Genetic Analyses of Strains Isolated from Salmonid Fish of Different Geographic Origin Document the Connection between Pathogenicity and Molecular Diversity.

is recognized as one of the most important oomycetes pests of salmon and trout species. The amplified fragment length polymorphism (AFLP) and method sequence data of the internal transcribed spacer (ITS) were used to study the genetic diversity and relationships of spp. collected from Canada, Chile, Japan, Norway and Scotland.

Efficacy and safety of boric acid as a preventive treatment against Saprolegnia infection in Nile tilapia (Oreochromis niloticus).

Saprolegniosis is a worldwide fungal-like infection affecting freshwater fishes and their eggs. Reports show high mortalities and subsequent economic losses annually from Saprolegnia infections. Most therapeutants against Saprolegnia spp.

The mycobiota of the production environments of traditional Norwegian salted and dried mutton (pinnekjøtt).

In 2013, mould growth on Norwegian ready-to-sell pinnekjøtt (dried and cured lamb ribs) lead to the withdrawal of 200 tons of the product. The aim of this study was to identify the mycobiota at two Norwegian production sites and determine which species present the highest risk for reduced product quality and safety. A total of 485 samples from 2014, 2015 and 2016 were analysed for Penicillium and Aspergillus species.

The Microbiome and Metabolites in Fermented Pu-erh Tea as Revealed by High-Throughput Sequencing and Quantitative Multiplex Metabolite Analysis.

Pu-erh is a tea produced in Yunnan, China by microbial fermentation of fresh Camellia sinensis leaves by two processes, the traditional raw fermentation and the faster, ripened fermentation. We characterized fungal and bacterial communities in leaves and both Pu-erhs by high-throughput, rDNA-amplicon sequencing and we characterized the profile of bioactive extrolite mycotoxins in Pu-erh teas by quantitative liquid chromatography-tandem mass spectrometry. We identified 390 fungal and 629 bacterial OTUs from leaves and both Pu-erhs.

Profile and Morphology of Fungal Aerosols Characterized by Field Emission Scanning Electron Microscopy (FESEM).

Fungal aerosols consist of spores and fragments with diverse array of morphologies; however, the size, shape, and origin of the constituents require further characterization. In this study, we characterize the profile of aerosols generated from , and grown for 8 weeks on gypsum boards. Fungal particles were aerosolized at 12 and 20 L min using the Fungal Spore Source Strength Tester (FSSST) and the Stami particle generator (SPG).

Diversity of Aquatic Pseudomonas Species and Their Activity against the Fish Pathogenic Oomycete Saprolegnia.

Emerging fungal and oomycete pathogens are increasingly threatening animals and plants globally. Amongst oomycetes, Saprolegnia species adversely affect wild and cultivated populations of amphibians and fish, leading to substantial reductions in biodiversity and food productivity. With the ban of several chemical control measures, new sustainable methods are needed to mitigate Saprolegnia infections in aquaculture.

Indirect Immunodetection of Fungal Fragments by Field Emission Scanning Electron Microscopy.

Submicronic fungal fragments have been observed in in vitro aerosolization experiments. The occurrence of these particles has therefore been suggested to contribute to respiratory health problems observed in mold-contaminated indoor environments. However, the role of submicronic fragments in exacerbating adverse health effects has remained unclear due to limitations associated with detection methods.

Invasive slug populations (Arion vulgaris) as potential vectors for Clostridium botulinum.

Background: Norwegian meadows, including those for silage production, are recently found heavily invaded by the slug Arion vulgaris in exposed areas. As a consequence, large numbers of slugs might contaminate grass silage and cause a possible threat to animal feed quality and safety. It is well known that silage contaminated by mammalian or avian carcasses can lead to severe outbreaks of botulism among livestock.

Submicronic fungal bioaerosols: high-resolution microscopic characterization and quantification.

Submicronic particles released from fungal cultures have been suggested to be additional sources of personal exposure in mold-contaminated buildings. In vitro generation of these particles has been studied with particle counters, eventually supplemented by autofluorescence, that recognize fragments by size and discriminate biotic from abiotic particles. However, the fungal origin of submicronic particles remains unclear.

Molecular detection and genotyping of Aphanomyces astaci directly from preserved crayfish samples uncovers the Norwegian crayfish plague disease history.

Aphanomyces astaci causes crayfish plague in European freshwater crayfish, but most historical epizootics lack agent isolation and identification. Although declared as crayfish plague outbreaks by the Norwegian Competent Authorities, only presumptive diagnoses without agent isolation exist from Norwegian epizootics until 2005. Molecular methods now allow both A.

Role of pathogen-derived cell wall carbohydrates and prostaglandin E2 in immune response and suppression of fish immunity by the oomycete Saprolegnia parasitica.

Saprolegnia parasitica is a freshwater oomycete that is capable of infecting several species of fin fish. Saprolegniosis, the disease caused by this microbe, has a substantial impact on Atlantic salmon aquaculture. No sustainable treatment against saprolegniosis is available, and little is known regarding the host response.

