Living on apples - anthropogenic influence on microbial communities of apple fruits

Microbial communities on non-processed foods are complex with unknown effects on food quality and human health. It is generally assumed that the ecology of the microflora associated with apples reflects the environment of the orchard, handling, harvesting, and storage. We performed a comparative field trial to assess how anthropogenic factors, such as organic and conventional farming practices, influence the microbial community of apple fruits. Apples are an economically important crop in Switzerland. In 2004, we harvested apple fruits cv. Golden Delicious of five pairs of organic/ conventional farms at five different locations in Switzerland. We combined classical microbiological methods and genetic tools to characterize the cultivable and uncultivable microflora of apple fruits. Morphologically distinct mold and yeast colonies were recovered from apple fruit surface (epiphytes) or from underneath the skin (endophytes) and recorded on nutrient agar. We also started to develop culture-independent molecular DNA-techniques (e.g. PCR of internal transcribed spacer region, ITS) for species identification and fungal community studies. Several white and red/pink yeasts and yeastlike fungi were the predominant epiphytes. Morphologically different molds formed almost exclusively the endophytic microflora. The yeast-like fungi were more abundantly and more frequently found on organic apple fruits whereas red/pink yeasts prevailed on conventional fruits. We found higher numbers of endophytic molds and more morphological types in organic fruits. These results suggest that the microbial community of apple fruits adapts to the farming practice, a feature which might be useful for authenticity and food quality

PathOrganic – Risks and Recommendations Regarding Human Pathogens in Organic Vegetable Production Chains

PathOrganic assesses risks associated with the consumption of fresh and minimally processed vegetables due to the prevalence of bacterial human pathogens in plant produce. The project evaluates whether organic production poses a risk on food safety, taking into consideration sources of pathogen transmission (e.g. animal manure). The project also explores whether organic versus conventional production practices may reduce the risk of pathogen manifestation. In Europe, vegetable-linked outbreaks are not well investigated. A conceptual model together with novel sampling strategies and specifically adjusted methods provides the basis for large-scale surveys of organically grown plant produce in five European countries. Critical control points are determined and evaluated and factors contributing to a food safety problem are analyzed in greenhouse and field experiments. The project aims at developing a quantitative risk assessment model and at formulating recommendations for improving food safety in organic vegetable production

Editor's Choice - Infective Native Aortic Aneurysms: A Delphi Consensus Document on Terminology, Definition, Classification, Diagnosis, and Reporting Standards.

There is no consensus regarding the terminology, definition, classification, diagnostic criteria, and algorithm, or reporting standards for the disease of infective native aortic aneurysm (INAA), previously known as mycotic aneurysm. The aim of this study was to establish this by performing a consensus study. The Delphi methodology was used. Thirty-seven international experts were invited via mail to participate. Four two week Delphi rounds were performed, using an online questionnaire, initially with 22 statements and nine reporting items. The panellists rated the statements on a five point Likert scale. Comments on statements were analysed, statements revised, and results presented in iterative rounds. Consensus was defined as ≥ 75% of the panel selecting "strongly agree" or "agree" on the Likert scale, and consensus on the final assessment was defined as Cronbach's alpha coefficient > .80. All 38 panellists completed all four rounds, resulting in 100% participation and agreement that this study was necessary, and the term INAA was agreed to be optimal. Three more statements were added based on the results and comments of the panel, resulting in a final 25 statements and nine reporting items. All 25 statements reached an agreement of ≥ 87%, and all nine reporting items reached an agreement of 100%. The Cronbach's alpha increased for each consecutive round (round 1 = .84, round 2 = .87, round 3 = .90, and round 4 = .92). Thus, consensus was reached for all statements and reporting items. This Delphi study established the first consensus document on INAA regarding terminology, definition, classification, diagnostic criteria, and algorithm, as well as reporting standards. The results of this study create essential conditions for scientific research on this disease. The presented consensus will need future amendments in accordance with newly acquired knowledge

Effects of selected pesticides and adjuvants on germination and vegetative growth of Phomopsis amaranthicola, a biocontrol agent for Amaranthus spp.

Summary: Phomopsis amaranthicola, a bioherbicide agent for Amaranthus spp., was tested in vitro for its compatibility with commercial formulations of 16 adjuvants, 24 herbicides, nine fungicides and four insecticides at 2X, 1X (highest labelled product dose rate), 0.75X, 0.5X and 0.25X concentrations. These chemicals were tested for their effects on spore germination. Selected herbicides and fungicides at 1X were also tested for their influence on colony growth and sporulation. All tested compounds were finally categorized in compatibility classes regarding germination, mycelial growth and sporulation such as low, medium and high compatibility. High compatibility in terms of germination and fungal colony growth was only observed with the herbicide bentazone. Many of the adjuvants tested were highly compatible in the germination studies. Most fungicides and insecticides had medium and low compatibility with P. amaranthicola. Effects of pesticides on spore germination did not fully correspond with their effects on colony growth. Thus, it is possible to integrate the use of P. amaranthicola with some herbicides, fungicides, insecticides and adjuvants but not others. A case-by-case selection of application methods, such as tank-mix or sequential application, along with proper timing of applications of the fungus and the chemical agents will be necessary

Integration of quality parameters into food safety focused HACCP systems

Integration of quality parameters into food safety focused HACCP systems

Crystal growth and spectroscopic characterization of Tm3+-doped KYb(WO4)2 single crystals.

