Surveillance for European bat lyssavirus in Swiss bats

Most countries in Western Europe are currently free of rabies in terrestrial mammals. Nevertheless, rabies remains a residual risk to public health due to the natural circulation of bat-specific viruses, such as European bat lyssaviruses (EBLVs). European bat lyssavirus types 1 and 2 (EBLV-1 and EBLV-2) are widely distributed throughout Europe, but little is known of their true prevalence and epidemiology. We report that only three out of 837 brains taken from bats submitted to the Swiss Rabies Centre between 1976 and 2009 were found by immunofluorescence (FAT) to be positive for EBLVs. All three positive cases were in Myotis daubentoni, from 1992, 1993 and 2002. In addition to this passive surveillance, we undertook a targeted survey in 2009, aimed at detecting lyssaviruses in live bats in Switzerland. A total of 237 bats of the species M. daubentoni, Myotis myotis, Eptesicus serotinus and Nyctalus noctula were captured at different sites in western Switzerland. Oropharyngeal swabs and blood from each individual were analysed by RT-PCR and rapid fluorescent focus inhibition test (RFFIT), respectively. RNA corresponding to EBLV-2 was detected from oropharyngeal swabs of a single M. daubentoni bat, but no infectious virus was found. Molecular phylogenetic analysis revealed that the corresponding sequence was closely related to the other EBLV-2 sequences identified in previous rabies isolates from Swiss bats (particularly to that found at Geneva in 2002). Three M. daubentoni bats were found to be seropositive by RFFIT. In conclusion, even though the prevalence is low in Switzerland, continuous management and surveillance are required to assess the potential risk to public healt

Single-cell analysis: visualizing pharmaceutical and metabolite uptake in cells with label-free 3D mass spectrometry imaging

Detecting metabolites and parent compound within a cell type is now a priority for pharmaceutical development. In this context, three-dimensional secondary ion mass spectrometry (SIMS) imaging was used to investigate the cellular uptake of the antiarrhythmic agent amiodarone, a phospholipidosis-inducing pharmaceutical compound. The high lateral resolution and 3D imaging capabilities of SIMS combined with the multiplex capabilities of ToF mass spectrometric detection allows for the visualization of pharmaceutical compound and metabolites in single cells. The intact, unlabeled drug compound was successfully detected at therapeutic dosages in macrophages (cell line: NR8383). Chemical information from endogenous biomolecules was used to correlate drug distributions with morphological features. From this spatial analysis, amiodarone was detected throughout the cell with the majority of the compound found in the membrane and subsurface regions and absent in the nuclear regions. Similar results were obtained when the macrophages were doped with amiodarone metabolite, desethylamiodarone. The FWHM lateral resolution measured across an intracellular interface in a high lateral resolution ion images was approximately 550 nm. Overall, this approach provides the basis for studying cellular uptake of pharmaceutical compounds and their metabolites on the single cell level

Antibody reactivity to the immunodominant epitopes of the caprine arthritis-encephalitis virus gp38 transmembrane protein associates with the development of arthritis.

High titers of antibodies to caprine arthritis-encephalitis virus (CAEV) envelope (Env) glycoproteins are found in infected goats developing a progressive arthritis. In order to identify linear B epitopes of the CAEV Env, which may be involved in the immunopathology of arthritis, we constructed a lambda gt11 Env expression library. By combining library screening with sera from naturally infected Swiss goats with an enzyme immunoassay with overlapping peptides (pepscan), four group-specific epitopes could be precisely defined in the transmembrane envelope proteins: TM1 to TM4, including a conserved structure (TM3) that corresponds to the immunodominant epitope of human immunodeficiency virus type 1 and other lentiviruses. A panel of 190 CAEV naturally infected goat serum samples, obtained from animals with defined clinical status, was tested for reactivity to synthetic peptides corresponding to the TM epitopes in an enzyme-linked immunosorbent assay. Antibody reactivity to two epitopes was highly associated (TM3, P = 0.002, and TM4, P < 0.001) with the presence of clinically detectable arthritis. Such an association is absent for anti-Gag antibody. Antibodies to the immunodominant structures of the TM glycoprotein could thus have an important role in the immunopathogenic process leading to disease