Fungi and Mycotoxins in Feed Intended for Sows at Different Reproductive Stages in Argentina

The aim of this study was to evaluate fungi and contamination levels of aflatoxin B1, ochratoxin A, fumonisin B1, and zearalenone in raw materials and finished feed intended for sows at different reproductive stages. Total fungi, Aspergillus, Penicillium, and Fusarium species occurrence, were examined. Aspergillus flavus, A. niger aggregate spp., and F. verticillioides were the prevalent species. Fungal counts exceeded the levels proposed as feed hygienic quality limits (1 × 104 colony forming units) at all reproductive stages. Aflatoxin B1, ochratoxin A, fumonisin B1, and zearalenone were detected by high-pressure liquid chromatography. Aflatoxin levels in 80% samples of finished sow feeds were over the permitted levels of 0.02 μg g−1 (mean 228.2 ± 95 μg Kg−1). Fumonisin B1 was detected in all tested raw materials at levels that varied from 50.3 to 1137.64 μg Kg−1 and finished feed samples at levels that ranged from 99.8 to 512.4 μg Kg−1. Aflatoxin B1, zearalenone, and ochratoxin A were not detected in raw materials. All finished feeds were negative for zearalenone contamination whereas all nonpregnant gilt samples were contaminated with low OTA levels (mean 0.259 ± 0.123). 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

Resíduos de aflatoxina B1 em fígado de codornas japonesas (Coturnix japonica) expostas a alimentos contaminados e à corticosterona exógena

The combined effect of aflatoxin B1 (AFB1 ) exposition and stress induced by corticosterone (CORT) upon the residual aflatoxin levels in livers of Japanese quail was examined. A total of 144 Japanese quail (Coturnix japonica) were divided into 6 treatments with 6 replicates per treatment, each containing 2 males and 2 females. The different treatments resulted from the combination of the presence or absence of CORT in drinking water (5 mg/L) with the presence or absence of AFB1 supplementation (100 or 500 ng/g). Dietary treatments were offered from 5 to 11 weeks of age. The different diets were: Treatment (T) 1: basal diet (B) AFB1 (15 ng/g); T2: B plus AFB1 (100 ng/g); T3: B plus AFB1 (500 ng/g); T4: B plus CORT (5 mg/L); T5: B plus AFB1 (100 ng/g) and CORT (5 mg/L); and T6: B plus AFB1 (500 ng/g) and CORT (5 mg/L). The residual levels of AFB1 were remarkably higher in livers of birds fed with AFB1 in comparison with those belonging to the group that received a combination of AFB1 and CORT (P< 0.05). A plausible explanation about the facts that could be responsible for observed reduction in the toxin carryover in liver was suggested. These results are very striking and may constitute the start point for a series of studies that aim to elucidate the precise influence of hypothalamic-pituitary-adrenal axis (HPA) response to stress in birds exposed to AFB.Estudou-se o efeito combinado da exposição à aflatoxina B1 (AFB1 ) e o estresse induzido por corticosterona (CORT) sobre os níveis de residuais de AFB1 em fígados de codornas japonesas. Um total de 144 codornas japonesas (Coturnix japonica) foram divididas em 6 tratamentos com 6 repetições por tratamento, cada uma contendo 2 machos e 2 fêmeas. As dietas dos tratamentos foram oferecidas da 5ª até a 11ª semana de idade. Os diferentes tratamentos resultaram da combinação da presença ou ausência de CORT na água de beber (5 mg / L), com a presença ou ausência de suplementação AFB1 (100 ou 500 ng /g) As dietas diferentes foram: Tratamento (T) 1: dieta basal (B) AFB1 (15 ng/g); T2: B mais AFB1 (100 ng / g); T3: B mais AFB1 (500 ng / g); T4: B mais CORT (5 mg / L); T5: B mais AFB1 (100 ng / g) e CORT (5 mg / L), e T6: B mais AFB1 (500 ng / g) e CORT (5 mg / L). Os níveis residuais de AFB1 foram significativamente mais elevados em fígados de aves alimentadas com AFB1 em comparação com os que pertencem ao grupo que recebeu uma combinação de AFB1 e CORT (P< 0,05). Sugere-se uma possível explicação para a redução dos níveis da toxina observada naqueles animais submetidos a dieta com CORT. Estes resultados constituem-se de um ponto de início para uma série de estudos que visam a elucidar a influência da resposta do eixo hipotalâmico-hipofisário-adrenais (HPA) ao stress em aves expostas a AFB.Fil: Magnoli, Alejandra Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural de Rio de Janeiro; BrasilFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marin, Raul Hector. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Negligible effects of tryptophan on the aflatoxin adsorption of sodium bentonite

