14 research outputs found

    First isolation and characterization of clinical signs of polymicrobial infection by Aeromonas jandiae, Aeromonas hydhophila and Edwardsiella tarda in disease outbreak of fingerlings Arapaima gigas (pirarucu).

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    The topic of bacterial polymicrobial infection, still little studied in fish farming, has been demonstrating to be an important cause of economic losses in aquiculture. The Brazilian national production of Arapaima gigas, Schinz 1822 (pirarucu) in 2014 was around 12 tons. In Brazil, there is little information on the diversity of bacteria in aquatic ecosystems, mainly on the pirarucu microbiota, as well as on the bacteria that cause diseases in this fish of great importance for Brazilian and Amazonian aquaculture. However, identification and characterization of diseases caused by bacteria are of great importance for the sustainability of productive chain of fish farming. The aim of this study was to report the first polymicrobial outbreak in newly acquired pirarucus from commercial fish farming, which resulted in significant financial losses, which resulted mortality of approximately 1,400 farmed fingerlings. Fish with and without external signs of bacteriosis were collected for bacteriological analyzes. The isolated bacterial strains were characterized according to traditional taxonomical analyses and were identified as Aeromonas jandaei, Aeromonas hydrophila, and Edwardsiella tarda. In the pirarucus tegument with aeromonose and edwardsielose, lesions that varied in shape, extension and size were observed, and such lesions occurred mainly in the tail and fins of the fish. Anorexia, loss of balance with erratic movement, reduction of respiratory movements, depigmentation along the body with hemorrhagic foci, necrotic hemorrhages in internal organs such as kidney, liver and modified swimming bladder were found. In addition, to splenomegaly and ascites containing mucous-yellow fluid, deposition of sanguineous fluid in the abdominal cavity, hyperemia, enlargement of the gallbladder, abdominal cavity with swelling and small areas of liver hemorrhage were observed. These characterization of clinical signs related with polymicrobial infections can help fish farmers in the early identification of diseases, allowing thus the appropriate management of treatment. Therefore, further studies are needed to better understand the immune response of these fish during mixed bacterial infections, because these may have a major impact on the development of new strategies for disease control and vaccination programs in this fish to mitigate the bacteriosis in fish farms

    Experimental co-infection by Aeromonas hydrophila and Aeromonas jandaei in pirarucu Arapaima gigas (Pisces: Arapaimidae).

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    In fish, bacteriosis has been widely linked with Aeromonas species, but co-infection by these bacteria has been little addressed. The aims of this study were to report on an outbreak of disease in pirarucu Arapaima gigas caused by Aeromonas and to investigate experimental co-infection and characterize resistance profile, virulence factors and phenotypic and molecular differentiation. Fish samples with clinical signs of bacteriosis were collected and used to study experimental co-infection. The bacterial isolates were characterized phenotypically as Aeromonas hydrophila and Aeromonas jandaei. Virulence genes aerA, gcat, lip, dnase and hlyA were detected using the polymerase chain reaction, while the alt, act and ser genes were not found. Resistance to imipenem and ceftriaxone was observed; however, all isolates were susceptible to most of the antibiotics assayed. Phenotypic tests to determine the presence of metallo-β-lactamases showed positivity only for A. jandaei strains. Assays for the resistance genes kpc, ndm, imp, oxa-48 and vim showed negative results. The co-infection and pathogenicity of A. hydrophila in association with A. jandaei in A. gigas, established in accordance with Koch's postulate, provided experimental support for the existence of synergism between these bacteria. This has several implications relating to occurrences of this co-infection and determinants of virulence

    The Use of Phage-Displayed Peptide Libraries to Develop Tumor-Targeting Drugs

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    Monoclonal antibodies have been successfully utilized as cancer-targeting therapeutics and diagnostics, but the efficacies of these treatments are limited in part by the size of the molecules and non-specific uptake by the reticuloendothelial system. Peptides are much smaller molecules that can specifically target cancer cells and as such may alleviate complications with antibody therapy. Although many endogenous and exogenous peptides have been developed into clinical therapeutics, only a subset of these consists of cancer-targeting peptides. Combinatorial biological libraries such as bacteriophage-displayed peptide libraries are a resource of potential ligands for various cancer-related molecular targets. Target-binding peptides can be affinity selected from complex mixtures of billions of displayed peptides on phage and further enriched through the biopanning process. Various cancer-specific ligands have been isolated by in vitro, in vivo, and ex vivo screening methods. As several peptides derived from phage-displayed peptide library screenings have been developed into therapeutics in current clinical trials, which validates peptide-targeting potential, the use of phage display to identify cancer-targeting therapeutics should be further exploited

    Nonsurgical management and 2-year follow-up by means of cone beam computed tomography of an invasive cervical resorption in a molar

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    Background: Invasive cervical resorption (ICR) is a relatively uncommon form of external tooth resorption, characterized by an invasive nature. It is usually painless and detection of lesions is often made incidentally. Three-dimensional imaging techniques, such as cone beam computed tomography (CBCT), are useful in the diagnosis and management of ICR as the true extent of the defect cannot always be estimated using conventional radiographs. Aim: The aim of this article is to report on the successful treatment of ICR in mandibular first molar by nonsurgical approach and follow-up by means of CBCT. Case report: An 18-year-old patient was referred with a complaint of unusual radiolucency in the mesial cervical area of tooth #19 with unknown etiology. Cone beam computed tomography was performed to assess the extent of the lesion in three spatial levels and diagnosis of Heithersay class III ICR was made. This case presented with ICR (Heithersay class III) on tooth #19. Nonsurgical root canal treatment and removal of the lesion from the coronal access was performed; the resorptive defect was filled with dual-cure, self-adhesive, resin-modified glass ionomer cement (RMGIC); 6-month follow-up X-ray film showed no changes at the lesion site and tooth was asymptomatic; 1-year follow-up X-ray film showed slight mesial bone loss and a probing depth of 3 mm; finally, 2-year follow-up CBCT images showed no recurrence and no further bone destruction at the lesion site. Conclusion: The intraoral radiographs revealed the resorptive changes in two dimensions; therefore, the actual extent and location of the lesions are not fully understood. On the contrary, CBCT is a very useful tool to achieve a proper diagnosis; it detects the extent of the defect more accurately and hence, improves the treatment outcomes of ICR. Clinical significance: The ICR is usually seen as a late complication to traumatic injuries of the teeth; it is essential, therefore, that the patients who were exposed to situations that can damage the integrity of periodontal tissue need to have careful periodic recalls and X-ray examinations

    The sandstone memory of the cenozoic evolution of the Southern Italy orogenic system

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    Meeting on Geodynamic and active tectonics of Tyrrenian AppennineConsiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal
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