Toscana virus (TOSV) is an emerging but neglected human pathogen currently circulating around the Mediterranean basin including North Africa. Human illness ranges from asymptomatic or mild flu-like syndromes to severe neurological diseases such as meningitis or meningoencephalitis. Despite its significant impact, understanding of TOSV transmission and epidemiology remains limited. Sand flies (Diptera: Phlebotominae), specifically Phlebotomus perniciosus and Phlebotomus perfiliewi, are believed to be the primary vectors of TOSV. However, the spread of TOSV to new geographical areas and its detection in other sand fly species suggest that additional species play a role in the circulation and transmission of this virus. This study investigated the vector competence of four sand fly species - P. tobbi, P. sergenti, P. papatasi, and Sergentomyia schwetzi - for two TOSV strains: 1500590 (TOSV A lineage) and MRS20104319501 (TOSV B lineage). Sand flies were orally challenged with TOSV via bloodmeals. None of the tested species showed susceptibility to the TOSV A strain. However, for TOSV B strain, P. tobbi demonstrated a high potential as a new vector, exhibiting high infection and dissemination rates. P. sergenti also showed some susceptibility to TOSV B, with the virus dissemination observed in all infected females. These finding suggests that P. tobbi and P. sergenti are new potential vectors for TOSV B. Given that P. tobbi and P. sergenti are the primary vectors of human leishmaniases in the Balkans, Turkey and Middle East, their susceptibility to TOSV could have significant epidemiological consequences. On the other hand, P. papatasi and S. schwetzi appeared refractory to TOSV B infection. Refractoriness of P. papatasi, a highly anthropophilic species distributed from the Mediterranean to the Middle East and India, suggests that this species does not contribute to TOSV circulation.
- MeSH
- Insect Vectors * virology MeSH
- Humans MeSH
- Phlebotomus * virology MeSH
- Psychodidae * virology classification MeSH
- Sandfly fever Naples virus * physiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Several new species of Leishmania have recently emerged in Europe, probably as the result of global changes and increased human migration from endemic areas. In this study, we tested whether two sand fly species, the Western Mediterranean Phlebotomus perniciosus and the Eastern Mediterranean P. tobbi, are competent vectors of L. donovani, L. major and L. martiniquensis. METHODOLOGY/PRINCIPAL FINDINGS: Sand flies were infected through the chick skin membrane using Leishmania species and strains of various geographical origins. Leishmania infections were evaluated by light microscopy and qPCR, and the representation of morphological forms was assessed from Giemsa-stained gut smears. Neither P. perniciosus nor P. tobbi supported the development of L. martiniquensis, but L. major and L. donovani in both species survived defecation of blood meal remnants, colonized the stomodeal valve and produced metacyclic stages. The results with L donovani have shown that infection rates in sand flies can be strain-specific; therefore, to determine vector competence or refractoriness, it is optimal to test at least two strains of Leishmania. CONCLUSIONS, SIGNIFICANCE: Both sand fly species tested are potential vectors of L. donovani and L. major in Mediterranean area. However, further studies will be needed to identify European vectors of L. martiniquensis and to test the ability of other European sand fly species to transmit L. major, L. donovani, L. tropica and L. infantum.
