Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain

Background: Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial public health relevance due to its potential role in transmitting several human pathogens. Out of the European countries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of Ae. albopictus and the extensive tourist influx from vector-endemic areas. This study aims to investigate the susceptibility of five Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV) strain. Methods: The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal (1.8 × 10 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively. The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay or RT-qPCR on ∼33 individuals per population. Results: The IR and DR ranged between 12-88%, and 0-60%, respectively, suggesting that ZIKV is capable of crossing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h after ZIKV exposure did not influence Ae. albopictus vector competence. Conclusions: The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae. albopictus

Control parameters on the fabrication of ZnO hollow nanocolumns

[EN] The present work reports on the fabrication of hollow ZnO nanocolumns by a sequential combination of electrochemical deposition, chemical attack and regeneration. Initially, ZnO nanocolumns were deposited in two different substrates, namely Fluor Tin Oxide and Indium Tin Oxide. In a further step, a statistical analysis on the most influencing control parameters in the dissolution stage to produce the hollow ZnO nanowires on the FTO substrates was carried out. The control variables considered were electrolyte concentration, dissolution time and temperature, whereas the output variable was the percentage of the hollow nanocolumns obtained. The statistical analysis consisted of a two-level factorial design of experiments on three variables, therefore involving a series of 8 experiments. An analysis of variance (ANOVA) on the results was also carried out. The results showed that all the control variables were significant, the most important being the dissolution time.This work was supported by the Spanish Government through MCINN Grant MAT2009-14625-C03-03, Generalitat Valenciana programme PROMETEO/2009/063 and European Commission through NanoCIS project FP7-PEOPLE-2010-IRSES (ref. 269279). Technical support given to the authors by the Servei de Microscopia at the Universitat Politecnica de Valencia (Spain) is greatly acknowledged.Cembrero Cil, J.; Busquets Mataix, DJ.; Rayón Encinas, E.; Pascual Guillamón, M.; Pérez Puig, MA.; Marí Soucase, B. (2013). Control parameters on the fabrication of ZnO hollow nanocolumns. Materials Science in Semiconductor Processing. 16:211-216. https://doi.org/10.1016/j.mssp.2012.04.014S2112161

Effect of Merocyanine 540 on Langmuir-Blodgett films and liposomes of zwitterionic, anionic and cationic lipid composition

The interaction of the anionic probe Merocyanine 540 (MC540) with mono and bilayers of different lipid composition has been analyzed in order to get insight in the lipid charge influence on probe activity. The Langmuir-Blodgett technique showed that MC540 was able to incorporate predominantly into cationic lipid monolayers composed of Dimyristoyl phosphatidyl choline/Dimyristoyl trimethyl ammonium-propane (DMPC/DMPTAP) (75:25, mol:mol). However, at low surface pressures, the probe could also allocate into the interface of the zwitterionic Dimyristoyl phosphatidyl choline (DMPC) and the anionic Dimyristoyl phosphatidyl choline/ Dimyristoyl phosphatidyl glycerol (DMPCI/DMPG) (75:25, mol:mol) thus indicating a low interaction with these lipid compositions. These results were in agreement with the studies performed with Large Unilamelar Vesicles (LUVs) of the Same lipid compositions based in the spectroscopic analysis of probe absorption maxima modification upon its incorporation into the lipid bilayers

Perturbations induced by synthetic peptides belonging to the E2 structural protein of hepatitis G virus (GBV-C/HGV) in lipid membranes: A differential scanning calorimetry study

In the present work we report the perturbations induced on multilamellar liposomes (MLVs) of different phospholipid composition (DPPC, DMPC, DMPC/DMPG) by peptides that belong to hepatitis G virus (GBV-CHGV). A differential scanning calorimetty (DSC) study was performed with MLVs in the presence of increasing amounts of the three synthetic overlapping peptides from GBV-C/HGV, namely E2(17-26), E2(12-26) and E2(7-26) sequences

Interaction of a hepatitis A synthetic antigen [105,109ABU]VP3(101-121) with lipid monolayers

We describe the synthesis and characterization of an antigenic peptide : [105,109ABU]VP3(101-121), corresponding to the (101-121) sequence of VP3 protein from Hepatitis A virus. The physicochemical properties of the peptide were studied using lipid monolayers as a model membrane by means the Langmuir-Blodgett film technique. The main goal of the research was to get insight into the possible mechanism of action of the peptide at the membrane level and therefore, to better understand the proliferation and infection processes of the virus in the host. For that reason, interaction of the peptide with neutral, anionic and cationic phospholipids was studied by the determination of the penetration kinetics and compression isotherms. The peptide had surface activity, concentration dependent and was able to incorporate into lipid monolayers

Refined Route Instructions Using Topological Stages of Closeness

Abstract. In pedestrian navigation, navigators are free to choose any passable way. Because of this characteristic, accurate route instructions are important when navigating from waypoint to waypoint. In this paper, a theoretical frame-work is described for dealing with position uncertainty in pedestrian guiding systems. Stages of closeness are defined based on the topological relation be-tween the navigator and a waypoint. These stages of closeness allow for refin-ing route instructions and, therefore, leading to more accurate navigation and increased efficiency of the system

Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain

Background: Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial public health relevance due to its potential role in transmitting several human pathogens. Out of the European countries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of Ae. albopictus and the extensive tourist influx from vector-endemic areas. This study aims to investigate the susceptibility of five Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV) strain. Methods: The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal (1.8 × 10 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively. The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay or RT-qPCR on ∼33 individuals per population. Results: The IR and DR ranged between 12-88%, and 0-60%, respectively, suggesting that ZIKV is capable of crossing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h after ZIKV exposure did not influence Ae. albopictus vector competence. Conclusions: The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae. albopictus