Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 64-83).

Aspergillus flavusis a filamentous fungusthat causes an ear and kernel rot in maize (Zea mays L.). It produces a toxic secondary metabolite, aflatoxin, on the colonized maize kernels. Aflatoxin is a carcinogen to humans and animals. The toxin is also an immunosuppressant and causes aspergillosis in immune compromised individuals. Therefore, the presence of aflatoxin in food is strictly regulated by governmental agencies. Contaminated food leads to severe loss in profit and in marketable yield. There has been extensive research to investigate resistance of maize toA. flavus. Certain lines of maize exhibit increased resistance to A. flavus and aflatoxin accumulation compared to others and correlated with that are proteins and metabolites that differ in abundance in those lines. Among them are members of the cupin superfamily of proteins and products of special nitrogen metabolism (derived from glutamate). The goal here was to identify networks underlying disease resistance indifferent maize genotypes through the identification of protein-protein interactions and the analysis of transcript abundance profiles realting to cupins and glutamate. The outcome will be an understanding of host resistance to A. flavussufficient to develop methods to prevent pre-harvest contamination by aflatoxin. A protein abundant in resistant maize was identified as a cupin and named ZmCUP1. The cDNA isolation, expression in E. coliand characterization of the protein encoded by the mRNA, Zmcup1, lead to the discovery that the ZmCUP1 protein had anti fungal properties and oxalate decarboxylase activity (EC 4.1.1.2). Another part of the project aimed at understanding the involvement of a transgene that encoded bacterial NADPH-glutamate dehydrogenase (GDHA; EC 4.2.3.1) that reduced aflatoxin accumulation by half. A maize partial predicted protein to protein interactome was built and used to identify potential interactions between proteins expressed differentially in lines of maize resistant to A. flavus. These interactions were characterized in-silico and one specific interaction, between Zmcup1 and a maize zinc finger protein was characterized in vitro.

A avaliação da capacidade produtora de micotoxinas vem sendo utilizada como uma importante ferramenta na identificação de espécies conhecidamente toxigênicas. Poucos são os métodos rápidos e alternativos disponíveis para a determinação do potencial toxigênico de espécies do gênero Aspergillus. Neste contexto, o objetivo deste trabalho foi avaliar a capacidade produtora de aflatoxina B1, em diferentes condições de cultivo, por três isolados de Aspergillus flavus, produtores de aflatoxina B1. O delineamento experimental baseou-se em um planejamento 2³ completo, tendo como variáveis independentes a temperatura (20-40°C), o tempo de incubação (7-21 dias) e o pH (2,0-6,0) nos meio sintéticos (YES, CYA e Sabouraud). As melhores condições encontradas foram aplicadas em testes com meio natural (arroz) e isolados a principio não-aflatoxigênicos. Aflatoxina B1 foi extraída diretamente dos meios sintéticos com clorofórmio e do arroz com metanol. A identificação e quantificação do composto foi realizada por Cromatografia em Camada Delgada e Fotometria Fotográfica. O meio YES se mostrou o melhor para detecção do potencial toxigênico, seguidos de melhor pH 4,0 e 5,2, e temperatura de 20º e 25ºC e tempo de incubação de 11 e 14 dias. O isolado A43, em temperatura de 25º, pH 5,2 e tempo de incubação de 11 dias, mostrou a maior produção de aflatoxina B1, com 206,05 ng. No arroz, os isolados revelaram produção de aflatoxina, apenas a partir do 14ºdia. Dos 30 isolados a princípio não-aflatoxigênicos testados inicialmente em agar coco, 12 apresentaram resultado positivo nos meios e condições aqui apresentados. / Mycotoxins producing capacity evaluation has being used as an important tool, in the identification of toxigenic species. A few of them are available as alternative rapid methods for the determination of the toxigenic potential of species Aspergillus. The objective of this work was to evaluate the aflatoxin B1 producing capacity in different conditions of culture by three Aspergillus flavus. The experimental delineation was based on a 2³ factorial design. To test the effect of three independent variables, the temperature (20-40°C), the incubation time (7-21 days) and pH (2,0 -6,0) in the synthetic medium (YES, CYA and Sabouraud) were applied in the program STATISCA 7.0. The best joined conditions had been applied in tests with natural medium (rice) and isolated tested as nonaflatoxigenics. Aflatoxin B1 was extracted directly from sintetic mediuns by chloroform and from rice by methanol. Thin-layer chromatography (TLC) and Photometric Photography were the methods utilized for the identification and quantification of aflatoxin B1. YES was the best medium for the detention of toxigenic potential, at pH 4,0 and 5,2, temperature of 20º and 25ºC and incubation time of 11 and 14 days. The isolated A43, at temperature of 25ºC, pH 5,2 and incubation time of 11 days showed the biggest aflatoxin B1 production (206,05 ng). Aflatoxin production in rice occurred only after 14 days. 12 of the 30 non aflatoxigenic isolates showed aflatoxin production in the media and conditions tested.

