WorldWideScience

Sample records for alters bacterial attachment

  1. Stimulation of bacterial DNA synthesis by algal exudates in attached algal-bacterial consortia

    International Nuclear Information System (INIS)

    Murray, R.E.; Cooksey, K.E.; Priscu, J.C.

    1986-01-01

    Algal-bacterial consortia attached to polystyrene surfaces were prepared in the laboratory by using the marine diatom Amphora coffeaeformis and the marine bacterium Vibrio proteolytica (the approved name of this bacterium is Vibrio proteolyticus. The organisms were attached to the surfaces at cell densities of approximately 5 x 10 4 cells cm -2 (diatoms) and 5 x 10 6 cells cm -2 (bacteria). The algal-bacterial consortia consistently exhibited higher rates of [ 3 H]thymidine incorporation than did biofilms composed solely of bacteria. The rates of [ 3 H]thymidine incorporation by the algal-bacterial consortia were fourfold greater than the rates of incorporation by monobacterial biofilms 16 h after biofilm formation and were 16-fold greater 70 h after biofilm formation. Extracellular material released from the attached Amphora cells supported rates of bacterial activity (0.8 x 10 -21 mol to 17.9 x 10 -21 mol of [ 3 H]thymidine incorporated cell -1 h -1 ) and growth (doubling time, 29.5 to 1.4 days) comparable to values reported for a wide variety of marine and freshwater ecosystems. In the presence of sessile diatom populations, DNA synthesis by attached V. proteolytica cells was light dependent and increased with increasing algal abundance. The metabolic activity of diatoms thus appears to be the rate-limiting process in biofilm development on illuminated surfaces under conditions of low bulk-water dissolved organic carbon

  2. Some quantitative data on bacterial attachment to pyrite

    NARCIS (Netherlands)

    Florian, B.; Noël, N.; Thyssen, C.; Felschau, I.; Sand, W.

    2011-01-01

    Bacterial attachment and biofilm formation are important for microbial bioleaching of metal sulfides, however, many details of the role played by bacteria are still unknown. Attachment as the first step in biofilm formation is critical. Our investigations are focused on these processes to control

  3. Locomotion of bacteria in liquid flow and the boundary layer effect on bacterial attachment

    International Nuclear Information System (INIS)

    Zhang, Chao; Liao, Qiang; Chen, Rong; Zhu, Xun

    2015-01-01

    The formation of biofilm greatly affects the performance of biological reactors, which highly depends on bacterial swimming and attachment that usually takes place in liquid flow. Therefore, bacterial swimming and attachment on flat and circular surfaces with the consideration of flow was studied experimentally. Besides, a mathematical model comprehensively combining bacterial swimming and motion with flow is proposed for the simulation of bacterial locomotion and attachment in flow. Both experimental and theoretical results revealed that attached bacteria density increases with decreasing boundary layer thickness on both flat and circular surfaces, the consequence of which is inherently related to the competition between bacterial swimming and the non-slip motion with flow evaluated by the Péclet number. In the boundary layer, where the Péclet number is relatively higher, bacterial locomotion mainly depends on bacterial swimming. Thinner boundary layer promotes bacterial swimming towards the surface, leading to higher attachment density. To enhance the performance of biofilm reactors, it is effective to reduce the boundary layer thickness on desired surfaces. - Highlights: • Study of bacterial locomotion in flow as an early stage in biofilm formation. • Mathematical model combining bacterial swimming and the motion with flow. • Boundary layer plays a key role in bacterial attachment under flow condition. • The competition between bacterial swimming and the motion with flow is evaluated

  4. Locomotion of bacteria in liquid flow and the boundary layer effect on bacterial attachment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chao, E-mail: zhangchao@cqu.edu.cn [Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030 (China); Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030 (China); Liao, Qiang, E-mail: lqzx@cqu.edu.cn [Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030 (China); Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030 (China); Chen, Rong, E-mail: rchen@cqu.edu.cn [Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030 (China); Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030 (China); Zhu, Xun, E-mail: zhuxun@cqu.edu.cn [Key Laboratory of Low-grade Energy Utilization Technologies and Systems (Chongqing University), Ministry of Education, Chongqing 400030 (China); Institute of Engineering Thermophysics, Chongqing University, Chongqing 400030 (China)

