The comparison of susceptibility patterns of Gram-negative invasive and non-invasive pathogens in Estonian hospitals

A total of 560 invasive and 1062 non-invasive isolates were collected. The antimicrobial susceptibility of invasive versus non-invasive Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae isolates were evaluated using the E-tests. The equal domination of Gram-negative among both invasive and non-invasive pathogens was estimated in our study if contaminants were excluded. The emergence trend of Gram-positive microbes especially of coagulase negative staphylococci may be proved only after application of exclusive algorithms. Due to similar susceptibility, the data of non-invasive Gram-negative pathogens can be useful to predict resistance of invasive ones. Also, the surveillance of invasive pathogens provides useful information about the general susceptibility of pathogens.     

Cytotoxicity of albebetin oligomers depends on cross-beta-sheet formation

Prefibrillar cytotoxicity was suggested as a common amyloid characteristic. We showed two types of albebetin prefibrillar oligomers are formed during incubation at pH 7.3. Initial round-shaped oligomers consist of 10-15 molecules determined by atomic force microscopy, do not bind thioflavin-T and do not affect viability of granular neurons and SH-SY5Y cells. They are converted into ca. 30-40-mers possessing cross-beta-sheet and reducing viability of neuronal cells. Neither monomers nor fibrils possess cytotoxicity. We suggest that oligomeric size is important for stabilising cross-beta-sheet core critical for cytotoxicity. As albebetin was used as a carrier-protein for drug delivery, examination of amyloidogenicity is required prior polypeptide biomedical applications.     

Global changes in cellular gene expression during bacteriophage PRD1 infection

Virus-induced changes in cellular gene expression and host physiology have been studied extensively. Still, there are only a few analyses covering the entire viral replication cycle and whole-host gene pool expression at the resolution of a single gene. Here we report changes in Escherichia coli gene expression during bacteriophage PRD1 infection using microarray technology. Relative mRNA levels were systematically measured for over 99% of the host open reading frames throughout the infection cycle. Although drastic modifications could be detected in the expression of individual genes, global changes at the whole-genome level were moderate. Notably, the majority of virus-induced changes took place only after the synthesis of virion components, indicating that there is no major reprogramming of the host during early infection. The most highly induced genes encoded chaparones and other stress-inducible proteins.     

MURC/cavin-4 Is Co-Expressed with Caveolin-3 in Rhabdomyosarcoma Tumors and Its Silencing Prevents Myogenic Differentiation in the Human Embryonal RD Cell Line

The purpose of this study was to investigate whether MURC/cavin-4, a plasma membrane and Z-line associated protein exhibiting an overlapping distribution with Caveolin-3 (Cav-3) in heart and muscle tissues, may be expressed and play a role in rhabdomyosarcoma (RMS), an aggressive myogenic tumor affecting childhood. We found MURC/cavin-4 to be expressed, often concurrently with Cav-3, in mouse and human RMS, as demonstrated through in silico analysis of gene datasets and immunohistochemical analysis of tumor samples. In vitro expression studies carried out using human cell lines and primary mouse tumor cultures showed that expression levels of both MURC/cavin-4 and Cav-3, while being low or undetectable during cell proliferation, became robustly increased during myogenic differentiation, as detected via semi-quantitative RT-PCR and immunoblotting analysis. Furthermore, confocal microscopy analysis performed on human RD and RH30 cell lines confirmed that MURC/cavin-4 mostly marks differentiated cell elements, colocalizing at the cell surface with Cav-3 and labeling myosin heavy chain (MHC) expressing cells. Finally, MURC/cavin-4 silencing prevented the differentiation in the RD cell line, leading to morphological cell impairment characterized by depletion of myogenin, Cav-3 and MHC protein levels. Overall, our data suggest that MURC/cavin-4, especially in combination with Cav-3, may play a consistent role in the differentiation process of RMS.     

Structure-activity relationship study on human urotensin II.

The vasoactive cyclic undecapeptide urotensin-II (U-II) has been identified as an endogenous ligand for the G-protein coupled receptor now referred to as the UT receptor. The U-II/UT receptor system might be relevant for cardiovascular functions. A structure-activity study of human U-II investigating 31 peptides in the rat aorta bioassay is reported. Ala- and D-scan investigations indicated that the sequence Phe6-Trp7-Lys8-Tyr9 is essential for biological activity and that Lys8 and Tyr9 are particularly important. These two residues were substituted with a series of coded and non-coded amino acids. These studies demonstrated that the positive charge of the primary aliphatic amine at position 8 and its relative spatial orientation is crucial for both receptor occupation and activation, while the only chemical requirement at position 9 is the presence of an aromatic moiety. Moreover, this study led to the identification of UT receptor partial agonists (compounds 23 and 24) which can be used as chemical templates for further investigations aimed at the identification of selective antagonists.     