- MeSH
- Insect Vectors * parasitology physiology MeSH
- Chickens parasitology MeSH
- Leishmania * physiology classification genetics MeSH
- Leishmaniasis transmission parasitology MeSH
- Humans MeSH
- Phlebotomus * parasitology physiology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Verifying the speaker of a speech fragment can be crucial in attributing a crime to a suspect. The question can be addressed given disputed and reference speech material, adopting the recommended and scientifically accepted likelihood ratio framework for reporting evidential strength in court. In forensic practice, usually, auditory and acoustic analyses are performed to carry out such a verification task considering a diversity of features, such as language competence, pronunciation, or other linguistic features. Automated speaker comparison systems can also be used alongside those manual analyses. State-of-the-art automatic speaker comparison systems are based on deep neural networks that take acoustic features as input. Additional information, though, may be obtained from linguistic analysis. In this paper, we aim to answer if, when and how modern acoustic-based systems can be complemented by an authorship technique based on frequent words, within the likelihood ratio framework. We consider three different approaches to derive a combined likelihood ratio: using a support vector machine algorithm, fitting bivariate normal distributions, and passing the score of the acoustic system as additional input to the frequent-word analysis. We apply our method to the forensically relevant dataset FRIDA and the FISHER corpus, and we explore under which conditions fusion is valuable. We evaluate our results in terms of log likelihood ratio cost (Cllr) and equal error rate (EER). We show that fusion can be beneficial, especially in the case of intercepted phone calls with noise in the background.
- MeSH
- Speech Acoustics MeSH
- Algorithms MeSH
- Humans MeSH
- Linguistics MeSH
- Likelihood Functions MeSH
- Speech MeSH
- Forensic Sciences * methods MeSH
- Support Vector Machine MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Chronic hepatitis B (CHB) is caused by the Hepatitis B virus (HBV) and affects millions of people worldwide. Developing an effective CHB therapy requires using in vivo screening methods, such as mouse models reflecting CHB based on hydrodynamic delivery of plasmid vectors containing a replication-competent HBV genome. However, long-term expression of HBV proteins is accompanied by production of progeny virions, thereby requiring a Biosafety Level (BSL) 3 animal facility. In the present study, we introduced a point mutation in the START codon of the HBV polymerase to develop a mouse model reflecting chronic hepatitis B infection without formation of viral progeny. We induced the mouse model by hydrodynamic injection of adeno-associated virus plasmid vector (pAAV) and minicircle plasmid (pMC) constructs into C57Bl/6 and C3H/HeN mouse strains, monitoring HBV antigens and antibodies in blood by enzyme-linked immunosorbent assay and analyzing liver expression of HBV core antigen by immunohistology. Persisting expression of viral antigens over 140 days (study endpoint) was observed only in the C3H/HeN mouse strain when using pAAV/1.2HBV-A and pMC/1.0HBV-D with pre-C and pre-S recombination sites. In addition, pAAV/1.2HBV-A in C3H/HeN sustained HBV core antigen positivity up to the study endpoint in C3H/HeN mice. Moreover, introducing the point mutation in the START codon of polymerase effectively prevented the formation of viral progeny. Our study establishes an accessible and affordable experimental paradigm for developing a robust mouse model reflecting CHB suitable for preclinical testing of anti-HBV therapeutics in a BSL2 animal facility.
- MeSH
- Hepatitis B, Chronic * genetics MeSH
- Codon, Initiator MeSH
- Disease Models, Animal MeSH
- Mutation MeSH
- Mice, Inbred C3H MeSH
- Mice MeSH
- Hepatitis B virus genetics MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Sergentomyia minuta (Diptera: Phlebotominae) is an abundant sand fly species in the Mediterranean basin and a proven vector of reptile parasite Leishmania (Sauroleishmania) tarentolae. Although it feeds preferentially on reptiles, blood meal analyses and detection of Leishmania (Leishmania) infantum DNA in wild-caught S. minuta suggest that occasional feeding may occur on mammals, including humans. Therefore, it is currently suspected as a potential vector of human pathogens. METHODS: A recently established S. minuta colony was allowed to feed on three reptile species (i.e. lizard Podarcis siculus and geckos Tarentola mauritanica and Hemidactylus turcicus) and three mammal species (i.e. mouse, rabbit and human). Sand fly mortality and fecundity were studied in blood-fed females, and the results were compared with Phlebotomus papatasi, vector of Leishmania (L.) major. Blood meal volumes were measured by haemoglobinometry. RESULTS: Sergentomyia minuta fed readily on three reptile species tested, neglected the mouse and the rabbit but took a blood meal on human. However, the percentage of females engorged on human volunteer was low in cage (3%) and feeding on human blood resulted in extended defecation times, higher post-feeding mortality and lower fecundity. The average volumes of blood ingested by females fed on human and gecko were 0.97 μl and 1.02 μl, respectively. Phlebotomus papatasi females readily fed on mouse, rabbit and human volunteer; a lower percentage of females (23%) took blood meal on the T. mauritanica gecko; reptilian blood increased mortality post-feeding but did not affect P. papatasi fecundity. CONCLUSIONS: Anthropophilic behaviour of S. minuta was experimentally demonstrated; although sand fly females prefer reptiles as hosts, they were attracted to the human volunteer and took a relatively high volume of blood. Their feeding times were longer than in sand fly species regularly feeding on mammals and their physiological parameters suggest that S. minuta is not adapted well for digestion of mammalian blood. Nevertheless, the ability to bite humans highlights the necessity of further studies on S. minuta vector competence to elucidate its potential role in circulation of Leishmania and phleboviruses pathogenic to humans.
