Exposición crónica a hongos productores de aflatoxinas relacionada a daños hepáticos en chinchillas (chinchilla lanigera) destinadas a la producción de piel

Chinchilla pelt is a rare and expensive fur. Therefore, breeding these animals is a profitable activity. Confirmed acute cases of aflatoxin intoxication have been reported in Argentinean farms. The aims of this study were i) to evaluate mycobiota and AFB1 -producing species in chinchilla feeds ii) to investigate their natural AFB1 contamination and iii) to analyze histopathological lesions in chinchilla livers. Feed samples (A: fur chinchillas, B: mother chinchillas, C: lucerne cubes) were collected from a factory and a farm. Livers of sacrificed chinchilla from the farm were macroscopically and microscopically examined. Total fungal counts of feed C exceeded 1x104 CFU g-1. Aspergillus, Fusarium and Penicillium were the prevalent genera, while A. flavus, A. fumigatus, F. verticillioides and F. proliferatum were the prevalent species. 50 % of A. flavus strains from factory samples and 69.7 % from farm samples produced 2.78 to 8. 64 µg g-1 and 0.66 to 58.8 µg g-1 AFB1 , respectively. Aflatoxin B1 was detected only in feeds from the farm, finding the highest incidence in feed C. Toxin levels varied between 1.90 and 97.34 µg kg-1 AFB1 . Mean levels in feed A and C exceeded 20 µg kg-1. Macroscopic examination of livers revealed normal appearance, size and color. However, histopathological examination indicated 63.3 % showed slight to moderate lipid degeneration with diffuse cytoplasm vacuolation, 9 % intense lipid cytoplasm vacuolation and 27.3 % hydropic degeneration and nuclear vacuolation in hepatocytes. A periodic monitoring of aflatoxins in feeds and their ingredients can prevent acute outbreaks and economic losses caused by chronic exposure.La piel de chinchilla es una de las más exóticas y apreciadas en el mercado internacional. La cría de estos animales es una actividad muy rentable. En Argentina, se han detectado casos de aflatoxicosis aguda en criaderos. Los objetivos de este trabajo fueron: i) estudiar la micobiota y los hongos productores de aflatoxina B1 (AFB1 ) presentes en alimento para chinchillas. ii) analizar la contaminación natural con AFB1 de estos alimentos iii) buscar lesiones histopatológicas en hígados de chinchillas de los criaderos. Se recolectaron muestras de diferentes alimentos (A: chinchilla piel, B: chinchilla madre, C: cubos de alfalfa) en una fábrica y un criadero localizados en la ciudad de Rio Cuarto, en la región central de Argentina. Los hígados de las chinchillas sacrificadas en el criadero fueron analizados macroscópica y microscópicamente. Los recuentos fúngicos totales fueron mayores a 1x104 UFC g-1. Aspergillus, Fusarium y Penicillium fueron los géneros prevalentes, mientras que A. flavus, A. fumigatus, F. verticillioides y F. proliferatum fueron las especies aisladas con mayor frecuencia. 50 % de las cepas de A. flavus aisladas de la fábrica y 69.7 % de las aisladas del criadero produjeron 2.78 a 8.64 µg g-1 y 0.66 a 58.8 µg g-1 de AFB1 , respectivamente. Se detectó AFB1 sólo en las muestras del criadero, con mayor incidencia en el alimento C. Los niveles de toxina variaron entre 1.90 y 97.34 µg kg-1. Los niveles promedios en A y C fueron superiores a 20 µg kg-1. El análisis macroscópico de los hígados reveló apariencia, tamaño y color normal. El análisis microscópico indicó que 63.3 % de los hígados presentaron degeneración lipídica leve a moderada con vacuolización difusa del citoplasma, 9 % presentaron vacuolización lipídica intensa y 27.3 % degeneración hidrópica y vacuolización nuclear en los hepatocitos. El monitoreo periódico de La calidad de los alimentos e ingredientes usados en la alimentación de chinchillas puede evitar intoxicaciones agudas y pérdidas económicas causadas por la exposición crónica a aflatoxinas.Fil: Landa, Maria Florencia. 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: 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; ArgentinaFil: Pena, Gabriela Alejandra. 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: Bagnis, Guillermo. 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: Rosa, Carlos Alberto da Rocha. Conselho Nacional de Pesquisas Científicas; 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; Argentin

