A M Dalcero

Universidad Nacional de Río Cuarto, Río Cuarto, Provincia de Cordoba, Argentina

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Publications (38)61.67 Total impact

  • Article: Effect of monogastric and ruminant gastrointestinal conditions on in vitro aflatoxin B1 adsorption ability by a montmorillonite.
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    ABSTRACT: The main objective of this study was to evaluate the interference of environment components on the in vitro evaluation of aflatoxin B1 adsorption capacity of sodium bentonite under simulated gastrointestinal conditions of monogastric and ruminant animals. Sodium bentonite showed a high aflatoxin B1 affinity with all of the assays. Langmuir or sigmoid isotherms were found in different assays. Both the affinities and the surface excesses at monolayer saturation were affected by the buffer components. The specific influence of ions in each buffer solution was investigated. A significant decrease in the surface excess at monolayer saturation was observed under ionic strength control. A change in the isotherm shape from sigmoidal to Langmuir was observed with the increase in the sodium chloride concentration. This was attributed to the decrease in the importance of lateral interaction between adsorbed toxin molecules compared with surface-molecules interactions under a high salt coverage. The presence of rumen fluid components in the adsorption environment decreased the aflatoxin B1 maximum adsorption capacity of sodium bentonite. Despite the high affinity of this adsorbent to capture aflatoxin B1, different substances present in the environment could affect the adsorption capacity, at least at low toxin concentrations that mimic chronic exposure. The environment of the gastrointestinal tract, in either monogastric or ruminant animals, affect in vivo aflatoxin B1 adsorption by sodium bentonite and should be taken into account when an in vitro performance evaluation is done.
    Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 04/2013;
  • Article: Fungi and mycotoxins in silage: an overview.
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    ABSTRACT: The present revision shows the early and current knowledge in the field of silage fungi and mycotoxins explaining the relevance of fungi and mycotoxins in silage. The problem does not end in animal disease or production losses since mycotoxins in feed can lead to the presence of their metabolic products in dairy products which will be eventually affecting human health, mainly infants. Silage is green forage preserved by lactic fermentation under anaerobic conditions. This ecosystem maintains its quality and nutritional value depending on interactions among physical, chemical and biological agents. Forages used for ensilage are naturally in contact with yeasts and filamentous fungi and the contamination often occurs in the field and can also occur during harvesting, transport, storage. Moreover, post harvest poor management can lead to a rapid spoilage. Studies on fungal contamination of dairy cattle feed have shown how corn silage influences the contamination degree of feed supplied to livestock. Increasing knowledge in this area will help elucidate the influence that this microbiota exerts on production and/or degradation of mycotoxins present in silage. Some of these fungi, although opportunist pathogens, are relevant epidemiologically; and represent a high risk of contamination to farm workers who handle them improperly. © 2013 The Authors Journal of Applied Microbiology © 2013 The Society for Applied Microbiology.
    Journal of Applied Microbiology 02/2013; · 2.34 Impact Factor
  • Article: Statistical optimization of culture conditions for biomass production of probiotic gut-borne Saccharomyces cerevisiae strain able to reduce fumonisin B(1).
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    ABSTRACT: AIM: to evaluate the ability of probiotic Saccharomyces cerevisiae RC016 strain to reduce fumonisin B(1) (FB(1) ) in vitro and to optimize the culture conditions for the growth of the yeast employing surface response methodology. METHODS AND RESULTS: Using Plackett-Burman screening designs (PBSD) and central composite designs (CCD), an optimized culture medium containing (g l(-1) ): fermentable sugars provided by sugar cane molasses (CMs), yeast extract (YE) and (NH(4) )(2) HPO(4) (DAP) was formulated. The S. cerevisiae RC016 strain showed the greatest binding at all assayed FB(1) concentration. The CMs, YE, DAP concentrations and incubation time influenced significantly the biomass of S. cerevisiae RC016. CONCLUSION: A combination of CMs 17%; YE 4.61 g L(-1) and incubation time 60 h was optimum for maximum biomass of S. cerevisiae RC016. © 2013 The Authors Journal of Applied Microbiology © 2013 The Society for AppliedMicrobiology.