A avaliação da capacidade produtora de micotoxinas vem sendo utilizada como uma importante ferramenta na identificação de espécies conhecidamente toxigênicas. Poucos são os métodos rápidos e alternativos disponíveis para a determinação do potencial toxigênico de espécies do gênero Aspergillus. Neste contexto, o objetivo deste trabalho foi avaliar a capacidade produtora de aflatoxina B1, em diferentes condições de cultivo, por três isolados de Aspergillus flavus, produtores de aflatoxina B1. O delineamento experimental baseou-se em um planejamento 2³ completo, tendo como variáveis independentes a temperatura (20-40°C), o tempo de incubação (7-21 dias) e o pH (2,0-6,0) nos meio sintéticos (YES, CYA e Sabouraud). As melhores condições encontradas foram aplicadas em testes com meio natural (arroz) e isolados a principio não-aflatoxigênicos. Aflatoxina B1 foi extraída diretamente dos meios sintéticos com clorofórmio e do arroz com metanol. A identificação e quantificação do composto foi realizada por Cromatografia em Camada Delgada e Fotometria Fotográfica. O meio YES se mostrou o melhor para detecção do potencial toxigênico, seguidos de melhor pH 4,0 e 5,2, e temperatura de 20º e 25ºC e tempo de incubação de 11 e 14 dias. O isolado A43, em temperatura de 25º, pH 5,2 e tempo de incubação de 11 dias, mostrou a maior produção de aflatoxina B1, com 206,05 ng. No arroz, os isolados revelaram produção de aflatoxina, apenas a partir do 14ºdia. Dos 30 isolados a princípio não-aflatoxigênicos testados inicialmente em agar coco, 12 apresentaram resultado positivo nos meios e condições aqui apresentados. / Mycotoxins producing capacity evaluation has being used as an important tool, in the identification of toxigenic species. A few of them are available as alternative rapid methods for the determination of the toxigenic potential of species Aspergillus. The objective of this work was to evaluate the aflatoxin B1 producing capacity in different conditions of culture by three Aspergillus flavus. The experimental delineation was based on a 2³ factorial design. To test the effect of three independent variables, the temperature (20-40°C), the incubation time (7-21 days) and pH (2,0 -6,0) in the synthetic medium (YES, CYA and Sabouraud) were applied in the program STATISCA 7.0. The best joined conditions had been applied in tests with natural medium (rice) and isolated tested as nonaflatoxigenics. Aflatoxin B1 was extracted directly from sintetic mediuns by chloroform and from rice by methanol. Thin-layer chromatography (TLC) and Photometric Photography were the methods utilized for the identification and quantification of aflatoxin B1. YES was the best medium for the detention of toxigenic potential, at pH 4,0 and 5,2, temperature of 20º and 25ºC and incubation time of 11 and 14 days. The isolated A43, at temperature of 25ºC, pH 5,2 and incubation time of 11 days showed the biggest aflatoxin B1 production (206,05 ng). Aflatoxin production in rice occurred only after 14 days. 12 of the 30 non aflatoxigenic isolates showed aflatoxin production in the media and conditions tested.