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

Optimization and production of probiotic and antimycotoxin yeast biomass using bioethanol industry waste via response surface methodology

Saccharomyces cerevisiae RC016 presents probiotic and mycotoxin adsorbent properties for use as feed additive. The improvement of S. cerevisiae RC016 biomass production using an agro-industrial waste such as Dried Distillers'Grains and Solubles (DDGs) that pollute the environment can contribute to sustainable development of the process and reduce the costs of large-scale production. In order to avoid theobstruction of the fermentor?s stirring mechanism with solid particles a novel pre treatment of DDGs was conducted to concentrate carbon sources levels. The design of experiments were performed using four factor-three-level Box-Behnken design (carbon source concentration, nitrogen source concentration, yeast extract concentration and incubation time) coupled with response surface methodology to evaluate theinteraction between two factors in order to determine the optimum process conditions. A quadratic model was suggested for the predictionof biomass production. The F-value and p-value of the model indicated that it was statistically significant at 95 percent confidence interval. Inaddition, R2 value of the model indicated an acceptable accuracy. The results were validated at bioreactor level showing that the specific growthrate on the optimized medium (0.34h-1) increased 112.5% compared to the initial non-optimized medium (0.16h-1), the duplication time showeda decrease of 52.9%. Optimization enabled productivity (0.451gL-1h-1) nine times higher than the initial one (0.062gL-1h-1), thus 65% more biomass was obtained (5.20gL-1). The use of biomass DDGse derived from bioethanol production promotes the sustainable and green way of biomass production.Fil: Fochesato, Analía Silvia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología. Cátedra de Micología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Galvagno, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Dogi, Cecilia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología. Cátedra de Micología; ArgentinaFil: Cerrutti, Patricia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Industrias. Carrera de Especialista en Area de Bromatología y Tecnología de la Industrialización de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez Pereyra, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología. Cátedra de Micología; ArgentinaFil: Flores, Marcelo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología. Cátedra de Micología; Argentin

Intestinal toxicity of deoxynivalenol is limited by Lactobacillus rhamnosus RC007 in pig jejunum explants

Probiotics have been explored to stimulate gut health in weaned pigs, when they started to consume solid diet where mycotoxins could be present. The aim of this study was to evaluate the effect of Lactobacillus rhamnosus RC007 on the intestinal toxicity of deoxynivalenol (DON) in an ex vivo model. Jejunal explants, obtained from 5-week-old crossbred castrated male piglets, were kept as control, exposed for 3 h to 10 μM DON, incubated for 4 h with 109 CFU/mL L. rhamnosus, or pre-incubated 1 h with 109L. rhamnosus and exposed to DON. Histological lesions were observed, para- and transcellular intestinal permeability was measured in Ussing chambers. The expression levels of mRNA encoding six inflammatory cytokines (CCL20, IL-10, IL-1β, TNFα, IL-8 and IL-22) were determined by RT-PCR. The expressions of the phosphorylated MAP kinases p42/p44 and p38 were assessed by immunoblotting. Exposure to DON induced histological changes, significantly increased the expression of CCL20, IL-1β, TNFα, IL-8, IL-22 and IL-10, increased the intestinal paracellular permeability and activated MAP kinases. Incubation with L. rhamnosus alone did not have any significant effect. By contrast, the pre-incubation with L. rhamnosus reduced all the effects of DON: the histological alterations, the pro-inflammatory response, the paracellular permeability and the phosphorylation of MAP kinases. Of note, L. rhamnosus did not adsorb DON and only slightly degrade the toxin. In conclusion, L. rhamnosus RC007 is a promising probiotic which, included as feed additive, can decrease the intestinal toxicity of DON.Fil: García, Gisela Romina. 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: Payros, Delphine. Instituto National de Recherches Agronomiques. Centre de Recherches de Toulouse; Francia. Université Paul Sabatier; FranciaFil: Pinton, Philippe. Instituto National de Recherches Agronomiques. Centre de Recherches de Toulouse; Francia. Université Paul Sabatier; FranciaFil: Dogi, Cecilia Ana. 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: Laffitte, Joëlle. Instituto National de Recherches Agronomiques. Centre de Recherches de Toulouse; Francia. Université Paul Sabatier; FranciaFil: Neves, Manon. Instituto National de Recherches Agronomiques. Centre de Recherches de Toulouse; Francia. Université Paul Sabatier; FranciaFil: 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: 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; ArgentinaFil: Oswald, Isabelle P.. Instituto National de Recherches Agronomiques. Centre de Recherches de Toulouse; Francia. Université Paul Sabatier; Franci

