55 research outputs found
Virus Diversity and Loads in Crickets Reared for Feed: Implications for Husbandry
Insects generally have high reproductive rates leading to rapid population growth and high local densities; ideal conditions for disease epidemics. The parasites and diseases that naturally regulate wild insect populations can also impact when these insects are produced commercially, on farms. While insects produced for human or animal consumption are often reared under high density conditions, very little is known about the microbes associated with these insects, particularly those with pathogenic potential. In this study we used both target-free and targeted screening approaches to explore the virome of two cricket species commonly reared for feed and food, Acheta domesticus and Gryllus bimaculatus. The target-free screening of DNA and RNA from a single A. domesticus frass sample revealed that only 1% of the nucleic acid reads belonged to viruses, including known cricket, insect, bacterial and plant pathogens, as well as a diverse selection of novel viruses. The targeted screening revealed relatively high levels of Acheta domesticus densovirus, invertebrate iridovirus 6 and a novel iflavirus, as well as low levels of Acheta domesticus volvovirus, in insect and frass samples from several retailers. Our findings highlight the value of multiple screening approaches for a comprehensive and robust cricket disease monitoring and management strategy. This will become particularly relevant as-and-when cricket rearing facilities scale up and transform from producing insects for animal feed to producing insects for human consumption
Genome dynamics of Bartonella grahamii in micro-populations of woodland rodents
<p>Abstract</p> <p>Background</p> <p>Rodents represent a high-risk reservoir for the emergence of new human pathogens. The recent completion of the 2.3 Mb genome of <it>Bartonella grahamii</it>, one of the most prevalent blood-borne bacteria in wild rodents, revealed a higher abundance of genes for host-cell interaction systems than in the genomes of closely related human pathogens. The sequence variability within the global <it>B. grahamii </it>population was recently investigated by multi locus sequence typing, but no study on the variability of putative host-cell interaction systems has been performed.</p> <p>Results</p> <p>To study the population dynamics of <it>B. grahamii</it>, we analyzed the genomic diversity on a whole-genome scale of 27 <it>B. grahamii </it>strains isolated from four different species of wild rodents in three geographic locations separated by less than 30 km. Even using highly variable spacer regions, only 3 sequence types were identified. This low sequence diversity contrasted with a high variability in genome content. Microarray comparative genome hybridizations identified genes for outer surface proteins, including a repeated region containing the <it>fha </it>gene for filamentous hemaggluttinin and a plasmid that encodes a type IV secretion system, as the most variable. The estimated generation times in liquid culture medium for a subset of strains ranged from 5 to 22 hours, but did not correlate with sequence type or presence/absence patterns of the <it>fha </it>gene or the plasmid.</p> <p>Conclusion</p> <p>Our study has revealed a geographic microstructure of <it>B. grahamii </it>in wild rodents. Despite near-identity in nucleotide sequence, major differences were observed in gene presence/absence patterns that did not segregate with host species. This suggests that genetically similar strains can infect a range of different hosts.</p
Structural magnetic resonance imaging findings and histopathological correlations in motor neuron diseasesâA systematic review and meta-analysis
OBJECTIVES
The lack of systematic evidence on neuroimaging findings in motor neuron diseases (MND) hampers the diagnostic utility of magnetic resonance imaging (MRI). Thus, we aimed at performing a systematic review and meta-analysis of MRI features in MND including their histopathological correlation.
METHODS
In a comprehensive literature search, out of 5941 unique publications, 223 records assessing brain and spinal cord MRI findings in MND were eligible for a qualitative synthesis. 21 records were included in a random effect model meta-analysis.
RESULTS
Our meta-analysis shows that both T2-hyperintensities along the corticospinal tracts (CST) and motor cortex T2-hypointensitites, also called "motor band sign", are more prevalent in ALS patients compared to controls [OR 2.21 (95%-CI: 1.40-3.49) and 10.85 (95%-CI: 3.74-31.44), respectively]. These two imaging findings correlate to focal axonal degeneration/myelin pallor or glial iron deposition on histopathology, respectively. Additionally, certain clinical MND phenotypes such as amyotrophic lateral sclerosis (ALS) seem to present with distinct CNS atrophy patterns.