    2015-06-12

    The formation of biofilm greatly affects the performance of biological reactors, which highly depends on bacterial swimming and attachment that usually takes place in liquid flow. Therefore, bacterial swimming and attachment on flat and circular surfaces with the consideration of flow was studied experimentally. Besides, a mathematical model comprehensively combining bacterial swimming and motion with flow is proposed for the simulation of bacterial locomotion and attachment in flow. Both experimental and theoretical results revealed that attached bacteria density increases with decreasing boundary layer thickness on both flat and circular surfaces, the consequence of which is inherently related to the competition between bacterial swimming and the non-slip motion with flow evaluated by the Péclet number. In the boundary layer, where the Péclet number is relatively higher, bacterial locomotion mainly depends on bacterial swimming. Thinner boundary layer promotes bacterial swimming towards the surface, leading to higher attachment density. To enhance the performance of biofilm reactors, it is effective to reduce the boundary layer thickness on desired surfaces. - Highlights: • Study of bacterial locomotion in flow as an early stage in biofilm formation. • Mathematical model combining bacterial swimming and the motion with flow. • Boundary layer plays a key role in bacterial attachment under flow condition. • The competition between bacterial swimming and the motion with flow is evaluated.

  5. Locomotion of bacteria in liquid flow and the boundary layer effect on bacterial attachment.

    Science.gov (United States)

    Zhang, Chao; Liao, Qiang; Chen, Rong; Zhu, Xun

    2015-06-12

    The formation of biofilm greatly affects the performance of biological reactors, which highly depends on bacterial swimming and attachment that usually takes place in liquid flow. Therefore, bacterial swimming and attachment on flat and circular surfaces with the consideration of flow was studied experimentally. Besides, a mathematical model comprehensively combining bacterial swimming and motion with flow is proposed for the simulation of bacterial locomotion and attachment in flow. Both experimental and theoretical results revealed that attached bacteria density increases with decreasing boundary layer thickness on both flat and circular surfaces, the consequence of which is inherently related to the competition between bacterial swimming and the non-slip motion with flow evaluated by the Péclet number. In the boundary layer, where the Péclet number is relatively higher, bacterial locomotion mainly depends on bacterial swimming. Thinner boundary layer promotes bacterial swimming towards the surface, leading to higher attachment density. To enhance the performance of biofilm reactors, it is effective to reduce the boundary layer thickness on desired surfaces. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Influence of Physicochemical Aspects of Substratum Nano surface on Bacterial Attachment for Bone Implant Applications

    International Nuclear Information System (INIS)

    Mediaswanti, K.

    2016-01-01

    Biofilm formation on implant materials is responsible for peri prosthetic infections. Bacterial attachment is important as the first stage in biofilm formation. It is meaningful to understand the influence of nano structured surface on bacterial attachment. This review discusses the influence of physicochemical aspects of substratum nano surface on bacterial attachment.

  7. Effects of altered groundwater chemistry upon the pH-dependency and magnitude of bacterial attachment during transport within an organically contaminated sandy aquifer

    Science.gov (United States)

    Harvey, Ronald W.; Metge, David W.; Barber, Larry B.; Aiken, George R.

    2010-01-01

    The effects of a dilute (ionic strength = 5 ?? 10-3 M) plume of treated sewage, with elevated levels (3.9 mg/L) of dissolved organic carbon (DOC), upon the pH-dependency and magnitude of bacterial transport through an iron-laden, quartz sand aquifer (Cape Cod, MA) were evaluated using sets of replicate, static minicolumns. Compared with uncontaminated groundwater, the plume chemistry diminished bacterial attachment under mildly acidic (pH 5.0-6.5) in-situ conditions, in spite of the 5-fold increase in ionic strength and substantively enhanced attachment under more alkaline conditions. The effects of the hydrophobic neutral and total fractions of the plume DOC; modest concentrations of fulvic and humic acids (1.5 mg/L); linear alkyl benzene sulfonate (LAS) (25 mg/L); Imbentin (200 ??g/L), a model nonionic surfactant; sulfate (28 mg/L); and calcium (20 mg/L) varied sharply in response to relatively small changes in pH, although the plume constituents collectively decreased the pH-dependency of bacterial attachment. LAS and other hydrophobic neutrals (collectively representing only ???3% of the plume DOC) had a disproportionately large effect upon bacterial attachment, as did the elevated concentrations of sulfate within the plume. The findings further suggest that the roles of organic plume constituents in transport or bacteria through acidic aquifer sediments can be very different than would be predicted from column studies performed at circumneutral pH and that the inorganic constituents within the plume cannot be ignored.

