Real-Time High Resolution 3D Imaging of the Lyme Disease Spirochete Adhering to and Escaping from the Vasculature of a Living Host

Pathogenic spirochetes are bacteria that cause a number of emerging and re-emerging diseases worldwide, including syphilis, leptospirosis, relapsing fever, and Lyme borreliosis. They navigate efficiently through dense extracellular matrix and cross the blood–brain barrier by unknown mechanisms. Due to their slender morphology, spirochetes are difficult to visualize by standard light microscopy, impeding studies of their behavior in situ. We engineered a fluorescent infectious strain of Borrelia burgdorferi, the Lyme disease pathogen, which expressed green fluorescent protein (GFP). Real-time 3D and 4D quantitative analysis of fluorescent spirochete dissemination from the microvasculature of living mice at high resolution revealed that dissemination was a multi-stage process that included transient tethering-type associations, short-term dragging interactions, and stationary adhesion. Stationary adhesions and extravasating spirochetes were most commonly observed at endothelial junctions, and translational motility of spirochetes appeared to play an integral role in transendothelial migration. To our knowledge, this is the first report of high resolution 3D and 4D visualization of dissemination of a bacterial pathogen in a living mammalian host, and provides the first direct insight into spirochete dissemination in vivo

Nowe trendy w produkcji biopaliwa

There has been performed a prognosis of development of biofuel production which allows stating that during 2020-2025 year our country is capable to fully provide itself with biofuel, by refusing oil products. For the development of conventional biodiesel production, like raw materials may be used superfluous animal fat, by ratios of oil, used for baking, and camelina sativa oil, allowing achieving the requirements of standards. Production of biofuel of the second generation is distinguished by almost two times better effect of environment protection, when evaluating discharges of gases to the atmosphere which causes the greenhouse effect. Production of such biofuel in Lithuania is promising, when evaluating the po¬tential of biomass resources. Production of synthetic fuel (Fisher-Tropsh diesel and petrol, bioDME, biometanol, biohydrogen) from raw materials, having lignocelluloses, is made of two main processes: production of synthesis gas (gassing of biomass) and subsequent gas, refined by the synthesis, conversion to fuel. There was instituted the potential of biomass, suitable for the biofuel of the second generation: conditionally dry biomass (without rapidly growing bushes) is 9390 thousands tons of dry material in a year; wet biomass - 2060 thousands tons of dry material in a year (excluding superfluous animal fat which is distinguished by a slight potential and quantity of spirit wash)Vytauto Didžiojo universitetasŽemės ūkio akademij

Social and personal competences of technical institute of higher education’s students: forming and development

In this article the contents of social – personal competence, conditions of their formation and development are disclosed: application of developing technologies and collective forms of training; maintenance of a social – professional orientation of educational process and amplification of interdisciplinary communications; realization of the occupations directed on self-knowledge, selfdevelopment, development of communicative qualities; stimulation of professional and business dialogue. Results of research on formation and development of social – personal competence of students of branch GOU VPO «South-Ural state university» in Snezhinsk are given.В статье раскрывается содержание социально-личностных компетенций, условия их формирования и развития: применение развивающих технологий и коллективных форм обучения; обеспечение социально-профессиональной направленности образовательного процесса и усиление междисциплинарных связей; проведение занятий, направленных на самопознание, саморазвитие, развитие коммуникативных качеств; стимуляция профессионального и делового общения. Приведены результаты исследования по формированию и развитию социально-личностных компетенций студентов филиала ГОУ ВПО «Южно-Уральский государственный университет» в г. Снежинске

Complementation of a Nonmotile flaB Mutant of Borrelia Burgdorferi by Chromosomal Integration of a Plasmid Containing a Wild-Type flaB Allele

With the recent identification of antibiotic resistance phenotypes, the use of reporter genes, the isolation of null mutants by insertional inactivation, and the development of extrachromosomal cloning vectors, genetic analysis of Borrelia burgdorferi is becoming a reality. A previously described nonmotile, rod-shaped, kanamycin-resistant B. burgdorferi flaB::Km null mutant was complemented by electroporation with the erythromycin resistance plasmid pED3 (a pGK12 derivative) containing the wild-type flaB sequence and 366 bp upstream from its initiation codon. The resulting MS17 clone possessed erythromycin and kanamycin resistance, flat-wave morphology, and microscopic and macroscopic motility. Several other electroporations with plasmids containing wild-type flaB and various lengths (198, 366, or 762 bp) of sequence upstream from the flaB gene starting codon did not lead to functional restoration of the nonmotile flaB null mutant. DNA hybridization, PCR analysis, and sequencing indicated that the wild-type flaB gene in nonmotile clones was present in the introduced extrachromosomal plasmids, while the motile MS17 clone was a merodiploid containing single tandem chromosomal copies of mutated flaB::Km and wild-type flaB with a 366-bp sequence upstream from its starting codon. Complementation was thus achieved only when wild-type flaB was inserted into the borrelial chromosome. Several possible mechanisms for the failure of complementation for extrachromosomally located flaB are discussed

