Biomedical subjects

B J Blanchfield

Publications and source records attributed to B J Blanchfield.

9 recordsLinked to original sources

PubMed1980

Screening Fusarium strains isolated from overwintered Canadian grains for trichothecenes.

A survey of 38 samples of Canadian overwintered grains showed that 14 (37%) contained viable Fusarium. Of a total of 38 Fusarium isolates, cultured on autoclaved corn, 20 (from 7 grain samples) showed toxicity to brine shrimp larvae and 12 (from 5 samples) produced levels of trichothecenes detectable by thin layer chromatography. The principal trichothecene found was T-2 toxin, produced by 10 strains and accompanied in half of these by neosolaniol; some of these strains were identified as F. sporotrichioides Sherbakoff. Two strains of F. poae (Peck) Wollenw. formed small amounts of diacetoxyscirpenol. T-2 toxin was the most toxic of 8 trichothecenes tested on brine shrimp larvae; the wide range of toxicities limits the usefulness of this bioassay as a general screening method for trichothecenes.

Canada↗

PubMed1979

Toxins of molds from decaying tomato fruit.

Among 27 mold isolates from decaying tomatoes, culture filtrates or ethyl acetate extracts of 8 isolates grown in yeast extract-sucrose medium were markedly toxic (mortality, greater than 50%) to brine shrimp larvae. The toxicity of six of these isolates could be attributed to the presence of citrinin, tenuazonic acid, or T-2 toxin. Ethyl acetate extracts of five Alternaria isolates and one Fusarium isolate were mutagenic for Salmonella typhimurium strains. In ripe tomatoes inoculated with toxin-producing isolates and incubated at 25 degrees C, one Alternaria alternata isolate produced tenuazonic acid in seven of seven tomatoes at levels of up to 106 micrograms/g and alternariol methyl ether in one of the seven tomatoes at 0.8 microgram/g. Another A. alternata isolate produced tenuazonic acid or alternariol methyl ether at much lower levels in only three of seven tomatoes. Patulin and citrinin were produced by a Penicillium expansum isolate at levels of up to 8.4 and 0.76 microgram/g, respectively. In tomatoes incubated at 15 degrees C, a Fusarium sulphureum isolate produced T-2 toxin, HT-2 toxin, and neosolaniol at levels of up to 37.5, 37.8 and 5.6 micrograms/g, respectively. If these mycotoxins are thermostable, they may occur at detectable levels in tomato products whenever partially moldy tomatoes are used as raw material.

Animals↗

PubMed1977

Study of conditions of production of roquefortine and other metabolites of Penicillin roqueforti.

Experiments to determine optimum yields of roquefortine, isofumigaclavine A, and PR toxin, metabolites from Penicillum roqueforti Thom, were performed. Four strains, isolated from blue cheese, and five liquid media were evaluated, although not all permutations were studied. Sucrose (15%)-yeast extract (2%) was the medium chosen for time-course studies at 25 and 15 degrees C using one favorable strain. At 25 degrees C, maximum estimated yields of roquefortine were about 100 mg/liter in the mycelium by 16 days, and no subsequent degradation of this alkaloid was observed. On the other hand, production of PR toxin in the medium peaked at 770 mg/liter at 21 days. At 15 degrees C, yields of roquefortine and PR toxin after 49 days were 60 to 70% of the maximum yields obtained at 25 degrees C. However, about three times more isofumigaclavine A (up to 11 mg/liter) was formed in the mycelium at 15 degrees C than at 25 degrees C. All four strains of P. roqueforti procedure both roquefortine and PR toxin on the sucrose-yeast extract medium at 25 degrees C; isofumigaclavine A was detected in all but one strain grown on this medium.

Cheese↗

PubMed1974