35 research outputs found
Geographical Variability Affects CCHFV Detection by RT-PCR: A Tool for In-Silico Evaluation of Molecular Assays
The Crimean-Congo hemorrhagic fever virus (CCHFV) is considered to be a major emerging infectious threat, according to the WHO R&D blueprint. A wide range of CCHFV molecular assays have been developed, employing varied primer/probe combinations. The high genetic variability of CCHFV often hampers the efficacy of available molecular tests and can affect their diagnostic potential. Recently, increasing numbers of complete CCHFV genomic sequences have become available, allowing a better appreciation of the genomic evolution of this virus. We summarized the current knowledge on molecular methods and developed a new bioinformatics tool to evaluate the existing assays for CCHFV detection, with a special focus on strains c
First observation of the decay and a measurement of the ratio of branching fractions
The first observation of the decay using
data collected by the LHCb detector at a centre-of-mass energy of 7 TeV,
corresponding to an integrated luminosity of 36 pb, is reported. A
signal of events is obtained and the absence of signal is
rejected with a statistical significance of more than nine standard deviations.
The branching fraction is measured relative to
that of : , where the first uncertainty is statistical, the second systematic and
the third is due to the uncertainty on the ratio of the and
hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269
Observation of CP violation in B+ to DK+ decays
An analysis of B+ to DK+ and B+ to Dpi+ decays is presented where the D meson
is reconstructed in the two-body final states: K+pi-, K+K-, pi+pi- and pi+K-.
Using 1.0 fb-1 of LHCb data, measurements of several observables are made
including the first observation of the suppressed mode B+ to DK+, D to pi+K-.
CP violation in B+ to DK+ decays is observed with 5.8 sigma significance
Determination of gamma and-2 beta(s) from charmless two-body decays of beauty mesons
Using the latest LHCb measurements of time-dependent CP violation in the
B^0_s -> K^+K^- decay, a U-spin relation between the decay amplitudes of B^0_s
-> K^+K^- and B^0 -> \pi^+\pi^- decay processes allows constraints to be placed
on the angle gamma of the unitarity triangle and on the B^0_s mixing phase
-2\beta_s. Results from an extended approach, which uses additional inputs on
B^0 -> \pi^0\pi^0 and B^+ -> \pi^+\pi^0 decays from other experiments and
exploits isospin symmetry, are also presented. The dependence of the results on
the maximum allowed amount of U-spin breaking is studied. At 68% probability,
the value \gamma = ( 63.5 +7.2 -6.7 ) degrees modulo 180 degrees is determined.
In an alternative analysis, the value -2\beta_s = -0.12 +0.14 -0.16 rad is
found. In both measurements, the uncertainties due to U-spin breaking effects
up to 50% are included.Comment: updated to v2 with minor changes after journal revie
Search for CP violation in and decays
A search for \CP violation in Cabibbo-suppressed and decays is performed using collision data, corresponding to an integrated luminosity of 3~fb, recorded by the LHCb experiment. The individual -violating asymmetries are measured to be \begin{eqnarray*} \mathcal{A}_{CP}^{D^{\pm}\rightarrow K^0_{\mathrm{S}} K^{\pm}} & = & (+0.03 \pm 0.17 \pm 0.14) \% \mathcal{A}_{CP}^{D^{\pm}_{s}\rightarrow K^0_{\mathrm{S}} \pi^{\pm}} & = & (+0.38 \pm 0.46 \pm 0.17) \%, \end{eqnarray*} assuming that violation in the Cabibbo-favoured decays is negligible. A combination of the measured asymmetries for the four decay modes and gives the sum In all cases, the first uncertainties are statistical and the second systematic. The results represent the most precise measurements of these asymmetries to date and show no evidence for CP violation
Flaviviruses identified in mosquitoes collected in Veneto and Trentino Alto-Adige regions (North-East Italy)
The genus Flavivirus (family Flaviviridae) comprises more than 70 viruses, divided according to their ecological and epidemiological characteristics, and disease associations in three groups: 1) those infecting a range of vertebrate hosts through mosquito or tick bites, called âarthropod-borne virusesâ, 2) those spread by an unknown vector, presumed to be limited to infect vertebrates only, and 3) apparently limited to insects alone, called âinsect-specific flavivirusesâ (âISFsâ). In the first group are present some important or emerging human pathogens, as West Nile virus (WNV) and Usutu virus (USUV). ISFs replicate only in mosquito-derived cells and the first of them to be discovered was Cell Fusing Agent virus, isolated in 1975 from a Aedes aegypti cell line. During the last decades, many others have been isolated and identified, in different geographic regions, from field collected mosquitoes belonging to different species. Other ISFs have been only detected through molecular methods but not isolated. Despite their non-pathogenicity to humans and animals, ISFs have recently gained attention with respect to their ecological and evolutionary relationships with other important flaviviruses. A particular focus of interest is the possible interaction of these viruses within the same vector that can leadto different results as âsuperinfection exclusionâ or ehnanced transmission or replication. In Trentino the only evidence of WNV and USUV have been seroconversion in sentinel chickens in 2005, but ISFs have been detected since 2007. A completely different ecoepidemiological situation is present in Veneto since WNV and USUV have been detected in several studies during the last decades, but there is only one report regarding the detection of ISFs in this region.