    Journal of Applied Microbiology 01/2013; · 2.34 Impact Factor
  • Article: In vitro study on the effect of Saccharomyces cerevisiae strains on growth and mycotoxin production by Aspergillus carbonarius and Fusarium graminearum.
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    ABSTRACT: The effect of Saccharomyces cerevisiae RC008 and RC016 strains, previously selected based on their aflatoxin B(1) mycotoxin binding ability and beneficial properties, against Aspergillus carbonarius and Fusarium graminearum under different interacting environmental conditions was evaluated. In vitro studies on the lag phase, growth rate and ochratoxin A/zearalenone and DON production were carried out under different regimens of a(w) (0.95 and 0.99); pH (4 and 6); temperature (25 and 37°C) and oxygen availability (normal and reduced). Both yeast strains showed antagonistic activity and decreasing growth rate compared to the control. In general, the RC016 strain showed the greatest inhibitory activity. Except at the interacting condition 0.95 a(W), normal oxygen availability and 37°C, at both pH values, A. carbonarius and F. graminearum were able to produce large amounts of mycotoxins in vitro. In general, a significant decrease in levels of mycotoxins in comparison with the control was observed. S. cerevisiae RC008 and RC016 could be considered as effective agents to reduce growth and OTA, ZEA and DON production at different interacting environmental conditions, related to those found in stored feedstuff. The beneficial and biocontrol properties of these strains are important in their use as novel additives for the control of mycotoxigenic fungi in stored feedstuffs.
    International journal of food microbiology 11/2012; 161(3):182-188. · 3.01 Impact Factor
  • Article: Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B1 production at different interacting environmental conditions, in vitro.
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    ABSTRACT: The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B(1) binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B(1) production were carried out in vitro under different regimes of a (w) (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB(1) in vitro. A significant decrease of AFB(1) levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400 ng ml(-1). S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB(1) production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.
    Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 07/2012; 29(9):1443-9.
  • Article: Combined effects of aflatoxin B1 and corticosterone treatment on selected performance indices and liver histopathology in Japanese quail.
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    ABSTRACT: Animal feed may be contaminated with different mycotoxins, with aflatoxin B(1) (AFB(1)) being a very common and toxic compound. Considering that birds normally have to cope with different stressful situations at the same time, the present study aims to evaluate the effects of feed contamination with AFB(1) in combination with corticosterone treatment in drinking water (a model to induce physiological stress in birds) on selected performance indices: BW, feed conversion, egg production, and macroscopic and microscopic liver alterations. At 5 wk of age, quails were randomly assigned to 1 of 6 dietary treatment groups that resulted from the combination of the presence or absence of corticosterone in drinking water (5 mg/L) with the presence or absence of AFB(1) contamination (0, 100, or 500 μg/kg). The animals remained in these treatments from 5 to 11 wk of age. There were 6 replicates per treatment, each containing 2 males and 2 females. Contamination with 100 μg of AFB(1) per kilogram of feed induced no changes in BW, feed conversion, and egg production parameters. Quail fed with 500 μg of AFB(1) per kilogram of feed showed significant decreases in BW and feed consumption compared with their control counterparts. Corticosterone in combination with 500 μg of AFB(1) per kilogram of feed intensified the negative effects observed on BW and feed consumption and also had negative effects on feed conversion rate and egg production parameters, suggesting that the adverse effects of contamination with AFB(1) are intensified in situations of chronic stress. Quail treated with 500 µg of AFB(1) per kilogram showed hepatocytes with degree 1 and 2 lesions, and all quail treated with 500 µg of AFB(1) per kilogram of feed in combination with corticosterone showed degree 2 liver lesions (i.e., hepatocytes with fatty macro and microvacuoles and necrosis). This result is also consistent with the hypothesis that chronic stress exacerbates the effect of AFB(1) contamination. In conclusion, this study suggests that the negative effects of AFB(1) contamination are increased when overlapped with chronic stressful stimulation.
    Poultry Science 02/2012; 91(2):354-61. · 1.73 Impact Factor
  • Article: Effect of feed contamination with aflatoxin B1 and administration of exogenous corticosterone on Japanese quail biochemical and immunological parameters.
