Viral nervous necrosis in gilthead sea bream (Sparus aurata) caused by reassortant betanodavirus RGNNV/SJNNV : an emerging threat for Mediterranean aquaculture

Viral nervous necrosis (VNN) certainly represents the biggest challenge for the sustainability and the development of aquaculture. A large number of economically relevant fish species have proven to be susceptible to the disease. Conversely, gilthead sea bream has generally been considered resistant to VNN, although it has been possible to isolate the virus from apparently healthy sea bream and sporadically from affected larvae and postlarvae. Unexpectedly, in 2014-2016 an increasing number of hatcheries in Europe have experienced mass mortalities in sea bream larvae. Two clinical outbreaks were monitored over this time span and findings are reported in this paper. Despite showing no specific clinical signs, the affected fish displayed high mortality and histological lesions typical of VNN. Fish tested positive for betanodavirus by different laboratory techniques. The isolates were all genetically characterized as being reassortant strains RGNNV/SJNNV. A genetic characterization of all sea bream betanodaviruses which had been isolated in the past had revealed that the majority of the strains infecting sea bream are actually RGNNV/SJNNV. Taken together, this information strongly suggests that RGNNV/SJNNV betanodavirus possesses a particular tropism to sea bream, which can pose a new and unexpected threat to the Mediterranean aquaculture

Detection and characterization of a rhabdovirus causing mortality in black bullhead catfish, Ameiurus melas

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Metastatic tumors to the pancreas: a systematic review and meta-analysis

INTRODUCTION: Metastases to the pancreas from other primary tumors are increasingly recognized in clinical practice, but the real role of surgery remains unclear. This study was designated to evaluate by a meta-analytic approach the results of surgical treatment for the most common malignancies metastasizing to the pancreas. EVIDENCE ACQUISITION: MEDLINE, PubMED, Scopus and Web of Sciences were searched from January 2000 to December 2015. Studies reporting postoperative complications, postoperative mortality, disease-free and overall survival of patients undergoing resection for secondary tumours of the pancreas, were included. EVIDENCE SYNTHESIS: Fourteen publication with 281 patients met the inclusion criteria and were subjected to the analysis. Operative morbidity and mortality were 34% and 1.3% respectively. Pancreatic resection for renal cell cancer showed better survival compared to other non-renal cell cancer (ratio of mean 1.83; 95% CI: 1.42-2.36, I2=74.52%, P<0.001). Disease-free interval was longer for metastatic renal cell carcinoma patients (mean difference 6.36, 95% CI: 3.803-8.912 years, I2=76:54%, P<0.001). A meta-regression was used to correlate the two endpoints and showed that a longer DFI is associated to a longer survival. CONCLUSIONS: Pancreatic resection for metastasis should be reserved to patients in good health conditions, with isolated disease from renal cell cancer. For other types of tumor, surgery should be performed only in individual basis. There is a need of studies evaluating the role of chemotherapy in the neoadjuvant setting or the best sequential use of multimodality treatment (targeted therapy, radiotherapy, surgery, etc.)

Systematic Review and Meta-Analysis of Surgical Treatment for Isolated Local Recurrence of Pancreatic Cancer

Purpose: To perform a systematic review and meta-analysis on the outcome of surgical treatment for isolated local recurrence of pancreatic cancer. Methods: A systematic review and meta-analysis based on Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines was conducted in PubMed, Scopus, and Web of Science. Results: Six studies concerning 431 patients with recurrent pancreatic cancer met the inclusion criteria and were included in the analysis: 176 underwent redo surgery, and 255 received non-surgical treatments. Overall survival and post-recurrence survival were significantly longer in the re-resected group (ratio of means (ROM) 1.99; 95% confidence interval (CI), 1.54\u20132.56, I2 = 75.89%, p = 0.006, and ROM = 2.05; 95% CI, 1.48\u20132.83, I2 = 76.39%, p = 0.002, respectively) with a median overall survival benefit of 28.7 months (mean difference (MD) 28.7; 95% CI, 10.3\u201347.0, I2 = 89.27%, p < 0.001) and median survival benefit of 15.2 months after re-resection (MD 15.2; 95% CI, 8.6\u201321.8, I2 = 58.22%, p = 0.048). Conclusion: Resection of isolated pancreatic cancer recurrences is safe and feasible and may offer a survival benefit. Selection of patients and assessment of time and site of recurrence are mandatory

Viral nervous necrosis in gilthead sea bream (Sparus aurata) caused by reassortant betanodavirus RGNNV/SJNNV: an emerging threat for Mediterranean aquaculture

Viral nervous necrosis (VNN) certainly represents the biggest challenge for the sustainability and the development of aquaculture. A large number of economically relevant fish species have proven to be susceptible to the disease. Conversely, gilthead sea bream has generally been considered resistant to VNN, although it has been possible to isolate the virus from apparently healthy sea bream and sporadically from affected larvae and postlarvae. Unexpectedly, in 2014-2016 an increasing number of hatcheries in Europe have experienced mass mortalities in sea bream larvae. Two clinical outbreaks were monitored over this time span and findings are reported in this paper. Despite showing no specific clinical signs, the affected fish displayed high mortality and histological lesions typical of VNN. Fish tested positive for betanodavirus by different laboratory techniques. The isolates were all genetically characterized as being reassortant strains RGNNV/SJNNV. A genetic characterization of all sea bream betanodaviruses which had been isolated in the past had revealed that the majority of the strains infecting sea bream are actually RGNNV/SJNNV. Taken together, this information strongly suggests that RGNNV/SJNNV betanodavirus possesses a particular tropism to sea bream, which can pose a new and unexpected threat to the Mediterranean aquaculture

Antigenic drift in H5N1 avian influenza virus in poultry is driven by mutations in major antigenic sites of the hemagglutinin molecule analogous to those for human influenza virus

H5N1 highly pathogenic avian influenza virus has been endemic in poultry in Egypt since 2008, notwithstanding the implementation of mass vaccination and culling of infected birds. Extensive circulation of the virus has resulted in a progressive genetic evolution and an antigenic drift. In poultry, the occurrence of antigenic drift in avian influenza viruses is less well documented and the mechanisms remain to be clarified. To test the hypothesis that H5N1 antigenic drift is driven by mechanisms similar to type A influenza viruses in humans, we generated reassortant viruses, by reverse genetics, that harbored molecular changes identified in genetically divergent viruses circulating in the vaccinated population. Parental and reassortant phenotype viruses were antigenically analyzed by hemagglutination inhibition (HI) test and microneutralization (MN) assay. The results of the study indicate that the antigenic drift of H5N1 in poultry is driven by multiple mutations primarily occurring in major antigenic sites at the receptor binding subdomain, similarly to what has been described for human influenza H1 and H3 subtype viruses

Table1_Tilapia lake virus: A structured phylogenetic approach.DOCX

Tilapia Lake Virus (TiLV), also known as Tilapia tilapinevirus, is an emerging pathogen affecting both wild and farmed tilapia (Oreochromis spp.), which is considered one of the most important fish species for human consumption. Since its first report in Israel in 2014, Tilapia Lake Virus has spread globally causing mortality rates up to 90%. Despite the huge socio-economic impact of this viral species, to date the scarce availability of Tilapia Lake Virus complete genomes is severely affecting the knowledge on the origin, evolution and epidemiology of this virus. Herein, along with the identification, isolation and complete genome sequencing of two Israeli Tilapia Lake Virus deriving from outbreaks occurred in tilapia farms in Israel in 2018, we performed a bioinformatics multifactorial approach aiming to characterize each genetic segment before carrying out phylogenetic analysis. Results highlighted the suitability of using the concatenated ORFs 1, 3, and 5 in order to obtain the most reliable, fixed and fully supported tree topology. Finally, we also attempted to investigate the presence of potential reassortment events in all the studied isolates. As a result, we report a reassortment event detected in segment 3 of isolate TiLV/Israel/939-9/2018 involved in the present study, and confirmed almost all the other events previously reported.</p

Molecular Basis for Antigenic Diversity of Genus Betanodavirus.

Betanodaviruses are the causative agents of viral nervous necrosis (VNN), a devastating disease for the Mediterranean mariculture. Four different betanodavirus species are recognized, Striped jack-, Redspotted grouper-, Tiger puffer-, and Barfin flounder nervous necrosis virus (SJNNV, RGNNV, TPNNV and BFNNV), but there is little knowledge on their antigenic properties. In order to describe the serological relationships among different betanodavirus genotypes, serum neutralization assays were performed using rabbit polyclonal antisera against eight fish nodaviruses that cover a wide species-, temporal-, spatial- and genetic range. The results indicate that the SJNNV and RGNNV are antigenically distinct, constituting serotypes A and C, respectively. The TPNNV and BFNNV, the latter representing cold-water betanodaviruses, are antigenically related and cluster within serotype B. The reassortant viruses RGNNV/SJNNV and SJNNV/RGNNV group within serotypes A and C, respectively, indicating that the coat protein encoded by RNA2 acts as major immunoreactivity determinant. Immunostaining of in vitro expressed wild type and chimeric capsid proteins between the RGNNV and the SJNNV species indicated that the C-terminal part of the capsid protein retains the immunoreactive portion. The amino acid (aa) residues determining RGNNV and SJNNV antigenic diversity were mapped to aa residues 217-256 and aa 257-341, respectively. Neutralization of reverse genetics derived chimeric viruses indicated that these areas determine the neutralizing epitopes. The data obtained are crucial for the development of targeted serological tests for the diagnosis of VNN, and informative for development of cross-protective vaccines against various betanodavirus genotypes

Image3_Tilapia lake virus: A structured phylogenetic approach.pdf

Tilapia Lake Virus (TiLV), also known as Tilapia tilapinevirus, is an emerging pathogen affecting both wild and farmed tilapia (Oreochromis spp.), which is considered one of the most important fish species for human consumption. Since its first report in Israel in 2014, Tilapia Lake Virus has spread globally causing mortality rates up to 90%. Despite the huge socio-economic impact of this viral species, to date the scarce availability of Tilapia Lake Virus complete genomes is severely affecting the knowledge on the origin, evolution and epidemiology of this virus. Herein, along with the identification, isolation and complete genome sequencing of two Israeli Tilapia Lake Virus deriving from outbreaks occurred in tilapia farms in Israel in 2018, we performed a bioinformatics multifactorial approach aiming to characterize each genetic segment before carrying out phylogenetic analysis. Results highlighted the suitability of using the concatenated ORFs 1, 3, and 5 in order to obtain the most reliable, fixed and fully supported tree topology. Finally, we also attempted to investigate the presence of potential reassortment events in all the studied isolates. As a result, we report a reassortment event detected in segment 3 of isolate TiLV/Israel/939-9/2018 involved in the present study, and confirmed almost all the other events previously reported.</p