Leucoencephalomalacia is a highly fatal neurologic disorder of equidae. This intoxication is due to fumonisins, metabolism products from Fusarium moniliforme. This fungus is a frequent corn and its by-products contaminant. Clinical signs appear after repeated feeding of moldy corn during several weeks to several months. Diagnosis of this intoxication is based on: (i) anatomo-pathological examination of the brain and (ii) fumonisin B1 quantitative analysis in food. Increasing reported cases to CNITV (Centre National d'information Toxicologique Veterinaire) prove the importance of this pathology, still unrecognized by french veterinarians. We present here a typical case and an overview of the other reported cases to CNITV.

Following our investigations on red pigments and monascidin co-production by Monascus species, the antibiotic called monascidin A was characterized as citrinin. Evidence was given by qualitative methods, mass spectra and NMR. Citrinin, a nephrotoxic agent was produced both by Monascus purpureus and Monascus ruber, either in submerged culture of concentrations of 270 and 340 mg/l, respectively, or in solid state culture of concentration of 100 and 300 mg/kg dried matter, respectively. Since citrinin is a toxic product, it is essential that the production of red pigments as food additives from Monascus spp. avoid the occurrence of citrinin.

Sixty strains of F. moniliforme were isolated from 73 samples of corn seeds harvested by hand. These strains were cultivated on hydrated (50%) and sterilized corn, in optimal condition for fumonisin B1 (FB1) production: 22-degrees-C, 28 days. Weekly analysis of FB1 was performed by instrumentalized planar chromatography. 95% of strains produced more than 50 mg FB1/g corn: 50% producing over 800 mg/g might be considered as actually toxigenic in agronomic situation. Half-life times of FB1 in corn was definitely longer than different thermal treatments (50 to 150-degrees-C). As a consequence, first, of the high frequency of F. moniliforme and toxigenesis of strains, and, secondly, of FB1 stability, contamination of corn and its derivatives is a permanent threat, confirmed by occasional acute toxicosis.

Cutaneous lesions were observed in three geldings on a new lot of straw. A suspicion of stachybotryotoxicosis was based on epidemiological considerations. It was confirmed by laboratory investigation (isolation of the strain, skin test). They recovered on administration of amoxicillin and the contaminated straw was destroyed.

The occurrence of a few cases of equine leukoencephalomalacia in France has indicated a potentially widespread, low-level contamination of corn by fumonisins. To develop strategies for prevention, biotic and abiotic factors in fumonisin B-1 (FB1) production and stability were investigated. The potential for FB1 production from 2 groups of Fusarium moniliforme strains was tested in corn cultures. The first group consisted of 48 strains that were previously isolated from corn, asparagus, watermelon, and vanilla. The second group consisted of 25 strains that were freshly isolated from corn. Respective frequencies in the first and second groups of strains and in each toxigenic class were as follows: 23 and 0%, <50 mu g/g; 16 and 12%, 50- 200 mu g/g; 23 and 4%, 200-800 mu g/g; 33 and 68%, 800-3200 mu g/g; and 5 and 16%, >3200 mu g/g. The initial rate of FB1 production decreased in the following order of temperature: 20, 25, 15, 30, 10 degrees C. FB1 was not detected at 5, 35, or 40 degrees C. Also, no FB1 was detected in confined atmosphere at 25 degrees C during In weeks. Significant amounts (>200 mu g/g) of FB1 were produced within 12 days, in laboratory conditions, with moisture contents of corn frequently encountered at harvest (greater than or equal to 27%). Thermal decomposition of FB1 in dried corn culture followed a first-order reaction. Half-life times at 150, 125, and 100 degrees C were 10, 38, and 175 min, respectively. Therefore, contamination of foods and feeds by this stable mycotoxin is, theoretically, a permanent threat.