CONCLUSIONS
Although CST T2-hyperintensities and the "motor band sign" are non-specific imaging features, they can be leveraged for diagnostic workup of suspected MND cases, together with certain brain atrophy patterns. Collectively, this study provides high-grade evidence for the usefulness of MRI in the diagnostic workup of suspected MND cases.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42020182682
Dilated Virchow-Robin spaces are a marker for arterial disease in multiple sclerosis
BACKGROUND
Virchow-Robin spaces (VRS) have been associated with neurodegeneration and neuroinflammation. However, it remains uncertain to what degree non-dilated or dilated VRS reflect specific features of neuroinflammatory pathology. Thus, we aimed at investigating the clinical relevance of VRS as imaging biomarker in multiple sclerosis (MS) and to correlate VRS to their histopathologic signature.
METHODS
In a cohort study comprising 142 MS patients and 30 control subjects, we assessed the association of non-dilated and dilated VRS to clinical and magnetic resonance imaging (MRI) outcomes. Findings were corroborated in a validation cohort comprising 63 MS patients. Brain blocks from 6 MS patients and 3 non-MS controls were histopathologically processed to correlate VRS to their tissue substrate.
FINDINGS
In our actively treated clinical cohort, the count of dilated centrum semiovale VRS was associated with increased T1 and T2 lesion volumes. There was no systematic spatial colocalization of dilated VRS with MS lesions. At tissue level, VRS mostly corresponded to arteries and were not associated with MS pathological hallmarks. Interestingly, in our ex vivo cohort comprising mostly progressive MS patients, dilated VRS in MS were associated with signs of small vessel disease.
INTERPRETATION
Contrary to prior beliefs, these observations suggest that VRS in MS do not associate with an accumulation of immune cells. But instead, these findings indicate vascular pathology as a driver and/or consequence of neuroinflammatory pathology for this imaging feature.
FUNDING
NIH, Swedish Society for Medical Research, Swiss National Science Foundation and University of Zurich
A Phase II Trial of a Personalized, Dose-Intense Administration Schedule of (177)Lutetium-DOTATATE in Children With Primary Refractory or Relapsed High-Risk Neuroblastoma-LuDO-N
Background:& nbsp;Half the children with high-risk neuroblastoma die with widespread metastases. Molecular radiotherapy is an attractive systemic treatment for this relatively radiosensitive tumor. I-131-mIBG is the most widely used form in current use, but is not universally effective. Clinical trials of (177)Lutetium DOTATATE have so far had disappointing results, possibly because the administered activity was too low, and the courses were spread over too long a period of time, for a rapidly proliferating tumor. We have devised an alternative administration schedule to overcome these limitations. This involves two high-activity administrations of single agent Lu-177-DOTATATE given 2 weeks apart, prescribed as a personalized whole body radiation absorbed dose, rather than a fixed administered activity. "A phase II trial of (177)Lutetium-DOTATATE in children with primary refractory or relapsed high-risk neuroblastoma - LuDO-N " (EudraCT No: 2020-004445-36, Identifier: NCT04903899) evaluates this new dosing schedule.& nbsp;Methods:& nbsp;The LuDO-N trial is a phase II, open label, multi-center, single arm, two stage design clinical trial. Children aged 18 months to 18 years are eligible. The trial is conducted by the Nordic Society for Pediatric Hematology and Oncology (NOPHO) and it has been endorsed by SIOPEN (). The Karolinska University Hospital, is the sponsor of the LuDO-N trial, which is conducted in collaboration with Advanced Accelerator Applications, a Novartis company. All Scandinavian countries, Lithuania and the Netherlands participate in the trial and the UK has voiced an interest in joining in 2022.& nbsp;Results:& nbsp;The pediatric use of the Investigational Medicinal Product (IMP) Lu-177-DOTATATE, as well as non-IMPs SomaKit TOC (R) (Ga-68-DOTATOC) and LysaKare (R) amino acid solution for renal protection, have been approved for pediatric use, within the LuDO-N Trial by the European Medicines Agency (EMA). The trial is currently recruiting. Recruitment is estimated to be finalized within 3-5 years.& nbsp;Discussion:& nbsp;In this paper we present the protocol of the LuDO-N Trial. The rationale and design of the trial are discussed in relation to other ongoing, or planned trials with similar objectives. Further, we discuss the rapid development of targeted radiopharmaceutical therapy and the future perspectives for developing novel therapies for high-risk neuroblastoma and other pediatric solid tumors.Peer reviewe
