| incidence of aflatoxin-potential contamination in spanish sausages. | 525 strains of moulds were isolated from 8 samples of red pepper (capsicum annuum) and from 3 samples of black pepper (piper nigrum). these spices were commonly added to the various kinds of spanish sausages, specially to the spanish "chorizo". of these 525 isolated moulds, 100 belonged to the aspergillus flavus group. 69 were isolated from red pepper and 31 from black pepper. of these strains, 28 strains isolated from red pepper were found positive in producing aflatoxin b1 while only 8 of the ... | 1977 | 613913 |
| in defence of aldehyde-osmium fixation and critical-point drying for characterization of seed-storage fungi by scanning electron microscopy. | low-temperature scanning electron microscopy cannot be used as a general approach when resolution of definitive surface features is required for fungal characterization, because of the production of a pervading exudate by some of the species, strains or varieties. as the resolution of the light microscope is obviously limiting, scanning electron microscopy remains the best microscopical mode. results are presented for four species within the aspergillus flavus group which indicate that minimal ( ... | 1991 | 1960714 |
| production of aflatoxins by strains of the aspergillus flavus group maintained in atcc. | a total of 169 strains of the aspergillus reference cultures in the aspergillus flavus group maintained in the american type culture collection (atcc) were studied for their aflatoxin-producing abilities in rice, peanut and semisynthetic medium, utilizing high pressure liquid chromatography. fifty-nine of the strains examined were positive for aflatoxin formation. no strains of the food fungi a. oryzae or a. sojae produced detectable levels of aflatoxins, while 33-85% of the strains of a. flavus ... | 1986 | 3083260 |
| influence of subculturing on aflatoxin production by strains of aspergillus flavus group. | | 1972 | 4631237 |
| aflatoxigenic isolates of aspergillus flavus from pecans. | of 120 isolates of the aspergillus flavus group from pecans used in bakery products, 85 were shown to produce aflatoxin on yeast extract sucrose medium. extracts from moldy sections of raw pecans obtained commercially at the retail level showed aflatoxin-like spots on thin-layer chromatography. cooked (autoclaved) pecans inoculated with toxigenic isolates of a. flavus were also good substrates for aflatoxin production. | 1970 | 5415207 |
| experimental study of the pathogenicity of aspergilli for mice. | the relative virulence was determined for 14 species of aspergilli, by inoculating normal mice intravenously with graded doses of spores. eleven were found to possess some degree of virulence, whereas three others were avirulent. members of the aspergillus flavus group were the only species that consistently killed mice with doses as low as 10(4) viable spores. when the in vivo fate of spores was compared for a virulent and an avirulent strain of aspergillus, spores of the latter were cleared ra ... | 1967 | 6051365 |
| viable fungi in corn dust. | numbers of viable fungal propagules in corn dusts in southern georgia were estimated during various farm and grain elevator operations in 1979, 1980, and 1982. a six-stage andersen sampler for viable microbial particles was used to sample the dusts with various agar media. the most abundant fungi in corn dusts were species of yeasts: aspergillus, penicillium, cladosporium, alternaria. helminthosporium, and fusarium. however, the relative abundance of these fungi differed between years. there was ... | 1984 | 6696425 |
| pyrolysis-gas-liquid chromatography of fungi: differentiation of species and strains of several members of the aspergillus flavus group. | four fungi of the aspergillus flavus group were differentiated to the species level and strain level by pyrolysis-gas-liquid chromotography. comparisons of pyrochromatograms revealed more similarities than dissimilarities among both species and strains in the pyrolytic elution patterns. quantitative analysis was made by comparing the number of peaks in which two strains or reference species agreed or disagreed, the degree of superimposability between the pyrolytic elution patterns of strains and ... | 1970 | 5492442 |
| aflatoxin production of species and strains of the aspergillus flavus group isolated from field crops. | peanuts, cottonseed, rice, and sorghum from texas were sampled over a 3-year period. to insure adequate isolation of alfatoxin-producing species of fungi, low-quality lots were sampled at a rate greater than their respective proportional representation. aflatoxins were found each year in peanut and cottonseed and were found in 2 of 3 years in rice and sorghum. aflatoxins were detected in all four crops. the aspergillus flavus group was much more prevalent in peanut and rice than in cottonseed an ... | 1973 | 4197766 |
