cells. Embryonic midbrain cells were extracted from 12 day gestation rat embryos, and cultured for 96 hr. OTA ibhibited cell differentiation about 50% over control. We also tested whether OTA-induced embryotoxicity would be associated with oxidative damages. We measured the ${\gamma}$-glutamyltranspeptidase (${\gamma}$-GT) and glutathione peroxidase (GPX) activities, and glutathione (GSH) content in both cultured whole embryos and embryonic midbrain cells. OTA decreased GSH content, whereas slightly increased ${\gamma}$-GT activity, but GPX activity was not significantly changed. These results show that OTA caused the microcephaly and its effect may be partially due to the inhibition of cell differentiation of embryonic midbrain cells, but the role of oxidative damages is not clear in embryotoxicity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.1
• /
• pp.114-121
• /
• 2012

The potential for ochratoxin A (OTA) degradation by swine intestinal microbiota was assessed in the current study. Intestinal content that was collected aseptically from swine was spiked with 100 ppb OTA and incubated for 6 and 12 h at $39^{\circ}C$. An OTA assay was conducted using the incubated samples, and it was found that 20% of the OTA toxin was detoxified, indicating the presence of microbes capable of OTA degradation. Twenty-eight bacterial species were isolated anaerobically in M 98-5 media and 45 bacterial species were isolated using nutrient broth aerobically. Screening results showed that one anaerobic bacterial isolate, named MM11, detoxified more than 75% of OTA in liquid media. Furthermore, 1.0 ppm OTA was degraded completely after 24 h incubation on a solid 'corn' substrate. The bacterium was identified by 16S rDNA sequencing as having 97% sequence similarity with Eubacterium biforme. The isolation of an OTA-degrading bacterium from the swine natural flora is of great importance for OTA biodegradation and may be a valuable potential source for OTA-degradation enzymes in industrial applications.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.1
• /
• pp.83-92
• /
• 2009

Individual immunochromatographic assays (ICG) for ochratoxin A (OTA) and zearalenone (ZEA) were optimized and used in the development of a one-step simultaneous immunochromatographic assay (OS-ICG) for the rapid multianalysis of two mycotoxins in corn samples. The nitrocellulose membrane of the OS-ICG was treated with OTA-bovine serum albumin (BSA), ZEA-ovalbumin (OVA), and anti-mouse IgG in the OTA test, ZEA test, and control zones, respectively. Monoclonal antibody-gold conjugates (OTA3 MAb-gold and ZEA2C5 MAb-gold) were sprayed onto the conjugate pad. The visual detection limits were 2.5 and 5 ng/ml for OTA and ZEA, respectively, and the results were obtained within 15 min after starting the analysis. An efficient, simple, and rapid extraction method using 30% MeOH/PBS was established and validated by analyzing the corn samples spiked with OTA/ZEA mixtures (0/0, 5/10, 10/20, and $20/30\;{\mu}g/kg$). The cut-off values of the OS-ICG for the spiked corn were 5 and $10\;{\mu}g/kg$ for OTA and ZEA, respectively. Natural corn samples were analyzed by OS-ICG, direct competitive enzyme-linked immunosorbent assay (DC-ELISA), and HPLC. Results of the OS-ICG were in good agreement with those obtained by DC-ELISA and HPLC. The developed OS-ICG offers a rapid, easy-to-use, and portable analytical system and can be used as a convenient qualitative tool for the on-site simultaneous determination of OTA and ZEA in cereals, food, and agricultural products in one analytical cycle.

• Journal of Life Science
• /
• v.16 no.6
• /
• pp.1006-1013
• /
• 2006

To High Throughput Screening (HTS), a homogeneous fluorescence polarization immunoassay (FPIA) was developed for the quantitative determination of ochratoxin A(OTA) using a $Victor^3$ (PerkinElmer). The homologous tracer, fluorescein-labelled OTA-EDF were synthesized and a specific OTA antibody has been used in the development of the method. It allowed the determination of OTA in the concentration range 0.5-200 ng/ml, with the detection limit of 0.3 ng/ml. The method developed was highly specific and reproducible. OTA spikes in unpolished rice extracts were determinable by FPIA with good recovery. For naturally contaminated unpolished rice samples some disagreement was observed between the results obtained by FPIA and HPLC, which could be related to the a little matrix effect observed for FPIA. Further research is needed to validate the procedure. On the basis of these initial results, this FPIA appears to meet the performance criteria for OTA screening of food samples without a complicated clean-up.

• Journal of the East Asian Society of Dietary Life
• /
• v.21 no.2
• /
• pp.222-227
• /
• 2011

The Aspergillus sp. is well known as a fungus that causes black mold disease and secretes ochratoxin A (OTA). Our study found that infection by this fungus via inoculation onto grapes produced more severe symptom in wounded berries than in fresh berries. Furthermore, OTA contents were higher on the grape skins than in the fleshy portions of the grapes. OTA accumulated during the first 3 days after inoculation, but then gradually decreased. The OTA contents in wine made from 5 kg of grapes which included 400 g of infected grapes ranged from 0.17 to 0.37 ${\mu}g/mL$. An investigation of 25 marketed commercial wines showed the OTA contents were <1.2 ${\mu}g/mL$ which is lower than the limit of 2 ${\mu}g/mL$ established by the Korea Food & Drug Administration.

• Korean Journal of Microbiology
• /
• v.55 no.3
• /
• pp.226-233
• /
• 2019

Ochratoxin A (OTA) that is one of mycotoxins produced mainly by Aspergillus spp. is a common contaminant of stored grains and poses health hazards to human and livestock. The aim of this study is to explore the ability of isolated bacteria Bacillus subtilis AF13 and Streptomyces shenzhenensis YR226 to inhibit growth and OTA production of 3 ochratoxigenic Aspergillus strains. The antifungal activity against mycelial growth and sporulation of Aspergillus strains was examined by coculture with AF13 and YR226 on potato dextrose agar plate. AF13 and YR226 reduced 77.58 and 78.48% of fungal colony radius, respectively, and both strains inhibited fungal sporulation up to 99% in 10 days of incubation. YR226 also reduced more than 91% of spore germination of 3 fungal strains. When Aspergillus strains were cocultured with AF13 or YR226 in yeast extract sucrose medium, mycelial growth and OTA production decreased in all three fungal strains. In particular, AF13 completely inhibited the mycelial growth of A. alutaceus and inhibited its OTA production by 99%, and YR226 also reduced mycelial growth and toxin production up to 99%, respectively. Antimicrobial substances produced by AF13 and YR226 included siderophore, chitinase, protease, ${\beta}$-1,3-glucanase and biosurfactant. These results suggest that AF13 and YR226 can be used in a biological method to prevent valuable crops against mycotoxigenic fungi, and therefore decrease economic damage in agriculture and feed industry.