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    ABSTRACT: Stress is the loss of homeostasis by external forces or stressors. Manipulation, transport, contamination, and other procedures involved in production could be considered stressors. Contamination is a problem commonly faced by producers in the poultry industry. Aflatoxicosis is one of the most common infections resulting from feed contaminated with Aspergillus flavus and Aspergillus parasiticus. This study evaluated the potential effects of the combined administration of aflatoxin B(1) (AFB(1)) and corticosterone on biochemical (concentration of globulins, proteins, and albumin) and immunological (inflammatory response and heterophil:lymphocyte ratio) parameters of Japanese quail. Potential sex effects on those parameters were also considered. The provision of corticosterone in drinking water is a method used for mimicking the effects of chronic stress in avian species. At 35 d of age, 24 mixed-sex groups of 4 animals (2 males and 2 females) were housed in cages and assigned to 1 of 4 treatments: plain drinking water and laying diet, corticosterone administration in drinking water, feed contamination with AFB(1) (100 μg/kg of feed), or corticosterone plus AFB(1) administration. There were 6 cages per treatment. No significant effect of sex in any of the parameters analyzed was detected. Hypoproteinemia, hypoalbuminemia, and hypoglobulinemia were observed in animals treated with corticosterone or contaminated feed. These responses were exacerbated when the factors were combined. The immunodepressive effect of corticosterone administration was confirmed, and a higher effect was noticed when combined with the aflatoxin contamination. Aflatoxin contamination affected birds' physiology similar to a chronic stressor stimulation because it elevates the heterophil:lymphocyte ratio. This study suggests that the effects of the AFB(1) contamination are further increased when overlapped with a chronic stressful stimulation and emphasizes the importance of controlling potential stressor combinations during animal rearing to preserve not only the animal's health status but also their welfare.
    Poultry Science 01/2012; 91(1):47-54. · 1.73 Impact Factor
  • Article: Sodium bentonite and monensin under chronic aflatoxicosis in broiler chickens.
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    ABSTRACT: Clay feed additives have been increasingly incorporated into animal diets to prevent aflatoxicosis. Due to the nonselective nature of the binding interaction, many important components of the diets could also be made unavailable because of these feed additives. The anticoccidial monensin (MON) could also be sequestered by these clays. The use of sodium bentonite (Na-B) from a mine in the province of Mendoza, Argentina, was investigated as a sequestering agent to prevent the effects of 100 µg/kg of dietary aflatoxin B(1) (AFB(1)). In vitro studies demonstrated that the above Na-B was a good candidate to prevent aflatoxicosis. They also showed that MON competes with AFB(1) for the adsorption sites on the clay surface and effectively displaces the toxin when it is in low concentration. Even though the levels of MON in diets, approximately 55 mg/kg, are high enough to not be significantly changed as a consequence of the adsorption, they can further affect the ability of the clays to bind low levels of AFB(1). An in vivo experiment carried out with poultry showed that 100 µg/kg of AFB(1) does not significantly change productive or biochemical parameters. However, liver histopathology not only confirmed the ability of this particular Na-B to prevent aflatoxicosis but also the decrease of this capacity in the presence of 55 mg/kg of MON. This is the first report stressing this fact and further research should be performed to check if this behavior is a characteristic of the assayed Na-B or of this type of clay. On the other hand, the presence of MON should also be taken into account when assaying the potential AFB(1) binding ability of a given bentonite.
    Poultry Science 02/2011; 90(2):352-7. · 1.73 Impact Factor
  • Article: A survey on distribution and toxigenicity of Aspergillus section Flavi in poultry feeds.