Ecosystem functioning along gradients of increasing hypoxia and changing soft-sediment community types
Marine ecosystems world-wide are threatened by oxygen deficiency, with potential serious consequences for ecosystem functioning and the goods and services they provide. While the effects of hypoxia on benthic species diversity are well documented, the effects on ecosystem function have only rarely been assessed in real-world settings. To better understand the links between structural changes in macro- and meiofaunal communities, hypoxic stress and benthic ecosystem function (benthic nutrient fluxes, community metabolism), we sampled a total of 11 sites in Haystensfjord and Askerofjord (Swedish west coast) in late summer, coinciding with the largest extent and severity of seasonal hypoxia in the area. The sites spanned oxic to anoxic bottom water, and a corresponding gradient in faunal diversity. Intact sediment cores were incubated to measure fluxes of oxygen and nutrients (NO3-, NO2-, NH4+, PO43-, SiO4) across the sediment-water interface. Sediment profile imaging (SPI) footage was obtained from all sites to assess structural elements and the bioturbadon depth, and additional samples were collected to characterise sediment properties and macro- and meiofaunal community composition. Bottom-water O-2 concentration was the main driver of macrofauna communities, with highest abundance and biomass, as well as variability, at the sites with intermediate O-2 concentration. Meiofauna on the other hand was less sensitive to bottom-water O-2 concentration. Oxygen was the main driver of nutrient fluxes too, but macrofauna as well meiofauna were also significant predictors; DistLM analyses indicated that O-2 concentration, macrofaunal abundance or biomass, and meiofaunal abundance collectively explained 63%, 30% and 28% of the variation in sediment O-2 consumption, NH4+ flux and PO43+ flux, respectively. The study provides a step towards a more realistic understanding of the link between benthic fauna and ecosystem functioning, and the influence of disturbance on this relationship, which is important for management decisions aimed at protecting the dwindling biodiversity in the coastal zones around the world.Peer reviewe
Run-Off Replication of Host-Adaptability Genes Is Associated with Gene Transfer Agents in the Genome of Mouse-Infecting Bartonella grahamii
The genus Bartonella comprises facultative intracellular bacteria adapted to mammals, including previously recognized and emerging human pathogens. We report the 2,341,328 bp genome sequence of Bartonella grahamii, one of the most prevalent Bartonella species in wild rodents. Comparative genomics revealed that rodent-associated Bartonella species have higher copy numbers of genes for putative host-adaptability factors than the related human-specific pathogens. Many of these gene clusters are located in a highly dynamic region of 461 kb. Using hybridization to a microarray designed for the B. grahamii genome, we observed a massive, putatively phage-derived run-off replication of this region. We also identified a novel gene transfer agent, which packages the bacterial genome, with an over-representation of the amplified DNA, in 14 kb pieces. This is the first observation associating the products of run-off replication with a gene transfer agent. Because of the high concentration of gene clusters for host-adaptation proteins in the amplified region, and since the genes encoding the gene transfer agent and the phage origin are well conserved in Bartonella, we hypothesize that these systems are driven by selection. We propose that the coupling of run-off replication with gene transfer agents promotes diversification and rapid spread of host-adaptability factors, facilitating host shifts in Bartonella
MetsÀtuhot vuonna 2022
Luonnonvarakeskus tuottaa vuosittaista MetsÀtuhot - raporttisarjaa. Raporteissa kÀydÀÀn lÀpi mitÀ metsissÀ, taimitarhoilla sekÀ puisto- ettÀ pihapuilla menneenÀ vuonna tapahtui eri tuhonaiheuttajien osalta. LisÀksi raportissa kÀydÀÀn lÀpi muitakin metsien mielenkiintoisiÀ ilmiöitÀ, vaikkeivat ne varsinaisia tuhoja olisivatkaan olleet. Vuosi 2022 oli tÀltÀ osin mielenkiintoinen, sillÀ helteisen kesÀn 2021 jÀljet nÀkyivÀt osin vasta tÀllöin.
Vuonna 2022 kirjanpainajan (Ips typographus) takia hakattiin metsiÀ metsÀkeskuksen kerÀÀmien ilmoitusten perusteella enemmÀn kuin kertaakaan tilastointihistoriassa (2 834 ha). Laji myös parveili aiempaa runsaampana Luken feromoniseurannan pohjoisimmilla alueilla. Kirjanpainajan lisÀksi myös toinen havupuiden kaarnakuoriainen, kuusentÀhtikirjaaja, aiheutti nÀkyviÀ latvakuolemia kuuselle eri puolilla Suomea. Molempien ilmiöiden takana vaikutti paitsi kuoriaisille kohtuullinen kesÀ 2022, niin ennen kaikkea helteinen ja lÀmmin kesÀ 2021. Ilmiö konkretisoikin omalla tavallaan ilmaston lÀmpenemisen mahdollisia vaikutuksia metsissÀmme.
