Effects of schistosoma mansoni worms and eggs on circulating cholesterol and liver lipids in mice

It has previously been shown that experimental infections of the parasitic trematode Schistosoma mansoni, the adult worms of which reside in the blood stream of the mammalian host, significantly reduced atherogenesis in apolipoprotein E gene knockout (apoE(-/-)) mice. These effects occurred in tandem with a lowering of serum total cholesterol levels in both apoE(-/-) and random-bred laboratory mice and a beneficial increase in the proportion of HDL to LDL cholesterol. To better understand how the parasitic infections induce these effects we have here investigated the involvement of adult worms and their eggs on lipids in the host. Our results indicate that the serum cholesterol-lowering effect is mediated by factors released from S. mansoni eggs, while the presence of adult worms seemed to have had little or no effect. It was also observed that high levels of lipids, particularly triacylglycerols and cholesteryl esters, present in the uninfected livers of both random-bred and apoE(-/-) mice fed a high-fat diet were not present in livers of the schistosome-infected mice. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Orphan worms and, homeless parasites enhance bilaterian diversity

Microscopic endoparasites belonging to the Phylum Myxozoa provide a striking example of how much there is still to be learned about the diversity of the Metazoa. Recent research on myxozoans has provided new insights into evolution within the Bilateria, revealing unparalleled levels of morphological simplification associated with parasitism, a home for an orphan worm, and a hypothesis of the endosymbiotic origin(s) for extrusible intracellular organelles in myxozoans and cnidarians. In addition, discovery of the source of a devastating disease of salmonid fish has enabled researchers to identify two ancient clades within the Myxozoa, and has exposed new mysteries concerning myxozoan life-cycle evolution and evolutionary diversification. This plethora of new insights exemplifies the fundamental value of studying obscure organisms.

Mercury and methylmercury bioaccumulation by polychaete worms is governed by both feeding ecology and mercury bioavailability in coastal mudflats

Polychaete worms are abundant in many mudflats but their importance to coastal food web Hg biomagnification is not known. We sampled sediments and polychaete worms from mudflats in the Bay of Fundy to investigate the bioaccumulation of mercury (Hg) and methylmercury (MeHg) in the coastal invertebrate food web. Hg concentrations in the sediments were low (<20 μg kg−1). Labile Hg (methanol/KOH sediment extraction) in surface sediments (0–1 cm) was positively correlated with Hg bioaccumulation by surface sediment-ingesting polychaetes but, surprisingly, there was a negative correlation between δ15N (i.e. trophic level) and THg bioaccumulation factors in polychaete worms. Worms feeding on deeper sediments contained the greatest MeHg concentrations (69.6 μg kg−1). Polychaetes are an important vector for Hg biomagnification to the coastal avian food web. This research demonstrates that feeding depth and method of feeding are more important than trophic position or sediment Hg concentrations for predicting Hg bioaccumulation.

Rapid, automated detection of stem canker symptoms in woody perennials using artificial neural network analysis

Background Pseudomonas syringae can cause stem necrosis and canker in a wide range of woody species including cherry, plum, peach, horse chestnut and ash. The detection and quantification of lesion progression over time in woody tissues is a key trait for breeders to select upon for resistance. Results In this study a general, rapid and reliable approach to lesion quantification using image recognition and an artificial neural network model was developed. This was applied to screen both the virulence of a range of P. syringae pathovars and the resistance of a set of cherry and plum accessions to bacterial canker. The method developed was more objective than scoring by eye and allowed the detection of putatively resistant plant material for further study. Conclusions Automated image analysis will facilitate rapid screening of material for resistance to bacterial and other phytopathogens, allowing more efficient selection and quantification of resistance responses.

Is the OECD acute worm toxicity test environmentally relevant? The effect of mineral form on calculated lead toxicity

In a series of experiments the toxicity of lead to worms in soil was determined following the draft OECD earthworm reproduction toxicity protocol except that lead was added as solid lead nitrate, carbonate and sulphide rather than as lead nitrate solution as would normally be the case. The compounds were added to the test soil to give lead concentrations of 625-12500 pg Pb g-1 of soil. Calculated toxicities of the lead decreased in the order nitrate > carbonate > sulphide, the same order as the decrease in the solubility of the metal compounds used. The 7-day LC50 (lethal concentration when 50% of the population is killed) for the nitrate was 5321 +/- 275 mug Pb g(-1) of soil and this did not change with time. The LC50 values for carbonate and sulphide could not be determined at the concentration ranges used. The only parameter sensitive enough to distinguish the toxicities of the three compounds was cocoon (egg) production. The EC50S for cocoon production (the concentration to produce a 50% reduction in cocoon production) were 993, 8604 and 10 246 mug Pb g(-1) of soil for lead nitrate, carbonate and sulphide, respectively. Standard toxicity tests need to take into account the form in which the contaminant is present in the soil to be of environmental relevance. (C) 2002 Elsevier Science Ltd. All rights reserved.

