Developing the MAR databases – Augmenting Genomic Versatility of Sequenced Marine Microbiota

This thesis introduces the MAR databases as marine-specific resources in the genomic landscape. Paper 1 describes the curation effort and development leading to the MAR databases being created. It results in the highly valued reference database MarRef, the broader MarDB, and the marine gene catalog MarCat. Definition of a marine environment, the curation process, and the Marine Metagenomics Portal as a public web-service are described. It facilitates scientists to find marine sequence data for prokaryotes and to explore rich contextual information, secondary metabolites, updated taxonomy, and helps in evaluating genome quality. Many of these database advancements are covered in Paper 2. This includes new entries and development of specific databases on marine fungi (MarFun) and salmon related prokaryotes (SalDB). With the implementation of metagenome assembled and single amplified genomes it leads up to the database quality evaluation discussed in Paper 3. The lack of quality control in primary databases is here discussed based on estimated completeness and contamination in the genomes of the MAR databases. Paper 4 explores the microbiota of skin and gut mucosa of Atlantic salmon. By using a database dependent amplicon analysis, the full-length 16 rRNA gene proved accurate, but not a game-changer in taxonomic classification for this environmental niche. The proportion of dataset sequences lacking clear taxonomic classification suggests lack of diversity in current-day databases and inadequate phylogenetic resolution. Advancing phylogenetic resolution was the subject of Paper 5. Here the highly similar species of genus Aliivibrio became delineated using six genes in a multilocus sequence analysis. Five potentially novel species could in this way be delineated, which coincided with recent genome-wide taxonomy listings. Thus, Paper 4 and 5 parallel those of the MAR databases by providing insight into the inter-relational framework of bioinformatic analysis and marine database sources

FAIR+E pathogen data for surveillance and research: lessons from COVID-19

The COVID-19 pandemic has exemplified the importance of interoperable and equitable data sharing for global surveillance and to support research. While many challenges could be overcome, at least in some countries, many hurdles within the organizational, scientific, technical and cultural realms still remain to be tackled to be prepared for future threats. We propose to (i) continue supporting global efforts that have proven to be efficient and trustworthy toward addressing challenges in pathogen molecular data sharing; (ii) establish a distributed network of Pathogen Data Platforms to (a) ensure high quality data, metadata standardization and data analysis, (b) perform data brokering on behalf of data providers both for research and surveillance, (c) foster capacity building and continuous improvements, also for pandemic preparedness; (iii) establish an International One Health Pathogens Portal, connecting pathogen data isolated from various sources (human, animal, food, environment), in a truly One Health approach and following FAIR principles. To address these challenging endeavors, we have started an ELIXIR Focus Group where we invite all interested experts to join in a concerted, expert-driven effort toward sustaining and ensuring high-quality data for global surveillance and research

An Insight into the Aliivibrio genus. A comparative study on relationships and traits of species within the genus Aliivibrio

Few studies have emphasized on the genus Aliivibrio as a whole and lags behind the better known Vibrio. Nevertheless, the Aliivibrio has for several decades been associated with species expressing bioluminescence like the Aliivibrio fischeri, but has also been linked to costly diseases in the fish farming industry such as Aliivibrio salmonicida. In an attempt to gain insight in the genus on a broad level, Aliivibrio genomes were sequenced, assembled and annotated prior to phylogenetic and pan-genome analysis. Additionally, mapping of genes related to quorum sensing and the CRISPR defense system was performed in a comparative manner. Works like this have never been carried out before on this scale for the Aliivibrio and is needed to better understand the complexity of this genus

D3.3 (M18) - Report on curation in core ELIXIR registries (an ELIXIR Norway ELIXIR3 deliverable)

This report serves as an update on the progress of WP3 Task 3.4 in ELIXIR3, in support of curation efforts on content in repositories of metadata, datasets, tools, training, workflows, and other resources, in line with the ELIXIR Platforms. The report documents progress made, methods used, and plans for the near future as of month 18 of a 48-month timeline. ELIXIR Norway extends support to numerous internal and external service providers in Norway, in cases where the services have been accepted as ELIXIR Services. Being an ELIXIR Service comes with many advantages, from gaining exposure to a broader range of potential users to a raised profile throughout ELIXIR, that can help secure future funding, among other benefits. While these Services maintain specific operational responsibilities, ELIXIR Norway offers versatile infrastructure-related support. We provide a first-line helpdesk, potential Node e-infrastructure integration (where feasible), service monitoring, and metrics collection. Our technology hub further enriches this by imparting best practices and standards, and hosting workshops and conferences. The inception of Task 3.4 is based on observations that most ELIXIR Norway Services do not promote available resources sufficiently, including relevant ontologies, essential repositories like Bio.tools and FAIRsharing, and key Services from other ELIXIR Platforms. The primary objective of the Task is to assist service providers, task forces, and other Tasks and work packages in effectively using available resources for maximum benefit. The work in this Task has been aligned with, and partially builds up on the work performed in the European context in the H2020 project ELIXIR-CONVERGE (February 2020 - July 2023) (871074)

Phylogenetic Revision of the Genus Aliivibrio: Intra- and Inter-Species Variance Among Clusters Suggest a Wider Diversity of Species