- MeSH
- DNA genetics MeSH
- Lizards * MeSH
- Rabbits MeSH
- Leishmania * genetics MeSH
- Humans MeSH
- Mice MeSH
- Phlebotomus * parasitology MeSH
- Psychodidae * parasitology MeSH
- Mammals genetics MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Humans MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Hyalomma marginatum and Hyalomma rufipes are important vectors of Crimean-Congo Hemorrhagic Fever Virus (CCHFV) in North Africa and Southern Europe. They are occasionally also reported from Central and Western Europe where they are likely introduced from their natural range by migratory birds. In this study, we report findings and molecular identification of adults and one nymph of H. marginatum and H. rufipes, primarily from horses from different regions of the Czech Republic. While the number of the reported ticks is small, this is likely to be an underrepresentation of the actual number. Due to their vector competence for CCHFV and potential expansion into new areas with a changing climate, surveillance programs in Europe are warranted.
- MeSH
- Hemorrhagic Fever, Crimean * MeSH
- Ixodidae * MeSH
- Ticks * MeSH
- Horses MeSH
- Humans MeSH
- Hemorrhagic Fever Virus, Crimean-Congo * MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
Anaplasma phagocytophilum is the causative agent of tick-borne fever (TBF) and human granulocytic anaplasmosis (HGA) and is currently considered an emerging disease in the USA, Europe, and Asia. The increased prevalence of A. phagocytophilum as a human pathogen requires the detailed characterization of human isolates and the implementation of appropriate animal models. In this study, we demonstrated that the dynamics of infection with the human isolate of A. phagocytophilum NY-18 was variable in three different strains of mice (SCID, C3H/HeN, BALB/c). We further evaluated the ability of Ixodes ricinus to acquire and transmit A. phagocytophilum NY-18 and compared it with Ixodes scapularis. Larvae of both tick species effectively acquired the pathogen while feeding on infected mice. The infection rates then decreased during the development to nymphs. Interestingly, molted I. ricinus nymphs were unable to transmit the pathogen to naïve mice, which contrasted with I. scapularis. The results of our study suggest that I. ricinus is not a competent vector for the American human Anaplasma isolate. Further studies are needed to establish reliable transmission models for I. ricinus and European human isolate(s) of A. phagocytophilum.
- Publication type
- Journal Article MeSH
Oncolytic virotherapies (OV) hold immense clinical potential. OV based on human adenoviruses (HAdV) derived from HAdV with naturally low rates of pre-existing immunity will be beneficial for future clinical translation. We generated a low-seroprevalence HAdV-D10 serotype vector incorporating an αvβ6 integrin-selective peptide, A20, to target αvβ6-positive tumor cell types. HAdV-D10 has limited natural tropism. Structural and biological studies of HAdV-D10 knob protein highlighted low-affinity engagement with native adenoviral receptors CAR and sialic acid. HAdV-D10 fails to engage blood coagulation factor X, potentially eliminating "off-target" hepatic sequestration in vivo. We engineered an A20 peptide that selectively binds αvβ6 integrin into the DG loop of HAdV-D10 fiber knob. Assays in αvβ6+ cancer cell lines demonstrated significantly increased transduction mediated by αvβ6-targeted variants compared with controls, confirmed microscopically. HAdV-D10.A20 resisted neutralization by neutralizing HAdV-C5 sera. Systemic delivery of HAdV-D10.A20 resulted in significantly increased GFP expression in BT20 tumors. Replication-competent HAdV-D10.A20 demonstrated αvβ6 integrin-selective cell killing in vitro and in vivo. HAdV-D10 possesses characteristics of a promising virotherapy, combining low seroprevalence, weak receptor interactions, and reduced off-target uptake. Incorporation of an αvβ6 integrin-selective peptide resulted in HAdV-D10.A20, with significant potential for clinical translation.
- Publication type
- Journal Article MeSH
The current population worldwide extensively uses social media to share thoughts, societal issues, and personal concerns. Social media can be viewed as an intelligent platform that can be augmented with a capability to analyze and predict various issues such as business needs, environmental needs, election trends (polls), governmental needs, etc. This has motivated us to initiate a comprehensive search of the COVID-19 pandemic-related views and opinions amongst the population on Twitter. The basic training data have been collected from Twitter posts. On this basis, we have developed research involving ensemble deep learning techniques to reach a better prediction of the future evolutions of views in Twitter when compared to previous works that do the same. First, feature extraction is performed through an N-gram stacked autoencoder supervised learning algorithm. The extracted features are then involved in a classification and prediction involving an ensemble fusion scheme of selected machine learning techniques such as decision tree (DT), support vector machine (SVM), random forest (RF), and K-nearest neighbour (KNN). all individual results are combined/fused for a better prediction by using both mean and mode techniques. Our proposed scheme of an N-gram stacked encoder integrated in an ensemble machine learning scheme outperforms all the other existing competing techniques such unigram autoencoder, bigram autoencoder, etc. Our experimental results have been obtained from a comprehensive evaluation involving a dataset extracted from open-source data available from Twitter that were filtered by using the keywords "covid", "covid19", "coronavirus", "covid-19", "sarscov2", and "covid_19".
- MeSH
- COVID-19 * MeSH
- Humans MeSH
- Pandemics MeSH
- SARS-CoV-2 MeSH
- Social Media * MeSH
- Social Networking MeSH
- Machine Learning MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In the past few decades, the relevance of Dirofilaria immitis and Dirofilaria repens, causing cardiopulmonary and subcutaneous dirofilariosis in dogs and cats, and of Angiostrongylus vasorum, causing canine angiostrongylosis, has steadily increased in Central and Northern Europe. In this review, a summary of published articles and additional reports dealing with imported or autochthonous cases of these parasites is provided for Central (Austria, Czechia, Germany, Hungary, Luxemburg, Poland, Slovakia, Slovenia, and Switzerland) and Northern (Denmark, Finland, Iceland, Norway, and Sweden) Europe. Research efforts focusing on Dirofilaria spp. and A. vasorum have varied by country, and cross-border studies are few. The housing conditions of dogs, pet movements, the spread of competent vectors, and climate change are important factors in the spread of these nematodes. Dogs kept outside overnight are a major factor for the establishment of Dirofilaria spp. However, the establishment of invasive, diurnal, synanthropic, competent mosquito vectors such as Aedes albopictus may also influence the establishment of Dirofilaria spp. The drivers of the spread of A. vasorum remain not fully understood, but it seems to be influenced by habitats shared with wild canids, dog relocation, and possibly climatic changes; its pattern of spreading appears to be similar in different countries. Both Dirofilaria spp. and A. vasorum merit further monitoring and research focus in Europe.
- Publication type
- Journal Article MeSH
- Review MeSH