Asymmetrical flagellar rotation in Borrelia burgdorferi nonchemotactic mutants

The Lyme disease spirochete Borrelia burgdorferi has bundles of periplasmic flagella subpolarly located at each cell end. These bundles rotate in opposite directions during translational motility. When not translating, they rotate in the same direction, and the cells flex. Here, we present evidence that asymmetrical rotation of the bundles during translation does not depend upon the chemotaxis signal transduction system. The histidine kinase CheA is known to be an essential component in the signaling pathway for bacterial chemotaxis. Mutants of cheA in flagellated bacteria continually rotate their flagella in one direction. B. burgdorferi has two copies of cheA designated cheA1 and cheA2. Both genes were found to be expressed in growing cells. We reasoned that if chemotaxis were essential for asymmetrical rotation of the flagellar bundles, and if the flagellar motors at both cell ends were identical, inactivation of the two cheA genes should result in cells that constantly flex. To test this hypothesis, the signaling pathway was completely blocked by constructing the double mutant cheA1∷kan cheA2∷ermC. This double mutant was deficient in chemotaxis. Rather than flexing, it failed to reverse, and it continually translated only in one direction. Video microscopy of mutant cells indicated that both bundles actively rotated. The results indicate that asymmetrical rotation of the flagellar bundles of spirochetes does not depend upon the chemotaxis system but rather upon differences between the two flagellar bundles. We propose that certain factors within the spirochete localize at the flagellar motors at one end of the cell to effect this asymmetry

HLA-DQ haplotypes in 15 different populations

In order to understand the forces governing the evolution of the DQ molecule, PCR-based methods have been used to type the DQA1 and DQB1 loci encoding this heterodimer on 2,807 chromosomes from 15 different populations including Africans, Asians, Amerindians and Caucasians. These ethnically diverse samples represent a variety of population substructures and include small, isolated populations as well as larger populations where admixture has occurred. Nine DQA1 alleles and 18 DQB1 alleles have been identified which make up 42 distinct DQ haplotypes. Some haplotypes are found in all ethnic groups while others are confined to a single ethnic group or population. Despite evidence of recombination between the DQA1 and DQB1 loci, there are no examples of a haplotype carrying a DQw1-associated alpha chain and a DQw2-, DQw3-, or DQw4-associated beta chain in cis (and vice versa). These data suggest that these haplotypes, which encode unstable heterodimers, are rapidly removed from the population through natural selection

HLA-DQ haplotypes in 15 different populations

In order to understand the forces governing the evolution of the DQ molecule, PCR-based methods have been used to type the DQA1 and DQB1 loci encoding this heterodimer on 2,807 chromosomes from 15 different populations including Africans, Asians, Amerindians and Caucasians. These ethnically diverse samples represent a variety of population substructures and include small, isolated populations as well as larger populations where admixture has occurred. Nine DQA1 alleles and 18 DQB1 alleles have been identified which make up 42 distinct DQ haplotypes. Some haplotypes are found in all ethnic groups while others are confined to a single ethnic group or population. Despite evidence of recombination between the DQA1 and DQB1 loci, there are no examples of a haplotype carrying a DQw1-associated alpha chain and a DQw2-, DQw3-, or DQw4-associated beta chain in cis (and vice versa). These data suggest that these haplotypes, which encode unstable heterodimers, are rapidly removed from the population through natural selection

Genetic variability and linkage disequilibrium within the HLA-DP region: analysis of 15 different populations.

In order to understand the forces governing the evolution of the genetic diversity in the HLA-DP molecule, polymerase chain reaction (PCR)-based methods were used to characterize genetic variation at the DPA1 and DPB1 loci encoding this heterodimer on 2,807 chromosomes from 15 different populations including individuals of African, Asian, Amerindian, Indian and European origin. These ethnically diverse samples represent a variety of population substructures and include small, isolated populations as well as larger, presumably admixed populations. Ten DPA1 and 39 DPB1 alleles were identified and observed on 87 distinct DP haplotypes, 34 of which were found to be in significant positive linkage disequilibrium in at least one population. Some haplotypes were found in all ethnic groups while others were confined to a single ethnic group or population. Strong positive global linkage disequilibrium (Wn) between DPA1 and DPB1 was present in all 15 populations. The African populations displayed the lowest values of Wn whereas the Amerindian populations displayed near absolute disequilibrium. Analysis of the distribution of haplotypes using the normalized deviate of the Ewens-Watterson homozygosity statistic, F, suggests that DP haplotypes encoding the functional heterodimer are subject to much lower degrees of balancing selection than other loci within the HLA region. Finally, neighbor joining tree analyses demonstrate the power of haplotype diversity for inferring the relationships between the different populations