1,721,178 research outputs found
Population abundance, structure and movements of the European pond turtle, Emys orbicularis (Linnaeus 1758) based on capture-recapture data in a Venice Lagoon wetland area, Italy
No full textA freshwater turtle monitoring programme along the inland margins of the Venice lagoon was initiated in 2019 in collaboration with the World Wild Fund for Nature (WWF-Italy). From a total of 336 European pond turtles (Emys orbicularis) captured and marked, 97 freshwater turtles were recaptured at least once (28.9% return rate) providing important information on population size, structure and movements of mature individuals within the study area. The population size was estimated with capture-recapture method (Capture-Mark-Recapture-CMR) at 1009.4 ± 365.2 pond turtles, with a mean density of 252.3 ± 91.3 ind./ha. The analysis of the movements showed that the average distance covered intra-water bodies was: 146.79 ± 117.08 m for females and 125.43 ± 112.34 m for males. A total of 17 E. orbicularis (eight females and nine males) out of 97 turtles changed the water body during the study period from April to early September. Only a female freshwater turtle migrated in all three study sites, being recaptured 1502.32 m from the tagging site. The percentage of captures was significantly higher in two canals than in the brackish lake habitat. Further research should address spatial distribution at a finer scale to evaluate the preferential habitat for threatened E. orbicularis populations in a transitional water system as the lagoon
Controlled uptake of PFOA in adult specimens of Paracentrotus lividus and evaluation of gene expression in their gonads and embryos
Full text linkPerfluorooctanoic acid (PFOA) has been largely used in the manufacturing industry but a few years ago it turned out to be a dangerous pollutant which is now of concern for terrestrial and aquatic environments. Here, we investigated the bioaccumulation of PFOA in the sea urchin Paracentrotus lividus after exposure to different concentrations of the pollutant for 28 days. We observed rapid uptake of PFOA in the coelomic fluid collected weekly during the exposure period and high bioaccumulation in gonads at the end of the experiment. Interestingly, animals were also able to fast depurate when relocated to a clean environment. In addition, to assess the effect of PFOA on sea urchins' physiological pathways, we analysed the expression profile of some marker genes both in the gonads and in the embryos obtained from parents exposed to PFOA. Our results suggest that PFOA is a persistent, bioaccumulative compound that adversely affects the health of the exposed organisms and their offspring by causing significant changes in the expression of some key target genes and the occurrence of developmental anomalies in the embryos
Evolutionary conserved pathway of the innate immune response after a viral insult in Paracentrotus lividus sea urchin
No full textDespite the apparent simplicity of the body organization of echinoderms, their immune system is competent to perform a complex innate immune response, which is far from being well understood. The echinoderms represent the most advanced invertebrates that form a bridge with the primitive chordates. In fact, they possess numerous receptors and effectors that are used to obtain a fast immune response. After an infection, the humoral and cellular immune response determines a network in which the main protagonists are membrane and endosomal receptors. The recognition of nonself molecules by specific membrane receptors triggers the immune response, stimulating consecutive intracellular events. We have previously shown how the polyinosinic–polycytidylic acid (polyI:C) that mimics a viral infection is able to induce an immune response in the sea urchin Paracentrotus lividus immune cells. It activates a specific membrane receptor belonging to the Toll-like receptor (TLR) family. Here, we show the activated expression pattern of some genes involved in the downstream cascade of TLR signalling pathway, such as Pl-Tbk and Pl-Irf, whose partial sequence was isolated from P. lividus immune cells. Their mRNA expression increases consequentially to the polyI:C stimulation and in a temporal way. In addition, we analysed the expression of Pl-NF-kB and we found that its upregulation was time-dependent, preceding Pl-Tbk and Pl-Irf increase. Protein analysis showed that also some cytokine (TNF-α and IL-1α) expression increased after polyI:C insult. Therefore, the purpose of this study was to discover the molecular mechanisms of the innate defence strategies, similarly to vertebrates, implemented by the sea urchins in order to cope with viral infection challenge
