Analyses of the Expression, Immunohistochemical Properties and Serodiagnostic Potential of Schistosoma japonicum Peroxiredoxin-4

Background Schistosoma japonicum, which inhabits the mesenteric vein of the mammalian hosts for about 20 to 30 years, is subjected to the oxidative stresses from the host defense mechanism during their intra-mammalian stages. To counteract this host immune attack, the parasite utilizes their antioxidant system for survival inside the host. Peroxiredoxins (Prxs), thiol-specific antioxidant proteins, play an essential role for protecting the parasite against oxidative stress by reducing hydrogen peroxide to water. Only three types of 2-Cys Prxs have been previously characterized in S. japonicum whereas a fourth Prx has been identified for Schistosoma mansoni as Prx-4. A sequence coding homologous to this gene in the S. japonicum database was identified, characterized and expressed as recombinant SjPrx-4 protein (rSjPrx-4). Furthermore, rSjPrx-4 was evaluated in this study for its diagnostic potentials in detecting S. japonicum infection in humans. Results The gene found in the parasite genome contained 2 active-site cysteines with conserved sequences in the predicted amino acid (AA) sequence and showed 75% identity with that of the previously characterized Prx (TPx-1) of S. japonicum. The gene was expressed in different stages of schistosome life-cycle with highest transcription level in the adult male. The gene was cloned into a plasmid vector and then transfected into Escherichia coli for expression of rSjPrx-4. Anti-rSjPrx-4 mouse sera recognized native SjPrx-4 in egg and adult worm lysate by western blotting. The result of a mixed function oxidation assay in which rSjPrx-4 prevented the nicking of DNA from hydroxyl radicals confirmed its antioxidant activity. Subsequently, immunolocalization analysis showed the localization of SjPrx-4 inside the egg, on the tegument and in the parenchyma of the adult worm. Enzyme-linked immunosorbent assay results showed that rSjPrx-4 has 83.3% sensitivity and 87.8% specificity. Its diagnostic potential was further evaluated in combination with recombinant SjTPx-1 protein, yielding an improved sensitivity and specificity of 90% and 92.7%, respectively. Conclusions These results suggest that SjPrx-4 plays a role as an antioxidant dealing with oxidative stresses of S. japonicum, and its diagnostic potential improved by coupling it with SjTPx-1 is a proof for developing a serological test with better diagnostic performance for human schistosomiasis

Infection and tissue distribution of highly pathogenic avian influenza A type H5N1 (clade 2.3.4.4b) in red fox kits (Vulpes vulpes)

ABSTRACTAvian influenza H5N1 is a highly pathogenic virus that primarily affects birds. However, it can also infect other animal species, including mammals. We report the infection of nine juvenile red foxes (Vulpes vulpes) with Highly Pathogenic Avian Influenza A type H5N1 (Clade 2.3.4.4b) in the spring of 2022 in the central, western, and northern regions of New York, USA. The foxes displayed neurologic signs, and examination of brain and lung tissue revealed lesions, with brain lesions ranging from moderate to severe meningoencephalitis. Analysis of tissue tropism using RT-PCR methods showed a comparatively lower Ct value in the brain, which was confirmed by in situ hybridization targeting Influenza A RNA. The viral RNA labelling was highly clustered and overlapped the brain lesions, observed in neurons, and grey matter. Whole viral genome sequences obtained from the affected foxes were subjected to phylogenetic and mutation analysis to determine influenza A clade, host specificity, and potential occurrence of viral reassortment. Infections in red foxes likely occurred due to preying on infected wild birds and are unlikely due to transmission between foxes or other mammals

Infection and tissue distribution of Highly Pathogenic Avian Influenza A type H5N1 (clade 2.3.4.4b) in Red Fox kits (<i>Vulpes vulpes</i>)

Avian influenza H5N1 is a highly pathogenic virus that primarily affects birds. However, it can also infect other animal species, including mammals. We report the infection of nine juvenile red foxes (Vulpes vulpes) with Highly Pathogenic Avian Influenza A type H5N1 (Clade 2.3.4.4b) in the spring of 2022 in the central, western, and northern regions of New York, USA. The foxes displayed neurologic signs, and examination of brain and lung tissue revealed lesions, with brain lesions ranging from moderate to severe meningoencephalitis. Analysis of tissue tropism using RT-PCR methods showed a comparatively lower Ct value in the brain, confirmed by in situ hybridization targeting Influenza A RNA. The viral RNA labelling was highly clustered and overlapped the brain lesions, neurons, and grey matter. Whole genome sequences obtained from the affected foxes were subjected to phylogenetic and mutation analysis to determine influenza A clade, host specificity, and potential occurrence of viral reassortment. Infections in red foxes likely occurred due to preying on infected wild birds and are unlikely due to transmission between foxes or other mammals.</p

Understanding the public attitude towards sharks for improving their conservation

12 pages, 5 figures, 3 tables, supplementary material https://doi.org/10.1016/j.marpol.2021.104811Sharks are among the oldest residents of the planet, they possess a unique value as top predators and constitute irreplaceable elements of marine ecosystems. Unfortunately, contemporary narratives widely presented in popular mainstream media have attached an utterly negative connotation to sharks, propagating an unsubstantiated and fabricated image of them as implacable and voracious predators. Recently a lot of attention is devoted to understanding the public perception towards sharks in order to promote their conservation given that a quarter of all shark species are facing extinction. This work assessed the current attitude of the public towards sharks on a global scale, utilizing modern technology through a single protocol that explored the importance of factors like culture, history, or educational level in shaping attitudes. We collected 13,800 questionnaires from 137 countries, with 25 countries presenting more than 100 answers each, representing in total 92% of the filled questionnaires. A generally positive attitude towards sharks emerged from our study, influenced significantly by several factors including knowledge and participation in marine conservation projects. Interestingly, shark attacks emerged as an important factor, with countries having high numbers of shark attacks exhibiting a highly positive attitude towards sharks, potentially because their citizens are more aware of the issue and the importance of sharks for the marine ecosystems. Guidelines for shifting public attitude towards sharks and consequently advancing shark conservation were also drawnThis work has been partially funded by the Oceans Past Platform (COST Action IS1403) and the Department of Animal Production, Fisheries & Aquaculture of the University of Patras, Greece and the Biology Department of the University of Padova, Italy as part of IG Ph.D. thesisWith the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe