Fusarium graminearum species complex occurrence on soybean and F. graminearum sensu stricto inoculum maintenance on residues in soybean-wheat rotation under field conditions.

AIMS: The aims of this study were to determine the occurrence of Fusarium graminearum species complex (FGSC) on soybean pods, seeds and roots, including rhizoplane, during the period of soybean crop in rotation with wheat and to evaluate the FGSC dynamics on wheat and soybean residues during two soybean growing seasons in rotation with wheat, particularly F. graminearum sensu stricto (FGss). METHODS AND RESULTS: Soybean roots, pods and seeds were analysed during 2012/13 and 2013/14 seasons. The morphological identification of FGSC and mycotoxin analysis was done. Crop residues were taken in both soybean season in wheat rotation and FGss were quantificated by real-time PCR. The results showed that Fusarium species, mainly FGSC, survive in a soybean crop in rotation with wheat. Isolation frequency of these species was higher on soybean pods than on seeds at R6 stage. Deoxynivalenol contamination on soybean seeds was higher in the 2013/14 season in comparison with the 2012/13 season. Low isolation levels of Fusarium species and species that did not belong to FGSC were observed in soybean root, whereas in rhizoplane a higher level was observed. Fusarium species inoculum on residues remained stable during crop succession and the FGSC were recovered from both wheat and soybean residues. Real time PCR data showed a higher DNA concentration of FGss in wheat residues in the first developmental stages of soybean plants, being the levels more significant during 2012/13 season. With regard to soybean residues collected during the wheat growing stages, an increase in DNA from anthesis until wheat harvest was observed. CONCLUSIONS: In a no-till production system, the populations of FGSC can colonize wheat and soybean residues to become an inoculum source. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides new data on the occurrence of FGSC populations in soybean plant and FGss on residues in soybean-wheat rotation, a cultural practice commonly used in in Argentina.

Toxigenic fungal species and natural occurrence of mycotoxins in crops harvested in Argentina / Especies fúngicas toxigénicas y ocurrencia natural de micotoxinas en cultivos y productos cosechados en Argentina

Abstract Mycotoxins are secondary metabolites produced by fungal species that mainly belong to Aspergillus, Fusarium, Penicillium and Alternaria, which can grow in a variety of crops including cereals, oilseeds and fruits. Consequently, their prevalence in foods and by-products not only affects human and animal health but also causes important losses in both domestic and international markets. This review provides data about toxigenic fungal species and mycotoxin occurrence in different crops commonly grown in Argentina. This information will be relevant to establish adequate management strategies to reduce the impact of mycotoxins on human food and animal feed chains and to implement future legislation on the maximum permitted levels of these fungal metabolites.

Resumen Las micotoxinas son metabolitos secundarios producidos por diferentes especies fúngicas pertenecientes, principalmente, a los géneros Aspergillus, Fusarium, Penicillium y Alternaria. Dichos microorganismos pueden crecer en una gran variedad de cultivos, entre los que se incluyen cereales, oleaginosas y frutas. La presencia de micotoxinas en alimentos y subproductos no sólo afecta la salud humana y animal, sino que también causa pérdidas importantes en los mercados nacionales e internacionales. Esta revisión proporciona datos sobre la prevalencia de especies fúngicas toxigénicas y de micotoxinas en diferentes cultivos y productos cosechados en Argentina. Dicha información será relevante para establecer estrategias de manejo adecuadas para reducir la entrada de las micotoxinas en las cadenas alimentarias del hombre y de los animales, así como para establecer futuras legislaciones sobre los niveles máximos permitidos de dichos metabolitos.

Small low-risk pulmonary nodules on chest digital radiography: can we predict whether the nodule is benign?