The main objective of this study was to determine if the competitive adsorption of tryptophan (Trp) and aflatoxin B1 (AFB1) could potentially affect the ability of a sodium bentonite (NaB) to prevent aflatoxicosis in monogastric animals. The adsorption of Trp and AFB1 on this adsorbent is fast and could be operating on the same time-scale making competition feasible. In vitro competitive adsorption experiments under simulated gastrointestinal conditions were performed. A high affinity of the clay for Trp and NaB was observed. The effect of an excess of KCl to mimic the ionic strength of the physiological conditions were also investigated. A six-times decrease in the Trp surface excess at saturation was observed. A similar behaviour was previously found for AFB1 adsorption. Taking into account the amount of Trp adsorbed by the clay and the usual adsorbent supplementation level in diets, a decrease in Trp bioavailability is not expected to occur. Tryptophan adsorption isotherms on NaB were ‘S’-shaped and were adjusted by the Frumkin–Fowler–Guggenheim model. The reversibility of the adsorption processes was investigated in order to check a potential decrease in the ability of NaB to protect birds against chronic aflatoxicoses. Adsorption processes were completely reversible for Trp, while almost irreversible for AFB1. In spite of the high affinity of the NaB for Trp, probably due to the reversible character of Trp adsorption, no changes in the AFB1 adsorption isotherm were observed when an excess of the amino acid was added to the adsorption medium. As a consequence of the preferential and irreversible AFB1 adsorption and the reversible weak binding of Trp to the NaB, no changes in the aflatoxin sorption ability of the clay are expected to occur in the gastrointestinal tract of birds.Fil: Magnoli, Alejandra Paola. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Copia, P.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Monge, Maria del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Magnoli, Carina Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Survey of Aspergillus section Flavi presence in agricultural soils and effect of glyphosate on nontoxigenic A. flavus growth on soil-based medium

Aims To evaluate the cultivable mycobiota from agricultural soils exposed to pesticides, the aflatoxigenic capacity of Aspergillus section Flavi strains and the effect of glyphosate on lag phase and growth rates of native nontoxigenic Aspergillus flavus under different water potential (MPa) conditions on soil-based medium. Methods and Results Culturable mycobiota analysis from different agricultural soils was performed by the surface spread method. The effect of glyphosate (0–20 mmol l−1) on the growth of A. flavus strains was evaluated on a soil extract solid medium. Mycobiota analysis of crop soils showed the presence of twenty-one genera of filamentous fungi. Aspergillus flavus and Aspergillus niger aggregate strains were isolated from the three soil types. Ninety-two per cent of A. flavus strains were toxigenic. In vitro assay results showed that at −0·70 MPa, a significant increase in growth rate in all strains was recorded at 5 and 20 mmol l−1 of glyphosate. At −2·78 MPa, this parameter remained constant at all glyphosate concentrations, except in GM4 strain where an increase in growth rate was recorded with increasing pesticide concentrations. At −7·06 MPa, a significant increase in growth rate has also been observed in GM 3 strain with 5 mmol l−1 and in GM 4 strain with 10 and 20 mmol l−1. Conclusions This study showed that the imperfecti fungi Aspergillus spp., Penicillium spp., Trichoderma spp., Cladosporium spp. and Paecilomyces spp. are isolated as prevalent groups in agricultural soil exposed to pesticides, and the capacity of nontoxigenic A. flavus strains to tolerate different glyphosate concentrations under different water potential (MPa) conditions. Significance and Impact of the Study This manuscript makes a contribution to the knowledge of cultivable fungal populations from agricultural soils exposed to pesticides and the glyphosate tolerance of A. flavus strains.Fil: Carranza, Cecilia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Bergesio, Maria Virginia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Barberis, Carla Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Chiacchiera, Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Magnoli, Carina Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentin

Efecto de la inactivación térmica sobre la estructura química de la pared celular de Pichia kudriavzevii