In this paper we present the crystal growth and optical characterization of thulium-doped KYb(WO4)2 ~hereafter KYbW!. We grew thulium-doped KYbW monoclinic single crystals with optimal crystalline quality by the top-seeded-solution-growth ~TSSG! slow-cooling method. Thulium spectroscopy was characterized in this host. The Judd-Ofelt parameters determined were V250.14310220 cm2, V450.21310220 cm2, and V650.10310220 cm2. The room temperature lifetimes measured for KYbW:Tm 1% were t(1G4) 560–70 ms, t(3H4)590 ms and t(3F4)5200 ms. We calculated the emission cross section for several channels. There was an important blue emission after pumping resonantly to the stoichiometric ytterbium at 980 nm, and we studied the emission channels of thulium. The presence of thulium luminescence is proof of the large transfer of energy in this compound

Surveying Pathogenic Bacteria in Vegetables

Bacterial pathogens have increasingly been identified as disease causing agents in vegetable-linked outbreaks. Consumers nowadays show higher demands for fresh or minimally processed fruits and vegetables, and at the same time potential sources of pathogen infestation are increasing due to the more frequent use of animal manures as fertilizers in organic than in conventional agriculture. On the other hand, a higher antagonistic potential against invading pathogens is implicated from the more diverse microbiota in organic soils. Vegetable-associated outbreaks in Europe are not well documented, and guidelines are missing for reducing risks of pathogen infestation. Thus, a survey on organically grown vegetables has been carried out by the “PathOrganic” consortium in five countries. In total, 4620 plants of lettuce, 1900 plants of spinach and 500 carrots from 14 fields were collected and by using PCR based detection methods were analyzed for the prevalence of pathogenic E. coli, Salmonella sp., Staphylococcus aureus, Listeria sp. and Campylobacter spp. Common protocols were used regarding harvest and sample preparation; and molecular analyses were shared among labs according to expertise. Preceding the vegetable screenings, animal manures of various origin used for fertilizing the fields were analyzed for the presence of the same pathogens, aimed at pin-pointing potential sources of contamination. Results of the vegetable and manure surveys are presented and the concept of microbiological risk assessment followed in the project is discussed. Besides yielding a large dataset concerning pathogen infestation of vegetables and manures, the screenings provided a collection of vegetable-derived pathogen isolates available for further analysis. Together with information obtained in experimental assays, the survey results may enlarge our understanding of vegetable-associated human pathogenic bacteria and their interrelations with common microbial colonizers of plants and soils

Utilização de glifosato para o controle de ferrugem da soja Glyphosate application on soybean rust control

O objetivo deste trabalho foi avaliar o efeito de glifosato sobre a germinação de esporos de Phakopsora pachyrhizi e no controle da ferrugem da soja, aplicado preventiva e erradicativamente, em condições controladas. A germinação de esporos foi avaliada tendo-se vertido, em meio de cultura, soluções de esporos com diferentes concentrações do glifosato (0, 100, 1.000, 10.000 e 20.000 ppm) e fungicidas. Para avaliar o controle da ferrugem, plantas foram pulverizadas com glifosato, com variação da dose e do momento, tendo-se medido a severidade da doença. Houve efeito do produto sobre os esporos do fungo, o que reduziu sua germinação. As pulverizações em plantas, em casa de vegetação, mostraram um efeito do produto sobre a ferrugem, quando aplicado preventivamente, porém com período de proteção curto e fungitoxicidade inferior à do fungicida tebuconazole. O uso do glifosato, avaliado nesse ensaio, não deve ser visto como medida de manejo de ferrugem, e não interfere nas práticas habituais de controle da ferrugem da soja.<br>The objective of this work was to evaluate the effect of glyphosate on the germination of Phakopsora pachyrhizi spores, and on soybean rust control; applications were either preventive or eradicative under controlled conditions. The germination of spores was evaluated by pouring spores solutions on culture medium, with different concentrations of glyphosate (0, 100, 1,000, 10,000 and 20,000 ppm) and fungicides. For the rust control evaluation, plants were sprayed with glyphosate, varying doses and moments, and estimating the disease severity. The product reduced spores germination. Plants sprayed in greenhouse conditions, showed effect of the product on rust, when applied preventively, but with short protection period and lower fungus toxicity than tebuconazole fungicide. The use of glyphosate, evaluated in this trial, must not be taken as a rust management measure, and should not interfere in usual practices for soybean rust control