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    ABSTRACT: Thirty-five samples of poultry feeds and corresponding raw materials (maize, soybean and meat meal) from a processing plant were analyzed to evaluate the distribution and toxigenicity of Aspergillus section Flavi isolates. Mycological analysis of the samples indicated the presence of five fungal genera (Aspergillus, Penicillium, Fusarium, Cladosporium, and Eurotium). Aspergillus flavus was the predominant species being present in 48.5% of the analyzed samples. Ninety-one isolates belonging to Aspergillus section Flavi were isolated; ninety were identified as A. flavus and only one as A. parasiticus. Fifty-seven isolates were capable of producing sclerotia, 41 were identified as L-type strains and 16 as type S. Fifty-seven percent of the isolates produced AFB₁ levels ranging from 0.05 μg/kg to 27.7 μg/kg whereas 86.8% produced CPA from 1.5 μg/kg to 137.8 μg/kg. L-strains produced from 0.05 to 14.8 μg/kg of aflatoxin and type S produced levels from 0.05 to 1.65 μg/kg. No significant differences in CPA production among S- and L-strains were observed. Sclerotial isolates produced AFB₁ levels ranging between 0.05 and 27.7 μg/kg and CPA levels from 3.8 to 47.3 μg/kg. More than half of the A. flavus isolates were able to produce AFB and CPA simultaneously. Twenty percent of the 35 samples were contaminated with aflatoxin B₁ whereas 34.3% were contaminated with CPA. The high rate of CPA producing isolates represents a potential risk of contamination with this toxin in poultry feeds.
    International journal of food microbiology 01/2011; 146(1):38-43. · 3.01 Impact Factor
  • Article: Effect of low levels of aflatoxin B₁ on performance, biochemical parameters, and aflatoxin B₁ in broiler liver tissues in the presence of monensin and sodium bentonite.
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    ABSTRACT: Aflatoxins (AF) are a major problem in broiler production and are significant economic and public health burdens worldwide. A commercial sodium bentonite (Na-B) adsorbent was used to prevent the effect of AF [50 µg of aflatoxin B₁ (AFB₁)/kg of feed] in broiler productivity, biochemical parameters, macroscopic and microscopic liver changes, and AFB₁ liver residues. The influence of Na-B (0.3%) and monensin (MON, 100 mg/kg), alone or in combination, was investigated in depth. The dietary treatments were as follows: treatment (T) 1: basal diet (B); T2: B + MON; T3: B + Na-B; T4: B + Na-B + MON; T5: B + AFB₁; T6: B + AFB₁ + Na-B + MON; T7: B + AFB₁ + MON; T8: B + AFB₁ + Na-B. Birds were fed dietary treatments for 28 d (d 18 to 46). No significant differences (P < 0.05) were observed among treatments with respect to broiler performance, biochemical parameters, or relative liver weights. With the exception of T8, all livers showed histopathological alterations, with accumulation of fat vacuoles. The normal appearance of livers from T8 showed the protective effect of Na-B against aflatoxicosis. The residual AFB₁ levels in livers from T5 to T8 ranged from 0.2 to 1.0 ng/g and were higher in livers from T6 (P < 0.05). Results of this study indicate a competition between AFB₁ and MON for adsorption sites on Na-B when feed contains low levels of the toxin, indicating a nonselective adsorption capacity of this particular Na-B. In addition, significant levels of AFB₁ in livers indicate that this determination is an important technique not only for diagnosis of aflatoxicosis in broilers, but also for quality control of avian products.
    Poultry Science 01/2011; 90(1):48-58. · 1.73 Impact Factor
  • Article: Food-grade antioxidants and antimicrobials to control growth and ochratoxin a production by Aspergillus section Nigri on peanut kernels.
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    ABSTRACT: Each year, a significant portion of the peanuts produced cannot be marketed because of fungal disease at the postharvest stage and mycotoxin contamination. Antioxidants could be used as an alternative to fungicides to control ochratoxigenic fungi in peanuts during storage. This study was carried out to determine the effect of the antioxidant butylated hydroxyanisole (BHA) and the antimicrobial propyl paraben (PP) on the lag phase before growth, growth rate, and ochratoxin A (OTA) production by Aspergillus section Nigri strains in peanut kernels under different conditions of water activity (aw) and temperature. At 20 mM/g BHA, 18 degrees C, and 0.93 aw, complete inhibition of growth occurred. For PP, there was no growth at 20 mM/g, 18 degrees C, and 0.93, 0.95, and 0.98 aw. BHA at 20 mM/g inhibited OTA production in peanuts by Aspergillus carbonarius and Aspergillus niger aggregate strains at 0.93 aw and 18 degrees C. PP at 20 mM/g completely inhibited OTA production at 18 degrees C. The results of this work suggest that PP is more appropriate than BHA for controlling growth and OTA production by Aspergillus section Nigri species in peanut kernels.