To gain a better understanding regarding the presence of flaviviruses in these two regions characterized by strong differences in environmenthal, meteoclimatic and ecoepidemiological conditions, we carried out a mosquito screening to detect flaviviruses. Mosquitoes were collected from May to October 2012, using 20 and 10 traps BG-Sentinel (Veneto and Trentino, respectively), located half in a rural and half in an urban environment, with BG-lure attractant and dry ice, checked weekly. Mosquitoes captured were killed at -80°C, identified to species level and pooled according to date, location, species and gender and stored at -80°C until molecular analysis. After RNA extraction, we used a generic RT-nested-PCR targeted on a region of the NS5 gene for the screening of flaviviruses. The phylogenetic analysis were realized on a fragment of 1000bp. For samples positive at the generic NS5 RT-nested-PCR, virus isolation was attempted in C6/36 cell lines (from Aedes albopictus mosquito). Fresh supernatants and cells from cell cultures with evident cytopathic effect, were used for electron microscopy studies.
In Veneto we collected a total of 52096 female and 1190 male mosquitoes, belonging to Oc. geniculatus, Oc. caspius, Cx. pipiens, Cx. territans, Cx. modestus, Cs. annulata, An. plumbeus, An. maculipennis, Ae. cinereus/geminus, Ae. albopictus, Ae. vexans and Ae. koreicus species. We detected USUV in Cx. pipiens, and AeFV in Cx. pipiens and in Ae. albopictus. In another pool of Cx. pipiens we also found sequences of an ISF never reported before in literature that could be considered as a new insect-specific flavivirus. We successfully isolated in cell culture AeFV from one pool of Ae. albopictus, with evident cytopathic effect (CPE) (cell aggregation). Transmission electron microscopy performed on C6/36 cells infected by AeFV confirmed the presence of flaviviruses.
In Trentino we collected a total of 1622 female and 464 male mosquitoes, belonging to Oc. geniculatus, Cx. pipiens, Cx. hortensis, An. plumbeus, An. maculipennis and Ae. albopictus. We detected only AeFV in pools of Ae. Albopictus, that was also successfully isolated in cell culture. In 1 pool we obtained evident CPE and by electronic microscopy we detected viral particles with the tipical morphological characteristics of Rhabdovirus.
Our results confirm the different eco-epidemiological situation present in North-east Italy underlined by previous studies. They strongly support the importance of the influence of the climatic conditions on the transmission viral cycle. Moreover they suggest that a high prevalence of ISFs could damper replication and transmission of other more pathogenic viruse
Understanding the impact on human and wildlife health of the invasive alien mosquito species Aedes albopictus in Northern Italy
Aedes albopictus is among the most widespread alien species in the world and its introduction and spread in northern Italy has been documented since 1990. While its impact on human health is well known in this area not only for its nuisance but also for being the most important vector involved in the 2007 epidemics of Chikungunya (CHIKV), its role as a bridge vector of infections impacting both human health and wildlife is less understood. In fact, extensive epidemics of West Nile virus (WNV)
and Usutu Virus (USUV) have been recently documented within the study area. Although referred to as an anthropophilic species, there is evidence of its relative ornithophily. To better understand its role as bridge vector for human and wildlife diseases in Italy, we carried out mosquito samplings within two regions (Trentino and Veneto) from 2011 to 2013. A total of 4613 unfed female and 1976 males were screened for Flaviviruses, while 86 fed females were screened to identify the host used by the mosquito for its blood meal. The virological screening identified the occurrence of Aedes
flavivirus (AeFV) in a significant number of pools tested (14.6% in Trentino and 19.3% in Veneto) while no positive samples were obtained for West Nile virus or Usutu virus. Blood meal analysis of the engorged females identified the following host species: Homo sapiens (88.3%), Erinaceus europaeus (2.3%), Coturnix japonica (1.2%), Passer montanus (1.2%) and Turdus merula (1.2%). These preliminary finding indicate the ability of this species to feed also on non-human hosts and thus act as an additional potential bridge vector of pathogens among wildlife and humans, although in this study we could not identify West Nile or Usutu virus in our sample
Identificazione di Flavivirus in zanzare raccolte in Veneto e Trentino
