785 research outputs found

    Vector competence for West Nile virus and St. Louis encephalitis virus (flavivirus) of three tick species of the genus Amblyomma (Acari: Ixodidae)

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    Many species of Amblyomma ticks are commonly found infesting wild birds in South America, where birds are important hosts for several arboviruses, such as West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). In this study, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick species: Amblyomma ovale, Amblyomma tigrinum, and Amblyomma tonelliae. Larval and nymphal ticks of each species were allowed to feed on chicks needle inoculated with WNV or SLEV. All three Amblyomma species acquired either WNV or SLEV through larval feeding, with infection rates varying from 3.1% to 100% for WNV and from 0% to 35.7% for SLEV in engorged larvae. Transstadial perpetuation of the viruses was demonstrated in the molted nymphs, with WNV infection rates varying from 0% to 33.7% and SLEV infection rates from 13.6% to 23.8%. Although nymphal ticks also acquired either virus through feeding, transstadial perpetuation to adult ticks was lower, with virus detection in only 3.2% of A. tigrinum and 11.5% of A. tonelliae unfed adult ticks. On the other hand, vector competence for nymphs (exposed to WNV or SLEV through larval feeding) and adult ticks (exposed to WNV or SLEV through larval or nymphal feeding) was null in all cases. Although our results indicate transstadial perpetuation of WNV or SLEV in the three tick species, the ticks were not competent to transmit these agents to susceptible hosts. The role of these ixodid tick species in the epidemiology of WNV and SLEV might be insignificant, even though at least A. ovale and A. tigrinum are frequent bird ticks in Latin America, so the virus could survive winter in the fed larvae. However, future studies are required to determine the implications that this could have, as well as analyze the vector competence of other common bird tick species in South America.Fil: Flores, Fernando Sebastián. Universidad Nacional de Córdoba. Facultad de Medicina; ArgentinaFil: Zanluca, Camila. Instituto Carlos Chagas, Curitiba;Fil: Guglielmone, Alberto Alejandro. Instituto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Duarte dos Santos, Claudia N.. Instituto Carlos Chagas, Curitiba;Fil: Labruna, Marcelo B.. Universidade de Sao Paulo; BrasilFil: Diaz, Luis Adrian. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Universidad Nacional de Córdoba; Argentin

    CellProfiler plugins -- an easy image analysis platform integration for containers and Python tools

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    CellProfiler is a widely used software for creating reproducible, reusable image analysis workflows without needing to code. In addition to the >90 modules that make up the main CellProfiler program, CellProfiler has a plugins system that allows for creation of new modules which integrate with other Python tools or tools that are packaged in software containers. The CellProfiler-plugins repository contains a number of these CellProfiler modules, especially modules that are experimental and/or dependency-heavy. Here, we present an upgraded CellProfiler-plugins repository with examples of accessing containerized tools, improved documentation, and added citation/reference tools to facilitate the use and contribution of the community.Comment: 17 pages, 2 figures, 1 tabl

    Rickettsia parkeri in Brazil

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    We report finding Rickettsia parkeri in Brazil in 9.7% of Amblyomma triste ticks examined. An R. parkeri isolate was successfully established in Vero cell culture. Molecular characterization of the agent was performed by DNA sequencing of portions of the rickettsial genes gltA, htrA, ompA, and ompB

    Genomic analysis of the function of the transcription factor gata3 during development of the Mammalian inner ear

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    We have studied the function of the zinc finger transcription factor gata3 in auditory system development by analysing temporal profiles of gene expression during differentiation of conditionally immortal cell lines derived to model specific auditory cell types and developmental stages. We tested and applied a novel probabilistic method called the gamma Model for Oligonucleotide Signals to analyse hybridization signals from Affymetrix oligonucleotide arrays. Expression levels estimated by this method correlated closely (p<0.0001) across a 10-fold range with those measured by quantitative RT-PCR for a sample of 61 different genes. In an unbiased list of 26 genes whose temporal profiles clustered most closely with that of gata3 in all cell lines, 10 were linked to Insulin-like Growth Factor signalling, including the serine/threonine kinase Akt/PKB. Knock-down of gata3 in vitro was associated with a decrease in expression of genes linked to IGF-signalling, including IGF1, IGF2 and several IGF-binding proteins. It also led to a small decrease in protein levels of the serine-threonine kinase Akt2/PKB beta, a dramatic increase in Akt1/PKB alpha protein and relocation of Akt1/PKB alpha from the nucleus to the cytoplasm. The cyclin-dependent kinase inhibitor p27(kip1), a known target of PKB/Akt, simultaneously decreased. In heterozygous gata3 null mice the expression of gata3 correlated with high levels of activated Akt/PKB. This functional relationship could explain the diverse function of gata3 during development, the hearing loss associated with gata3 heterozygous null mice and the broader symptoms of human patients with Hearing-Deafness-Renal anomaly syndrome

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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