West Nile Virus lineage 2 overwintering in Italy

In January 2022, West Nile virus (WNV) lineage 2 (L2) was detected in an adult female goshawk rescued near Perugia in the region of Umbria (Italy). The animal showed neurological symptoms and died 15 days after its recovery in a wildlife rescue center. This was the second case of WNV infection recorded in birds in the Umbria region during the cold season, when mosquitoes, the main WNV vectors, are usually not active. According to the National Surveillance Plan, the Umbria region is included amongst the WNV low-risk areas. The necropsy evidenced generalized pallor of the mucous membranes, mild splenomegaly, and cerebral edema. WNV L2 was detected in the brain, heart, kidney, and spleen homogenate using specific RT-PCR. Subsequently, the extracted viral RNA was sequenced. A Bayesian phylogenetic analysis performed through a maximum-likelihood tree showed that the genome sequence clustered with the Italian strains within the European WNV strains among the central-southern European WNV L2 clade. These results, on the one hand, confirmed that the WNV L2 strains circulating in Italy are genetically stable and, on the other hand, evidenced a continuous WNV circulation in Italy throughout the year. In this report case, a bird-to-bird WNV transmission was suggested to support the virus overwintering. The potential transmission through the oral route in a predatory bird may explain the relatively rapid spread of WNV, as well as other flaviviruses characterized by similar transmission patterns. However, rodent-to-bird transmission or mosquito-to-bird transmission cannot be excluded, and further research is needed to better understand WNV transmission routes during the winter season in Ital

Spatial and temporal dynamics of West Nile virus between Africa and Europe

It is unclear whether West Nile virus (WNV) circulates between Africa and Europe, despite numerous studies supporting an African origin and high transmission in Europe. We integrated genomic data with geographic observations and phylogenetic and phylogeographic inferences to uncover the spatial and temporal viral dynamics of WNV between these two continents. We focused our analysis towards WNV lineages 1 (L1) and 2 (L2), the most spatially widespread and pathogenic WNV lineages. Our study shows a Northern-Western African origin of L1, with back-and-forth exchanges between West Africa and Southern-Western Europe; and a Southern African origin of L2, with one main introduction from South Africa to Europe, and no back introductions observed. We also noticed a potential overlap between L1 and L2 Eastern and Western phylogeography and two Afro-Palearctic bird migratory flyways. Future studies linking avian and mosquito species susceptibility, migratory connectivity patterns, and phylogeographic inference are suggested to elucidate the dynamics of emerging viruse

First Report of Septicaemic Listeriosis in a Loggerhead Sea Turtle (Caretta caretta) Stranded along the Adriatic Coast: Strain Detection and Sequencing

Simple Summary Listeria is a ubiquitous bacterium responsible for outbreaks in humans and animals. Therefore, marine monitoring and detection of this bacterium are important for public health. This work presents the first case of Listeria monocytogenes in a stranded loggerhead sea turtle (Caretta caretta) with a severe septicaemic infection. Gross and microscopic lesions showed chronic inflammation of all tissues due to septicaemia. Furthermore, a microbiological investigation confirmed the presence of L. monocytogenes. Whole-genome sequencing (WGS) was performed on isolated colonies for deep characterization of the strain, and antibiotic resistance genes were identified from the sequence. Although there are increasing reports on the prevalence of Listeria monocytogenes in wild species, this is the first case of listeriosis in sea turtle. An adult female Caretta caretta was rescued after being stranded alive along the coast of the Abruzzo region (Italy) in summer 2021. The turtle died in 6 days due to respiratory failure. The necropsy showed widespread organ lesions, such as yellow foci of necrosis in many organs, gastrointestinal erosions, pericarditis, and granulomatous pneumonia. Microbiological and histological analyses were performed on several organs. Listeria monocytogenes was isolated from multiple organs, indicating a case of septicaemic listeriosis, and the genome was sequenced and characterized. All the colonies analysed belonged to the same strain serogroup IVb, ST388, and CC388

Whole Genome Sequencing Characterization of HEV3-e and HEV3-f Subtypes among the Wild Boar Population in the Abruzzo Region, Italy: First Report

Hepatitis E virus (HEV) is an emergent zoonotic pathogen, causing worldwide acute and chronic hepatitis in humans. HEV comprises eight genotypes and several subtypes. HEV genotypes 3 and 4 (HEV3 and HEV4) are zoonotic. In Italy, the most part of HEV infections (80%) is due to autochthonous HEV3 circulation of the virus, and the key role played by wild animals is generally accepted. Abruzzo is an Italian region officially considered an HEV “hot spot”, with subtype HEV3-c being up to now the only one reported among wild boars. During the year 2018–2019, a group of wild boars in Abruzzo were screened for HEV; positive RNA liver samples were subjected to HEV characterization by using the whole genome sequencing (WGS) approach methodology. This represents the first report about the detection of HEV-3 subtypes e and f in the wild boar population in this area. Since in Italy human infections from HEV 3-e and f have been associated with pork meat consumption, our findings deserve more in-depth analysis with the aim of evaluating any potential correlation between wild animals, the pork chain production and HEV human infections

Unveiling the immunomodulatory shift: Epithelial-mesenchymal transition Alters immune mechanisms of amniotic epithelial cells

Epithelial-mesenchymal transition (EMT) changes cell phenotype by affecting immune properties of amniotic epithelial cells (AECs). The present study shows how the response to lipopolysaccharide of cells collected pre- (eAECs) and post-EMT (mAECs) induces changes in their transcriptomics profile. In fact, eAECs mainly upregulate genes involved in antigen-presenting response, whereas mAECs over-express soluble inflammatory mediator transcripts. Consistently, network analysis identifies CIITA and Nrf2 as main drivers of eAECs and mAECs immune response, respectively. As a consequence, the depletion of CIITA and Nrf2 impairs the ability of eAECs and mAECs to inhibit lymphocyte proliferation or macrophage-dependent IL-6 release, thus confirming their involvement in regulating immune response. Deciphering the mechanisms controlling the immune function of AECs pre- and post-EMT represents a step forward in understanding key physiological events wherein these cells are involved (pregnancy and labor). Moreover, controlling the immunomodulatory properties of eAECs and mAECs may be essential in developing potential strategies for regenerative medicine applications

Novel Amplicon-Based Sequencing Approach to West Nile Virus

West Nile virus is a re-emerging arbovirus whose impact on public health is increasingly important as more and more epidemics and epizootics occur, particularly in America and Europe, with evidence of active circulation in Africa. Because birds constitute the main reservoirs, migratory movements allow the diffusion of various lineages in the world. It is therefore crucial to properly control the dispersion of these lineages, especially because some have a greater health impact on public health than others. This work describes the development and validation of a novel whole-genome amplicon-based sequencing approach to West Nile virus. This study was carried out on different strains from lineage 1 and 2 from Senegal and Italy. The presented protocol/approach showed good coverage using samples derived from several vertebrate hosts and may be valuable for West Nile genomic surveillance