    Journal of food protection 08/2010; 73(8):1493-501. · 1.94 Impact Factor
  • Article: Naturally occurring aflatoxin M(1) in raw bulk milk from farm cooling tanks in Argentina.
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    ABSTRACT: The aim was to carry out a survey of aflatoxin M(1) (AFM(1)) in raw whole milk from bulk tanks. The sample collection was performed in farms located in one the most important milk-production zones in the centre of Argentina. A total of 94 samples of milk from 47 dairy farms were analysed. AFM(1) analysis involved the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) with prior purification of the extracts using immunoaffinity columns. AFM(1) incidence in raw milk was high as 63.8% and levels were between not detected to 0.07 microg l(-1). Several contaminated samples (39%) were over the European Commission limit for infant milk (0.025 microg l(-1)), although none of samples were above Argentine legislation. Estimates of AFM(1) intake were assessed for different age populations. The average AFM(1) estimated daily intakes were 1.6, 0.5, 0.17 ng kg(-1) body weight day(-1) for 4-year-old babies, young children, and adults, respectively. All tested farms used pastures and silages at similar composition. Even though some farms (13) employed high-risk supplementary feeds, such as peanut pod and/or cotton seed, no statistically significant differences were observed between groups. Information from AFM(1) levels in milk in Argentina is limited. A systematic AFM(1) monitoring programme must be performed by means of accurate and reliable analytical techniques as a strategy for protecting milk consumers.
    Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment 03/2010; 27(3):373-9.
  • Article: Aspergillus fumigatus toxicity and gliotoxin levels in feedstuff for domestic animals and pets in Argentina
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    ABSTRACT: Aims:  To evaluate gliotoxin production by Aspergillus fumigatus strains isolated from feedstuff intended for domestic animals and pets, and to determine the amount of gliotoxin in these substrates.Methods and Results:  A total of 150 feedstuff samples were collected. They were composed of 30 samples each of five different feed types (pigs, poultry, cattle, horse and pets). Aspergillus fumigatus gliotoxin production ability and gliotoxin presence in feedstuff was determined by HPLC. Aspergillus fumigatus strains were isolated from all of the tested samples. Strains from cattle, horses and pet food were able to produce gliotoxin. Corn silage samples intended for cattle did not show gliotoxin contamination. All the other tested samples had gliotoxin levels ranging from 29 to 209 μg g−1. Horse and poultry feed samples had the greatest contamination frequency.Conclusions:  Feed samples contaminated with gliotoxin are potentially toxic to animals.Significance and Impact of the Study:  The presence of gliotoxin could affect animal productivity and health. Moreover, there are risks of contamination to farm workers handling improperly stored animal feed. Aspergillus fumigatus strains isolated from different sources should be investigated to determine prevention and control strategies.
    Letters in Applied Microbiology 12/2009; 50(1):77 - 81. · 1.62 Impact Factor
  • Article: Aspergillus fumigatus toxicity and gliotoxin levels in feedstuff for domestic animals and pets in Argentina.
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    ABSTRACT: To evaluate gliotoxin production by Aspergillus fumigatus strains isolated from feedstuff intended for domestic animals and pets, and to determine the amount of gliotoxin in these substrates. A total of 150 feedstuff samples were collected. They were composed of 30 samples each of five different feed types (pigs, poultry, cattle, horse and pets). Aspergillus fumigatus gliotoxin production ability and gliotoxin presence in feedstuff was determined by HPLC. Aspergillus fumigatus strains were isolated from all of the tested samples. Strains from cattle, horses and pet food were able to produce gliotoxin. Corn silage samples intended for cattle did not show gliotoxin contamination. All the other tested samples had gliotoxin levels ranging from 29 to 209 microg g(-1). Horse and poultry feed samples had the greatest contamination frequency. Feed samples contaminated with gliotoxin are potentially toxic to animals. The presence of gliotoxin could affect animal productivity and health. Moreover, there are risks of contamination to farm workers handling improperly stored animal feed. Aspergillus fumigatus strains isolated from different sources should be investigated to determine prevention and control strategies.
