Rain and temperature are reportedly of major importance in infection and colonization of wheat by Fusarium graminearum (teleomorph Gibberella zeae). The present review was undertaken to estimate changes in wheat scab in Hokkaido, northern Japan during 1980 to 2000 and to correlate these changes with weather variables. The results indicated that the abnormal low temperature at June to July and rainfall at August (over 200mm) are the most critical factors determining severe scab damage of wheat crops in Obihiro area, Hokkaido. There were close correlation between abnormal weather conditions and deoxynivalenol contamination in scab damaged wheat grains.
Thirty-five of 102 extracts obtained from freshly isolated fungal strains showed the antifungal activity against either pathogenic filamentous fungi or pathogenic yeasts. The extract of Aspergillus sp. IFM51759 (Aspergillus versicolor group), which showed the characteristic antifungal activity against Aspergillus fumigatus, one of the major opportunistic human pathogen causing APBA etc., prompted us to isolate antifungal compounds. A new furanone derivative, epimusacin D (1), was isolated along with three known pyranone derivatives, asperlin (2), acetylphomalactone (3), and the diastereomer of asperlin (4). The structure of epimusacin D (1) was determined from the analysis of the spectroscopic investigation. The antifungal activity of the above four compounds were discussed.
Interactive effects between emodin and genistein were investigated using the rat vascular smooth muscle cell line A-10. Genistein significantly retarded the proliferation. While emodin alone also retarded the proliferation, its effect was reversed in the presence of genistein. It appeared that emodin cancelled the effect of genistein. Exposure to high concentrations of genistein resulted in a reduction of TNF-αinduced MCP-1 secretion. Concomitant treatments of emodin and genistein had more effect on TNF-α induced MCP-1 secretion compared to emodin treatment alone. A slight decrease in TIMP-2 secretion was observed in 100μM genistein-treated cells, and the results of concomitant treatments of emodin and genistein showed the same tendencies as those seen with MCP-1 secretion. Consequently, it is likely that their effects on MCP-1 and TIMP-2 secretions were additive. With regard to MCP-1 and TIMP-2 secretions, it is suggested that emodin and genistein share the same signal transduction pathways, and thus reinforce the signal transduction to exert the additive effects. Conversely, emodin appeared to interfere with the effect of genistein on proliferation, suggesting that the mechanism of inhibition of proliferation is different from those of the other two phenomena.
The result from 1994 to 2000 of the inspection for aflatoxin in raw peanuts at the time of import into Japan are discribed. From 1994 to March 11, 1999, the aflatoxin inspection of peanuts required that puliverze grain of 50 g taken from 1 kg of raw peanuts and tested. After March 12, 1999, the Food Hygiene Law modified the aflatoxin inspection, and required that 1 kg of peanuts be pulverized, and then that 50 g taken from this amount be tested. For the period from 1994 to 1998, aflatoxin was detected in 69 (0.9 %) of 8040 samples large and small kernel type of peanuts, and of these 69 samples, 29 (0.4 %) had more than 10 ppb of aflatoxin B1. The aflatoxin B1 contamination ranged from 0.2 ppb to 4900 ppb. For the piriod from 1999 to 2000, aflatoxin was detected in 355 (6.9 %) of 5108 samples of large and small kernel type of peanuts, and of these 355 samples, 145 (2.8 %) had more than 10 ppb of aflatoxin B1. The contamination range from 0.2 ppb to 760 ppb. This increased incidence of aflatoxin detection after is due to the modify of the aflatoxin inspection, which enhanced the inspection at the time of the importation raw peanuts.
The traditional analysis of mycotoxins in food and feed required considerable time, large volume of solvents and often, special techniques. To overcome these problems, we developed the new analytical method for ochratoxin A (OTA) using the immunoaffinity column (IAC) specific for ochratoxin A (OTA) in 1990. The advantage of this method was one-step removal of interfering substances from samples. Moreover, the detection limit of 0.05 μg/kg for OTA in coffee beans was achieved. Using the IAC cleanup and HPLC with fluorometric or electrochemical detection, the surveys of aflatoxins (AFs) and OTA in green and roasted coffee beans, AFs in spices, and AFs, OTA, zearalenone (ZEN) and β-zearalenol (β-ZEL) in beers were conducted. With the use of IACs in the cleanup steps, the parts-per-trillion ranges of mycotoxins were detectable. The detection limits were 0.002 μg/kg for AFB1 in coffee beans and spices, and 0.05 μg/kg for OTA in coffee beans, 0.0005 μg/L for AFB1, 0.0010 μg/L for OTA, 0.020 μg/L for ZEN and β-ZEL in beer samples. This paper also describes the effects of the elimination of fungi, AFB1 and OTA in green coffee beans by handpicking.
A various policy for the safety of feed is tried based on the Law concerning Safety Assurance and Quality Improvement of Feed (the Feed Safety Law). As the regulation of the mycotoxin, a temporary standard value by the notice is decided about aflatoxin B1, zearalenone, deoxynivalenol. However the regulation is a temporary standard value by administrative advice. As for this temporary standard value, in the future, it decides to specify a permission standard in the Feed Safety Law and the reviewing has started. We introduce the overview of the legal system about the mycotoxin and the feed safety law.
The National Fertilizer and Feed Inspection Station assumes responsibility for the development of methods for animal feed analysis in Japan. The methods are recommended for adoption as official methods in Japan to be used by the National Fertilizer and Feed Inspection Station and other laboratories in the analysis of commercial feeds. Every effort is made to ensure that the results obtained are of a high quality by evaluating and validating the methods and through having a quality control system in place. Our standard method development manual requires several stages be followed in the development of a new method. These include inhouse validation of the method, a collaborative study and evaluation by a committee. Quality control is achieved by routinely participating in laboratory proficiency tests and by ensuring that laboratory equipment is maintained to a high standard.
In Japan, the outbreak of mycotoxicosis in cattle and poultry is not many in number. However, annual mean of the temperature in Japan is still increasing and the risk of animals exposed by mycotoxin may increase. We have been investigating the mycotoxicosis in cattle and poultry and we could show six cases of mycotoxicosis which were suspected in this report. In case 1, incidence of cattle affected with aflatoxicosis were shown and aflatoxin and sterigmatocystin were detected in feed. In case 2, incidence of chicks affected with aflatoxin and the detection of aflatoxin B1 were shown. In case 3, swine nephritis induced by ochratoxin was shown. In case 4, the detection of aflatoxin B1 in blood of chicks and the feed was shown. In case 5, isolation of Aspergillus flavus in penguin was reported. In case 6, ascites of chicks in south district in Kyushu Island was shown and incidences by mycotoxins were suspected. In general, diagnosis of mycotoxicosis is complicate because many other diseases must be negative and mycotoxins should be detected in feed and organs in the affected animals.