Gli âInsect specific flavivirusâ (ISFs) sono Flavivirus (famiglia Flaviviridae) che apparentemente infettano solo insetti, recentemente scoperti e identificati in un numero crescente di regioni geografiche e specie di zanzare. Tra i Flavivirus sono inoltre presenti importanti agenti patogeni per gli animali e lâuomo, quali West Nile virus e Usutu virus (USUV). Recentemente si stanno studiando le possibili relazioni ecologiche ed evolutive tra i vari Flavivirus e in particolare, le conseguenze della loro interazione all'interno del vettore su replicazione e trasmissione virale. Per approfondire la conoscenza circa la presenza di Flavivirus in Trentino e Veneto, due regioni diverse per caratteristiche ambientali, meteoclimatiche ed ecoepidemiologiche, da maggio a ottobre 2012 abbiamo realizzato una cattura di zanzare, impiegando trappole BG-Sentinel collocate in ambiente rurale e urbano. Per lo screening dei Flavivirus, abbiamo utilizzato una generic RT-nested-PCR mirata su una regione del gene NS5 e lâanalisi filogenetica Ăš stata realizzata su un frammento di 1000bp dello stesso gene. Abbiamo tentato lâisolamento virale su linee cellulari C6/36 (da Aedes albopictus) di alcuni campioni positivi. I surnatanti freschi e le cellule di colture cellulari con evidente effetto citopatico, sono stati utilizzati per studi di microscopia elettronica (ME). In Veneto abbiamo raccolto 52.096 zanzare femmine e 1190 maschi appartenenti alle specie Oc. geniculatus, Oc. caspius, Cx. pipiens, Cx. territans, Cx. modestus, Cs. annulata, An. plumbeus, An. maculipennis, Ae. cinereus/geminus, Ae. albopictus, Ae. vexans e Ae. koreicus. Abbiamo rilevato USUV in Cx. pipiens, e un ISFs, lâAedesFlavivirus (AeFV), in Cx. pipiens e Ae. albopictus. In un altro pool di Cx. pipiens abbiamo trovato identificato una presunta nuova sequenza di ISF. In Trentino abbiamo raccolto 1.622 zanzare femmine e 464 maschi appartenenti alle specie Oc. geniculatus, Cx. pipiens, Cx. hortensis, An. plumbeus, An. maculipennis e Ae. albopictus, rilevando AeFV in pools di Ae. albopictus. Alcuni AeFV sono stati isolati in coltura cellulare e identificati in ME. Il nostro studio riporta per la prima volta la presenza di sequenze di AeFV in Cx. pipiens, conferma la diversa situazione eco-epidemiologica precedentemente rilevata nel Nord-est Italia e lâelevata prevalenza di AeVF in Ae. albopictus, evidenziando lâelevato grado di identitĂ nucleotidica tra virus circolanti nelle due aree di studio. Inoltre, sostiene lâidea dellâinfluenza delle condizioni climatiche sul ciclo di trasmissione virale e suggerisce che unâelevata prevalenza di ISFs puĂČ influenzare replicazione e trasmissione di altri virus piĂč patogeni. Ulteriori studi sperimentali sono necessari per confermare tale ipotes
The contribution of the European high containment laboratories during the 2014-2015 Ebola Virus Disease emergency
Since December 2013, the world has experienced the worst ever epidemic of Ebola virus disease (EVD), which has caused thousands of deaths in several West African countries. When the epidemic began, the European Union (EU) was not unprepared, thanks to the 10-year-long commitment of the European Commission (EC) to fund several networks in the area of highly infectious diseases. The European Network of Biosafety-Level 4 (BSL-4) laboratories (Euronet-P4, later called ENP4-Lab) was one of them; it has been operating since 2004, bringing together the facilities where RiskGroup 4 (RG-4) pathogens such as Ebola virus can be safely handled. In 2010, with the aim of increasing European preparedness in the fight against highly infectious trans-border threats, a new Joint Action was launched, resulting from the union of the networks that had previously worked on the diagnostics of highly infectious viruses and bacteria: ENP4-Lab and EQADeBa (Establishment of Quality Assurance for Detection of Highly Pathogenic Bacteria of Potential Bioterrorism Risk). (...)The authors are grateful to the European Commission and CHAFEA for financially and technically supporting the following Networks: EURONET-P4 2003214, ENP4Lab 2006208, QUANDHIP 2010-21-02, and EMLab (European Mobile Laboratory Project). Part of this work was also supported by the Italian Ministry of Health, âRicerca Correnteâ grants awarded to the âLazzaro Spallanzaniâ National
Institute for Infectious Diseases-IRCCS, Rome, Italy.info:eu-repo/semantics/acceptedVersio
First observation of Bs â J/Ïf0(980) decays
Using data collected with the LHCb detector in protonâproton collisions at a centre-of-mass energy of 7 TeV, the hadronic decay is observed. This CP eigenstate mode could be used to measure mixing-induced CP violation in the system. Using a fit to the Ï+Ïâ mass spectrum with interfering resonances gives . In the interval ±90 MeV around 980 MeV, corresponding to approximately two full f0 widths we also find , where in both cases the uncertainties are statistical and systematic, respectively