Histone Deacetylase Inhibitors from Marine Invertebrates
Full text linkHistone deacetylases (HDACs) are key components of the epigenetic machinery controlling gene expression. They are involved in chromatin remodeling events via post-translational histone modifications but may also act on nonhistone proteins, influencing many fundamental cellular processes. Due to the key involvement of HDACs in serious human pathologies, including cancer, HDAC inhibitors (HDACis) have received increased attention in recent years. It is known that marine invertebrates produce significant amounts of secondary metabolites showing active pharmacological properties and an extensive spectrum of biomedical applications. The aim of this review is to gather selected studies that report the extraction and identification of marine invertebrate-derived compounds that possess HDACi properties, grouping the producing species according to their taxonomic hierarchy. The molecular, biochemical, and/or physiological aspects, where available, and modes of action of these naturally occurring HDACis will be recapitulated, taking into consideration their possible utilization for the future design of analogs with increased bioavailability and efficacy, less toxicity, and, also, higher isoform selectivity
Antibacterial activity of Pleurotus species
No full textBasidiomycetes express promising antitumor, immune modulating, cardiovascular and hypercholesterolemia, antiviral, antibacterial and antiparasitic effects (Wasser & Weis, 1999; Reshetnikov et al., 2001; Wasser, 2002, Didukh et al., 2003). They are also well known for their safety and efficacy as functional foods and dietary supplements (Wasser & Akavia, 2008). The antibacterial and antiviral value of different genera of Basidiomycetes has been tested by different authors (Benedict & Brady, 1972; Donnelly et al., 1986; Gao et al., 2003;). In particular the antibacterial and antiparasitic therapeutic effects were investigated in the genera Flammulina P. Karst, Fomes (Fr.) Fr., Ganoderma P. Karst., Grifola Gray, Lentinus Fr., Piptoporus P. Karst, Schizophyllum (Fr.), Trametes Fr., and Volvariella (Fr.) P. Kumm. (Wasser & Weis, 1999). As regards the genus Pleurotus (Fr.) P. Kumm., the basidiomata of Pleurotus ostreatus (Jacq.) P. Kumm. shows antibacterial and antiparasitic effects as non-commercially developed mushroom product. The extracts of P. ostreatus EVFB1 and EVFB4 were tested by Vamanu et al. (2011) proved narrow antibacterial activity against Gram-negative and Gram-positive bacteria such as Escherichia coli CBAB 2, Bacillus cereus CMGB 215, and Listeria innocua CMGB 218. The antimicrobial activity of P. eryngii var. ferulae grown on various agrowastes were investigated by Akyuz & Kirbag (2009) on Bacillus megaterium DSM 32, Staphylococcus aureus COWAN 1, Escherichia coli ATCC 25922, Klebsiella pneumoniae FMC 5, Candida albicans FMC 17, Candida glabrata ATCC 66032, Trichophyton spp., and Epidermophyton spp.
This abstract focusing on antibacterial activity of Pleurotus species growing as saprophytes on rot roots of plants of Apiaceae family. The basidiomata of P. eryngii (DC.) Quél. var. eryngii, P. eryngii var. ferulae (Lanzi) Sacc., P. eryngii var. elaeoselini Venturella, Zervakis & La Rocca and, P. nebrodensis (Inzenga) Quél., were collected in pastures and meadows of Sicily. This is as special group of Pleurotus mushrooms which appears in nature in close association with plants of family Apiaceae,. In particular, species like P. eryngii var. eryngii and P. nebrodensis are typical constituents of the Mediterranean fungal diversity and are particularly popular as choice edible mushrooms (Zervakis & Venturella, 2002). The complete mushroom basidiomata (cap, gills, and stipe) were cleaned of debris (without washing) with a knife, and kept at minus 80°C prior to sample preparation. To extract the cationic peptides, 500 mg of freeze-dried mushrooms were dissolved in 5 ml of extraction solution (10% acetic acid in phosphate saline buffer) and sonicated for 1 min at 0°C (1 pulse s 1, 70% duty cycle) and centrifuged at 27,000 g for 30 min at 4°C to remove any precipitate. After centrifugation, the supernatants were freeze-dried to be later redissolved in H2O.
