Lineage 2 West Nile virus (WNV) caused a vast epidemic in Europe in 2018, with the highest incidence being recorded in Italy. To reconstruct the evolutionary dynamics and epidemiological history of the virus in Italy, 53 envelope gene and 26 complete genome sequences obtained from human and animal samples were characterised by means of next-generation sequencing. Phylogenetic analysis revealed two Italian strains originating between 2010 and 2012: clade A, which apparently became extinct in 2013–2014, and clade B, which was responsible for the 2018 epidemic. The mean genetic distances in clade B increased over time and with the distance between sampling locations. Bayesian birth-death and coalescent skyline plots of the clade B showed that the effective number of infections and the effective reproduction number (Re) increased between 2015 and 2018. Our data suggest that WNV-2 entered Italy in 2011 as a result of one or a few penetration events. Clade B differentiated mainly as a result of genetic drift and purifying selection, leading to the appearance of multiple locally circulating sub-clades for different times. Phylodynamic analysis showed a current expansion of the infection among reservoir birds and/or vectors.
The Anopheles maculipennis complex consists of several mosquito species, including some primary malaria vectors. Therefore, the presence of a species in a particular area significantly affects public health. In this study, 1252 mosquitoes were collected in northern Italy, representing four identified species of the Anopheles maculipennis complex (Anopheles daciae sp. inq., Anopheles maculipennis s. s., Anopheles atroparvus and Anopheles melanoon). The sequences of two DNA markers, mitochondrial cytochrome c oxidase I (COI) and nuclear internal transcribed spacer 2 (ITS2), were generated. DNA-based species delimitation analyses were performed, incorporating public sequences, with distance-based and coalescent tree-based methods to confirm the actual species boundaries within the complex. While some morphospecies were unequivocally delimited by all methods and markers, COI analysis splitted An. maculipennis s. s. into two well-supported groups. However, molecular delimitation failed in recognizing An. daciae sp. inq. and An. messeae as two separate evolutionary entities. Species delimitation was further tested with a morphometric approach, which clearly differentiated species collected in the survey area. These findings underscore how challenging the characterization of the taxonomy of the complex is, providing evidence of potential introgression events in An. maculipennis s. s. and suggesting the need for robust evidence to support An. daciae sp. inq. and An. messeae as distinct species.
4 August 2023 in International Journal for Parasitology: Parasites and Wildlife
The recent expansion of the habitat of several wildlife species, comprising anthropized areas, is a relevant risk factor for many zoonotic diseases and should be considered in national and regional sanitary monitoring systems. We evaluated adult intestinal Taenia spp. parasites isolated from wild carnivores and cystic larval forms isolated from wild mammals analysed at the Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia-Romagna (IZSLER) as part of the regional wildlife sanitary surveillance plan. Then, we assessed parasite species through molecular analysis (multiplex PCR followed by ribosomal 12S subunit gene sequencing) in order to update the epidemiological situation on Taeniids infection in the Emilia-Romagna wildlife, reporting the prevalence of each isolated species. The most commonly isolated species was Taenia serialis, which we detected in both wolves and foxes as definitive hosts and in roe deer as intermediate host. More attention on the distribution of Taeniids in wildlife should be paid, considering their potential zoonotic role: several Taenia spp. (Taenia solium, Taenia multiceps, Taenia serialis, Taenia brauni, Taenia glomerulatus) are known for causing coenurosis in humans, with possible severe or fatal outcomes.
The cheese (or ham) skipper, Piophila casei (Linnaeus), belongs to the family Piophilidae and is a detritivore species that feeds on decaying organic matter. Its larvae are commonly found on high-protein substrates (including carcasses), with a life cycle that is strongly influenced by environmental temperature and food nature. In this study, we investigated development time and larval length of P. casei reared on Parma ham PDO (Protected Designation of Origin) at five constant temperatures (20, 22, 24, 26, 28 °C). We calculated the accumulated degree days (ADD) and constructed isomegalen- and isomorphen-diagrams to estimate the infestation time. The minimum development threshold (tL) obtained by extrapolating the development rates measured between 20 °C and 28 °C was 9.91 °C, resulting in ADDs (oviposition–eclosion) of 216.9, 219.9, 220.7, 209.2, and 220.1 at 20, 22, 24, 26, and 28 °C, respectively.
Purpose The aim of this study was to describe the occurrence and phylogenetic diversity of Hepatozoon spp. in small mammals from the Emilia-Romagna region, northern Italy, and to assess their genetic relationships with previously described lineages. Methods Tissue samples (spleen and ear) from wild animals belonging to eight small mammal species were examined. Molecular screening was performed using PCR targeting the 18 S rRNA gene of Hepatozoon spp. Positive amplicons were sequenced and analyzed using phylogenetic methods to determine their taxonomic placement, and one positive fresh sample was additionally subjected to histopathological characterization. Results Hepatozoon DNA was detected in two rodent species, the brown rat (Rattus norvegicus) and the European edible dormouse (Glis glis). Sequences showed high identity (98.9–100%) with Hepatozoon sp. previously reported in rodents from Spain and Tanzania, and 98.32–98.9% identity with Hepatozoon ophisauri. Phylogenetic analysis placed the sequences from R. norvegicus within a rodent-associated clade, whereas those from G. glis formed a distinct lineage related to Hepatozoon detected in a great gerbil. Histopathological analysis in a European edible dormouse revealed multifocal pulmonary granulomatous inflammatory lesions associated with intracytoplasmic parasitic zoites and developmental stages consistent with type I and type II meronts. Conclusion This study provides molecular evidence of distinct Hepatozoon lineages in European rodents, potentially representing undescribed taxa, and highlights the need for integrative studies combining molecular, morphological, and ecological data.