| [applications of molecular biology techniques for the control of aflatoxin contamination]. | aflatoxins are mycotoxins produced by species of aspergillus flavus group. these toxins have received increased attention from the food industry and the general public because they shown a high toxicity against humans and animal. different methods are applying to control the aflatoxin contamination. but these conventional methods do not seem to resolve the problem. so, new methods using techniques in biotechnology are now being developed: a) inhibit the biosynthetic and secretory process respons ... | 1993 | 8484919 |
| considerations on the distribution of aflatoxigenic aspergillus flavus in feeds. | the distribution of aflatoxin producing isolates of the aspergillus flavus group in feeds was studied. aflatoxin production was investigated by a sequential method previously reported (fluorescence in coconut agar medium, rapid extraction from a wheat medium, and total extraction from the same wheat medium). twenty-seven of 32 samples contained a. flavus, and 21 of them had at least one aflatoxicogenic isolate of a. flavus. of the 115 isolates analysed, 65 produced aflatoxins, mainly b aflatoxin ... | 1988 | 3148863 |
| invertase production of common storage moulds in food and feed grains as a possibility for rapid detection of aspergillus flavus group and aspergillus fumigatus. | invertase production of grain storage moulds was studied. aspergillus spp. and penicillium spp. were grown in a sucrose based liquid medium, at 37 degrees c. the a. flavus group (a. flavus, a. parasiticus, a. nomius, a. oryzae) and a. fumigatus showed a fast growth and intense invertase activity, while other aspergillus spp. and penicillium spp. grew slower and produced less invertase. the pattern of accumulated reducing sugar after 20 and 48 h of incubation was characteristic to the species stu ... | 2000 | 11078169 |
| comparison of some screening methods for aflatoxigenic moulds. | thirty seven strains of the aspergillus flavus group isolated from animal mixed feeds have been screened for their ability to produce aflatoxins in yeast extract and sucrose (yes), aflatoxin producing ability (apa), and coconut agar medium (cam) media. the concentration and detection of the aflatoxins by different methods is compared. five known aflatoxin-positive and one aflatoxin-negative strains have been used as controls. only 5 out of the 37 strains (13.5%) were aflatoxin-producers in yes m ... | 1988 | 3146701 |
| aflatoxin-producing potential of aspergillus flavus strains isolated from spanish poultry feeds. | a total of 126 fungal strains belonging to the aspergillus flavus group isolated from commercial poultry mixed feeds were studied. one hundred and twenty-five were identified as a. flavus and one as a. parasiticus. forty nine strains (39%) produced aflatoxins on a crushed moist wheat medium (28 degrees c/10 days), whereas only sixteen (13%) showed specific fluorescence on aflatoxin-producing ability medium. in both media, mainly aflatoxins b1 and b2 were detected, the average concentration of af ... | 1986 | 3095643 |
| analytical methods for aflatoxins in corn and peanuts. | aflatoxin determinations can be approached many ways. peanuts and corn are more often contaminated with aflatoxins b1 and b2 than with aflatoxins b1, b2, g1, and g2. some countries are only interested in b1 content and others are interested in the total aflatoxin content. it is essential to safely handle all experimental materials associated with aflatoxin analyses or the aflatoxigenic fungi. visual screening of suspect peanut lots, based on the presence of conidial heads of the aspergillus flav ... | 1989 | 2730149 |
| polymerase chain reaction-mediated characterization of molds belonging to the aspergillus flavus group and detection of aspergillus parasiticus in peanut kernels by a multiplex polymerase chain reaction. | the aspergillus flavus group covers species of a. flavus and aspergillus parasiticus as aflatoxin producers and aspergillus oryzae and aspergillus sojae as koji molds. genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. therefore, a polymerase chain reaction (pcr)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic pr ... | 2002 | 12030297 |
| the occurrence of aflatoxins in mustard and mustard products. | natural occurrence of aflatoxins at concentrations of 750, 87 and 1420 micrograms/kg was recorded in 44, 33 and 80 samples out of 100 samples each of seeds, oil and cakes of mustard respectively. out of 17 species of fungi isolated from mustard seeds, percentage incidence of the aspergillus flavus group was maximum during monsoon and summer. twenty-five per cent of isolates (out of 1143 isolates screened) of the a. flavus group were toxigenic, producing different components of aflatoxins in vary ... | 1990 | 2118457 |