An instrumental TLC method has been developed for quantification of fumonisin B-1 (FB1), a mycotoxin from Fusarium moniliforme (Sheldon), in corn. Samples of ground corn free from FB1 were spiked at different levels (5 to 350 mg/kg) with crude FB1 extracts. After extraction and purification by solid phase extraction, FB1 was separated by 2-step TLC and quantified by scanning densitometry after postchromatographic derivatization.The suitability of various solvent systems for dissolution of FB1 was studied, as was their influence on spotting. Two reagents, p-anisaldehyde and ninhydrin were compared in terms of sensitivity, specificity, and stability of detection, the higher response and lower limit of detection being obtained with p-anisaldehyde. A delay of 30 min. between derivatization and quantification minimized the error resulting from response decay.The repeatability of the calibration curve fluctuated from 2 to 10 % (RSD) and the limit of detection was 51.1 ng for standards and 100 ng for extracts. The limit of quantification was 100 mg/kg (ppm) without purification and 5 ppm after purification. Recoveries were greater than 80 % for levels in excess of 25 ppm and 67.6 % at the limit of quantification (5 ppm).The main source of error was the error of spotting: +/-4.02 % (RSD). Intraplate and interplate variation were +/-4.98 % and +/-6.50 % (RSD), respectively. The technique appeared adequate for detection of FB1 in foodstuffs at the maximum recommended level (5 ppm).

Fumonisin B 1 (FB 1 ) is a mycotoxin from Fusarium moniliforme that is frequently associated with corn. Thermal treatments are used in many processes concerning this cereal and its derivatives. The thermostability of this toxin in dry contaminated corn, resulting from F. moniliforme culture, was studied in different time-temperature combinations. FB 1 was quantified by instrumentalized thin-layer chromatography after a two-step sequential development and postchromatographic derivatization by p -anisaldehyde. The identity of FB 1 in extracts, before and after heat treatments, was confirmed by high-pressure liquid chromatography. For each temperature, the natural logarithm of the ratio of resulting FB 1 on initial content (In C / C 0 ) is linearly correlated to exposure time. The calculated half-lives ( L 50 ), corresponding to the 50% value, were 10 min, 38 min, 175 min, and 8 h at 150, 125, 100, and 75�C, respectively. There is a linear relationship between calculated L 50 s on a logarithmic scale and temperature. Therefore FB 1 is not significantly destroyed by the main drying processes of corn or thermal treatments used for its derivatives. Other associated means are required for detoxification.

The spreading of Fusarium in the environment, for the biological control, can lead to a secondary contamination of the foodstuffs. Furthermore, many species of the genus Fusarium can elaborate different mycotoxins. The toxinogenesis of 73 strains, isolated from various foodstuffs (cereals, fruits and vegetables, ...) has been tested in vitro. Fusarochromanone wasn't detected in any strains; zearalenone arid deoxynivalenol were produced respectively by 59 and 12,3 % of the isolates; despite a significative frequency (14 %), the potentiel hazard of contamination with the skin necrotizing trichothecenes appears low. In the cultures of 2 strains selected for the biological control, none of those mycotoxins were detected. This checking study concerning the non-toxigenicity of strains is a required step to allow the domestication of Micromycetes.

Delayed fungal impairments ("green mold") appeared iri mold ripened sausages: Penicillium frequentans Westling (= P. glabrum (Wehmer) Westling) on the sausage body and Aspergillus repens de Bary (= Eurotium repens de Bary) on the ends. Mycological studies on raw materials, air and surfaces of different rooms led to determine their origins: - A. repens came from pepper; - P. frequentans, present everywhere in the factory, grew in ripening rooms. Ecological study of these species, in comparison with P. nalgiovense Laxa (starter mold), explained their development localisation and period. Experimental contaminations at different steps of the process outlined that the critical moment took place before incubators. Comprehensive measures to limit development (in ripening rooms), origin and cross contamination eliminated more than 80% impairments. Investigations on more competitive strains of P. nalgiovense and P. chrysogenum Thom would improve such a prevention.

Facial eczema is a hepatogenous photosensitivity mycotoxicosis resulting from sporidesmin ingestion. The morphological characters of toxigenic strains of P. chartarum are reported and the effect of temperature on growth and mycotoxin production are studied. The temperature range for which there is an actual risk of toxin accumulation (20-25 degrees C) is much narrower than for an appreciable growth (5-30 degrees C).