The influence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test

Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC(50)s for 14 and 28 days were 5311 and 5395 mug(Pb) g(soil)(-1) respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 mug(Pb) g(soil)(-1). The concentration of lead in the worms was determined at various sampling times. Uptake at so' Sol both concentrations was linear with time. Worms in the 5000 mug g(-1) soil accumulated lead at a faster rate (3.16 mug Pb g(tissue)(-1) day(-1)) tiss than those in the 3000 mug g(-1) soil (2.21 mug Pb-tissue g(-1) day(-1)). The third experiment was a timed experiment with worms cultivated in tiss soil containing 7000 mugPb g(soil)(-1). Soil and lead nitrate solution were mixed and stored at 20 degreesC. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 It when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration time of artificially amended Pb-bearing soils increases the bioavailability of Pb decreases. Thus addition of worms shortly after addition of Pb to soils may result in the over-estimate of Pb toxicity to worms. The current OECD acute worm toxicity test fails to take these two phenomena into account thereby reducing the environmental relevance of the contaminant toxicities it is used to calculate. (C) 2002 Elsevier Science Ltd. All rights reserved.

Earthworms produce granules of intricately zoned calcite

Earthworms of the family Lumbricidae, which includes many common species, produce and secrete up to millimeter-sized calcite granules, and the intricate fine-scale zoning of their constituent crystals is unique for a biomineral. Granule calcite is produced by crystallization of amorphous calcium carbonate (ACC) that initially precipitates within the earthworm calciferous glands, then forms protogranules by accretion on quartz grain cores. Crystallization of ACC is mediated by migrating fluid films and is largely complete within 24 11 of ACC production and before granules leave the earthworm. Variations in the density of defects formed as a byproduct of trace element incorporation during calcite crystall growth have generated zoning that can be resolved by cathodoluminescence imaging at ultraviolet to blue wavelengths and using the novel technique of scanning electron microscope charge contrast imaging. Mapping of calcite crystal orientations by electron backscatter diffraction reveals an approximate radial fabric to the granules that reflects crystal growth from internal nucleation sites toward their margins. The survival within granules of ACC inclusions for months after they enter soils indicates that they crystallize only within the earthworm and in the presence of fluids containing biochemical catalysts. The earthworm probably promotes crystallization of ACC in order to prevent remobilization of the calcium carbonate by dissolution. Calcite granules vividly illustrate the role of transient precursors in biomineralization, but the underlying question of why earth-worms produce granules in volumes sufficient to have a measurable impact on soil carbon cycling remains to be answered.

Dehydration does not affect the radial pressures produced by the earthworm Aporrectodea caliginosa

As a soil dries, the earthworms in that soil dehydrate and become less active. Moisture stress may weaken an earthworm, lowering the radial pressure that the animal can produce. This possibility was investigated for the earthworm Aporrectodea caliginosa (Savigny). Pressures were compared for saturated earthworms (worms taken from saturated soil) and stressed earthworms (worms that had been partially dehydrated by leaving them in dry soil). A load cell was used to record the forces that earthworms produced as they moved through artificial burrows (holes that had been drilled through blocks of aluminium or Perspex). The radial pressure was calculated using the forces exerted and the dimensions of the artificial burrows. There was a negative correlation between burrow diameter and radial pressure, although radial pressure was independent of the length of the block through which the earthworms had burrowed. The highest radial pressures were produced by the anterior segments of the animal. Partial dehydration caused the earthworms to become quiescent, but did not decrease the radial pressure that the earthworms produced. It is suggested that coelomic fluid is retained in the anterior segments while the rest of the animal dehydrates. Dehydrated earthworms became lethargic, and we suggest that lethargy is due to the loss of coelomic fluid from the posterior segments. Coelomic fluid is known to be lost through dorsal pores. In burrowing species of earthworm such as Aporrectodea caliginosa, these pores are only present on the posterior segments.