Genus Aliivibrio is known to harbor species exhibiting bioluminescence as well as pathogenic behavior affecting the fish farming industry. Current phylogenetic understanding of Aliivibrio has largely remained dormant after reclassification disentangled it from the Vibrio genus in 2007. There is growing evidence of wider diversity, but until now the lack of genomes and selective use of type strains have limited the ability to compare and classify strains firmly. In this study, a total of 143 bacterial strains, including 51 novel sequenced strains, were used to strengthen phylogenetic relationships in Aliivibrio by exploring intra-species and inter-species relations. Multilocus sequence analysis (MLSA), applying the six housekeeping genes 16S ribosomal RNA (rRNA), gapA, gyrB, pyrH, recA, and rpoA, inferred 12 clades and a singular branch in Aliivibrio. Along with four new phylogenetic clades, the MLSA resolved prior inconsistencies circumscribing Aliivibrio wodanis and formed a unique clade we propose as the novel species Aliivibrio sp. “friggae.” Furthermore, phylogenetic assessment of individual marker genes showed gyrB, pyrH, and recA superior to the 16S rRNA gene, resolving accurately for most species clades in Aliivibrio. In this study, we provide a robust phylogenetic groundwork for Aliivibrio as a reference point to classification of species

Full‐length 16S rRNA gene classification of Atlantic salmon bacteria and effects of using different 16S variable regions on community structure analysis

Understanding fish‐microbial relationships may be of great value for fish producers as fish growth, development and welfare are influenced by the microbial community associated with the rearing systems and fish surfaces. Accurate methods to generate and analyze these microbial communities would be an important tool to help improve understanding of microbial effects in the industry. In this study, we performed taxonomic classification and determination of operational taxonomic units on Atlantic salmon microbiota by taking advantage of full‐length 16S rRNA gene sequences. Skin mucus was dominated by the genera Flavobacterium and Psychrobacter. Intestinal samples were dominated by the genera Carnobacterium, Aeromonas, Mycoplasma and by sequences assigned to the order Clostridiales. Applying Sanger sequencing on the full‐length bacterial 16S rRNA gene from the pool of 46 isolates obtained in this study showed a clear assignment of the PacBio full‐length bacterial 16S rRNA gene sequences down to the genus level. One of the bottlenecks in comparing microbial profiles is that different studies use different 16S rRNA gene regions. Comparisons of sequence assignments between full‐length and in silico derived variable 16S rRNA gene regions showed different microbial profiles with variable effects between phylogenetic groups and taxonomic ranks

Full‐length 16S rRNA gene classification of Atlantic salmon bacteria and effects of using different 16S variable regions on community structure analysis

Understanding fish‐microbial relationships may be of great value for fish producers as fish growth, development and welfare are influenced by the microbial community associated with the rearing systems and fish surfaces. Accurate methods to generate and analyze these microbial communities would be an important tool to help improve understanding of microbial effects in the industry. In this study, we performed taxonomic classification and determination of operational taxonomic units on Atlantic salmon microbiota by taking advantage of full‐length 16S rRNA gene sequences. Skin mucus was dominated by the genera Flavobacterium and Psychrobacter. Intestinal samples were dominated by the genera Carnobacterium, Aeromonas, Mycoplasma and by sequences assigned to the order Clostridiales. Applying Sanger sequencing on the full‐length bacterial 16S rRNA gene from the pool of 46 isolates obtained in this study showed a clear assignment of the PacBio full‐length bacterial 16S rRNA gene sequences down to the genus level. One of the bottlenecks in comparing microbial profiles is that different studies use different 16S rRNA gene regions. Comparisons of sequence assignments between full‐length and in silico derived variable 16S rRNA gene regions showed different microbial profiles with variable effects between phylogenetic groups and taxonomic ranks

Pan genome and CRISPR analyses of the bacterial fish pathogen Moritella viscosa

Background: Winter-ulcer Moritella viscosa infections continue to be a significant burden in Atlantic salmon (Salmo salar L.) farming. M. viscosa comprises two main clusters that differ in genetic variation and phenotypes including virulence. Horizontal gene transfer through acquisition and loss of mobile genetic elements (MGEs) is a major driving force of bacterial diversification. To gain insight into genomic traits that could affect sublineage evolution within this bacterium we examined the genome sequences of twelve M. viscosa strains. Matches between M. viscosa clustered, regularly interspaced, short palindromic, repeats and associated cas genes (CRISPR-Cas) were analysed to correlate CRISPR-Cas with adaptive immunity against MGEs. Results: The comparative genomic analysis of M. viscosa isolates from across the North Atlantic region and from different fish species support delineation of M. viscosa into four phylogenetic lineages. The results showed that M. viscosa carries two distinct variants of the CRISPR-Cas subtype I-F systems and that CRISPR features follow the phylogenetic lineages. A subset of the spacer content match prophage and plasmid genes dispersed among the M. viscosa strains. Further analysis revealed that prophage and plasmid-like element distribution were reflected in the content of the CRISPR-spacer profiles. Conclusions: Our data suggests that CRISPR-Cas mediated interactions with MGEs impact genome properties among M. viscosa, and that patterns in spacer and MGE distributions are linked to strain relationships