  8. PCR-DGGE Analysis of Bacterial Population Attached to the Bovine Rumen Wall

    OpenAIRE

    Lukáš, F. (Filip); Šimůnek, J. (Jiří); Mrázek, J. (Jakub); Kopečný, J. (Jan)

    2010-01-01

    We isolated and amplified by PCR 16S rDNA from bacteria attached to the bovine rumen wall and analyzed it by denaturing gradient gel electrophoresis (DGGE) with subsequent sequence analysis. The attached bacterial community differed from the bacteria of rumen content; however, no differences were observed among the five epithelial sampling sites taken from each animal. The DGGE profile of the bacterial population attached to the rumen wall represented a high inter-animal variation.

  9. Structured attachment of bacterial molecular motors for defined microflow induction

    Directory of Open Access Journals (Sweden)

    Woerdemann Mike

    2014-01-01

    Full Text Available Bacterial rotational motor complexes that propel flagellated bacteria possess unique properties like their size of a few nanometres and the ability of selfreproduction that have led to various exciting applications including biohybrid nano-machines. One mandatory prerequisite to utilize bacterial nano motors in fluid applications is the ability to transfer force and torque to the fluid, which usually can be achieved by attachment of the bacterial cell to adequate surfaces. Additionally, for optimal transfer of force or torque, precise control of the position down to the single cell level is of utmost importance. Based on a PIV (particle image velocimetry evaluation of the induced flow of single bacteria,we propose and demonstrate attachment of arbitrary patterns of motile bacterial cells in a fast light-based two-step process for the first time to our knowledge. First, these cells are pre-structured by holographic optical tweezers and then attached to a homogeneous, polystyrene-coated surface. In contrast to the few approaches that have been implemented up to now and which rely on pre-structured surfaces, our scheme allows for precise control on a single bacterium level, is versatile, interactive and has low requirements with respect to the surface preparation.

  10. A simple method to assess bacterial attachment to surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    Sonak, S.; Bhosle, N.B.

    The crystal violet microplate adhension assay was modified to evaluate bacterial adhesion to metal and non-metal surfaces. Both viable cell count and the absorbance of the crystal violet stained cells attached to aluminium increased over the period...

  11. Photorhabdus adhesion modification protein (Pam) binds extracellular polysaccharide and alters bacterial attachment

    LENUS (Irish Health Repository)

    Jones, Robert T

    2010-05-12

    Abstract Background Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. Results A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28°C) and human (37°C) temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS)-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR) binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. Conclusions We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect through mediation of

  12. Photorhabdus adhesion modification protein (Pam) binds extracellular polysaccharide and alters bacterial attachment.

    Science.gov (United States)

    Jones, Robert T; Sanchez-Contreras, Maria; Vlisidou, Isabella; Amos, Matthew R; Yang, Guowei; Muñoz-Berbel, Xavier; Upadhyay, Abhishek; Potter, Ursula J; Joyce, Susan A; Ciche, Todd A; Jenkins, A Toby A; Bagby, Stefan; Ffrench-Constant, Richard H; Waterfield, Nicholas R

    2010-05-12

    Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28 degrees C) and human (37 degrees C) temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS)-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR) binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect through mediation of EPS properties. Despite

  13. Photorhabdus adhesion modification protein (Pam binds extracellular polysaccharide and alters bacterial attachment

    Directory of Open Access Journals (Sweden)