AIM: To evaluate digital chest radiography (CR) performance compared to computed tomography (CT) for characterising small low-risk pulmonary nodules detected incidentally in non-oncological patients. A second aim was to assess the prevalence of calcification and possible false-positive findings mimicking nodules. MATERIALS AND METHODS: Two hundred and seven patients who presented with a pulmonary nodule on CR and underwent CT were included prospectively. Nine radiologists blinded to the CT images reviewed the CRs assessing for the presence of nodules. Afterwards, the same radiologists evaluated the corresponding CT for the presence of nodules, dimensions, and calcification. If the nodule was not present on CT, it was considered a false-positive finding, and possible confounding factors on CR were investigated. RESULTS: Among all 213 nodules seen on CR, 32.4% were revealed to be false-positive findings on CT, mostly due to images formed by vessels (53.6%), osseous aetiologies (30.4%), and skin lesions (13%). Most nodules <6 mm detected on radiographies had benign calcification on CT (n=90; 67.7%). Comparatively, only 41.2% of nodules ≥6 mm on the CR had benign calcification. Among all nodules <6 mm detected on CR, 95.5% were calcified or not present at CT against 81.2% for those ≥6 mm (p<0.001). CONCLUSION: The present study demonstrated that 95.5% of pulmonary nodules smaller than 6 mm on CRs are either calcified (benign) or represent a false-positive finding on CT. These results suggest that nodule measures on CR smaller than 6 mm most likely represent a benign finding.

Two-year Experience of the "Organ Donation Week" of the Federal University of Health Sciences of Porto Alegre, Brazil.

BACKGROUND: Today, Brazil is the second country of the world in number of transplants. Nonetheless, waiting lists are getting longer. This lack of organs occurs mostly because of people's reduced knowledge about the donation process. With the aim of changing this scenario, in 2013 and 2014, "Organ Donation Week" events were held at the Federal University of Health Sciences of Porto Alegre. METHODS: During the 2 years, documentaries followed by a cycle of debates with experts in this area were exhibited. In 2013, a "flash-mob" took place, with the purpose of performing a "transplant waiting list" around the perimeter of Santa Casa's Hospital Complex. In 2014, a morning full of educational activities was planned for the pediatric patients from the Santo Antônio Children's Hospital and their relatives. RESULTS: It is estimated that approximately 1774 people were directly reached by the projects. Among these people, we can include medical students, healthcare professionals, university staff, transplanted patients, and their families. We believe that education and consciousness are central points in the donation and transplant process. Through this project, we could inform people about it, solving their doubts and myths and stimulating this kind of conversation among the family circle, making the moment when the family must make the decision much easier. CONCLUSIONS: Education and public awareness are essential for enhancing the number of organ donations. Therefore, events such as "Organ Donation Week" should be encouraged among medical schools.

Implementing Activities Developed by the Organ Transplantation Academic Society of the Hospital Dom Vicente Scherer: A Pilot Study.

BACKGROUND: The number of academic societies has been growing significantly in Brazilian universities, offering an extra opportunity for the development of educational activities and research. Because organ donation and transplantation is an area still insufficiently approached during the graduation of health professionals, we evaluated how academic societies might be a valuable tool. METHODS: Participants of the course promoted by the Organ Transplantation Academic Society of the Hospital Dom Vicente Scherer were evaluated through the use of a questionnaire and cognitive tests with 16 multiple-choice questions about topics approached during the course, before and after the lectures. Topics approached consisted of a general introduction about transplantation in Brazil, brain death, organ allocation and removal, post-transplant follow-up, and clinical cases. RESULTS: Of the 45 participants, 30 answered the tests at both times. The subjects were students of medicine, nursing, and phonoaudiology; 93.3% were organ donors, 84.6% said their families knew about this decision, and 65% had relatives who were organ donors. The mean score of correct answers was 7.63 of 16 before the activities and 12.54 after activities, demonstrating a 64.4% improvement. CONCLUSIONS: The improvement in performance suggests that academic societies are a useful resource for educational purposes and for students to get a deeper insight about organ donation and transplantation.

Evaluation of potential biocontrol agent for aflatoxin in Argentinean peanuts.