The extracts were tested for their in vitro growth inhibitory activity against a group of bacterial reference strains (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis RP62A, Pseudomonas aeruginosa ATCC 15442, Escherichia coli ATCC10536) of medical relevance. Minimal inhibitory concentrations (MICs), determined by using a broth dilution micro-method, ranged from 0.025% to 25% v/v. Further studies are in progress to evaluate their activity against the biofilm mode of growth of above mentioned pathogens
Antibacterial activity of Mediterranean Oyster Mushrooms, species of genus Pleurotus (Higher Basidiomycetes)
No full textExtracts of the Mediterranean culinary-medicinal Oyster mushrooms Pleurotus eryngii var. eryngii, P. eryngii var. ferulae, P. eryngii var. elaeoselini, and P. nebrodensis were tested for their in vitro growth inhibitory activity against a group of bacterial reference strains of medical relevance: Staphylococcus aureus ATCC 25923, S. epidermidis RP62A, Pseudomonas aeruginosa ATCC 15442, and Escherichia coli ATCC10536. All of the Pleurotus species analyzed inhibited the tested microorganisms in varying degrees. The data included in this paper for P. nebrodensis and P. eryngii var. elaeoselinii are new reports
Interaction between Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) and Steinernema carpocapsae
No full textDoes Bacillus thuringiensis Affect the Stress and Immune Responses of Rhynchophorus ferrugineus Larvae, Females, and Males in the Same Way?
Full text linkSIMPLE SUMMARY: Rhynchophorus ferrugineus is a destructive quarantine pest of palm trees, now widely distributed. Although broad-spectrum insecticides are often used to protect palm against R. ferrugineus, there is increasing concern about their effects on the environment and human health, especially where palm trees are located in urban areas. As an environmentally friendly entomopathogen, Bacillus thuringiensis (Bt) has been widely used to prevent other pest infestations. Although Bt products are the most sold bio-insecticides, there are still many interesting features to be investigated in the relationship of Bt and its hosts. We investigated the effect of Bt on larvae, females, and males. This research yielded experimental evidence of significant mortality and significant effects on immune system and stress answer. Within a few hours, stress due to Bt infection was detected in the hemocytes and in the brain providing better insights into the insect-pathogen interaction and highlighting the potential use of Bt in R. ferrugineus management. ABSTRACT: Bacillus thuringiensis (Bt) is considered a potentially useful entomopathogen against red palm weevil (RPW) Rhynchophorus ferrugineus. We compared the effects of Bt on mature larvae, females, and males. The pathogenicity of Bt was evaluated, estimating: Median Lethal Dose (LD(50)), Median Lethal Time (LT(50)), Total Hemocyte Count (THC), and Differential Hemocyte Counts (DHC), and the expression of the stress protein Heat Shock Protein 70 (Hsp 70) in hemocytes and the brain. Mortality exhibited a positive trend with the dosage and duration of exposure to Bt. Larvae were more susceptible than adults, and the LD(50) of females was almost double the value of that of the larvae. LT(50) value was higher for females than for males and larvae. Treatment with sub-lethal doses of Bt induced a decrease in THC in larvae, females, and males. In treated larvae, plasmatocytes decreased, while oenocytes and spherulocytes increased. In treated females, all types of hemocytes decreased, while in males the number of plasmatocytes decreased and granulocytes increased. We also registered the stress response directly on hemocytes showing that, already at 3 h after eating Bt, the expression of the stress protein Hsp 70 was modulated. This effect was also observed in brain tissue at 6 h after treatment. The results confirm that Bt treatment induces a pathogenic state in larvae and adults of both sexes, with effects after only a few hours from ingestion; however, the effects are different in magnitude and in type of target
The potential of antimicrobial peptides isolated from freshwater crayfish species in new drug development: A review
Full text linkThe much-publicised increased resistance of pathogenic bacteria to conventional antibiotics has focused research
effort on the characterization of new antimicrobial drugs. In this context, antimicrobial peptides (AMPs)
extracted from animals are considered a promising alternative to conventional antibiotics. In recent years,
freshwater crayfish species have emerged as an important source of bioactive compounds. In fact, these invertebrates rely on an innate immune system based on cellular responses and on the production of important
effectors in the haemolymph, such as AMPs, which are produced and stored in granules in haemocytes and
released after stimulation. These effectors are active against both Gram-positive and Gram-negative bacteria. In
this review, we summarise the recent progress on AMPs isolated from the several species of freshwater crayfish
and their prospects for future pharmaceutical applications to combat infectious agents
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