Novel 1,2-dihydroquinazolin-2-ones: Design,synthesis, and biological evaluation against Trypanosoma brucei

In 2014, a published report of the high-throughput screen of >42,000 kinase inhibitors from GlaxoSmithKline against T. brucei identified 797 potent and selective hits. From this rich data set, we selected NEU-0001101 (1) for hit-to-lead optimization. Through our preliminary compound synthesis and SAR studies, we have confirmed the previously reported activity of 1 in a T. brucei cell proliferation assay and have identified alternative groups to replace the pyridyl ring in 1. Pyrazole 24 achieves improvements in both potency and lipophilicity relative to 1, while also showing good in vitro metabolic stability. The SAR developed on 24 provides new directions for further optimization of this novel scaffold for anti-trypanosomal drug discovery.     

Influence of local and landscape factors on bumblebees in semi-natural meadows: a multiple-scale study in a forested landscape

Understanding the effects of local and landscape factors on bumblebees is relevant for the conservation of this group of pollinators. Bumblebees have been well-studied in agricultural landscapes of Western Europe, Asia and North America, but few studies have been developed on bumblebees in forest-dominated landscapes of Eastern Europe. We developed this study in 22 semi-natural meadows located in a patchy forested landscape of Estonia. We investigated the influence of habitat characteristics and landscape factors (calculated at four spatial scales: 250, 500, 1,000 and 2,000 m radius) on the total species richness and abundance of bumblebees. Correlation analysis, partial least squares (PLS) and stepwise forward-selection multiple regression analysis were applied in this study. The presence of a high diversity of flowering plants in semi-natural meadows may benefit the abundance of bumblebees. At the local level, patch area and shape seem to have positive and negative influences, respectively, on bumblebee species richness. At the landscape level, human settlements with the presence of gardens may favour bumblebee richness and abundance. Also, bumblebee species may increase with a high presence of meadows in the landscape, and may decrease with high percentages of forest and young forest. Overall, forested landscapes with a strong presence of edges and a diverse matrix may support a higher species richness and abundance of bumblebees. Both local and landscape factors should be considered when designing conservation strategies and agri-environmental measures.     

Delineating the Hemostaseome as an aid to individualize the analysis of the hereditary basis of thrombotic and bleeding disorders

Next-generation sequencing and genome-wide association studies represent powerful tools to identify genetic variants that confer disease risk within populations. On their own, however, they cannot provide insight into how these variants contribute to individual risk for diseases that exhibit complex inheritance, or alternatively confer health in a given individual. Even in the case of well-characterized variants that confer a significant disease risk, more healthy individuals carry the variant, with no apparent ill effect, than those who manifest disease. Access to low-cost genome sequence data promises to provide an unprecedentedly detailed view of the nature of the hereditary component of complex diseases, but requires the large-scale comparison of sequence data from individuals with and without disease to deliver a clinical calibration. The provision of informatics support remains problematic as there are currently no means to interpret the data generated. Here, we initiate this process, a prerequisite for such a study, by narrowing the focus from an entire genome to that of a single biological system. To this end, we examine the ‘Hemostaseome,’ and more specifically focus on DNA sequence changes pertaining to those human genes known to impact upon hemostasis and thrombosis that can be analyzed coordinately, and on an individual basis, to interrogate how specific combinations of variants act to confer disease predisposition. As a first step, we delineate known members of the Hemostaseome and explore the nature of the genetic variants that may cause disease in individuals whose hemostatic balance has become shifted toward either a prothrombotic or anticoagulant phenotype.     

Human microbial ecology: lactobacilli, probiotics, selective decontamination

Health care-associated infections are closely associated with different medical interventions which interrupt the balance of human microbiota. The occasional predominance of opportunistic pathogens may lead to their translocation into the lymph nodes and bloodstream, causing endogenous (primary or secondary) hospital infections. The question is raised as to if there is a possibility for prevention of the imbalance of GI microbiota during medical interventions in critically ill patients. Prophylactic selective decontamination of the digestive tract (SDD) simultaneously applies three to four different antimicrobials for the suppression of enteric aerobic microbes, which are potentially pathogenic microorganisms. However, there is no convincing evidence that the indigenous beneficial intestinal microbiota are preserved, resulting in reduced mortality of high-risk patients. In this overview, we have evaluated the antimicrobial treatment guidelines of the Infectious Diseases Society of America (IDSA) for intra-abdominal infections in adults and seniors according to their safety for different Lactobacillus spp. The data from our group and in the literature have shown that all tested lactobacilli strains (nearly one hundred) were insusceptible to metronidazole while different species of lactobacilli of the three fermentation groups expressed particular antibiotic susceptibility to vancomycin, cefoxitin, ciprofloxacin and some new tetracyclines. We have relied on microbial ecology data showing that the GI tracts of adults and the elderly are simultaneously colonised at least with several (four to a maximum of 12) Lactobacillus species expressing variable intrinsic insusceptibility to the aforementioned antimicrobials, according to the provided data in table. This finding offers the possibility of preserving the colonisation of the intestine with some beneficial lactobacilli during antimicrobial treatment in critically ill patients with health care-associated infections. Several probiotic Lactobacillus spp. strains are intrinsically resistant to antimicrobials and can be used during antibacterial therapy, however, their application as an additive to antimicrobial treatment in critically ill patients needs to be investigated in well-designed clinical trials.