Helteiden tuhoja lisÀÀvĂ€t vaikutukset eivĂ€t kuitenkaan nĂ€kyneet valtakunnan metsien inventoinnissa (VMI) samalla tavalla. VMI:ssĂ€ havaitut kirjanpainajatuhot jopa laskivat (-14 %) hieman vuoden takaisesta. TĂ€ssĂ€ on kuitenkin muistettava, ettĂ€ VMI otanta ei ole ajallisesti eikĂ€ spatiaaliselta tarkkuudeltaan soveltuva useimpien hyönteis- ja sienituhojen seurantaan. MerkittĂ€vimpinĂ€ tuhonaiheuttajina VMI:ssĂ€ olivat aiempien vuosien tapaan lumi, tuuli ja hirvielĂ€imet â eli tuhot, joita voidaan yleisesti havaita maastossa inventointiajankohdasta riippumatta.
LÀmpenevÀÀn ilmastoon reagoivat hyönteisten lisÀksi useat muutkin kotoperÀiset taudinaiheuttajat. Ne hyötyvÀt ilmastonmuutoksesta mm. laajentamalla esiintymisaluettaan sekÀ aiheuttamalla puissa enemmÀn vaurioita, etenkin kun sÀÀt muuttuvat suopeimmaksi niille, mutta huonommiksi niiden isÀntÀpuille. KuusenjuurikÀÀpÀÀ etelÀisempi mÀnnynjuurikÀÀpÀ (Heterobasidion annosum s.s.) raportoitiinkin vuonna 2022 Pohjois-Pohjanmaalta saakka. JuurikÀÀpÀtuhot myös lisÀÀntyivÀt noin 30 % vuonna 2022 edellisvuoteen verrattuna. LÀmpimÀt ja kuivat kesÀt ovat myös edesauttaneet tulokaslaji havuparikkaan (Diplodia sapinea) aiheuttaman taudin etelÀnversosurman puhkeamista. Havuparikkaan levinneisyysaluetta kartoitettiin vuonna 2022 kansalaistieteen avulla, ja sienen esiintyminen olikin ennakoitua laajempi. Myös tulokaslaji havununna (Lymantria monacha) tavattiin hieman aiempaa runsaampana lajin pohjoisemmilla esiintymisalueilla.
Vuonna 2022 pÀÀtÀÀn nostivat valitettavasti myös ilmastosta riippumattomat uhkatekijÀt: kansainvÀlisen kasvikaupan ja turismin mukana leviÀvÀt haitalliset vieraslajit. Uusia vierasperÀisiÀ tuhonaiheuttajia löydettiin niin taimitarhoilta, kuin puistopuistakin. Koivuilla todettiin Discula betulina-sienen aiheuttamaa versolaikkua, pihdoilta taas löydettiin pihtanÀppyÀ (Neonectria macrospora). Haitallisten vieraslajien leviÀminen on kansainvÀlinen ongelma, jolta pohjoinen Suomikaan ei ole turvassa. Luken tutkijat julkaisivat vuonna 2022 suomenkielisen artikkelisarjan mikÀ sisÀlsi tietoa useiden eri vieraslajien uhasta. Katsaus muistuttaa, ettei metsiemme valtapuilla useinkaan ole vastustuskykyÀ nÀitÀ uusia tuholaisia vastaan, mikÀ tekee niistÀ merkittÀvÀn uhan metsien terveydelle. Haitallisten vieraslajien leviÀmisen estÀminen on siis erityisen tÀrkeÀÀ niin nyt kuin tulevaisuudessakin. TÀssÀ kansainvÀlinen kasvikauppa on pahin uhkatekijÀ. Metsien ja puutarhojen osalta ulkomaisten taimien ja koristekasvien tuonti muodostaa tehokkaan haitallisten vieraslajien leviÀmisvÀylÀn. Kotimainen taimituotanto taasen tuottaa paitsi terveitÀ, niin myös alkuperÀltÀÀn tunnettuja ja laadultaan varmistettuja taimia. NÀitÀ taimia jokaisen tulisi suosia niin metsÀnuudistamisessa kuin kotipihoilla, sillÀ olemassa oleva lainsÀÀdÀntö ei kansainvÀlistÀ kasvikauppaa hillitse.