    Joyce Susan A

    2010-05-01

    Full Text Available Abstract Background Photorhabdus are Gram-negative nematode-symbiotic and insect-pathogenic bacteria. The species Photorhabdus asymbiotica is able to infect humans as well as insects. We investigated the secreted proteome of a clinical isolate of P. asymbiotica at different temperatures in order to identify proteins relevant to the infection of the two different hosts. Results A comparison of the proteins secreted by a clinical isolate of P. asymbiotica at simulated insect (28°C and human (37°C temperatures led to the identification of a small and highly abundant protein, designated Pam, that is only secreted at the lower temperature. The pam gene is present in all Photorhabdus strains tested and shows a high level of conservation across the whole genus, suggesting it is both ancestral to the genus and probably important to the biology of the bacterium. The Pam protein shows limited sequence similarity to the 13.6 kDa component of a binary toxin of Bacillus thuringiensis. Nevertheless, injection or feeding of heterologously produced Pam showed no insecticidal activity to either Galleria mellonella or Manduca sexta larvae. In bacterial colonies, Pam is associated with an extracellular polysaccharide (EPS-like matrix, and modifies the ability of wild-type cells to attach to an artificial surface. Interestingly, Surface Plasmon Resonance (SPR binding studies revealed that the Pam protein itself has adhesive properties. Although Pam is produced throughout insect infection, genetic knockout does not affect either insect virulence or the ability of P. luminescens to form a symbiotic association with its host nematode, Heterorhabditis bacteriophora. Conclusions We studied a highly abundant protein, Pam, which is secreted in a temperature-dependent manner in P. asymbiotica. Our findings indicate that Pam plays an important role in enhancing surface attachment in insect blood. Its association with exopolysaccharide suggests it may exert its effect

  14. Fabrication of a platform to isolate the influences of surface nanotopography from chemistry on bacterial attachment and growth.

    Science.gov (United States)

    Pegalajar-Jurado, Adoracion; Easton, Christopher D; Crawford, Russell J; McArthur, Sally L

    2015-03-26

    Billions of dollars are spent annually worldwide to combat the adverse effects of bacterial attachment and biofilm formation in industries as varied as maritime, food, and health. While advances in the fabrication of antifouling surfaces have been reported recently, a number of the essential aspects responsible for the formation of biofilms remain unresolved, including the important initial stages of bacterial attachment to a substrate surface. The reduction of bacterial attachment to surfaces is a key concept in the prevention or minimization of biofilm formation. The chemical and physical characteristics of both the substrate and bacteria are important in understanding the attachment process, but substrate modification is likely the most practical route to enable the extent of bacterial attachment taking place to be effectively controlled. The microtopography and chemistry of the surface are known to influence bacterial attachment. The role of surface chemistry versus nanotopography and their interplay, however, remain unclear. Most methods used for imparting nanotopographical patterns onto a surface also induce changes in the surface chemistry and vice versa. In this study, the authors combine colloidal lithography and plasma polymerization to fabricate homogeneous, reproducible, and periodic nanotopographies with a controllable surface chemistry. The attachment of Escherichia coli bacteria onto carboxyl (plasma polymerized acrylic acid, ppAAc) and hydrocarbon (plasma polymerized octadiene, ppOct) rich plasma polymer films on either flat or colloidal array surfaces revealed that the surface chemistry plays a critical role in bacterial attachment, whereas the effect of surface nanotopography on the bacterial attachment appears to be more difficult to define. This platform represents a promising approach to allow a greater understanding of the role that surface chemistry and nanotopography play on bacterial attachment and the subsequent biofouling of the surface.

  15. The physicochemical process of bacterial attachment to abiotic surfaces: Challenges for mechanistic studies, predictability and the development of control strategies.

    Science.gov (United States)

    Wang, Yi; Lee, Sui Mae; Dykes, Gary

    2015-01-01

    Bacterial attachment to abiotic surfaces can be explained as a physicochemical process. Mechanisms of the process have been widely studied but are not yet well understood due to their complexity. Physicochemical processes can be influenced by various interactions and factors in attachment systems, including, but not limited to, hydrophobic interactions, electrostatic interactions and substratum surface roughness. Mechanistic models and control strategies for bacterial attachment to abiotic surfaces have been established based on the current understanding of the attachment process and the interactions involved. Due to a lack of process control and standardization in the methodologies used to study the mechanisms of bacterial attachment, however, various challenges are apparent in the development of models and control strategies. In this review, the physicochemical mechanisms, interactions and factors affecting the process of bacterial attachment to abiotic surfaces are described. Mechanistic models established based on these parameters are discussed in terms of their limitations. Currently employed methods to study these parameters and bacterial attachment are critically compared. The roles of these parameters in the development of control strategies for bacterial attachment are reviewed, and the challenges that arise in developing mechanistic models and control strategies are assessed.