Metal bioaccumulation and cellular fractionation in an epigeic earthworm (Lumbricus rubellus): the interactive influences of population exposure histories, site-specific geochemistry and mitochondrial genotype

Subcellular fractionation techniques were used to describe temporal changes (at intervals from T0 to T70 days) in the Pb, Zn and P partitioning profiles of Lumbricus rubellus populations from one calcareous (MDH) and one acidic (MCS) geographically isolated Pb/Zn-mine sites and one reference site (CPF). MDH and MCS individuals were laboratory maintained on their native field soils; CPF worms were exposed to both MDH and MCS soils. Site-specific differences in metal partitioning were found: notably, the putatively metal-adapted populations, MDH and MCS, preferentially partitioned higher proportions of their accumulated tissue metal burdens into insoluble CaPO4-rich organelles compared with naive counterparts, CPF. Thus, it is plausible that efficient metal immobilization is a phenotypic trait characterising metal tolerant ecotypes. Mitochondrial cytochrome oxidase II (COII) genotyping revealed that the populations indigenous to mine and reference soils belong to distinct genetic lineages, differentiated by 13%, with 7 haplotypes within the reference site lineage but fewer (3 and 4, respectively) in the lineage common to the two mine sites. Collectively, these observations raise the possibility that site-related genotype differences could influence the toxico-availability of metals and, thus, represent a potential confounding variable in field-based eco-toxicological assessments.

Origin and evolution of a myxozoan worm

Buddenbrockia pluinatellae is an active, muscular, worm-shaped parasite of freshwater bryozoans. This rare and enigmatic animal has been assigned to the Myxozoa on the basis of 18S ribosomal DNA sequences and the presence of malacosporean spores. Here we report cloning of four homologous protein-coding genes from Buddenbrockia worms, the putatively conspecific sac-shaped parasite originally described as Tetracapsula bryozoides and the related sac-shaped parasite Tetracapsuloides bryosalmonae, the causative agent of proliferative kidney disease in salmonid fish. Analyses are consistent with the hypothesis that Buddenbrockia is indeed a malacosporean myxozoan, but do not provide support for conspecificity with either T. bryozoides or T. bryosalmonae. Implications for the evolution of worm-like body plans in the Myxozoa are discussed.

Comparative genome analysis provides insights into the evolution and adaptation of Pseudomonas syringae pv. aesculi on Aesculus hippocastanum.

A recently emerging bleeding canker disease, caused by Pseudomonas syringae pathovar aesculi (Pae), is threatening European horse chestnut in northwest Europe. Very little is known about the origin and biology of this new disease. We used the nucleotide sequences of seven commonly used marker genes to investigate the phylogeny of three strains isolated recently from bleeding stem cankers on European horse chestnut in Britain (E-Pae). On the basis of these sequences alone, the E-Pae strains were identical to the Pae type-strain (I-Pae), isolated from leaf spots on Indian horse chestnut in India in 1969. The phylogenetic analyses also showed that Pae belongs to a distinct clade of P. syringae pathovars adapted to woody hosts. We generated genome-wide Illumina sequence data from the three E-Pae strains and one strain of I-Pae. Comparative genomic analyses revealed pathovar-specific genomic regions in Pae potentially implicated in virulence on a tree host, including genes for the catabolism of plant-derived aromatic compounds and enterobactin synthesis. Several gene clusters displayed intra-pathovar variation, including those encoding type IV secretion, a novel fatty acid biosynthesis pathway and a sucrose uptake pathway. Rates of single nucleotide polymorphisms in the four Pae genomes indicate that the three E-Pae strains diverged from each other much more recently than they diverged from I-Pae. The very low genetic diversity among the three geographically distinct E-Pae strains suggests that they originate from a single, recent introduction into Britain, thus highlighting the serious environmental risks posed by the spread of an exotic plant pathogenic bacterium to a new geographic location. The genomic regions in Pae that are absent from other P. syringae pathovars that infect herbaceous hosts may represent candidate genetic adaptations to infection of the woody parts of the tree.

Impacts of changing air composition on severity of arable crop disease epidemics

This review assesses the impacts, both direct and indirect, of man-made changes to the composition of the air over a 200 year period on the severity of arable crop disease epidemics. The review focuses on two well-studied UK arable crops,wheat and oilseed rape, relating these examples to worldwide food security. In wheat, impacts of changes in concentrations of SO2 in air on two septoria diseases are discussed using data obtained from historical crop samples and unpublished experimental work. Changes in SO2 seem to alter septoria disease spectra both through direct effects on infection processes and through indirect effects on soil S status. Work on the oilseed rape diseases phoma stem canker and light leaf spot illustrates indirect impacts of increasing concentrations of greenhouse gases, mediated through climate change. It is projected that, by the 2050s, if diseases are not controlled, climate change will increase yields in Scotland but halve yields in southern England. These projections are discussed in relation to strategies for adaptation to environmental change. Since many strategies take10–15 years to implement, it is important to take appropriate decisions soon. Furthermore, it is essential to make appropriate investment in collation of long-term data, modelling and experimental work to guide such decision-making by industry and government, as a contribution to worldwide food security.

