Virucidal activity of three standard chemical disinfectants against Ebola virus suspended in tripartite soil and whole blood

Abstract Proper disinfection and inactivation of highly pathogenic viruses is an essential component of public health and prevention. Depending on environment, surfaces, and type of contaminant, various methods of disinfection must be both efficient and available. To test both established and novel chemical disinfectants against risk group 4 viruses in our maximum containment facility, we developed a standardized protocol and assessed the chemical inactivation of the two Ebola virus variants Mayinga and Makona suspended in two different biological soil loads. Standard chemical disinfectants ethanol and sodium hypochlorite completely inactivate both Ebola variants after 30 s in suspension at 70% and 0.5% v/v, respectively, concentrations recommended for disinfection by the World Health Organization. Additionally, peracetic acid is also inactivating at 0.2% v/v under the same conditions. Continued vigilance and optimization of current disinfection protocols is extremely important due to the continuous presence of Ebola virus on the African continent and increased zoonotic spillover of novel viral pathogens. Furthermore, to facilitate general pandemic preparedness, the establishment and sharing of standardized protocols is very important as it allows for rapid testing and evaluation of novel pathogens and chemical disinfectants

Presence and Persistence of Andes Virus RNA in Human Semen

When infecting humans, Andes orthohantavirus (ANDV) may cause a severe disease called hantavirus cardiopulmonary syndrome (HCPS). Following non-specific symptoms, the infection may progress to a syndrome of hemorrhagic fever combined with hyper-acute cardiopulmonary failure. The case fatality rate ranges between 25–40%, depending on the outbreak. In this study, we present the follow-up of a male patient who recovered from HCPS six years ago. We demonstrate that the ANDV genome persists within the reproductive tract for at least 71 months. Genome sequence analysis early and late after infection reveals a low number of mutations (two single nucleotide variants and one deletion), suggesting limited replication activity. We can exclude the integration of the viral genome into the host genome, since the treatment of the specimen with RNAse led to a loss of signal. We demonstrate a long-lasting, strong neutralizing antibody response using pseudovirions expressing the ANDV glycoprotein. Taken together, our results show that ANDV has the potential for sexual transmission

Regulation of Antigen-Specific Immunoglobulin G Subclasses in Response to Conserved and Polymorphic Plasmodium falciparum Antigens in an In Vitro Model

Cytophilic antibodies (Abs) play a critical role in protection against Plasmodium falciparum blood stages, yet little is known about the parameters regulating production of these Abs. We used an in vitro culture system to study the subclass distribution of antigen (Ag)-specific immunoglobulin G (IgG) produced by peripheral blood mononuclear cells (PBMCs) from individuals exposed to P. falciparum or unexposed individuals. PBMCs, cultivated with or without cytokines and exogenous CD40/CD40L signals, were stimulated with a crude parasite extract, recombinant vaccine candidates derived from conserved Ags (19-kDa C terminus of merozoite surface protein 1 [MSP1(19)], R23, and PfEB200), or recombinant Ags derived from the polymorphic Ags MSP1 block 2 and MSP2. No P. falciparum-specific Ab production was detected in PBMCs from unexposed individuals. PBMCs from donors exposed frequently to P. falciparum infections produced multiple IgG subclasses when they were stimulated with the parasite extract but usually only one IgG subclass when they were stimulated with a recombinant Ag. Optimal Ab production required addition of interleukin-2 (IL-2) and IL-10 for all antigenic preparations. The IgG subclass distribution was both donor and Ag dependent and was only minimally influenced by the exogenous cytokine environment. In vitro IgG production and subclass distribution correlated with plasma Abs to some Ags (MSP1(19), R23, and MSP2) but not others (PfEB200 and the three MSP1 block 2-derived Ags). Data presented here suggest that intrinsic properties of the protein Ag itself play a major role in determining the subclass of the Ab response, which has important implications for rational design of vaccine delivery

Chloroplast DNA polymorphism and phylogeography of a Central African tree species widespread in mature rainforests: Greenwayodendron suaveolens (Annonaceae)

Geographic patterns of genetic variation at chloroplast markers have been successfully used to address the phylogeography and the demographic history of many plant species. Very few studies have however been conducted in important tropical centers of plant biodiversity like the African rainforests. The phylogeography of a tree species widespread in Central African mature forests, Greenwayodendron suaveolens subsp. suaveolens (Annonaceae), was investigated in the Lower Guinea phytogeographic domain (essentially Gabon and Cameroon) by sequencing an intergenic spacer of the chloroplast genome (trnC-petN1R). A total of 11 polymorphic sites, including nine single nucleotide polymorphisms (SNPs), two insertions/deletions and two inversions, defined 12 haplotypes. The taxon is represented by two sympatric varieties (var. suaveolens and var. gabonica) that carried distinct and relatively divergent haplotypes. These varieties, also well distinguishable morphologically, might therefore represent true biological species. The variety suaveolens, more common and more widespread than the variety gabonica, was represented by ten haplotypes. This taxon showed a weak but statistically significant phylogeographic structure, indicating that two sets of related haplotypes essentially occurred respectively in the northern and the southern hemispheres. These results suggest that the distribution of Greenwayodendron suaveolens subsp. suaveolens, which is currently continuous in the Lower Guinea domain, might have been more fragmented in the past, possibly in relation with Pleistocene forest fragmentation. © 2010 Springer Science+Business Media, Inc.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Role for Mechanotransduction in Macrophage and Dendritic Cell Immunobiology

Item does not contain fulltextTissue homeostasis is not only controlled by biochemical signals but also through mechanical forces that act on cells. Yet, while it has long been known that biochemical signals have profound effects on cell biology, the importance of mechanical forces has only been recognized much more recently. The types of mechanical stress that cells experience include stretch, compression, and shear stress, which are mainly induced by the extracellular matrix, cell-cell contacts, and fluid flow. Importantly, macroscale tissue deformation through stretch or compression also affects cellular function.Immune cells such as macrophages and dendritic cells are present in almost all peripheral tissues, and monocytes populate the vasculature throughout the body. These cells are unique in the sense that they are subject to a large variety of different mechanical environments, and it is therefore not surprising that key immune effector functions are altered by mechanical stimuli. In this chapter, we describe the different types of mechanical signals that cells encounter within the body and review the current knowledge on the role of mechanical signals in regulating macrophage, monocyte, and dendritic cell function