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Presence of aiiA homologue genes encoding for N-Acyl homoserine lactone-degrading enzyme in aflatoxin B1-decontaminating Bacillus strains with potential use as feed additives

Microbial degradation of aflatoxins (AFs) is an alternative to the use of mycotoxin binders. The lactone ring is a possible target for microbial enzymes and its cleavage reduces AFs toxicity. The aim of this study was to isolate and identify Bacillus strains able to degrade AFB1 to less toxic metabolites and to identify aiiA genes encoding for N-acyl-homoserine lactone (AHL) lactonase to possibly correlate detoxification with the production of this enzyme. Eleven soilborne Bacillus strains were isolated and identified by MALDI-TOF MS. Ten cultures and eight cell free culture supernatants (CFCS) were able to significantly (P < 0.05) degrade 27.78?79.78% AFB1. Cell lysates were also able to degrade AFB1 (P < 0.05). Exposure to 70 and 80 °C did not affect enzyme activity. Aflatoxin B1 toxicity towards Artemia salina was reduced after degradation by each of the Bacillus strains. B. subtilis RC1B, B. cereus RC1C and B. mojavensis RC3B, amplified a fragment of 753 pb corresponding to the aiiA gene encoding for AHL lactonase. AFB1 degradation by the strains tested was due to the extracellular and intracellular enzymes. If demonstrated to be safe, these could be used to detoxify AFB1 in contaminated food or feed.Fil: Gonzalez Pereyra, Maria Laura. 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: Martínez, M. P.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; 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; Argentin

Probiotic bacteria and yeasts adsorb aflatoxin M1 in milk and degrade it to less toxic AFM1-metabolites

The presence of contaminants such as aflatoxins (AFs) in dairy products constitutes a serious risk to the health of consumers, especially children who are most sensitive to the adverse effects of AFs. The presence of Aflatoxin M1 (AFM1) in milk is a public health problem since dairy products are massively consumed worldwide. The aim of the present work was to select microorganisms capable of reducing AFM1 entry into the food chain through adsorption/degradation strategies. Moreover, the toxicity of AFM1 degradation products was evaluated. All tested strains had the capacity to adsorb 19%–61% AFM1 in milk. These strains also had the ability to degrade AFM1 into metabolites less toxic than the original toxin. Moreover, this is the first study to report harmless and probiotic Pediococcus pentosaceus and Kluveromyces marxianus have the ability to adsorb and degrade AFM1 to less toxic metabolites in milk.Fil: Martinez, Maria Pia. 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, 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: Gonzalez Pereyra, Maria Laura. 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: 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; Argentin

Antifungal and aflatoxin-reducing activity of extracellular compounds produced by soil Bacillus strains with potential application in agriculture

Toxigenic Aspergillus flavus and A. parasiticus fungal strains can contaminate a wide variety of food crops with the subsequent production of aflatoxins (AFs) resulting in severe economic losses and public health issues. Biological control is a promising approach to manage AFs contamination in pre- and post-harvested crops. In the present study, the effect of soil-borne Bacillus spp. strains on aflatoxigenic A. parasiticus growth and AFs production was evaluated and the culture supernatant of the most effective strain was evaluated for the presence of antifungal lipopeptides. Six Bacillus spp. strains were able to reduce A. parasiticus growth rate significantly (p < 0.05). Bacillus spp. RC1A was able to inhibit fungal growth almost completely, reducing growth rate to 0.16 mm/h and increasing Lag phase duration (31.72 h) (p < 0.0001). RC1A could also reduce AFB1 concentration produced by A. parasiticus (p < 0.0001). Organic solvent extraction and chromatographic analysis of RC1A culture supernatant showed the presence of bands corresponding to three of the main groups of lipopeptides (surfactin, iturin A and fengycin) at the expected retention factor (Rf) values; they were also confirmed by MALDI-MS analysis. These fractions were able to inhibit A. parasiticus growth and AFB1 production to non-detectable levels when tested separately in liquid culture media. The further study of the antifungal compounds produced by these strains will determine their potential use to manage AFs contamination in crops and feeds.Fil: Gonzalez Pereyra, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; ArgentinaFil: Martinez, Maria Pia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Petroselli, Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Erra Balsells, Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentin

Probiotic characteristics and aflatoxin B1 binding ability of Debaryomyces hansenii and Kazaschtania exigua from rainbow trout environment

The aim of this study was to evaluate probiotic properties and the aflatoxin B1 adsorption ability of yeasts isolated from rainbow trout intestine and fish feed to assess their use in the formulation of feed additives. Growth at pH 2, bacterial pathogens inhibition, bacterial pathogens co-aggregation, autoaggregation, homologous and heterologous inhibition against lactic acid bacteria were evaluated. Moreover, aflatoxin B1 adsorption was tested. All strains were able to maintain viable (107 cells/ml) at pH 2. All strains isolated from intestine were identified as Kazaschtania exigua, while strains isolated from feed were all identified as Debaryomyces hansenii. Kazaschtania exigua RC035 and RC037 showed the strongest antimicrobial activity while K. exigua RC037 and RC038 were the most efficient co-aggregating bacterial pathogens. All strains exhibited strong autoaggregation. None of the tested yeast strains showed homologous inhibition towards other yeasts and heterologous inhibition towards lactic acid bacteria strains. Debaryomyces hansenii RC031 demonstrated aflatoxin B1 adsorption capacity (21%). The results of the present study indicate that select strains of Kazaschtania exigua and D. hansenii showed potential to improve the health of rainbow trout by inhibiting pathogens and binding AFB1 and their use as probiotics may improve the production of rainbow trout in aquaculture systems.Fil: Martinez, Maria Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Gonzalez Pereyra, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Fernandez Juri, Maria Guillermina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Poloni, Valeria Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Microbiología e Inmunología; Argentin

Pediococcus acidolactici and Pediococcus pentosaceus isolated from a rainbow trout ecosystem have probiotic and ABF1 adsorbing/degrading abilities in vitro

Probiotics are being used in biological control of bacterial pathogens, as an alternative to antibiotics, to improve health and production parameters in fish farming. Fish farming production is severely affected by aflatoxins (AFs), which are a significant problem in aquaculture systems. Aflatoxins exert substantial impact on production, causing disease with high mortality and a gradual decline of reared fish stock quality. Some aspects of aflatoxicosis in fish, particularly its effects on the gastrointestinal tract, have not been well documented. The aim of the present study was to evaluate probiotic properties of lactic acid bacterial (LAB) strains isolated from rainbow trout intestine and feed. Moreover, AFB1-binding and/or degrading abilities were also evaluated to assess their use in the formulation of feed additives. Growth at pH 2, the ability to co-aggregate with bacterial pathogens, inhibition of bacterial pathogens, and determination of the inhibitory mechanism were tested. Aflatoxin B1 (AFB1) adsorption and degradation ability were also tested. All strains were able to maintain viable (107 cells ml?1) at pH 2. Pediococcus acidilactici RC001 and RC008 showed the strongest antimicrobial activity, inhibiting all the pathogens tested. The strains produced antimicrobial compounds of different nature, being affected by different treatments (catalase, NaOH and heating), which indicated that they could be H2O2, organic acids or proteins. All LAB strains tested showed the ability to coaggregate pathogenic bacteria, showing inhibition percentages above 40%. Pediococcus acidilactici RC003 was the one with the highest adsorption capacity and all LAB strains were able to degrade AFB1 with percentages higher than 15%, showing significant differences with respect to the control. The ability of some of the LAB strains isolated in the present work to compete with pathogens, together with stability against bile and gastric pH, reduction of bioavailability and degradation of AFB1, may indicate the potential of LAB for use in rainbow trout culture.Fil: Martinez, Maria Pia. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Gonzalez Pereyra, Maria Laura. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Pena, Gabriela Alejandra. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Poloni, Valeria Lorena. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Fernandez Juri, Maria Guillermina. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Cavaglieri, Lilia Reneé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto; Argentin