Species 2000 & ITIS Catalogue of Life, 2013 Annual Checklist

This release of the Catalogue of Life contains contributions from 132 databases with information on 1,352,112 species, 114,069 infraspecific taxa and also includes 928,147 synonyms and 408,689 common names covering the following groups: Viruses • Viruses and Subviral agents from ICTV_MSL UPDATED! Bacteria and Archaea from BIOS Chromista • Chromistan fungi from Species Fungorum Protozoa • Major groups from ITIS Regional, • Ciliates from CilCat, • Polycystines from WoRMS Polycystina UPDATED!, • Protozoan fungi from Species Fungorum and Trichomycetes database • Slime moulds from Nomen.eumycetozoa.com Fungi • Various taxa in whole or in part from CABI Bioservices databases (Species Fungorum, Phyllachorales, Rhytismatales, Saccharomycetes and Zygomycetes databases) and from three other databases covering Xylariaceae, Glomeromycota, Trichomycetes, Dothideomycetes • Lichens from LIAS UPDATED! Plantae (Plants) • Mosses from MOST • Liverworts and hornworts from ELPT • Conifers from Conifer Database • Cycads and 6 flowering plant families from IOPI-GPC, and 99 families from WCSP • Plus individual flowering plants families from AnnonBase, Brassicaceae, ChenoBase, Droseraceae Database, EbenaBase, GCC UPDATED!, ILDIS UPDATED!, LecyPages, LHD, MELnet UPDATED!, RJB Geranium, Solanaceae Source, Umbellifers. Animalia (Animals) • Marine groups from URMO, ITIS Global, Hexacorals, ETI WBD (Euphausiacea), WoRMS: WoRMS Asteroidea UPDATED!, WoRMS Bochusacea UPDATED!, WoRMS Brachiopoda UPDATED!, WoRMS Brachypoda UPDATED!, WoRMS Brachyura UPDATED!, WoRMS Bryozoa UPDATED!, WoRMS Cestoda NEW!, WoRMS Chaetognatha UPDATED!, WoRMS Cumacea UPDATED!, WoRMS Echinoidea UPDATED!, WoRMS Gastrotricha NEW!, WoRMS Gnathostomulida NEW!, WoRMS Holothuroidea UPDATED!, WoRMS Hydrozoa UPDATED!, WoRMS Isopoda UPDATED!, WoRMS Leptostraca UPDATED!, WoRMS Monogenea NEW!, WoRMS Mystacocarida UPDATED!, WoRMS Myxozoa NEW!, WoRMS Nemertea UPDATED!, WoRMS Oligochaeta UPDATED!, WoRMS Ophiuroidea UPDATED!, WoRMS Phoronida UPDATED!, WoRMS Placozoa NEW!, WoRMS Polychaeta UPDATED!, WoRMS Polycystina UPDATED!, WoRMS Porifera UPDATED!, WoRMS Priapulida NEW!, WoRMS Proseriata and Kalyptorhynchia UPDATED!, WoRMS Remipedia UPDATED!, WoRMS Scaphopoda UPDATED!, WoRMS Tanaidacea UPDATED!, WoRMS Tantulocarida UPDATED!, WoRMS Thermosbaenacea UPDATED!, WoRMS Trematoda NEW!, WoRMS Xenoturbellida UPDATED! • Rotifers, mayflies, freshwater hairworms, planarians from FADA databases: FADA Rotifera UPDATED!, FADA Ephemeroptera NEW!, FADA Nematomorpha NEW! & FADA Turbellaria NEW! • Entoprocts, water bears from ITIS Global • Spiders, scorpions, ticks & mites from SpidCat via ITIS UPDATED!, SalticidDB , ITIS Global, TicksBase, SpmWeb BdelloideaBase UPDATED! & Mites GSDs: OlogamasidBase, PhytoseiidBase, RhodacaridBase & TenuipalpidBase • Diplopods, centipedes, pauropods and symphylans from SysMyr UPDATED! & ChiloBase • Dragonflies and damselflies from Odonata database • Stoneflies from PlecopteraSF UPDATED! • Cockroaches from BlattodeaSF UPDATED! • Praying mantids from MantodeaSF UPDATED! • Stick and leaf insects from PhasmidaSF UPDATED! • Grasshoppers, locusts, katydids and crickets from OrthopteraSF UPDATED! • Webspinners from EmbiopteraSF UPDATED! • Bark & parasitic lices from PsocodeaSF NEW! • Some groups of true bugs from ScaleNet, FLOW, COOL, Psyllist, AphidSF UPDATED! , MBB, 3i Cicadellinae, 3i Typhlocybinae, MOWD & CoreoideaSF NEW!• Twisted-wing parasites from Strepsiptera Database UPDATED! • Lacewings, antlions, owlflies, fishflies, dobsonflies & snakeflies from LDL Neuropterida • Some beetle groups from the Scarabs UPDATED!, TITAN, WTaxa & ITIS Global • Fleas from Parhost • Flies, mosquitoes, bots, midges and gnats from Systema Dipterorum, CCW & CIPA • Butterflies and moths from LepIndex UPDATED!, GloBIS (GART) UPDATED!, Tineidae NHM, World Gracillariidae • Bees & wasps from ITIS Bees, Taxapad Ichneumonoidea, UCD, ZOBODAT Vespoidea & HymIS Rhopalosomatidae NEW!• Molluscs from WoRMS Mollusca NEW!, FADA Bivalvia NEW!, MolluscaFW NEW! & AFD (Pulmonata) • Fishes from FishBase UPDATED! • Reptiles from TIGR Reptiles • Amphibians, birds and mammals from ITIS Global PLUS additional species of many groups from ITIS Regional, NZIB and CoL China NEW!

Assessment of the anthelmintic activity of medicinal plant extracts and purified condensed tannins against free-living and parasitic stages of Oesophagostomum dentatum

Background: Plant-derived condensed tannins (CT) show promise as a complementary option to treat gastrointestinal helminth infections, thus reducing reliance on synthetic anthelmintic drugs. Most studies on the anthelmintic effects of CT have been conducted on parasites of ruminant livestock. Oesophagostomum dentatum is an economically important parasite of pigs, as well as serving as a useful laboratory model of helminth parasites due to the ability to culture it in vitro for long periods through several life-cycle stages. Here, we investigated the anthelmintic effects of CT on multiple life-cycles stages of O. dentatum. Methods: Extracts and purified fractions were prepared from five plants containing CT and analysed by HPLC-MS. Anthelmintic activity was assessed at five different stages of the O. dentatum life cycle; the development of eggs to infective third-stage larvae (L3), the parasitic L3 stage, the moult from L3 to fourth-stage larvae (L4), the L4 stage and the adult stage. Results: Free-living larvae of O. dentatum were highly susceptible to all five plant extracts. In contrast, only two of the five extracts had activity against L3, as evidenced by migration inhibition assays, whilst three of the five extracts inhibited the moulting of L3 to L4. All five extracts reduced the motility of L4, and the motility of adult worms exposed to a CT-rich extract derived from hazelnut skins was strongly inhibited, with electron microscopy demonstrating direct damage to the worm cuticle and hypodermis. Purified CT fractions retained anthelmintic activity, and depletion of CT from extracts by pre-incubation in polyvinylpolypyrrolidone removed anthelmintic effects, strongly suggesting CT as the active molecules. Conclusions: These results suggest that CT may have promise as an alternative parasite control option for O. dentatum in pigs, particularly against adult stages. Moreover, our results demonstrate a varied susceptibility of different life-cycle stages of the same parasite to CT, which may offer an insight into the anthelmintic mechanisms of these commonly found plant compounds.

The polychaete worm Nereis diversicolor increases mercury lability and methylation in intertidal mudflats

The polychaete worm Nereis diversicolor engineers its environment by creating oxygenated burrows in anoxic intertidal sediments. The authors carried out a laboratory microcosm experiment to test the impact of polychaete burrowing and feeding activity on the lability and methylation of mercury in sediments from the Bay of Fundy, Canada. The concentration of labile inorganic mercury and methylmercury in burrow walls was elevated compared to worm-free sediments. Mucus secretions and organic detritus in worm burrows increased labile mercury concentrations. Worms decreased sulfide concentrations, which increased Hg bioavailability to sulfate-reducing bacteria and increased methylmercury concentrations in burrow linings. Because the walls of polychaete burrows have a greater interaction with organisms, and the overlying water, the concentrations of mercury and methylmercury they contain is more toxicologically relevant to the base of a coastal food web than bulk samples. The authors recommend that researchers examining Hg in marine environments account for sediment dwelling invertebrate activity to more fully assess mercury bioavailability.