European Union Reference Laboratories support the National food, feed and veterinary Reference Laboratories with rolling out whole genome sequencing in Europe.

The Inter European Union Reference Laboratories (EURLs) Working Group on Next Generation Sequencing (NGS) involves eight EURLs for microbiological food and feed hazards and has been working since 2017 to promote the adoption of NGS by the National Reference Laboratories (NRLs) in the European Union. This work illustrates the results of the first 5 years of activity. By working together, the EURLs involved have released guidance documents for assisting NRLs in all the steps of NGS, helping the transition from classical molecular methods towards whole genome sequencing while ensuring harmonization, with the final aim of improving preparedness in the use of NGS to characterize microbial hazards and trace the sources of infection.

The efficiency of Nextera XT tagmentation depends on G and C bases in the binding motif leading to uneven coverage in bacterial species with low and neutral GC-content.

Whole-genome sequencing (WGS) is becoming the new standard for bacterial high-resolution typing and the performance of laboratories is being evaluated in interlaboratory comparisons. The use of the Illumina Nextera XT library preparation kit has been found to be associated with poorer performance due to a GC-content-dependent coverage bias. The bias is especially strong when sequencing low GC-content species.

A shotgun metagenomic investigation of the microbiota of udder cleft dermatitis in comparison to healthy skin in dairy cows.

Udder cleft dermatitis (UCD) is a skin condition affecting the fore udder attachment of dairy cows. UCD may be defined as mild (eczematous skin changes) or severe (open wounds, large skin changes). Our aims were to compare the microbiota of mild and severe UCD lesions with the microbiota of healthy skin from the fore udder attachment of control cows, and to investigate whether mastitis-causing pathogens are present in UCD lesions.

The Human Adenovirus Type 2 Transcriptome: An Amazing Complexity of Alternatively Spliced mRNAs.

We have used the Nanopore long-read sequencing platform to demonstrate how amazingly complex the human adenovirus type 2 (Ad2) transcriptome is with a flexible splicing machinery producing a range of novel mRNAs both from the early and late transcription units. In total we report more than 900 alternatively spliced mRNAs produced from the Ad2 transcriptome whereof more than 850 are novel mRNAs. A surprising finding was that more than 50% of all E1A transcripts extended upstream of the previously defined transcriptional start site.

The Most Frequently Used Sequencing Technologies and Assembly Methods in Different Time Segments of the Bacterial Surveillance and RefSeq Genome Databases.

Whole genome sequencing has become a powerful tool in modern microbiology. Especially bacterial genomes are sequenced in high numbers. Whole genome sequencing is not only used in research projects, but also in surveillance projects and outbreak investigations.

Mesenchymal transition and increased therapy resistance of glioblastoma cells is related to astrocyte reactivity.

Grade IV astrocytoma/glioblastoma multiforme (GBM) is essentially incurable, partly due to its heterogenous nature, demonstrated even within the glioma-initiating cell (GIC) population. Increased therapy resistance of GICs is coupled to transition into a mesenchymal (MES) cell state. The GBM MES molecular signature displays a pronounced inflammatory character and its expression vary within and between tumors.

Clonal Variation in Drug and Radiation Response among Glioma-Initiating Cells Is Linked to Proneural-Mesenchymal Transition.

Intratumoral heterogeneity is a hallmark of glioblastoma multiforme and thought to negatively affect treatment efficacy. Here, we establish libraries of glioma-initiating cell (GIC) clones from patient samples and find extensive molecular and phenotypic variability among clones, including a range of responses to radiation and drugs. This widespread variability was observed as a continuum of multitherapy resistance phenotypes linked to a proneural-mesenchymal shift in the transcriptome.

Genetic analysis of a Treponema phagedenis locus encoding antigenic lipoproteins with potential for antigenic variation.

Digital dermatitis (DD) is a painful and debilitating claw disease in cattle. Spirochetes of the genus Treponema are found in high numbers in the lesions and are likely to be involved in the pathogenesis. The occurrence of Treponema phagedenis in DD lesions, especially near the interface of healthy and diseased tissue, suggests that this species contributes to the development and/or progression of the lesions.

Plasmidome interchange between Clostridium botulinum, Clostridium novyi and Clostridium haemolyticum converts strains of independent lineages into distinctly different pathogens.

Clostridium botulinum (group III), Clostridium novyi and Clostridium haemolyticum are well-known pathogens causing animal botulism, gas gangrene/black disease, and bacillary hemoglobinuria, respectively. A close genetic relationship exists between the species, which has resulted in the collective term C. novyi sensu lato.

Small RNA sequence analysis of adenovirus VA RNA-derived miRNAs reveals an unexpected serotype-specific difference in structure and abundance.

Human adenoviruses (HAds) encode for one or two highly abundant virus-associated RNAs, designated VA RNAI and VA RNAII, which fold into stable hairpin structures resembling miRNA precursors. Here we show that the terminal stem of the VA RNAs originating from Ad4, Ad5, Ad11 and Ad37, all undergo Dicer dependent processing into virus-specific miRNAs (so-called mivaRNAs). We further show that the mivaRNA duplex is subjected to a highly asymmetric RISC loading with the 3'-strand from all VA RNAs being the favored strand, except for the Ad37 VA RNAII, where the 5'-mivaRNAII strand was preferentially assembled into RISC.

Microevolution during an Anthrax outbreak leading to clonal heterogeneity and penicillin resistance.

Anthrax is a bacterial disease primarily affecting grazing animals but it can also cause severe disease in humans. We have used genomic epidemiology to study microevolution of the bacterium in a confined outbreak in cattle which involved emergence of an antibiotic-resistant phenotype. At the time of death, the animals contained a heterogeneous population of Single Nucleotide Variants (SNVs), some being clonal but most being subclonal.