A avaliação da capacidade produtora de micotoxinas vem sendo utilizada como uma importante ferramenta na identificação de espécies conhecidamente toxigênicas. Poucos são os métodos rápidos e alternativos disponíveis para a determinação do potencial toxigênico de espécies do gênero Aspergillus. Neste contexto, o objetivo deste trabalho foi avaliar a capacidade produtora de aflatoxina B1, em diferentes condições de cultivo, por três isolados de Aspergillus flavus, produtores de aflatoxina B1. O delineamento experimental baseou-se em um planejamento 2³ completo, tendo como variáveis independentes a temperatura (20-40°C), o tempo de incubação (7-21 dias) e o pH (2,0-6,0) nos meio sintéticos (YES, CYA e Sabouraud). As melhores condições encontradas foram aplicadas em testes com meio natural (arroz) e isolados a principio não-aflatoxigênicos. Aflatoxina B1 foi extraída diretamente dos meios sintéticos com clorofórmio e do arroz com metanol. A identificação e quantificação do composto foi realizada por Cromatografia em Camada Delgada e Fotometria Fotográfica. O meio YES se mostrou o melhor para detecção do potencial toxigênico, seguidos de melhor pH 4,0 e 5,2, e temperatura de 20º e 25ºC e tempo de incubação de 11 e 14 dias. O isolado A43, em temperatura de 25º, pH 5,2 e tempo de incubação de 11 dias, mostrou a maior produção de aflatoxina B1, com 206,05 ng. No arroz, os isolados revelaram produção de aflatoxina, apenas a partir do 14ºdia. Dos 30 isolados a princípio não-aflatoxigênicos testados inicialmente em agar coco, 12 apresentaram resultado positivo nos meios e condições aqui apresentados. / Mycotoxins producing capacity evaluation has being used as an important tool, in the identification of toxigenic species. A few of them are available as alternative rapid methods for the determination of the toxigenic potential of species Aspergillus. The objective of this work was to evaluate the aflatoxin B1 producing capacity in different conditions of culture by three Aspergillus flavus. The experimental delineation was based on a 2³ factorial design. To test the effect of three independent variables, the temperature (20-40°C), the incubation time (7-21 days) and pH (2,0 -6,0) in the synthetic medium (YES, CYA and Sabouraud) were applied in the program STATISCA 7.0. The best joined conditions had been applied in tests with natural medium (rice) and isolated tested as nonaflatoxigenics. Aflatoxin B1 was extracted directly from sintetic mediuns by chloroform and from rice by methanol. Thin-layer chromatography (TLC) and Photometric Photography were the methods utilized for the identification and quantification of aflatoxin B1. YES was the best medium for the detention of toxigenic potential, at pH 4,0 and 5,2, temperature of 20º and 25ºC and incubation time of 11 and 14 days. The isolated A43, at temperature of 25ºC, pH 5,2 and incubation time of 11 days showed the biggest aflatoxin B1 production (206,05 ng). Aflatoxin production in rice occurred only after 14 days. 12 of the 30 non aflatoxigenic isolates showed aflatoxin production in the media and conditions tested.

Foi realizado um experimento no aviário experimental do Departamento de Zootecnia da Universidade de São Paulo (USP), na Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP com o objetivo de avaliar o efeito de dois níveis vitamínicos (comercial e OVN) com ou sem aflatoxina em dietas de frangos de corte no período de 1 a 42 dias. Foram utilizados 1800 pintinhos, machos, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2 x 2 x 2 (2 níveis vitamínicos - comercial e OVN, 2 níveis de aflatoxina - 0 ppm e 0,5 ppm, e 2 níveis de adsorventes - 0 e 10 kg/ton), totalizando 8 tratamentos com 15 repetições de 15 aves cada. As dietas foram fornecidas fareladas e a base de milho e farelo de soja, formuladas segundo os níveis praticados por uma integradora da região. Para avaliar o desempenho foram analisados o consumo de ração, ganho de peso e conversão alimentar de 1 a 49 dias. Para avaliação de carcaça (rendimento de carcaça, peito e pernas), determinação de incidência de BBS e determinação do peso das vísceras abdominais e coração foram abatidas duas aves por repetição aos 45 dias. Os resultados mostraram que frangos de corte, machos, alimentados com nível OVN de vitaminas, apresentaram melhor ganho de peso, conversão alimentar, rendimento de carcaça e peito quando comparado com o nível comercial de vitaminas (P<0,05) e que as dietas contendo 0,5 ppm de aflatoxinas resultaram em menor ganho de peso, rendimento de carcaça, porcentagem de peito e aumentou o tamanho do coração e fígado do animal (P<0,05). O uso de 10kg/ton de adsorvente só apresentou resultado positivo no final da vida dos animais (dos 39 a 49 dias) (P<0,05) e somente na conversão alimentar. Esse estudo permite concluir que a aflatoxina resulta em perdas de desempenho e rendimento de carcaças e que o fornecimento de níveis ótimos de vitaminas melhora os resultados dessas características. O uso de adsorventes se mostrou inviável nesse estudo. / An experiment was conducted in an experimental aviary the Department of Animal Science, University of São Paulo (USP), the Faculty of Animal Science and Food Engineering (FZEA) in Pirassununga/SP, to evaluate the performance, carcass characteristics and weight of offal in broiler chickens fed with two levels of vitamins (commercial and VNO) with or without aflatoxin in broiler diets. Were used 1800 chicks, male, Cobb 500 distributed in a completely randomized 2 x 2 x 2 factorial arrangement (two vitamin levels, two levels of aflatoxin and two levels of adsorbents), totaling eight treatments with 15 replicates of 15 birds each. Diets were fed mash and corn and soybean meal, formulated according to the levels charged by an integrator in the region. To evaluate the performance were analyzed feed intake, weight gain, feed conversion from 1 to 49 days. For evaluation of carcass yield (carcass, breast and legs), determination of the incidence of BBS and determination of the weight of the abdominal viscera and heart were killed two birds per replicate at 45 days. The results showed that broilers, males fed VNO level of vitamins showed better weight gain, feed conversion, carcass yield and breast when compared to the commercial level of vitamins (P<0.05) and that diets intoxicated with 0.5 ppm of aflatoxin resulted in less weight gain, carcass yield, percentage of breast and increased the size of the heart and liver of the animal (P<0.05). The use of adsorbent 10kg/ton only had a positive result at the end of life of animals (from 39 to 49 days) (P<0.05) and only in the feed. This study indicates that aflatoxin results in loss of performance and carcass yield and the provision of optimal levels of vitamins improved the results of these characteristics. The use of adsorbents in this study proved to be unfeasible.

Orientador : Lucia Maria Valente Soares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T02:12:47Z (GMT). No. of bitstreams: 1 Mariutti_LilianReginaBarros_M.pdf: 1680960 bytes, checksum: 54a05df2fbb3674f6e787d861ae60c73 (MD5) Previous issue date: 2003 / Resumo: Um recente relato da presença de Aspergillus flavus e Aspergillus parasiticus em polpa de tomate industrializada brasileira motivou preocupações quanto a possível presença de micotoxinas em produtos de tomate nacionais. Aspergillus fIavus e Aspergillus parasiticus são conhecidos produtores de aflatoxinas, uma família de toxinas com propriedades hepatotóxicas, mutagênicas, teratogênicas e carcinogênicas. No presente trabalho foi adaptado e avaliado um método para determinação de aflatoxinas em produtos de tomate por cromatografia de camada delgada com detecção por comparação visual com padrões. Para verificar a possível contaminação de produtos de tomate comercializados com aflatoxinas foram analisadas 63 amostras de produtos de tomate (polpa, extrato, purê, catchup, tomate desidratado e tomate seco conservado em óleo) provenientes de 5 Estados e uma do exterior, compreendendo 29 marcas. A avaliação do método para determinação das aflatoxinas em produtos de tomate resultou em uma recuperação médía de 86%, para as quatro aflatoxinas, em dois níveis de adição. Os limites de detecção para as aflatoxinas B1, B2, G1 e G2 variaram entre 2 e 7 mg/Kg dependendo do tipo de produto. As aflatoxinas não foram detectadas em nenhuma das amostras analisadas / Abstract: A recent report on the presence of Aspergillus flavus and Aspergillus parasiticus in tomato pulp from a Brazilian plant caused concern about the possible presence of mycotoxins in tomato products from local plants. Aspergillus flavus and Aspergillus parasiticus are known producers of aflatoxins, a group of toxins with hepatotoxic, mutagenic, teratogenic, and carcinogenic properties. In the present work a thin layer chromatographic method with visual detection for the determination of aflatoxins in tomato products was adapted and evaluated. In order to verify a possible contamination of tomato products with aflatoxins, 63 samples of tomato products (pulp, paste, purée, catsup, dehydrated tomato and dried tomatoes in oil preserve) from 5 states and one from abroad, totaling 29 brands, were analyzed. The method evaluation showed an average recovery of 86%, for all four aflatoxins, at two levels of addition. The detection limits for the aflatoxins 81, 82, G1 e G2 ranged from 2 and 7 mg/Kg depending on the type of product. Aflatoxins were not detected in any of the samples analyzed. / Mestrado / Mestre em Ciência de Alimentos

Orientador: Delia B. Rodriguez-Amaya / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T02:37:31Z (GMT). No. of bitstreams: 1 Navas_SandraAparecida_M.pdf: 2479689 bytes, checksum: 059ad37b33bafb968f424afd2d492264 (MD5) Previous issue date: 2003 / Resumo: Tendo em vista o fato das crianças serem mais sensíveis aos efeitos adversos de aflatoxina M1 (AFM1) e ocratoxina A (OTA) comparativamente aos adultos, este trabalho teve como objetivo padronizar metodologia para determinação de AFM1 e OTA em leite matemo, avaliar a incidência das citadas toxinas em Banco de Leite Humano do Hospital Regional Sul, da cidade de São Paulo, e correlacionar os resultados obtidos com a alimentação consumida pelas mães. Os métodos estabelecidos para a determinação de AFM1 e OT A envolveram extração da AFM1 com metanol e OT A com bicarbonato de sódio 1 % e metanol, seguido da limpeza por colunas de imunoafinidade com anticorpos especificos para cada micotoxina e separação por cromatografia líquida de alta eficiência e quantificação com detector de fluorescência. A confirmação de AFM1 foi realizada através da reação de derivatização com ácido trifluoroacético (TFA) e para OTA por meio da reação de derivatização com ácido clorídrico concentrado (HCI). O método estabelecido para AFM1 apresentou porcentagem de recuperação e coeficiente de variação de 93,6% e 17,S%, respectivamente para a contaminação de 0,01 ng/mL. Para o método de OTA, os valores correspondentes são 83,9% e 14,1% no mesmo nível de contaminação (0,01 ng/mL). O limite de quantificação para ambos os métodos foi de 0,01 ng/mL. Do total de SO amostras analisadas, apenas uma continha a AFM1 (2% do total), em nível de 0,024 ng/mL e duas com OTA (4% do total), em nível de 0,011 e 0,024 ng/mL. Portanto, houve baixa incidência de AFM1 e OTA em leite materno proveniente do Banco de Leite do Hospital Regional Sul da cidade de São Paulo / Abstract: Since infants are more susceptible than adults to the adverse effects of aflatoxin M1 (AFM1) and ochratoxin A (OTA) , this work was carried out to establish and evaluate methods for the determination of AFM1 and OT A in human milk collected by the Human Milk Bank of the Southern Regional Hospital, city of São Paulo, and correlate the incidence of these mycotoxins to the mothers' diets, information obtained through a questionnaire. The methods established for the determination of AFM1 and OT A involved the extraction of AFM1 with methanol and OT A with 1 % sodium bicarbonate and methanol, followed by clean-up with immunoaffinity columns with antibodies specific for each mycotoxin and quantification by high performance liquid chromatography with a fluorescent detector. Confirmation of the identity of AFM1 was carried out by derivatization with trifluoroacetic acid (TFA) and of OT A by derivatization with concentrated hydrochloric acid (HCI). The method established for AFM1 had mean recovery percentage and coefficient of variation of 93.6% and 17.5%, respectively, at the contamination levei of 0.01 ng/mL. For the OTA method, the corresponding values were 83.9% and 14.1% at the same levei of contamination. The limit of quantification for both methods was 0.01 ng/mL. Of a total of 50 samples analyzed, only one was contaminated with AFM1 (2%), at 0.024 ng/mL and two with OTA at 0.011 and 0.024 ng/ml. There was low incidence of AFM1 and OT A, therefore, in human milk from the Milk Bank of the Southern Regional Hospital, city of São Paulo / Mestrado / Mestre em Ciência de Alimentos

Aflatoxin B1 and T-2 toxin are mycotoxins, which produce their immunotoxic effects by affecting nonspecific and acquired immunity in different species. The mechanisms of their immunotoxicity are still obscure. Cytokines are the key signaling molecules during the immune response. In this study, expression of macrophage-produced cytokines Interleukin-lα (IL-lα), tumor necrosis factor (TNF), and IL-6, and lymphocyte-produced cytokines IL-2, interferon y (IFNy), and IL-3 was measured at the mRNA and protein levels, after in vitro activation with mitogens in AFB1-and T-2-toxin-exposed mice. Significant changes in the organ weights, especially in the mice exposed to a high dose of T-2 toxin, and no effect in AFB1-exposed mice were observed. ConA-induced production of IL-2, IFNy, and IL-3 mRNA and protein levels in AFB1-exposed mice showed a decrease in low dose groups (significant for IL-2 mRNA), but no change at other doses. However, in T-2-toxin-treated animals, there was a significant induction of IL-2 and IFNy mRNA in high and low doses and of IL-3 mRNA at the medium dose. The protein levels of IL-2 and IFNy did not follow the mRNA levels in high dose and the protein levels of IL-3 were significantly increased in medium and low doses. LPS-induced IL-lα and TNF mRNA and protein levels in AFB1-exposed mice were suppressed at the high dose while mRNA levels of both cytokines were increased significantly in the low and medium doses. Low and medium doses of AFB1 also significantly decreased IL-lα protein levels and the high dose decreased IL-6 protein. In T-2 toxin-treated mice, no significant difference in mRNA levels of these cytokines was observed but a general pattern of significant suppression of their protein levels (except IL-lα at medium dose) showed that both toxins regulate the cytokine expression differently. Based on the above discussed results and others, AFB1 may alter cell-mediated immunity by affecting the communication between macrophages and T lymphocytes through inhibiting the macrophage-producing cytokines. T-2 toxin-induced immunosuppression may be due not only to the inhibition of macrophage-producing cytokines, but also to the lack of effector cells to respond to the cytokines (IL-2, IFNy, and IL-3).

The pathogenesis of hepatotoxic and hepatocarcinogenic actions of the mycotoxin aflatoxin B1 (AFB1) involves initial bioactivation by microsomal cytochrome P450s (P450) to a reactive and electrophilic intermediate, exo-aflatoxin B1-8,9-epoxide (exo-AFBO). Poultry, especially turkeys, are extremely sensitive to AFB1, a condition associated with efficient epoxidation by P450s. The purpose of this research was to 1) discover and characterize the P450s in turkey liver responsible for AFB1 bioactivation, and 2) determine the relative importance of these P450s in turkey liver. Initial investigations led to the discovery of CYP1A5. We then identified CYP3A37, a human CYP3A4 homologue from turkey liver, which along with CYP1A5 plays an important role in the bioactivation of AFB1 to exo-AFBO. The E. coli-expressed CYP3A37 possessed striking similarities to human CYP3A4, in terms of its catalytic activities and the kinetics of AFB1 oxidation. After the discovery of CYP3A37, further research evaluated its relative importance to CYP1A5, with respect to the epoxidation of AFB1, to determine which of the homologues bioactivated relatively low "real world" AFB1 concentrations, reflective of the potential dietary exposure. Using antibodies directed to both the enzymes as tools in immuno-inhibition experiments, we determined that CYP1A5 contributes to about 98% of the exo-AFBO formation at the low AFB1 concentrations (0.1 µM), which led us to conclude that CYP1A5 is likely the dominant homologue involved in the extreme sensitivity of the turkeys to AFB1. CYP3A37 also efficiently epoxidated AFB1, but only at high concentrations of this mycotoxin, not likely to be achievable in turkey liver in vivo. Our research has helped shed light on the relative importance of CYP1A5 and CYP3A37 in the bioactivation of AFB1 to the toxic exo-AFBO, and thus on the mechanisms of the extreme sensitivity of turkeys to AFB1. Given that AFB1 is a ubiquitous component of corn-based poultry feed and contamination is practically unavoidable, we conducted further studies evaluating the chemopreventive action of probiotic bacteria, Lactobacillus, on AFB1 toxicity in turkeys. Probiotic bacteria are known to bind AFB1, thus reducing its bioavailability. A mix of probiotic bacteria provided protection against key endpoints of aflatoxicosis, like AFB1-induced reduction in body and liver weights. Our data demonstrate that Lactobacillus was protective against aflatoxicosis in turkeys, thus validating its use as a possible chemopreventive, thereby helping alleviate the significant annual losses to the poultry industry due to feed contamination by AFB1.