Survival of animal and human associated <i>Listeria monocytogenes</i> in drinking water and biofilms

Land slugs are occasionally observed as contaminants in groundwater wells and drinking water treatment plants including storage tanks. Slugs may feed on carrion and feces, and they are potential vectors of pathogens such as Listeria monocytogenes. We isolated L monocytogenes from the pest slug Arion vulgaris and examined the persistence and survival of human- and slug-derived L. monocytogenes in groundwater-based drinking water and biofilms. L monocytogenes survival was evaluated using cultivation and cultivation-independent techniques. L monocytogenes remained culturable for 35-47 days in drinking water with first-order decay rates between 0.314 and 0.457 hr1 (T99 &gt;10 days). Attachment of L monocytogenes to filter sand delayed washout from drinking water filters and increased persistence 2-3-fold. Indigenous biofilms stimulated initial surface attachment 10-100-fold butL. monocytogenes declined more rapidly in drinking water biofilms compared with virgin filters not colonized by microorganisms. Grazing by protozoa likely attenuated L monocytogenes survival in some drinking water biofilms. A comparable survival pattern was observed for L monocytogenes and the fecal indicator bacterium E. coli. The study suggests that live L monocytogenes can persist for weeks as sessile organisms in groundwater-based drinking water supplies and may subsequently be released to the drinking water.</p

Tekniske anvisninger for eDNA-baseret overvågning af ikke-hjemmehørende marine arter

Prosjektleder: Steen W. KnudsenDenne tekniske anvisning (TA) er en revideret udgave af de anvisninger, der tidligere er udarbejdet for Miljøstyrelsen og publiceret vinteren 2017/2018 (notat i 2017 og egentlig TA i 2018) og efterfølgende opdateret i januar 2020. De reviderede tekniske anvisninger indeholder en detaljeret protokol for hvordan miljø-DNA (environmental-DNA eller blot eDNA) kan indsamles, opbevares, oprenses og spores. Anvisningerne er delt i tre dele og omfatter (1) indsamling og filtrering af vand med instruktionerne for efterfølgende opbevaring af filterenheder, (2) ekstraktion af eDNA fra filterenheder, og (3) sporing af eDNA ved hjælp af PCR der kan kvantificere antallet af DNA-molekyler ekstraheret fra filterprøven. Den sidste del med kvantitativ sporing forudsætter, der er udviklet og testet artsspecifikke primere og prober for korrekt sporing af eDNA stammende kun fra de pågældende ikke-hjemmehørende arter.MiljøstyrelsenpublishedVersio

Ikke-hjemmehørende arter i marine områder

Projektleder Jesper H. AndersenDenne rapport omhandler ikke-hjemmehørende arter i de danske farvande og består af to dele. Den første vedrører en opdate-ring af den nationale liste over ikke-hjemmhørende arter i de danske farvande – også kaldet NIS-listen. Den anden del er en ana-lyse af de foreliggede data og informationer om forekomst af ikke-hjemmehørende arter i de danske farvande. Datagrundlaget er væsentligt forbedret siden den første nationale NIS-liste blev udarbejdet. De fire væsentligste forbedringer er: (1) data fra Statens Naturhistoriske Museums Fiskeatlas er nu med, (2) data fra NOVANA-overvågningen omfatter nu flere år (til og med 2018), (3) data fra 2017 om forekomsten af ikke-hjemmehørende arter i 16 danske havne er tilføjet, og (4) data for 2017 og 2018, baseret på eDNA-analyser på 33 stationer i NOVANA-programmet, er nu med. Med den ny NIS-liste og den landsdæk-kende analyse foreligger der nu en opdatering af forekomster af ikke-hjemmehørende arter, herunder fisk, i de danske farvande.publishedVersio

Tekniske anvisninger for eDNA-baseret overvågning af ikke-hjemmehørende marine arter

Forskningschef Jesper H. AndersenDisse tekniske anvisninger er en revideret udgave af de ansvisninger, der tidligere er udarbejdet for Miljøstyrelsen og publiceret vinteren 2017/2018. De reviderede tekniske anvisninger indeholder en detaljeret protokol for hvordan miljø-DNA (environ-mental-DNA eller blot eDNA) kan indsamles, opbevares, oprenses og spores. Anvisningerne er delt i tre dele og omfatter (1) indsamling og filtrering af vand med instruktionerne for efterfølgende opbevaring af filterenheder, (2) ekstraktion af eDNA fra filterenheder, og (3) sporing af eDNA ved hjælp af kvantitativ PCR. Den sidste del med kvantitativ sporing forudsætter, der er udviklet og testet artsspecifikke primere og prober for korrekt sporing af eDNA stammende kun fra ikke-hjemmehørende arter.Miljøstyrelsen (MST)publishedVersio

A baseline study of the occurrence of non-indigenous species in Danish harbours

Project Manager/Main Author Jesper H. AndersenWe report the first ever nation-wide study of the occurrence of non-indigenous species in Danish harbours. The sampling was car-ried out using both conventional and biomolecular methods (eDNA). In total, 16 harbours were covered – Esbjerg and Aarhus, the two largest harbours in Denmark, with intensive sampling and 14 harbours with a reduced programme. 26 non-indigenous species were recorded using conventional sampling and 13 species were recorded using eDNA-based methods. Excluding overlapping rec-ords, we have recorded a total of 34 non-indigenous species in the 16 harbours studied. Based on the results, we conclude the following: 1) more non-indigenous species are found in the western parts of Denmark (North Sea region) then in the eastern parts (Baltic Sea), and 2) a few species previously unseen in Danish marine waters were recorded, i.e. the two bristle worms Eteone het-eropoda (fam. Phyllodocidae) and Streblospio benedicti (fam. Spionidae). Further, we provide a proof-of-concept regarding the overarching objectives of the MONIS 1-3 projects and the eDNA-based test systems developed. The results constitute a baseline for future studies in Danish ports and other hotspot areas.publishedVersio

The diversity of population responses to environmental change

This is the final version. Available from Wiley via the DOI in this record.Data available from the Dryad Digital Repository: https:// doi.org/10.5061/dryad.d5f54s7The current extinction and climate change crises pressure us to predict population dynamics with ever-greater accuracy. Although predictions rest on the well-advanced theory of age-structured populations, two key issues remain poorly explored. Specifically, how the age-dependency in demographic rates and the year-to-year interactions between survival and fecundity affect stochastic population growth rates. We use inference, simulations and mathematical derivations to explore how environmental perturbations determine population growth rates for populations with different age-specific demographic rates and when ages are reduced to stages. We find that stage- vs. age-based models can produce markedly divergent stochastic population growth rates. The differences are most pronounced when there are survival-fecundity-trade-offs, which reduce the variance in the population growth rate. Finally, the expected value and variance of the stochastic growth rates of populations with different age-specific demographic rates can diverge to the extent that, while some populations may thrive, others will inevitably go extinct.Max Planck Society, Marie Curie FellowshipERCGerman Research FoundationSwiss National Science FoundationNational Science FoundationNational Institute of AgingRamon y Cajal Research GrantWenner-Gren FoundationLeakey FoundationNational Geographic SocietyZoological Society of San DiegoUniversity of PennsylvaniaArgentinean National Council of Researc