Luke kerÀÀ ja koosta myös kansalaisten tekemiÀ ilmoituksia havaituista puustotuhoista tai muista metsien ilmiöstÀ. Vuonna 2022 okakaarnakuoriaisten (Ips acuminatus) takia tehdyt tuhoilmoitukset jatkoivat kasvuaan vuodelta 2021. Ilmoituksissa ja niiden perusteella tehdyissÀ maastotarkastuksissa mÀntyjen todettiin kuolevan etenkin lounaisrannikolla, missÀ okakaarnakuoriaiset tuntuivat viihtyvÀn hyvin yhdessÀ havuparikkaan kanssa. Selvitys nÀiden kahden tuholaisen mahdollisesta yhteisvaikutuksesta Àkillisesti kuivuneiden mÀntyjen kuolemiin jatkuu Lukessa. TÀmÀn vuoden raporttiin omaksi tarinakseen nostettiin myös ilmoituksia kerÀnnyt lehtikuoriaisten runsas esiintyminen, missÀ etenkin lepillÀ esiintyvÀ idÀnlehtikuoriainen (Agelastica alni) oli nÀkyvÀssÀ roolissa.
Vaikka vuoden 2022 perusteella tilanne Suomen metsissÀ on tuhojen suhteen pÀÀosin hyvÀ, vuosi muistutti meitÀ konkreettisesti sekÀ muuttuvan ilmaston ettÀ kansainvÀlisen kasvikaupan meille tuomista uhkista. SekÀ vieras- ettÀ tulokaslajien aiheuttamat riskit tulevat kasvamaan lÀmpenevÀssÀ ilmastossa, sillÀ sen ansiosta nÀmÀ lajit pystyvÀt todennÀköisemmin vakiinnuttamaan asemansa uudella alueellaan. MeillÀ jo ongelmia aiheuttavien lajien kuten juurikÀÀvÀn tai kirjanpainajan osalta lÀmpenevÀ ilmasto ei niin ikÀÀn lupaa missÀÀn mÀÀrin hyvÀÀ metsillemme. Ollaksemme varautuneita mahdolliseen tuhojen Àkilliseen lisÀÀntymiseen tarvitsemme paitsi aktiivista seurantaa, niin myös perus- ja soveltavaa tutkimusta. sekÀ tarkempaa analyysiÀ siitÀ miten eri tuhonaiheuttajien uhat voivat meillÀ tulevaisuudessa realisoitua
Influence of Ocean Acidification on a Natural Winter-to-Summer Plankton Succession : First Insights from a Long-Term Mesocosm Study Draw Attention to Periods of Low Nutrient Concentrations
Every year, the oceans absorb about 30% of anthropogenic carbon dioxide (CO2) leading to a re-equilibration of the marine carbonate system and decreasing seawater pH. Today, there is increasing awareness that these changes-summarized by the term ocean acidification (OA)-could differentially affect the competitive ability of marine organisms, thereby provoking a restructuring of marine ecosystems and biogeochemical element cycles. In winter 2013, we deployed ten pelagic mesocosms in the Gullmar Fjord at the Swedish west coast in order to study the effect of OA on plankton ecology and biogeochemistry under close to natural conditions. Five of the ten mesocosms were left unperturbed and served as controls (similar to 380 mu atm pCO(2)), whereas the others were enriched with CO2-saturated water to simulate realistic end-of-the-century carbonate chemistry conditions (mu 760 mu atm pCO(2)). We ran the experiment for 113 days which allowed us to study the influence of high CO2 on an entire winter-to-summer plankton succession and to investigate the potential of some plankton organisms for evolutionary adaptation to OA in their natural environment. This paper is the first in a PLOS collection and provides a detailed overview on the experimental design, important events, and the key complexities of such a "long-term mesocosm" approach. Furthermore, we analyzed whether simulated end-of-the-century carbonate chemistry conditions could lead to a significant restructuring of the plankton community in the course of the succession. At the level of detail analyzed in this overview paper we found that CO2-induced differences in plankton community composition were non-detectable during most of the succession except for a period where a phytoplankton bloom was fueled by remineralized nutrients. These results indicate: (1) Long-term studies with pelagic ecosystems are necessary to uncover OA-sensitive stages of succession. (2) Plankton communities fueled by regenerated nutrients may be more responsive to changing carbonate chemistry than those having access to high inorganic nutrient concentrations and may deserve particular attention in future studies.Peer reviewe
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