Multiplex real-time PCR for detecting and typing Clostridium botulinum group III organisms and their mosaic variants.

Botulism is a neuroparalytic disease that can occur in all warm-blooded animals, birds, and fishes. The disease in animals is mainly caused by toxins produced by Clostridium botulinum strains belonging to group III, although outbreaks due to toxins produced by group I and II organisms have been recognized. Group III strains are capable of producing botulinum toxins of type C, D, and C/D and D/C mosaic variants.

Management of animal botulism outbreaks: from clinical suspicion to practical countermeasures to prevent or minimize outbreaks.

Botulism is a severe neuroparalytic disease that affects humans, all warm-blooded animals, and some fishes. The disease is caused by exposure to toxins produced by Clostridium botulinum and other botulinum toxin-producing clostridia. Botulism in animals represents a severe environmental and economic concern because of its high mortality rate.

In silico and in vitro evaluation of PCR-based assays for the detection of Bacillus anthracis chromosomal signature sequences.

Bacillus anthracis, the causative agent of anthrax, is a zoonotic pathogen that is relatively common throughout the world and may cause life threatening diseases in animals and humans. There are many PCR-based assays in use for the detection of B. anthracis.

Genome-wide relatedness of Treponema pedis, from gingiva and necrotic skin lesions of pigs, with the human oral pathogen Treponema denticola.

Treponema pedis and T. denticola are two genetically related species with different origins of isolation. Treponema denticola is part of the human oral microbiota and is associated with periodontitis while T.

The adenovirus VA RNA-derived miRNAs are not essential for lytic virus growth in tissue culture cells.

At late times during a lytic infection human adenovirus type 5 produces ∼10(8) copies per cell of virus-associated RNA I (VA RNAI). This short highly structured RNA polymerase III transcript has previously been shown to be essential for lytic virus growth. A fraction of VA RNAI is processed by Dicer into small RNAs, so-called mivaRNAIs, which are efficiently incorporated into the RNA-induced silencing complex.

The genetic integrity of bacterial species: the core genome and the accessory genome, two different stories.

Strains within a bacterial species typically have a set of conserved core genes and a variable set of accessory genes. The accessory genes often appear to move laterally between strains, thereby forming new trait combinations. Sometimes, genetic material also moves laterally between species, thereby resulting in diffuse borders between them.

Gegenees: fragmented alignment of multiple genomes for determining phylogenomic distances and genetic signatures unique for specified target groups.

The rapid development of Next Generation Sequencing technologies leads to the accumulation of huge amounts of sequencing data. The scientific community faces an enormous challenge in how to deal with this explosion. Here we present a software tool, 'Gegenees', that uses a fragmented alignment approach to facilitate the comparative analysis of hundreds of microbial genomes.

Horizontal gene transfer of toxin genes in Clostridium botulinum: Involvement of mobile elements and plasmids.

Intoxication with the potent botulinum neurotoxin (BoNT) gives rise to the serious paralytic illness botulism. BoNT is part of a complex that consists of the neurotoxin and several associated components, all encoded by the bont gene cluster. This gene cluster has likely been subjected to horizontal gene transfer between different groups of clostridia, which has given rise to the genetically diverse species Clostridium botulinum.

Complete genome sequence of Brachyspira intermedia reveals unique genomic features in Brachyspira species and phage-mediated horizontal gene transfer.

Background: Brachyspira spp. colonize the intestines of some mammalian and avian species and show different degrees of enteropathogenicity. Brachyspira intermedia can cause production losses in chickens and strain PWS/AT now becomes the fourth genome to be completed in the genus Brachyspira.

Clostridium botulinum group III: a group with dual identity shaped by plasmids, phages and mobile elements.

Background: Clostridium botulinum strains can be divided into four physiological groups that are sufficiently diverged to be considered as separate species. Here we present the first complete genome of a C. botulinum strain from physiological group III, causing animal botulism.

Towards an international standard for detection and typing botulinum neurotoxin-producing Clostridia types A, B, E and F in food, feed and environmental samples: a European ring trial study to evaluate a real-time PCR assay.

A real-time PCR method for detection and typing of BoNT-producing Clostridia types A, B, E, and F was developed on the framework of the European Research Project "Biotracer". A primary evaluation was carried out using 104 strains and 17 clinical and food samples linked to botulism cases. Results showed 100% relative accuracy, 100% relative sensitivity, 100% relative specificity, and 100% selectivity (inclusivity on 73 strains and exclusivity on 31 strains) of the real-time PCR against the reference cultural method combined with the standard mouse bioassay.

Accidental and deliberate microbiological contamination in the feed and food chains--how biotraceability may improve the response to bioterrorism.

A next frontier of the global food safety agenda has to consider a broad spectrum of bio-risks, such as accidental and intentional contaminations in the food and feed chain. In this article, the background for the research needs related to biotraceability and response to bioterrorism incidents are outlined. Given the current scale of international trade any response need to be considered in an international context.

A multiplex real-time PCR for identifying and differentiating B. anthracis virulent types.

Bacillus anthracis is closely related to the endospore forming bacteria Bacillus cereus and Bacillus thuringiensis. For accurate detection of the life threatening pathogen B. anthracis, it is essential to distinguish between these three species.

Bioinformatic tools for using whole genome sequencing as a rapid high resolution diagnostic typing tool when tracing bioterror organisms in the food and feed chain.

The rapid technological development in the field of parallel sequencing offers new opportunities when tracing and tracking microorganisms in the food and feed chain. If a bioterror organism is deliberately spread it is of crucial importance to get as much information as possible regarding the strain as fast as possible to aid the decision process and select suitable controls, tracing and tracking tools. A lot of efforts have been made to sequence multiple strains of potential bioterror organisms so there is a relatively large set of reference genomes available.