    Letters in Applied Microbiology 10/2009; 50(1):77-81. · 1.62 Impact Factor
  • Article: Mycological survey and ochratoxin A natural contamination of swine feedstuffs in Rio de Janeiro State, Brazil.
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    ABSTRACT: Mycotoxin contamination of animal feeds represents a hazard to human and animal health due to potential transmission to meat and milk. Barley by-products are alternative feeding supplies for animal production. The aims of this assay were to study the mycobiota of feedstuffs and finished swine feed, to determine the ability of Aspergillus and Penicillium isolates to produce ochratoxin A (OTA) and to evaluate OTA occurrence in these substrates. Corn, brewers' grains and finished swine feed samples were collected from different factories. Fungal counts were higher than 2.8x10(4)CFU g(-1). Fusarium, Aspergillus and Penicillium genera were isolated at high levels. A 23.7% of the isolates produced 9-116 microg kg(-1) of OTA in vitro. Corn samples (44%) were contaminated with 42-224 microg kg(-1) of OTA. Finished feed (31%) and brewers' grains samples (13%) were contaminated with 36-120 microg kg(-1) and 28-139 microg kg(-1) of OTA, respectively. This is the first scientific report on contamination by OTA-producer molds and OTA in swine feedstuffs from Brazil. The presence of OTA in raw materials and finished feed requires periodic monitoring to prevent mycotoxicoses in animal production, reduce economic losses and minimize hazards to human health.
    Toxicon 01/2009; 53(2):283-8. · 2.51 Impact Factor
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    Article: Mycobiota and aflatoxins in raw materials and pet food in Brazil.
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    ABSTRACT: Commercial feedstuffs are a basic element in modern pet husbandry in the world. In dogs, the effect of mycotoxins is severe and can lead to death. Few reports on the influence of dietary mycotoxins were found in the scientific literature. The aims of this work were to isolate and identify the mycoflora and to determine the aflatoxins (AFs) natural occurrence in raw materials and ready dry pet food. Therefore, the aflatoxigenic capacity of Aspergillus flavus species was investigated. Aspergillus was the prevalent genera (65-89%) followed by Penicillium and Fusarium spp. Aspergillus flavus was the most prevalent species, followed by Aspergillus sydowii, Aspergillus fumigatus and Aspergillus versicolor. Aspergillus flavus frequencies ranged from 58% to 86% except in sorghum meal. All samples assayed (except corn grains and ready pet food) showed Fusarium spp. contamination. Corn meal and corn meal and gluten samples had 100% Fusarium verticillioides. Fusarium graminearum was isolated from sorghum meal. Aspergillus flavus strains (75%) isolated from raw materials and 57% from pet food were able to produce AFs. All samples showed AFs contamination percentages over 70%; corn and sorghum meal obtained the highest AFs levels. Ready pet food did not show quantitative levels of the tested toxins. This is the first report of the aflatoxigenic capacity by A. flavus from Brazilian pet food.
    J Anim Physiol a Anim Nutr 07/2008; 92(3):377-83. · 0.86 Impact Factor
  • Article: Determination of mycobiota and mycotoxins in pig feed in central Argentina.
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    ABSTRACT: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home-corn grains intended for fattening pigs. Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin-layer chromatography and fumonisins by high-pressure liquid chromatography. Fungal counts were generally higher than 1 x 10(5) colony forming units (CFU) ml(-1). Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB(1) and FB(2) were detected in all feed and corn samples. Aflatoxin B(1) was detected in 33.33% of initial and growing feed and in 44.44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB(2), AFG(1), AFG(2) and ZEA presence during all growing stages tested. Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations. The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.
    Letters in Applied Microbiology 06/2008; 46(5):555-61. · 1.62 Impact Factor
  • Article: Fungi and selected mycotoxins from pre- and postfermented corn silage.