Biocontrol by competitive exclusion has been developed as the most promising means of controlling aflatoxins in peanuts. A 2-year study was carried out to determine the efficacy of an Aspergillus flavus strain as biocontrol agent to reduce aflatoxin production in peanuts under field conditions in Argentina. The competitive strain used was a nontoxigenic A. flavus (AFCHG2) naturally occurring in peanut from Córdoba, Argentina. The inoculum was produced through solid-state fermentation on long grain rice and applied at rate of 50kg inoculum/ha. The incidence of the released strain within the A. flavus communities in soil and peanuts was determined using the shift in the ratio toxigenic:nontoxigenic and VCG analysis. During the 2009/2010 growing season, treatments produced significant reductions in the incidence of toxigenic isolates of A. flavus/Aspergillus parasiticus in soil and peanuts. However, no preharvest aflatoxin contamination was observed. In the 2010/2011 growing season, plants were exposed to late season drought conditions that were optimal for aflatoxin contamination. Significant reductions in aflatoxin levels averaging 71% were detected in treated plots with different inoculation treatments. The results suggest that using the strategy of competitive exclusion A. flavus AFCHG2 can be applied to reduce aflatoxin contamination in Argentinean peanuts.

Trichothecenes and zearalenone production by Fusarium equiseti and Fusarium semitectum species isolated from Argentinean soybean.

Fusarium equiseti and Fusarium semitectum represent the most abundant species in the Fusarium complex isolated from flowers, soybean pods and seeds in Argentina. The aim of the present study was to assess the production of major type A and type B trichothecenes (diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin, nivalenol, deoxynivalenol) and zearalenone by 40 F. equiseti and 22 F. semitectum isolates on rice culture. Mycotoxins were determined by HPLC with fluorescence detection after derivatisation with 1-anthronylnitrile for type A trichothecenes (i.e. diacetoxyscirpenol, neosolaniol, T-2 toxin and HT-2 toxin), by HPLC with UV detection for type B trichothecenes (i.e. nivalenol and deoxynivalenol), and by TLC for zearalenone. A total of 22 of 40 F. equiseti isolates produced diacetoxyscirpenol, nivalenol and ZEA alone or in combination, whereas only two of 20 F. semitectum isolates were nivalenol and ZEA producers. Both Fusarium species did not produce any deoxynivalenol, neosolaniol, T-2 toxin and HT-2 toxin. The variable retention in toxigenicity displayed by both fungal species suggests that these species have a saprophytic lifestyle in the soybean agroecosystem in Argentina.

Natural deoxynivalenol occurrence and genotype and chemotype determination of a field population of the Fusarium graminearum complex associated with soybean in Argentina.

Soybean (Glycine max L.), the main source of protein throughout the world, is used both as a food and a feedstuff. Currently, limited information about the occurrence of Fusarium species and mycotoxins in soybean grain and by-products is available. The aims of the present study were: (1) to identify toxigenic Fusarium species associated with soybean during crop reproductive stages; (2) to determine the occurrence of deoxynivalenol (DON) and nivalenol (NIV) in soybean seeds; (3) to determine the genotype and chemotype of selected Fg complex strains using molecular and chemical analysis, respectively; and (4) to characterize the strains using AFLP(s) markers. One soybean field located at Córdoba Province, Argentina, was monitored and samples of soybean tissue were harvested at three reproductive stages: flowering (R2), full seed (R6) and full maturity (R8). A total of 389 Fusarium strains F. equiseti (40%) was the most frequently species recovered followed by F. semitectum (27%) and F. graminearum (Fg) (11%). From the 40 soybean samples analysed, only two presented detectable DON levels. Based on DON occurrence on soybean seeds at ripening stages, the toxigenic ability of Fg complex strains isolated from soybean seeds, pods and flowers were analysed. The trichothecene genotype was determined by a multiplex PCR using primers based on Tri3, Tri5 and Tri7 toxin genes and then the chemotype was verified by chemical analysis. Most Fg complex strains showed 15-ADON genotype and five strains presented a DON/NIV; these also produced both toxins under in vitro culture. Neither the NIV nor the 3-ADON genotypes were detected among the members of the population evaluated. All the 15-ADON genotype strains were characterized as F. graminearum sensu stricto (lineage 7), while the strains presented a DON/NIV genotype were characterized as F. meridionale (lineage 2). The present study contributes new information on the occurrence of Fusarium species and trichothecenes toxins on soybean at the pre-harvest stages. Also, this is the first report on the chemotype, genotype and lineages among Fg complex isolated from soybean.