Abdelhameed Elameen
Forsker
(+47) 926 08 797
abdelhameed.elameen@nibio.no
Sted
Ås - Bygg H7
Besøksadresse
Høgskoleveien 7, 1433 Ås
Forfattere
Michael Dondrup Atle Ove Martinussen Lisa Karine Haugland Jonas Brandenburg Oya Inanli Abdelhameed Elameen David William Peter Dolan Sushma Nagaraja Grellscheid Snorre Hagen Hannes Schroeder Tor Myking Hans Geir EikenSammendrag
The use of Saccharomyces cerevisiae to ferment alcoholic beverages is an ancient tradition, with genetic evidence indicating origins in Neolithic Asia, although the domestication process of the species is not fully understood. Kveik is a group of traditional yeasts used in farmhouse brewing in western Norway preserved through generations of rural brewing practice. While recent studies have highlighted the distinctiveness of kveik, its precise phylogenetic position, genetic diversity, and domestication history remain unclear. We performed whole-genome sequencing on 64 isolates from 25 traditional brewing cultures from Western Norway selected using cultural heritage criteria and generated telomere-to-telomere assemblies for selected strains. Phylogenomic and population genetic analyses reveal that kveik strains form a paraphyletic and early-diverging group with respect to other domesticated S. cerevisiae strains. Most strains exhibit low diversity among isolates from the same brewing culture, strong geographic clustering, and little evidence of gene flow or admixture. Mitochondrial genomes and Ty1 retrotransposon profiles corroborate this distinct lineage history. We further show that previously reported signals of gene flow between kveik and Asian fermentation strains are likely artifacts caused by population structure and selection. Divergence time estimates suggest that the common ancestor of beer, kveik, and other liquid-phase fermenting strains originated from ancestral populations 4,000 to 8,000 years ago. Our genomic resource sheds light on yeast evolution and domestication. Kveik likely comprises some of the oldest domesticated lineages in continuous use until today, connecting intangible cultural heritage to an early genetic origin.
Forfattere
Anne Straumfors Anani Komlavi Afanou Oda Astrid Haarr Foss Abdelhameed Elameen Mikkel Meyn Liljegren Hans Geir EikenSammendrag
Background: Pesticides are used in greenhouse cultivation to control fungi and pests and to shape plant growth. This influences microbial communities and may increase the selective pressure for resistant species development. Antimicrobial resistance (AMR) is a growing global health challenge, and while AMR dispersal through soil and water is well studied, the role of bioaerosols as AMR vectors remains insufficiently explored. Objectives: To explore the link between chemical pesticide and the prevalence of AMR genes in aerosols from greenhouses using pesticides and those not using them. Methods: Forty-nine fullshift personal samples of inhalable dust were collected in eight greenhouses from 2021 and 2024. Five greenhouses used chemical pesticides and three did not. DNA was extracted and screened for the presence of 45 clinically relevant AMR genes using HT-qPCR. Results: Twenty of the 45 screened genes were detected. Greenhouses using pesticides showed significantly higher AMR gene levels than those not using chemicals. Several genes, particularly β-lactam and tetracycline resistance genes, occurred in high concentrations, including extreme values exceeding 60,000 gene copies/m³. This suggest that pesticide-using greenhouses may represent a greater risk for AMR dispersal. In contrast, greenhouses without chemical pesticide showed lower and more stable AMR gene levels. Factors other than pesticide application may also contribute, such as import of treated plants, soil and fertilizer materials, plant types or individual workers. Further research is needed to assess the health risks for greenhouse workers and to support the development of effective strategies for preventing and controlling AMR spread.
Forfattere
Dalphy Ondine Camira Harteveld Abdelhameed Elameen Simo Maduna Adam Vivian-Smith Andrea Podavkova Sabine Oettl Stefanie Maria Primisser Jorunn BørveSammendrag
Small, superficial rot spots occurring around lenticels postharvest on apple in Norway have not been identified but were assumed to be underdeveloped Neofabraea lesions. Fungal isolation from such spots on fruit from the 2022 season revealed both Neofabraea perennans and Ramularia spp., identified by B-tubulin and ITS sequencing, respectively. In the 2023 season, isolations were made from fruit with spots resembling dry lenticel spot caused by Ramularia mali. The aim of this study was to identify the Ramularia species associated with the postharvest fruit spots in Norway. Multiple gene regions of five Norwegian isolates (E20, E21 from 2022; 13,15 and 18 from 2023) and three reference isolates, R. mali, R. eucalypti, and R. collo-cygni, were sequenced and used for phylogenetic analysis. The Norwegian isolates were distinct from the included reference isolates, but clustered with other Ramularia species. Isolates 13, 18 and E21 clustered with Ramularia vizellae, while isolates 15 and E20 were most closely related to Ramularia phacae-frigidae. Isolate E20 was sequenced using the Oxford Nanopore Technologies MinION platform. Pathogenicity was assessed in a field inoculation study using isolate E21, resulting in typical spot development on inoculated fruit. Ramularia vizellae has previously been reported from dead apple leaf litter and other woody hosts in the Netherlands and Iran, while R. phacae-frigidae was originally described from Phaca frigida in Switzerland. Neither species has previously been reported in association with apple fruit spotting. While Ramularia mali has caused outbreaks on apple in several European countries, recent studies hypothesize that the symptoms may be caused by a species complex with regional variation. The present results identify candidate species contributing to this complex in Norway and highlight the need for further studies to improve species delimitation and pathogenicity.