La incorporación de levaduras a la dieta de pollos parrilleros ha demostrado ser eficaz en la prevención de las aflatoxicosis por adsorción de AFB1 mediante su interacción con componentes de la pared celular. El espectro Infrarrojo de las levaduras es complejo como resultado de la contribución de los distintos componentes químicos presentes en las mismas. En particular, la técnica de DRIFT, solo permite evaluar las estructuras superficiales de la célula. Por lo que es importante recordar que la porción externa o pared celular está compuesta principalmente de mananoproteínas y β-glucanos (85- 90% de la masa seca de la pared celular) y una cantidad menor de quitina (1-3%) y lípidos (2-5%). Los espectros DRIFT de las levaduras evidenciaron la perdida de fosfolípidos y/o fosfatos inorgánicos en levaduras viables y el aumento relativo de los lípidos neutros en levaduras inactivas. Este último, correlacionado con el aumento en la intensidad de la banda asignada a los C=O. Del mismo modo, se observó la pérdida de agua ligada, responsable de la desaparición de la banda de adsorción intensa en el espectro infrarrojo. Se observó la pérdida de componentes proteicos evidenciados por el cambio en la estructura de los puentes H de las proteínas (se afecta la banda Amida I). Además, en ambos espectros se pudo apreciar las absorciones características de los estiramientos -O-H presente en los monosacáridos constituyentes de los β-glucanos. En conclusión, estos resultados son promisorios, debido a que, la inactivación térmica no genera la perdida de la capacidad de secuestrar la AFB1 de la levadura.Fil: Rodriguez, Marina Celeste. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: Monge, Maria del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: Magnoli, Alejandra Paola. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Instituto de Ciencias Veterinarias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Ciencias Veterinarias.; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaXXII Congreso Argentino de Fisicoquímica y Química InorgánicaLa PlataArgentinaUniversidad Nacional de La PlataAsociación Argentina de Investigación Fisicoquímic

Evaluation of the productive behavior of broiler chickens fed with yeast (Pichia kudriavzevii) alone and in combination with aflatoxin B1 and monensin

El objetivo de este trabajo fue evaluar la eficiencia in vivo de una cepa autóctona del medio ambiente aviar,Pichia kudriavzevii, para prevenir los efectos tóxicos de la aflatoxina B1 (AFB1) sola y en combinación con monensina (MON), sobre parámetros productivosen pollos parrilleros. Se utilizaron 120 pollos, 8 tratamientos, 3 réplicas, con 5 pollos por réplica (de un día de edad, Cobb). Las aves fueron alimentadas con una dieta iniciadora hasta el día 33 de edad. A partir de la dieta iniciadora se prepararon las diferentes dietas experimentales: tratamiento 1 (T1): dieta basal (DB); T2: dieta basal + monensina (50 mg/kg); T3: dieta basal + levadura (0,1%); T4: dieta basal + AFB1 (100 μg/kg); T5: dieta basal + monensina (50 mg/kg) + levadura (0,1%); T6: dieta basal + AFB1 (100 μg/kg) + levadura (0,1%); T7: dieta basal + AFB1 (100 μg/kg) + monensina (50 mg/kg) + levadura (0,1%); T8: dieta basal + AFB1 (100 μg/kg) + monensina (50 mg/kg). Los resultados obtenidos de los parámetros productivos evaluados (ganancia media diaria (GMD), consumo medio diario (CMD) e índice de conversión (IC)) demostraron que la adición de la levadura mejoró significativamente la GMD y CMD, mientras que el IC no mostró diferencias significativas (p<0,05). Además, no se observaron diferencias significativas entre los tratamientos (p<0,05) para el peso de carcasa, pata muslo, pechuga, órganos inmunológicos y parámetros bioquímicos. Este estudio permitió concluir que Pichia kudriavzevii no presentó un efecto tóxico en las aves, demostrando además que su eficiencia para adsorber aflatoxina B1 no fue afectada por la presencia de monensina.The aim of this work was to evaluate in vivo the efficiency of an autochthonous strain from the avian environment, Pichia kudriavzevii, to prevent the toxic effects of aflatoxin B1 (AFB1) alone and in combination with monensin (MON) on productive parameters in broiler chickens. Chikens (120) were used, 8 treatments, 3 replicas, with 5 chickens per replica (one-day-old, Cobb). The birds were fed with a starter diet until 33 days of age. Different experimental diets were prepared: treatment 1 (T1): basal diet (DB); T2: basal diet + monensin (50 mg/kg); T3: basal diet + yeast (0.1%); T4: basal diet + AFB1 (100 μg/kg); T5: basal diet + monensin (50 mg/kg) + yeast (0.1%); T6: basal diet + AFB1 (100 μg/kg) + yeast (0.1%); T7: basal diet + AFB1 (100 μg/kg) + monensin (50 mg/kg) + yeast (0.1%); T8: basal diet + AFB1 (100 μg/kg) + monensin (50 mg/kg). The average daily gain (GMD), the average daily consumption (CMD) and the conversion index (CI) were the productive parameters evaluated. These parameters showed that P. kudriavzevii addition significantly improved GMD and CMD, whereas IC did not show significant differences (p<0.05). Moreover, non-significant differences were observed among treatments (p<0.05) for the carcass weight, leg, breast, immunological organs and the biochemical parameters. In conclusion, P. kudriavzevii did not show toxic effects in broilers, in addition, the efficiency of this yeast to adsorb aflatoxin B1 was not affected by the presence of monensin.Fil: Magnoli, Alejandra Paola. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Reproducción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Poloni, Valeria Lorena. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Gonzalez Pereyra, Maria Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Pereyra, Carina Maricel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Gliotoxin contamination in and pre- and postfermented corn, sorghum and wet brewer's grains silage in Sao Paulo and Rio de Janeiro State, Brazil