| natural occurrence of toxigenic fungi and mycotoxins in rice bran. | thirty four samples of rice bran, of which 9 were from raw (untreated) rice (rr) and 25 from parboiled rice (pbr) were collected from commercial rice mills in and around madras and analysed for storage mycoflora and mycotoxins. fungi of the aspergillus flavus group were present in 29 of the 34 samples (8 from rr and 21 from pbr) in quantities ranging from less than 1-432 thousand propagules/g, though not always as the dominant mycoflora. fungal numbers were usually higher in rr than in pbr sampl ... | 1990 | 2114545 |
| use of nuclear dna restriction fragment length polymorphisms to analyze the diversity of the aspergillus flavus group: a. flavus, a. parasiticus, and a. nomius. | recombinant dna clones carrying high-copy or low-copy sequences from aspergillus nidulans and neurospora crassa were used to identify restriction fragment length polymorphisms (rflps) diagnostic for members of the a. flavus group: a. flavus, a. parasiticus, and a. nomius. these fungi were resolved into three distinct categories when they were grouped according to rflp patterns. subgroups within these categories were also evident. this limited rflp analysis of nuclear dna of members of the a. fla ... | 1990 | 1976300 |
| restriction enzyme analysis of mitochondrial dna of the aspergillus flavus group: a. flavus, a. parasiticus, and a. nomius. | mitochondrial dna restriction fragment length polymorphisms were identified that clearly distinguish aspergillus flavus, a. parasiticus, and a. nomius. mitochondrial dnas of a. flavus and a. parasiticus were found to be circular, and their size was estimated size to be 32 kilobases. a restriction map was constructed for the mitochondrial genome of an a. parasiticus isolate by using four restriction endonucleases. four genes tested were found to have the same order as in the mitochondrial genome ... | 1990 | 1976299 |
| transformation of sterigmatocystin and o-methylsterigmatocystin by aflatoxigenic and nonaflatoxigenic field isolates of the aspergillus flavus group. | transformation of sterigmatocystin and o-methylsterigmatocystin (two metabolic aflatoxin precursors) to aflatoxins by aflatoxigenic and nonaflatoxigenic field isolates of aspergillus flavus was studied. the 24 nonaflatoxigenic isolates investigated failed to transform both precursors. among the 8 aflatoxin-producing isolated used, 7 transformed both precursors whereas the remaining failed to transform both. according to these results, the usefulness of the measurement of enzymatic activities rel ... | 1991 | 1780000 |
| effects of aflatoxin on lymphoid cells of weanling rat. | aflatoxin (af), the hepatocarcinogenic food contaminant produced by the aspergillus flavus group of fungi, is known to interact with various vital processes, including the immune function. effects of long-term treatment of three dose levels of aflatoxin b1 (afb1) on lymphoid cells of weanling rats were studied. afb1 treatment caused a reduction in body weight gain, significantly (p less than 0.01) at the 700 microgram level. there was also a significant decrease in the weight of spleen and thymu ... | 1990 | 1697302 |
| a study on the isolation of aflatoxin-producing strains from agricultural products in korea. | in order to isolate aflatoxin-producing strains from agricultural products in the youngnam district of korea, rice, barley, unhulled barley, corn, soybean, meju (soybean paste), peanut, and soil samples were collected from markets or homes. from the 347 samples, 280 strains of aspergillus spp. were isolated. as a result of screening by thin layer chromatography (tlc), 29 strains showed fluorescent spot and four strains had the same rf values as those of standard aflatoxins. the percentage of con ... | 1992 | 1345443 |
| [invasive nasosinusal aspergillosis in an immunocompetent patient]. | the authors describe a case of invasive nasosinusal aspergillosis in an immunocompetent patient. after a careful bibliographic review, they emphasize that in the present case the diagnosis was made by means of fungal culture as the clinical picture, imaging techniques and histopathological findings were aspecific. the pathogenetic agent resulted aspergillus tamarii which belongs to the aspergillus flavus group and is one of the most unusual agents in literature. the treatment of choice, in the i ... | 1992 | 1307449 |
| evaluation of aspergillus differential medium. | the new aspergillus differential medium distinguishes effectively between members of the aspergillus flavus group and other aspergillus species of interest in medical mycology. | 1975 | 1225931 |
| [toxicogenic power of aspergillus flavus group strains]. | | 1977 | 418718 |
| [use of cell cultures and chick embryos for evaluating the toxicity of the aspergillus flavus group isolated from food products]. | | 1978 | 416994 |
| [effect of sterigmatocystin on the toxinogenesis of the aspergillus flavus group]. | the aflatoxinogenesis of aspergillus parasiticus is significantly enhanced by the presence, in the medium, of sterigmatocystin at a high level (35--50 microgram/ml); low concentrations, in the order of 175 microgram/ml, have no effect on the production of aflatoxins. during the period where the aflatoxinogenesis of the culture is high, no variation of the sterigmatocystin level is noted, experiments with 14c-sterigmatocystin indicate that the mold does not utilize the metabolite itself as a prec ... | 1979 | 119164 |
| regulation of aflatoxin biosynthesis. iii. comparative study of adenine nucleotide pool in aflatoxigenic and non-aflatoxigenic strains. | the adenine nucleotide pools were studied in toxigenic (nrrl 3240) and non-toxigenic (nrrl 3537) strains of aspergillus flavus group in relation to aflatoxin biosynthesis. the levels of adp and amp were comparatively low in the non-toxigenic strain throughout the growth period. in the toxigenic strain the levels of adp and amp increased significantly during the stationary phase. the atp content of the toxigencic strain had higher atp levels during the stationary phase compared to the toxigenic s ... | 1977 | 99643 |
| comparison of four media for the isolation of aspergillus flavus group fungi. | four agar media used to isolate aflatoxin producing fungi were compared for utility in isolating fungi in the aspergillus flavus group from agricultural soils collected in 15 fields and four states in the southern united states. the four media were aspergillus flavus and parasiticus agar (afpa, 14), the rose bengal agar described by bell and crawford (bcrb; 3), a modified rose bengal agar (m-rb), and czapek's-dox agar supplemented with the antibiotics in bc-rb (cz-rb). m-rb was the most useful f ... | 1994 | 8047107 |
| immunostimulating effects of protein a in immunosuppressed aflatoxin-intoxicated rats. | aflatoxin b1, the potent carcinogenic compound produced by the aspergillus flavus group of fungi on food and feed, induces immunosuppressive effects in rodents. in this communication, we report an immunomodulatory approach to abrogate aflatoxin b1-induced immunotoxicity in rats using protein a of staphylococcus aureus cowan 1. we have earlier demonstrated that protein a can protect the animals from toxicities induced by a number of drugs, chemicals and toxins. in the present study various combin ... | 1994 | 7705970 |
| aflatoxin-producing potential of aspergillus flavus and aspergillus parasiticus isolated from samples of smoked-dried meat. | over a period of three years 420 samples of various smoke-dried meat products, collected from individual households in different region of croatia were analysed for the presence of aflatoxigenic strains of the aspergillus flavus group. strains of a. flavus and a. parasiticus were present in 17.8% of the samples, and aflatoxin-producing ability was tested in 75 strains. in relation to sequential method of aflatoxin detection, 5 of 8 isolates were found in the first step (fluorescence in aflatoxin ... | 1995 | 7477245 |
| effects of soil moisture and temperature on preharvest invasion of peanuts by the aspergillus flavus group and subsequent aflatoxin development. | four soil temperature and moisture treatment regimens were imposed on florunner peanuts 94 days after planting in experimental plots in 1980. at harvest (145 days after planting), the incidence of the aspergillus flavus group and the aflatoxin concentration were greatest in damaged kernels. extensive colonization of sound mature kernels (smk) by the a. flavus group occurred with the drought stress treatment (56% kernels colonized); colonization was less in the irrigated plot (7%) and the drought ... | 1983 | 6402980 |
| investigation of reported aflatoxin production by fungi outside the aspergillus flavus group. | a screening study of 121 fungus isolates, representing 29 species, for aflatoxin synthesis demonstrated this property only in aspergillus flavus and a. parasiticus. eight of the organisms found negative were isolates reported by other investigators to produce aflatoxin. since similar negative reports have come from several other workers, it is concluded that only the a. flavus group of aspergillus can presently be certified as sources of these toxins. reasons for possible false-positive findings ... | 1968 | 5664105 |
| mycotoxigenic potential of aspergillus flavus strains isolated from groundnuts growing in israel. | two hundred strains of the aspergillus flavus group isolated from groundnuts (peanuts) growing in israel were examined for their ability to produce mycotoxins in potato dextrose (pd) broth. almost 77% of the isolates produced aflatoxin; aflatoxins b1 and b2 were formed by most of the isolates. simultaneous production of aflatoxins of groups b and g was detected in only 0.5% of the isolates. microscopic examination revealed that 98% of the isolates were a. flavus and only 2% a. parasiticus. cyclo ... | 1993 | 8413500 |
| taxonomic studies of the aflatoxin-producing strains in the aspergillus flavus group. | | 1970 | 5440999 |
