Kinetics of parasite burdens in blood and tissues during murine toxoplasmosis

A sensitive real-time PCR technique was used to examine the distribution of Toxoplasma gondii in the blood and tissues of mice during acute and chronic infection. Groups of Swiss Albino mice, inoculated i.p. with 10(2) or 10(6) tachyzoites of the RH strain as a typical type-1 strain, or fed 10 cysts of the Me49 strain as a typical type-2 strain, were killed at different time points post-infection (p.i.), and blood and organs including the lungs, brain and liver were harvested for DNA extraction. Toxoplasma DNA was quantified by a real-time PCR targeted at the 529bp gene fragment, with a detection limit of a single parasite per g/ml of tissue. The results showed a strain- and dose-dependent spread of Toxoplasma. In infection with type-1 parasites, in case of a high infective dose, Toxoplasma DNA was detected within 24h p.i. in all analyzed tissues including the brain. Conversely, in case of a low infective dose, parasitaemia was undetectable early p.i., at a time when Toxoplasma DNA was detected in the tissues, but reached very high levels as infection progressed. With both infective doses, pre-death parasite burdens were higher in the blood than in the tissues, whereas the same loads in the lungs suggest that reaching these Toxoplasma burdens may be critical for survival. In infection with Me49 parasites, steady high parasite burdens were noted up to the end of the experiment at d42 only in the brain, parasitaemia was low but detectable throughout, and Toxoplasma DNA was completely cleared only from the liver. These data are important to better understand the pathogenesis of toxoplasmosis, and also as baseline data for the experimental evaluation of novel chemotherapeutics.     

Genome sequence of "Pedosphaera parvula" Ellin514, an aerobic Verrucomicrobial isolate from pasture soil

"Pedosphaera parvula" Ellin514 is an aerobically grown verrucomicrobial isolate from pasture soil. It is one of the few cultured representatives of subdivision 3 of the phylum Verrucomicrobia. Members of this group are widespread in terrestrial environments.     

Sequential Photo-bleaching to Delineate Single Schwann Cells at the Neuromuscular Junction

Sequential photo-bleaching provides a non-invasive way to label individual SCs at the NMJ. The NMJ is the largest synapse of the mammalian nervous system and has served as guiding model to study synaptic structure and function. In mouse NMJs motor axon terminals form pretzel-like contact sites with muscle fibers. The motor axon and its terminal are sheathed by SCs. Over the past decades, several transgenic mice have been generated to visualize motor neurons and SCs, for example Thy1-XFP¹ and Plp-GFP mice², respectively.Along motor axons, myelinating axonal SCs are arranged in non-overlapping internodes, separated by nodes of Ranvier, to enable saltatory action potential propagation. In contrast, terminal SCs at the synapse are specialized glial cells, which monitor and promote neurotransmission, digest debris and guide regenerating axons. NMJs are tightly covered by up to half a dozen non-myelinating terminal SCs - these, however, cannot be individually resolved by light microscopy, as they are in direct membrane contact³.Several approaches exist to individually visualize terminal SCs. None of these are flawless, though. For instance, dye filling, where single cells are impaled with a dye-filled microelectrode, requires destroying a labelled cell before filling a second one. This is not compatible with subsequent time-lapse recordings³. Multi-spectral "Brainbow" labeling of SCs has been achieved by using combinatorial expression of fluorescent proteins⁴. However, this technique requires combining several transgenes and is limited by the expression pattern of the promoters used. In the future, expression of "photo-switchable" proteins in SCs might be yet another alternative⁵. Here we present sequential photo-bleaching, where single cells are bleached, and their image obtained by subtraction. We believe that this approach - due to its ease and versatility - represents a lasting addition to the neuroscientist''s technology palette, especially as it can be used in vivo and transferred to others cell types, anatomical sites or species⁶.In the following protocol, we detail the application of sequential bleaching and subsequent confocal time-lapse microscopy to terminal SCs in triangularis sterni muscle explants. This thin, superficial and easily dissected nerve-muscle preparation^7,8 has proven useful for studies of NMJ development, physiology and pathology⁹. Finally, we explain how the triangularis sterni muscle is prepared after fixation to perform correlated high-resolution confocal imaging, immunohistochemistry or ultrastructural examinations.     