The aim of this study was to determine total fungal counts and the relative density of Aspergillus fumigatus and related species in silage samples intended for bovines before and after fermentation as well as to monitor the natural occurrence of gliotoxin in silage samples (pre- and postfermentation). Methods and methods: The survey was performed in farms located in São Paulo and Rio de Janeiro States in Brazil. In addition, the ability of A. fumigatus strains and related species strains to produce gliotoxin was also evaluated. A total of 300 samples were taken, immediately after opening of the silo (3-5 months) and during the ensiling period. Fungal counts were done by the surface-spread method. Gliotoxin production ability of isolates and natural contamination were determined by HPLC. Results: All postfermented samples had a total number of moulds exceeding 1 × 10 4 CFU g -1, with Aspergillus sp. as the most prevalent genus. Frequency of strains, among A. fumigatus and related species, was able to produce gliotoxin was similar in pre- and postfermented samples, except for sorghum, which showed differences between both kinds of samples. The highest toxin levels were produced by strains isolated from postfermented samples. More than 50% of the samples showed gliotoxin contamination levels that exceeded concentrations known to induce immunosuppressive and apoptotic effects in cells. Conclusions: The present data suggest that care should be taken because gliotoxin contamination in feedstuffs could affect productivity and also present a health risk for herds. Significance and Impact of the Study: Gliotoxin was found at quite important concentrations levels in pre- and postfermented substrates and its presence could therefore probably affect the productivity and health of herds. Current conservation and management practices do not avoid contamination with A. fumigatus on silage. Therefore, farm workers should be adequately protected during its handling. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.Fil: Keller, Luiz Antonio Moura. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Keller, Kelly Moura. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Monge, Maria del Pilar. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: Pereyra, Carina Maricel. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: R Rosa, C. A.. Universidade Federal Rural do Rio de Janeiro; Brasi

Sodium bentonite and monensin under chronic aflatoxicosis in broiler chickens

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 B1 (AFB1). In vitro studies demonstrated that the above Na-B was a good candidate to prevent aflatoxicosis. They also showed that MON competes with AFB1 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 AFB1. An in vivo experiment carried out with poultry showed that 100 μg/kg of AFB1 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 AFB1 binding ability of a given bentonite. © 2011 Poultry Science Association Inc.Fil: Magnoli, Alejandra Paola. Universidad Nacional de Rio Cuarto. Facultad de Agronomia y Veterinaria. Instituto de Ciencias Veterinarias. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Instituto de Ciencias Veterinarias.; ArgentinaFil: Texeira González, Marcos Alexis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Rosa, Carlos Alberto da Rocha. Universidade Federal Rural do Rio de Janeiro; BrasilFil: Miazzo, Raul Daniel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Animal; ArgentinaFil: Cavaglieri, Lilia Reneé. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Magnoli, Carina Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; ArgentinaFil: Dalcero, Ana Maria. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigación en Micología y Micotoxicología. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación en Micología y Micotoxicología; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentin

Influence of the pesticides glyphosate, chlorpyrifos and atrazine on growth parameters of nonochratoxigenic Aspergillus section Nigri strains isolated from agricultural soils

This investigation was undertake to determine the effect of glyphosate, chlorpyrifos and atrazine on the lag phase and growth rate of nonochratoxigenic A. niger aggregate strains growing on soil extract medium at −0.70, −2.78 and −7.06 MPa. Under certain conditions, the glyphosate concentrations used significantly increased micelial growth as compared to control. An increase of about 30% was observed for strain AN 251 using 5 and 20 mg L−1 of glyphosate at −2.78 MPa. The strains behaved differently in the presence of the insecticide chlorpyrifos. A significant decrease in growth rate, compared to control, was observed for all strains except AN 251 at −2.78 MPa with 5 mg L−1. This strain showed a significant increase in growth rate. With regard to atrazine, significant differences were observed only under some conditions compared to control. An increase in growth rate was observed for strain AN 251 at −2.78 MPa with 5 and 10 mg L−1 of atrazine. By comparison, a reduction of 25% in growth rate was observed at −7.06 MPa and higher atrazine concentrations. This study shows that glyphosate, chlorpyrifos and atrazine affect the growth parameters of nonochratoxigenic A. niger aggregate strains under in vitro conditions.Fil: Carranza, Cecilia Soledad. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barberis, Carla Lorena. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chiacchiera, Stella Maris. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Magnoli, Carina Elizabeth. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin