RESUMO
The aim of the present study was to investigate the toxicity effects of cadmium-nickel (Cd-Ni) after single and mixtures exposures over the macrophyte Lemna gibba. Effects were assessed on growth, as frond number and fresh weight and biochemical parameters, such as total protein content and activity of antioxidant enzymes. Plants were exposed to single Cd and Ni in concentrations that ranged between 0.13-33 mg/L and 0.18 and 11.82 mg/L, respectively. For binary mixtures, individual metal IC50 values were used for selection of the evaluated concentrations. The experimental design consisted in three different ratios based on the concept of toxic units (TU), each ratio was evaluated by five different concentrations. Both single and mixture treatments were performed for 7 days following the conditions according to OECD (2006). Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Growth parameters showed a differential sensitivity after individual metal exposures. Cd was more toxic for L. gibba plants when fresh weight was considered, but on the contrary, considering frond number, Ni was the most toxic metal. IC50-7d, based on growth rate calculated on frond number were 17.8 and 2.47 mg/L, and on fresh weight were 1.08 and 3.89 mg/L, for Cd and Ni respectively. LOEC values for Cd were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight, respectively; while for Ni, these values were 0.92 and 11.82 mg/L. The three evaluated ratios for binary mixtures resulted in a high toxicity considering the same response variables in single metal exposures. Ratio 1 (2/3 TU Cd-1/3 TU Ni) was the most toxic considering both frond number and fresh weight, showing percentage inhibition of growth rates of 96 and 90%, respectively for the highest concentration. A modification of the protein content was observed in single, but especially in the mixture treatments. The activity of catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) was also affected in single and mixtures assays. APOX and GPOX showed a higher increase of its activities respect the controls after mixture treatments than for single metal treatments. Such optimization of the antioxidant system could be one of the causes of the antagonistic toxicity observed in mixture exposures. Concentration addition (CA) reference model, based on frond number, in Cd-Ni mixtures was not a good predictor to evaluate toxicity from dissolved metal concentration since the results showed that toxicity was less than additive, with an average of ΣTU = 2.17. The observed antagonisms resulted to be stronger in mixtures with higher metal concentrations.
Assuntos
Araceae , Cádmio , Níquel/toxicidade , Biomarcadores/metabolismo , Cádmio/toxicidade , Catalase , EcotoxicologiaRESUMO
In the present study, single and mixture effects of cadmium (Cd) and zinc (Zn) on Lemna gibba were analyzed and compared using growth parameters, based on frond number and fresh weight, and biochemical parameters, such as pigment, protein content and activity of antioxidant enzymes. Plants were exposed for 7 days to these metals in nutrient solution. Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Considering the growth parameters, Cd was found to be much more toxic than Zn. IC50-7d, based on growth rate calculated on frond number, were 17.8 and 76.73 mg/L, and on fresh weight were 1.08 and 76.93 mg/L, for Cd and Zn respectively. For Cd, LOEC values were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight respectively; while for Zn, at 20.1 and 74.6 mg/L. A high toxicity effect, considering the same response variables, was observed in plants exposed to the mixtures. Three fixed ratios, based on toxic units (TU) were assayed, ratio 1: 2/3 Cd-1/3 Zn, ratio 2: 1/2 Cd-1/2 Zn and ratio 3: 1/3 Cd-2/3 Zn. Ratio 3 (where Zn was added in higher proportion) was the less toxic. All concentrations of Ratio 1 and 2 significantly inhibited plant growth, showing a 100% inhibition of growth rate at the highest concentrations when based on frond number. Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls. In mixture tests, the activity of APOX and GPOX was significantly stimulated in plants exposed to all evaluated combinations, while CAT was mainly stimulated in Ratio 3. It was observed that the activity of the enzymes was increased in the mixtures compared with similar concentrations evaluated individually. APOX activity was observed to fit the CA model and following a concentration-response pattern. The response of this antioxidant enzyme could serve as a sensitive stressor biomarker for Cd-Zn interactions. Frond number in Cd-Zn mixtures was not well predicted from dissolved metal concentration in solution using concentration addition (CA) as reference model, as results showed that toxicity was more than additive, with an average of ΣTU = 0.75. This synergistic effect was observed up to 50 mg Zn/L in the mixture, but when it was present in higher concentrations a less than additive effect was observed, indicating a protective effect of Zn. A synergistic and dose-ratio deviations from CA model were also observed.
Assuntos
Araceae/fisiologia , Cádmio/toxicidade , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Catalase/metabolismo , Peroxidase/metabolismoRESUMO
The aim of this study was to compare the ecotoxicity of nickel (Ni) and zinc (Zn) assayed as single and as binary mixture. In addition, how were affected the population growth rates and oxidative stress biomarkers, comparing single to binary exposures. The toxicity tests were performed on Lemna gibba using a 7-day test. All calculations were made using measured total dissolved metal concentrations. IC50-7d, based on growth rate calculated on frond number and fresh weight, were 2.47/3.89 mg/L, and 76.73/76.93 mg/L, for Ni and Zn, respectively. Single metals affected plant growth following a non-linear concentration-response relationship. LOEC values for each metal were obtained at 0.92 and 20.1 mg/L for Ni and Zn, respectively. Biomarkers of the antioxidant response like Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls, but when similar concentrations were added as mixtures, that increase was reduced and inhibition with respect to the control was observed for GPOX. APOX showed the highest activity. The concentration addition (CA) approach was evaluated and resulted in a correct predictor of Ni-Zn mixture toxicity on Lemna gibba. This was made comparing the EC50 and LOEC, measured taking the growth rate as endpoint, with those expected values according to the CA model. However, the measured biomarkers indicating a positive response to free radicals did not fit to concentration addition model when assayed in the binary mixture. Also, the main activity response of these was observed within a range of concentrations below the LOEC values for the mixture.
Assuntos
Araceae/efeitos dos fármacos , Níquel/toxicidade , Estresse Oxidativo , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Araceae/crescimento & desenvolvimento , Araceae/fisiologia , Biomarcadores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Testes de ToxicidadeRESUMO
En la homeostasis de un individuo sano se desarrollan coágulos para prevenir la pérdida de sangre, pero las fallas del equilibrio hemostático pueden ocasionar obstrucción aguda de una arteria como fenómeno fisiopatológico principal, que puede beneficiarse del tratamiento trombolítico que consiste en la administración, por vía endovenosa o en ocasiones intraarterial, de medicamentos capaces de destruir los coágulos de fibrina y permitir que se restaure el flujo sanguíneo en el vaso sanguíneo. Esto se hace para evitar complicaciones como infarto cerebral, embolia pulmonar, trombosis venosa profunda e infarto agudo del miocardio.El siguiente documento es una revisión bibliográfica de la terapia fibrinolitica y su uso en estas entidades, teniendo en cuenta las recomendaciones de la Agency for Healthcare Research and Quality (AHRQ), usando PubMed como base datos de búsqueda principal. Se obtuvieron artículos sobre trombólisis en infarto agudo del miocardio, trombembolismo pulmonar y accidente cerebrovascular y según la pertinencia se procedió a su análisis para generar una recomendación
Homeostasis in healthy individuals develop clots to prevent blood loss, but failures can cause hemostatic imbalance, acute obstruction of artery as main underlying process which may benefit from thrombolytic therapy consisting of the intravenous or intraarterial administration of drugs capable of destroying fibrin clots and allow it to restore blood flow through the blood vessel. The following document provides a bibliographic review about fibrinolytic therapy and the use in these entities. Taking into account the agency's recommendations for "healthcare research and quality" (AHRQ), using PubMed as the primary search database. We obtained papers compatible with thrombolysis in acute myocardial infarction, pulmonary thrombembolism and cerebrovascular accident and according to the pertinence we proceeded to be analyzed to generate a recommendation.
Na homeostase de um indivíduo sadio são desenvolvidos coágulos para prevenir a perda de sangue, porém as falhas de equilíbrio homeostático podem ocasionar obstrução aguda de uma artéria como fenômeno trombolítico que consiste na administração por via endovenosa ou intra-arterial, de medicamentos que destroem coágulos de fibrina e permitem que seja restaurado o fluxo sanguíneo a traves do vaso sanguíneo. O presente documento é uma revisão bibliográfica a respeito da terapia fibrinolítica e seu uso nestas entidades, considerando as recomendações da agencia Healthcare research and quality (AHRQ), usando PubMed como base de dados de busca principal. Foram obtidos artigos compatíveis com trombolisis em infarto agudo do miocárdio, tromboembolismo pulmonar e acidente cerebrovascular e segundo a pertinência, foi analisado para gerar uma recomendação
Assuntos
Terapia Trombolítica , Terapêutica , Acidente Vascular Cerebral , Homeostase , Infarto do MiocárdioRESUMO
The aims of this study were: (i) to assess if carbamate pesticides and ammonium, widely detected in European freshwater bodies, can be considered ecologically relevant endocrine-disrupting chemicals (EDCs) for benthic and interstitial freshwater copepods; and (ii) to evaluate the potential of copepods as sentinels for monitoring ecosystem health. In order to achieve these objectives, four species belonging to the harpacticoid copepod genus Bryocamptus, namely B. (E.) echinatus, B. (R.) zschokkei, B. (R.) pygmaeus and B. (B.) minutus, were subjected to chronic exposures to Aldicarb and ammonium. A significant deviation from the developmental time of unexposed control cultures was observed for all the species in test cultures. Aldicarb caused an increase in generation time over 80% in both B. minutus and B. zschokkei, but less than 35% in B. pygmaeus and B. echinatus. Ammonium increased generation time over 33% in B. minutus, and 14, 12 and 3.5% for B. pygmaeus, B. zschokkei and B. echinatus, respectively. On the basis of these results it can be concluded that chronic exposure to carbamate pesticides and ammonium alters the post-naupliar development of the test-species and propose their potential role as EDCs, leaving open the basis to search what are the mechanism underlying. A prolonged developmental time would probably produce a detrimental effect on population attributes, such as age structure and population size. These deviations from a pristine population condition may be considered suitable biological indicators of ecosystem stress, particularly useful to compare polluted to unpolluted reference sites. Due to their dominance in both benthic and interstitial habitats, and their sensitivity as test organisms, freshwater benthic and hyporheic copepods can fully be used as sentinel species for assessing health condition of aquatic ecosystems as required by world-wide water legislation.
Assuntos
Copépodes/efeitos dos fármacos , Disruptores Endócrinos/toxicidade , Água Doce , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/crescimento & desenvolvimento , Monitoramento Ambiental , Feminino , MasculinoRESUMO
Melanoma is a common malignancy whose prevalence has been increasing, accounting for between 1 to 3 percent of cancers in the United States (USA), and is one of the most common types of cancer that metastasize to the gastrointestinal tract in advanced stages. It is reported that malignant melanoma (MM) either skin or mucous, can metastasize to virtually every organ in the human body. Although these have frequently secondary location in the gastrointestinal tract (GIT), where it is known to have special predilection, gastro intestinal metastasis are rarely found in the follow-up of these patients. Late diagnosis is due to its generally silent evolution. Endoscopy is a valuable tool both to confirm histological diagnosis, and monitoring of systemic therapies and palliative care locally. MM compromising the GIT is generally already spread by the time of diagnosis, in which case survival is only of 6 8 months, despite aggressive treatment. Hence the importance of anamnesis, to have a history of melanoma surgery, in addition to diligent physical examination that can reveal a primary skin or mucosal melanoma. All patients diagnosed with malignant melanoma should undergo endoscopic GIT studies.
El melanoma es una neoplasia frecuente, cuya prevalencia ha ido en aumento, representando entre 1 a 3 por ciento de los cánceres en EE.UU. y es una de las neoplasias que con mayor frecuencia presenta metástasis al tracto gastrointestinal en etapas avanzadas. Se ha reportado que el melanoma maligno (MM), ya sea cutáneo o mucoso, es capaz de producir metástasis a prácticamente todos los órganos del cuerpo humano. Aunque es frecuente su ubicación secundaria en el tracto gastrointestinal (TGI) por el cual se sabe que tiene especial predilección, rara vez se pesquisan metástasis gastrointestinales en el seguimiento de estos pacientes. El diagnóstico tardío se debe a que su evolución es generalmente silente. La endoscopia es una valiosa herramienta tanto para confirmar el diagnóstico histológico, como para el seguimiento de terapias sistémicas y tratamiento paliativo local. El MM con compromiso del TGI generalmente se encuentra diseminado al momento del diagnóstico; en cuyo caso la sobrevida es sólo de 6 a 8 meses, pese a un tratamiento agresivo. De ahí la importancia de la anamnesis, para contar con el antecedente de melanoma operado, además del examen físico acucioso que nos pueda dar cuenta de un melanoma primario en piel o mucosas visibles. Todo paciente con diagnóstico de melanoma maligno debería ser sometido a estudios endoscópicos del TGI.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Melanoma/patologia , Neoplasias Cutâneas/patologia , Neoplasias Gastrointestinais/secundário , Diagnóstico Diferencial , Endoscopia Gastrointestinal , Mucosa , Neoplasias Gastrointestinais/diagnósticoRESUMO
The sensitivity of harpacticoid copepods was tested against selected pollutants. Acute toxicity tests were carried out for five hyporheic species exposed to pesticides, ammonia, and metals. The stygoxene Bryocamptus zschokkei, B. minutus, B. pygmaeus and Attheyella crassa; and the stygophilous B. echinatus were sampled and cultured during 8 months in controlled conditions. A first test protocol is presented. The acute endpoints among species fell within one order of magnitude. The sensitivity among various species evaluated in this study is consistent and the choice of species for further sediment/groundwater assessment is not specific to a chemical class. These potential test organisms would be more suitable to protect meiofaunal communities.
Assuntos
Amônia/toxicidade , Copépodes/efeitos dos fármacos , Monitoramento Ambiental/métodos , Metais/toxicidade , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/crescimento & desenvolvimento , Água Doce , Dose Letal Mediana , Longevidade/efeitos dos fármacos , Especificidade da Espécie , Testes de Toxicidade AgudaRESUMO
Postoperative analgesia may be complicated by the occurrence of acute opiate tolerance and hyperalgesia. We present the case of a patient who underwent gynecological surgery that was complicated by intense pain in the immediate postoperative period. The pain was attributed to the development of acute opiate tolerance caused by the brief infusion of a high dose of remifentanil. The opiate tolerance was complicated by tactile hyperalgesia at the site of the surgical wound. Pain management with the usual dose of nonsteroidal anti-inflammatory drugs associated with a high dose of morphine (50 mg administered in less than 2 hours) produced no analgesic or adverse effects. The pain was finally brought under control by epidural perfusion of ropivacaine and fentanyl and subsequently maintained with multimodal analgesia.
Assuntos
Amidas/uso terapêutico , Analgesia Epidural , Analgésicos Opioides/uso terapêutico , Anestésicos Locais/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Fentanila/uso terapêutico , Hiperalgesia/induzido quimicamente , Morfina/uso terapêutico , Dor Pós-Operatória/induzido quimicamente , Piperidinas/efeitos adversos , Acetaminofen/administração & dosagem , Acetaminofen/uso terapêutico , Doenças dos Anexos/cirurgia , Amidas/administração & dosagem , Analgésicos não Narcóticos/uso terapêutico , Analgésicos Opioides/administração & dosagem , Anestésicos Locais/administração & dosagem , Anti-Inflamatórios não Esteroides/administração & dosagem , Resistência a Medicamentos , Tolerância a Medicamentos , Feminino , Fentanila/administração & dosagem , Humanos , Hiperalgesia/tratamento farmacológico , Histerectomia , Cetorolaco/administração & dosagem , Cetorolaco/uso terapêutico , Pessoa de Meia-Idade , Dor Pós-Operatória/tratamento farmacológico , Remifentanil , RopivacainaRESUMO
The genotoxicity of industrial soils was evaluated. A single cell electrophoresis assay or comet assay, using eleocyte cells of Eisenia foetida, was performed to assess the genotoxicity of aqueous elutions. These were obtained from industrial soils containing metals. All soil samples meet the environmental quality guidelines for metal concentrations. However, elutions have produced genotoxic effects at dilutions as low as 6%. Total metal concentrations for each aqueous elution could express synergistic effects of these compounds.
Assuntos
Resíduos Industriais , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/química , Poluentes do Solo/toxicidade , Solo/análise , Animais , Ensaio Cometa , Monitoramento Ambiental , Metais/análise , Mutagênicos/química , Mutagênicos/toxicidadeRESUMO
An ecotoxicologic study was performed to assess the environmental status of the Lujan River. It is an important freshwater system in the northeast of Buenos Aires Province, Argentina. Surface waters (SWs) and liquids effluents (LEs), before they reached the river, and sediments were assessed via acute toxicity screening using a battery of tests with native species. Additionally, the presence, in each LE and SW sample, of bioaccumulatable compounds was checked by SPME extraction and gas chromatograph-MS determination. An environmental risk assessment of each LE was carried out via toxic units and assessment factors approach and through extrapolation methods. Hazardous concentrations for each LE were compared with their river effluent concentrations. Ninety-one percent (91%) of the total toxic load of the river was due to 4 of 11 LEs (37%) evaluated. Although SW samples were not toxic, a real environmental risk was found for this freshwater environment. Sediment toxicity was found to be related to the proximity to pipe discharges. Bioaccumulatable compounds were found in SWs and in LEs. Esters of phthalic acids, morpholine, hydroquinone, and nonylphenol were found throughout the river at different sample sites and in different months during the 1-year sampling program.
Assuntos
Resíduos Industriais , Poluentes Químicos da Água/intoxicação , Animais , Argentina , Disponibilidade Biológica , Ecossistema , Cadeia Alimentar , Água Doce , Medição de Risco , Rios , Poluentes Químicos da Água/análiseRESUMO
Pimenta racemosa var. ozua (Myrtaceae) is a tropical plant, used in different inflammatory processes by the folk medicine of the Caribbean region. From the methanol extract of the leaves a terpenic compound identified as lupeol has been isolated for the first time in this species. The anti-inflammatory activity of the extract has been evaluated against two experimental models of acute inflammation: paw edema in rats, using carrageenan or dextran as phlogogen agents, and ear edema in mice, inducing the inflammation with 12-o-tetradecanoylphorbol acetate (TPA). Myeloperoxidase activity (MPO) was also assayed as an indicator of leukocytary migration in the inflamed ears. In the carrageenan test, the methanol extract (125 and 250 mg kg(-1) p.o.) had a dose-dependent and significant effect at different time intervals. On the contrary, when the dextran was injected in paw, the extract did not reduce the inflammation provoked. This behavior was similar to indomethacine (25 mg kg(-1)) used as a standard drug. In the TPA-induced ear edema, the methanol extract (0.5, 1 and 3 mg ear(-1)) significantly reduced the inflammation. In the MPO assay a significant inhibition of the enzyme was observed in the inflamed tissue in all the samples assayed. These results show that the methanol extract from the leaves of Pimenta racemosa var. ozua, is effective against acute inflammation processes, by oral route and when topically applied. The anti-inflammatory behavior of the extract was similar to that exhibited by the selective cyclo-oxygenase inhibitor, indomethacin. On the other hand, the reduction of MPO activity shows that the action mechanism is clearly related with the neutrophil migration.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Plantas Medicinais/química , Triterpenos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Carragenina , Inibição de Migração Celular , Dextranos , República Dominicana , Edema/induzido quimicamente , Edema/prevenção & controle , Inibidores Enzimáticos/farmacologia , Masculino , Camundongos , Triterpenos Pentacíclicos , Peroxidase/antagonistas & inibidores , Extratos Vegetais/farmacologia , Ratos , Ratos Wistar , Acetato de Tetradecanoilforbol , Triterpenos/química , Triterpenos/isolamento & purificaçãoRESUMO
In vitro studies indicated that a sodium bentonite (SB) from southern Argentina had a high ability to sorb aflatoxin B1 (AFB1) from aqueous solution. We evaluated this compound for its ability to reduce the effects of total aflatoxins (AF; 5 mg AFB1/kg) in the diet of growing broiler chickens from 30 to 52 d of age. The diets were amended with 0.3% Argentinean SB to determine the effect of this compound during aflatoxicosis. When compared with the controls, BW gains were significantly (P < 0.05) lower for broilers fed diets containing AF alone (1,865 vs. 1,552 g). No differences were found between the BW gains of broiler chickens fed diets without AF (1,785 g) and those of chickens fed AF + SB (1,809 g). These results suggest that effects of AF treatment were ameliorated when SB was used in the broiler chick diets. The AF significantly (P < 0.05) decreased feed efficiency. Liver, kidney, and pancreas relative weights increased in chickens fed the diet containing AF alone. Alterations in the levels of serum total protein, albumin (ALB), and globulins (GLOB) were observed for AF diets, and moderate protection was provided by the sorbent. The ALB:GLOB ratio decreased in both groups of birds fed with the AF-contaminated diet, and we observed a moderate increase in this ratio by 0.3% addition of SB. The histopathological findings in liver sections of broiler fed diets with AF + SB indicated a nonprotective effect of this adsorbent, because a moderate hepatic steatosis was observed.
Assuntos
Aflatoxina B1/toxicidade , Bentonita/farmacologia , Galinhas/crescimento & desenvolvimento , Doenças das Aves Domésticas/prevenção & controle , Adsorção , Aflatoxina B1/metabolismo , Ração Animal , Animais , Argentina , Bentonita/metabolismo , Bentonita/uso terapêutico , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Tamanho do Órgão , Doenças das Aves Domésticas/induzido quimicamente , Sensibilidade e Especificidade , Aumento de PesoRESUMO
Synthetic zeolites (NaX, NaY, NaA, and CaA) were evaluated in vitro for their ability to sorb aflatoxin (AF) B1 from an aqueous solution. Zeolite NaA (ZN) was selected to be tested in vivo because of its high affinity and its stable association with AFB1. This sorbent was incorporated into diets (1%) containing 2.5 mg/kg AFB1. Male broiler chicks from 21 to 42 d of age received ad libitum access to their respective diets and water. When compared with controls, BW gains were lower (P < 0.05) for broilers that were fed AF in their diets. No differences were found between the BW gains of chicks fed diets without AF and those of chicks fed AF + ZN, indicating almost total protection against the effects caused by AF. Liver weights were considerably higher in chicks fed a diet containing AF, compared with those of controls, nevertheless, no significant differences were found in feed:gain ratio among the groups. The findings of this research suggest that ZN can counteract some of the toxic effects of AF in growing broiler chicks.
Assuntos
Aflatoxina B1/toxicidade , Doenças das Aves Domésticas/induzido quimicamente , Doenças das Aves Domésticas/prevenção & controle , Zeolitas/uso terapêutico , Adsorção , Aflatoxina B1/química , Animais , Doença Hepática Induzida por Substâncias e Drogas , Galinhas , Fígado/patologia , Hepatopatias/prevenção & controle , Hepatopatias/veterinária , Masculino , Tamanho do Órgão , Vacúolos/patologia , Aumento de PesoAssuntos
Crustáceos/efeitos dos fármacos , Resíduos Industriais , Esgotos , Poluentes Químicos da Água/toxicidade , Agroquímicos , Bebidas Alcoólicas , Animais , Bioensaio , Fenômenos Químicos , Físico-Química , Indústria Alimentícia , Análise de Regressão , Taxa de Sobrevida , Curtume , Testes de ToxicidadeRESUMO
Fusarium species and fumonisin production by toxigenic strains were investigated. During 1996-1998, 158 samples of poultry feeds were collected from a factory located in the department of Rio Cuarto Córdoba province, Argentina. The most common species of Fusarium were F. moniliforme (60.7%) and F. nygamai (35.4%) followed by F. semitectum, F. subglutinans, F. proliferatum, F. dlamini, F. solani, F. oxysporum and F. napiforme. Fungal counts ranged from 1 x 10(3) to 8 x 10(5) CFU/g with mean values from 1.5 x 10(3) to 2.3 x 10(5) CFU/g. The highest counts were for F. dlamini, F. subglutinans, F. moniliforme and F. nygamai. Strains of F. moniliforme, F. nygamai, and E. proliferatum were screened for their potential to produce fumonisin B1 (FB1), fumonisin B2 (FB2) and fumonisin B3 (FB3) in corn grain. The samples were analysed using a modified high performance liquid chromatography method. The strains assayed, 43 strains, produced three fumonisins. There was a high degree of variability in the quantities of FB1, FB2, and FB3 produced. The toxin produced in highest levels by the majority of the strains was FB1. The range of concentration varied from 5.4 to 3,991, 1.01 to 189 and 0.4 to 765 ppm per gram of corn for FB1, FB2 and FB3 respectively. The toxigenic pattern of strains was normal, although two strains of F. moniliforme produced exceptionally high concentrations of FB3 and minor concentrations of FB2 and FB1. This is the first report from Argentina on Fusarium species in poultry feeds and fumonisin production by these strains.