Complete genome sequence of Thermaerobacter marianensis type strain (7p75a)

Thermaerobacter marianensis Takai et al. 1999 is the type species of the genus Thermaerobacter, which belongs to the Clostridiales family Incertae Sedis XVII. The species is of special interest because T. marianensis is an aerobic, thermophilic marine bacterium, originally isolated from the deepest part in the western Pacific Ocean (Mariana Trench) at the depth of 10.897m. Interestingly, the taxonomic status of the genus has not been clarified until now. The genus Thermaerobacter may represent a very deep group within the Firmicutes or potentially a novel phylum. The 2,844,696 bp long genome with its 2,375 protein-coding and 60 RNA genes consists of one circular chromosome and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Improvement of Aripiprazole Solubility by Complexation with (2-Hydroxy)propyl-β-cyclodextrin Using Spray Drying Technique

Due to the fact that the number of new poorly soluble active pharmaceutical ingredients is increasing, it is important to investigate the possibilities of improvement of their solubility in order to obtain a final pharmaceutical formulation with enhanced bioavailability. One of the strategies to increase drug solubility is the inclusion of the APIs in cyclodextrins. The aim of this study was to investigate the possibility of aripiprazole solubility improvement by inclusion in (2-hydroxy)propyl-β-cyclodextrin (HPBCD) and simultaneous manipulation of pH of the medium and addition of polyvinylpyrrolidone. Aripiprazole-HPBCD complexes were prepared by spray drying aqueous drug-HPBCD solutions, and their properties were compared with those prepared by solvent-drop co-grinding and physical mixing. The obtained powders were characterized by thermoanalytical methods (TGA and DSC), FTIR spectroscopy, their dissolution properties were assessed, while the binding of aripiprazole into the cavity of HPBCD was studied by molecular docking simulations. The solubilization capacity was found to be dependent on pH as well as the buffer solution's ionic composition. The presence of PVP in the formulation could affect the solubilization capacity significantly, but further experimentation is required before its effect is fully understood. On the basis of solubility studies, the drug/HPBCD stoichiometry was found to be 1:3. The spray-dried products were free of crystalline aripiprazole, they possessed higher solubility and dissolution rate, and were stable enough over a prolonged period of storage. Spray drying of cyclodextrin solutions proved to be an appropriate and efficient technique for the preparation of highly soluble inclusion compounds of aripiprazole and HPBCD.     

Genome sequence of the homoacetogenic bacterium Holophaga foetida type strain (TMBS4(T))

Holophaga foetida Liesack et al. 1995 is a member of the phylum Acidobacteria and is of interest for its ability to anaerobically degrade aromatic compounds and for its production of volatile sulfur compounds through a unique pathway. The genome of H. foetida strain TMBS4(T) is the first to be sequenced for a representative of the class Holophagae. Here we describe the features of this organism, together with the complete genome sequence (improved high quality draft), and annotation. The 4,127,237 bp long chromosome with its 3,615 protein-coding and 57 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Complete genome sequence of Haliscomenobacter hydrossis type strain (O)

Haliscomenobacter hydrossis van Veen et al. 1973 is the type species of the genus Haliscomenobacter, which belongs to order "Sphingobacteriales". The species is of interest because of its isolated phylogenetic location in the tree of life, especially the so far genomically uncharted part of it, and because the organism grows in a thin, hardly visible hyaline sheath. Members of the species were isolated from fresh water of lakes and from ditch water. The genome of H. hydrossis is the first completed genome sequence reported from a member of the family "Saprospiraceae". The 8,771,651 bp long genome with its three plasmids of 92 kbp, 144 kbp and 164 kbp length contains 6,848 protein-coding and 60 RNA genes, and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Effects of penicillin and erythromycin on adherence of invasive and noninvasive isolates of Streptococcus pyogenes to laminin

This study investigated the possible relationship between the invasiveness of group AStreptococcus (GAS) strains and their abilities to adhere tolaminin and assessed the effects of subinhibitory concentrations of penicillin anderythromycin on the ability of GAS to adhere to laminin. The adherence of noninvasiveand highly invasive isolates of GAS to laminin was significantly higher than theadherence displayed by isolates of low invasiveness. Antibiotic treatment causedsignificant reductions in adherence to laminin in all three groups of strains.Penicillin was more successful in reducing the adherence abilities of the tested GASstrains than erythromycin.     

Complete genome sequence of Jonesia denitrificans type strain (Prevot 55134)

Jonesia denitrificans (Prevot 1961) Rocourt et al. 1987 is the type species of the genus Jonesia, and is of phylogenetic interest because of its isolated location in the actinobacterial suborder Micrococcineae. J. denitrificans is characterized by a typical coryneform morphology and is able to form irregular nonsporulating rods showing branched and club-like forms. Coccoid cells occur in older cultures. J. denitrificans is classified as a pathogenic organism for animals (vertebrates). The type strain whose genome is described here was originally isolated from cooked ox blood. Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the genus for which a complete genome sequence is described. The 2,749,646 bp long genome with its 2558 protein-coding and 71 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.