| detection of aflatoxigenic molds in grains by pcr. | aflatoxins are carcinogenic metabolites produced by several members of the aspergillus flavus group in grains and floods. three genes, ver-1, omt-1, and apa-2, coding for key enzymes and a regulatory factor in aflatoxin biosynthesis, respectively, have been identified, and their dna sequences have been published. in the present study, three primer pairs, each complementing the coding portion of one of the genes, were generated. dna extracted from mycelia of five aspergillus species, four penicil ... | 1996 | 8795215 |
| evaluation of health aspects of kojic acid in food. | kojic acid is a fungal metabolite commonly produced by many species of aspergillus, acetobacter, and penicillium. the aspergillus flavus group has traditionally been used in the production of a number of foods, including miso (soybean paste), shoyu (soy sauce), and sake. kojic acid is widely used as a food additive for preventing enzymatic browning, and in cosmetic preparations as a skin-lightening or bleaching agent. because kojic acid is often produced during the fermentation of historically u ... | 2001 | 11259181 |
| progesterone side-chain degradation by some species of aspergillus flavus group. | seventy isolates belonging to 6 species and one variety of a. flavus group were shown to degrade the progesterone side-chain to yield delta 4-androstene-3,17-dione and testosterone. the isolates of five species (a. flavo-furcatis, a. flavus, a. oryzae, a. parasiticus and a. tamarii) possessed enzyme systems catalyzing the opening of ring d and formed testololactone as final steroid metabolite in addition to their ability to produce the above mentioned two products. 11 beta-hydroxy-delta 4-andros ... | 2000 | 11271808 |
| differentiation of aflatoxin-producing and non-producing strains of aspergillus flavus group. | aims: three conventional methods and a multiplex pcr procedure with a set of four primers (quadruplex-pcr) were used to differentiate between aflatoxin-producing and non-producing strains of the aspergillus flavus group. methods and results: by combining sets of primers for aflr, nor-1, ver-1 and omt-a genes of the aflatoxin biosynthetic pathway, quadruplex-pcr showed that aflatoxinogenic strains gave a quadruplet pattern, indicating the presence of all the genes involved in the aflatoxin biosyn ... | 2001 | 11559403 |
| development of a method for direct visual determination of aflatoxin production by colonies of the aspergillus flavus group. | this report describes a simple, rapid and reliable method for screening the aflatoxin production by moulds of the aspergillus flavus group. strains were cultivated on yeast extract agar to which methylated beta-cyclodextrin derivative plus sodium desoxycholate was added. production of aflatoxins was readily detectable by direct visualisation of a beige ring surrounding colonies after an incubation time of 3 days at 28 degrees c. when this ring was examined under uv light, it exhibited blue fluor ... | 2003 | 12706042 |
| a survey on distribution of aspergillus section flavi in corn field soils in iran: population patterns based on aflatoxins, cyclopiazonic acid and sclerotia production. | soil isolates of aspergillus section flavi from mazandaran and semnan provinces with totally different climatic conditions in iran were examined for aflatoxins (afs; b and g types), cyclopiazonic acid (cpa) and sclerotia production. a total of 66 aspergillus flavus group strains were identified from three species viz. aspergillus flavus, aspergillus parasiticus and aspergillus nomius in both locations. a. flavus (87.9%) was found to be the prominent species followed by a. nomius (9.1%) and a. pa ... | 2006 | 16482391 |
| systemic infection of stalks and ears of corn hybrids by aspergillus parasiticus. | this study was conducted to explore systemic infection by the aspergillus flavus group into corn ears via the stalk. an a. parasiticus mutant which produces norsolorinic (nor) acid (a visible orange intermediate of the aflatoxin biosynthetic pathway) was used in field studies to monitor systemic infection of corn stalk and ear tissues. corn hybrids resistant and susceptible to aflatoxin contamination were grown in the field and inoculated prior to tasseling by inserting a. parasiticus infested t ... | 2007 | 17763996 |
| relationship between meloidogyne arenaria and aflatoxin contamination in peanut. | damaged and developing kernels of peanut (arachis hypogaea) are susceptible to colonization by fungi in the aspergillus flavus group which, under certain conditions, produces aflatoxins prior to harvest. our objective was to determine whether infection of peanut roots and pods by meloidogyne arenaria increases aflatoxin contamination of the kernels when peanut is subjected to drought stress. the experiment was a completely randomized 2-x-2 factorial with 6 replicates/treatment. the treatment fac ... | 2004 | 19262803 |