Boric acid inhibits germination and colonization of Saprolegnia spores in vitro and in vivo.

Saprolegnia infections cause severe economic losses among freshwater fish and their eggs. The banning of malachite green increased the demand for finding effective alternative treatments to control the disease. In the present study, we investigated the ability of boric acid to control saprolegniosis in salmon eggs and yolk sac fry.

Deciphering microbial landscapes of fish eggs to mitigate emerging diseases.

Animals and plants are increasingly suffering from diseases caused by fungi and oomycetes. These emerging pathogens are now recognized as a global threat to biodiversity and food security. Among oomycetes, Saprolegnia species cause significant declines in fish and amphibian populations.

Development and reproduction of Saprolegnia species in biofilms.

Saprolegnia spp. can cause mortality and economic losses in freshwater fish and eggs. Biofilm formation is generally regarded as a virulence factor, and biofilms can be an important cause of infection recurrence.

Emerging pathogen Aspergillus calidoustus colonizes water distribution systems.

Recent studies have changed the taxonomy of Aspergillus section Usti, and a novel species, Aspergillus calidoustus, has been erected. It was also demonstrated that clinical isolates previously identified as A. ustus actually belong to the emerging pathogen A.

Fungal growth pattern, sources and factors of mould contamination in a dry-cured meat production facility.

The aims of this study were to investigate the patterns of fungal growth on dry-cured meat products, identify the important sources and factors of contamination and recommend intervention measures. The production processes of two smoked dry-cured hams and one unsmoked dry-cured leg of lamb were studied. A longitudinal observational study was performed to collect 642 samples from the meat, production materials, room installations and indoor and outdoor air of the production facility.

Microwell enumeration of viable Saprolegniaceae in water samples.

Existing methods for enumeration of viable Saprolegniaceae propagules in water are laborious, time consuming and prevent examination of large numbers of samples or samples with high spore loads. In the present study a microwell plate (MWP) assay for estimation of Saprolegniaceae in water samples, modified from Hagen (1992), was evaluated. The ability of the assay to recover Saprolegniaceae was assessed by applying it to spore suspensions with four predetermined concentrations, 500-10,000 spores per liter of samples tested.

DNA damage and DNA damage responses in THP-1 monocytes after exposure to spores of either Stachybotrys chartarum or Aspergillus versicolor or to T-2 toxin.

We have characterized cell death in THP-1 cells after exposure to heat-treated spores from satratoxin G-producing Stachybotrys chartarum isolate IBT 9631, atranone-producing S. chartarum isolate IBT 9634, and sterigmatocystin-producing Aspergillus versicolor isolate IBT 3781, as well as the trichothecenes T-2 and satratoxin G. Spores induced cell death within 3-6 h, with Stachybotrys appearing most potent.

Yeast diversity and dynamics in the production processes of Norwegian dry-cured meat products.

This study investigate the diversity and dynamics of yeasts in the production processes of one unsmoked and two smoked dry-cured meat products of a Norwegian dry-cured meat production facility. A longitudinal observational study was performed to collect 642 samples from the meat, production materials, room installations and indoor and outdoor air of the production facility. Nutrient rich agar media were used to isolate the yeasts.

Determination of cyclopiazonic acid in food and feeds by liquid chromatography-tandem mass spectrometry.

A new, fast and efficient multiple reaction monitoring (MRM) high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for the determination of cyclopiazonic acid (CPA) in mixed feed, wheat, peanuts and rice is presented. The analytical methodology involves sample extraction with an alkaline methanol-water mixture, defatting with hexane and quantification using HPLC-MS/MS without further treatment of sample extracts. Reversed-phase liquid chromatography using a C18 stationary phase coupled to negative mode electrospray triple quadrupole tandem mass spectrometry was applied.

The study of fungi in drinking water.

The occurrence of fungi in drinking water has received increased attention in the last decades, and fungi are now generally accepted as drinking water contaminants. The knowledge about the occurrence and diversity of fungi in water has increased considerably from a low knowledge base. However, the relevance of waterborne fungi for water quality and human health is poorly understood and still conflicting.

Moulds contaminants on Norwegian dry-cured meat products.

Dry-cured meat production has a long tradition in Norway. However, uncontrolled mould growth on the surface of the dry-cured meat products is causing significant quality problems. As some moulds are mycotoxigenic, their growth on the dry-cured meat products could also pose a serious health risk.

Exploring the species diversity of Trichoderma in Norwegian drinking water systems by DNA barcoding.

A total of 123 Trichoderma strains were isolated from Norwegian surface-sourced drinking water. The water samples included raw water, treated water, and water from private homes and hospital installations. Trichoderma species are difficult to differentiate morphologically, but recent molecular identification tools, including DNA barcoding, successfully distinguish between closely related species.