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    ABSTRACT: To determine fungal genera, Aspergillus and Fusarium species and aflatoxin B(1) (AFB(1)), zearalenone (ZEA), deoxynivalenol (DON), fumonisin B(1) (FB(1)) contamination from pre- and postfermented corn silage produced in the most important region of Argentina where silage practice is developed. Sampling of corn silos was performed manually through silos in transects at three levels: upper, middle and low sections. AFB(1) and FB(1) were quantified by high-performance liquid chromatography, zearalenone by enzyme-linked immunosorbent assay and DON by gas chromatography. Over 90% of the samples showed counts higher than 1 x 10(4) CFU g(-1). Aspergillus flavus and Fusarium verticillioides were the prevalent species. Some tested samples were contaminated with AFB(1), ZEA, DON and FB(1). This study demonstrates the presence of fungi and AFB(1), ZEA, DON and FB(1) contamination in corn silage in Argentina. This manuscript makes a contribution to the knowledge of mycotoxins in Argentinean silage in particular because the environmental conditions in this country differ from those of most reports. The comparison of pre- and postfermentation silage is also outstanding. Therefore, information on fungi and mycotoxins present in silage--an increasingly popular commodity--is useful to estimate potential risk for animal and human health.
    Journal of Applied Microbiology 05/2008; 104(4):1034-41. · 2.34 Impact Factor
  • Article: Determination of mycobiota and mycotoxins in pig feed in central Argentina
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    ABSTRACT: Aims: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home-corn grains intended for fattening pigs.Methods and Results: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin-layer chromatography and fumonisins by high-pressure liquid chromatography. Fungal counts were generally higher than 1 × 105 colony forming units (CFU) ml−1. Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB1 and FB2 were detected in all feed and corn samples. Aflatoxin B1 was detected in 33·33% of initial and growing feed and in 44·44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB2, AFG1, AFG2 and ZEA presence during all growing stages tested.Conclusions: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations.Significance and Impact of the Study: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.
    Letters in Applied Microbiology 03/2008; 46(5):555 - 561. · 1.62 Impact Factor
  • Article: The mycobiota and toxicity of equine feeds.
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    ABSTRACT: Feed contamination can lead to nutrient losses and detrimental effects on animal health and production. The purposes of this study were to investigate the mycobiota in equine mixed feeds and to determine natural contamination with aflatoxin B1 (AFB1) and fumonisin B1 (FB1). Fungal enumeration of equine feed samples was done. A commercially available enzyme-linked immunosorbent assay kit was applied to quantify AFB1 and FB1. A comparison between ELISA and HPLC was carried out. Feed mould counts ranged from <1 x 10(2) to 1 x 10(5) cfu/g. The most frequent genus isolated was Aspergillus (40.54%), followed by Penicillium (18.38%) and Fusarium (16.22%). The most prevalent Aspergillus sp. was A. flavus (36%). AFB1 values ranged between 0.01 and 99.4 microg/kg. FB(1) levels ranged between 0.01 and 7.49 microg/kg. HPLC and ELISA methods showed positive correlation for AFB1 and FB1 determinations (r = 0.9851 and r = 0.9791, respectively). The ELISA analytical method was efficient for AFB1 and FB1 detection. The scarcity of studies on natural fungal contamination and on the presence of AFB1 and FB1 in materials used as equine feed ingredients highlights the value and contribution of this study.
    Veterinary Research Communications 11/2007; 31(8):1037-45. · 0.82 Impact Factor

Institutions

  • 2004–2013
    • Universidad Nacional de Río Cuarto
      • • Departamento de Microbiología e Inmunología
      • • Departamento de Química
      Río Cuarto, Provincia de Cordoba, Argentina
  • 2008–2012
    • National Council of Scientific and Technical Research
      Buenos Aires, Buenos Aires F.D., Argentina
  • 2002–2009
    • Universidade Federal Rural do Rio de Janeiro (UFRRJ)
      • Departamento de Microbiologia e Imunologia Veterinária (DMIV)
      Rio de Janeiro, Rio de Janeiro, Brazil