  16. Stochasticity of bacterial attachment and its predictability by the extended derjaguin-landau-verwey-overbeek theory.

    Science.gov (United States)

    Chia, Teck Wah R; Nguyen, Vu Tuan; McMeekin, Thomas; Fegan, Narelle; Dykes, Gary A

    2011-06-01

    Bacterial attachment onto materials has been suggested to be stochastic by some authors but nonstochastic and based on surface properties by others. We investigated this by attaching pairwise combinations of two Salmonella enterica serovar Sofia (S. Sofia) strains (with different physicochemical and attachment properties) with one strain each of S. enterica serovar Typhimurium, S. enterica serovar Infantis, or S. enterica serovar Virchow (all with similar physicochemical and attachment abilities) in ratios of 0.428, 1, and 2.333 onto glass, stainless steel, Teflon, and polysulfone. Attached bacterial cells were recovered and counted. If the ratio of attached cells of each Salmonella serovar pair recovered was the same as the initial inoculum ratio, the attachment process was deemed stochastic. Experimental outcomes from the study were compared to those predicted by the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. Significant differences (P attached ratios for serovar pairs containing S. Sofia S1296a for all different ratios were apparent for all materials. For S. Sofia S1635-containing pairs, 7 out of 12 combinations of serovar pairs and materials had attachment ratios not significantly different (P > 0.05) from the initial ratio of 0.428. Five out of 12 and 10 out of 12 samples had attachment ratios not significantly different (P > 0.05) from the initial ratios of 1 and 2.333, respectively. These results demonstrate that bacterial attachment to different materials is likely to be nonstochastic only when the key physicochemical properties of the bacteria were significantly different (P theory could successfully predict the attachment of some individual isolates to particular materials but could not be used to predict the likelihood of stochasticity in pairwise attachment experiments.

  17. A simple technique to assess bacterial attachment to metal surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    Sonak, S.; Bhosle, N.B.

    attached bacterial cells with crystal violet (0.5%). The crystal violet stain from the cells was eluted with an aqueous solution of sodium deoxycholate (2%). The absorbance of the crystal violet stain in deoxycholate was measured at 570 nm. The viable cell...

  18. Does circumcision alter the periurethral uropathogenic bacterial flora

    African Journals Online (AJOL)

    Background: The aim of this study was to assess the pattern of periurethral bacterial flora in uncircumcised boys and to evaluate the effect of circumcision on alteration of periurethral uropathogenic bacterial flora. Materials and Methods: Pattern of periurethral bacterial flora before and after circumcision was studied ...

  19. Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material.

    Science.gov (United States)

    Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

    2013-09-01

    The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. E. coli counts were higher in hand-mixed materials (P 2.394). The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface.

  20. Tuning the Density of Poly(ethylene glycol Chains to Control Mammalian Cell and Bacterial Attachment

    Directory of Open Access Journals (Sweden)

    Ahmed Al-Ani

    2017-08-01

    Full Text Available Surface modification of biomaterials with polymer chains has attracted great attention because of their ability to control biointerfacial interactions such as protein adsorption, cell attachment and bacterial biofilm formation. The aim of this study was to control the immobilisation of biomolecules on silicon wafers using poly(ethylene glycol(PEG chains by a “grafting to” technique. In particular, to control the polymer chain graft density in order to capture proteins and preserve their activity in cell culture as well as find the optimal density that would totally prevent bacterial attachment. The PEG graft density was varied by changing the polymer solubility using an increasing salt concentration. The silicon substrates were initially modified with aminopropyl-triethoxysilane (APTES, where the surface density of amine groups was optimised using different concentrations. The results showed under specific conditions, the PEG density was highest with grafting under “cloud point” conditions. The modified surfaces were characterised with X-ray photoelectron spectroscopy (XPS, ellipsometry, atomic force microscopy (AFM and water contact angle measurements. In addition, all modified surfaces were tested with protein solutions and in cell (mesenchymal stem cells and MG63 osteoblast-like cells and bacterial (Pseudomonas aeruginosa attachment assays. Overall, the lowest protein adsorption was observed on the highest polymer graft density, bacterial adhesion was very low on all modified surfaces, and it can be seen that the attachment of mammalian cells gradually increased as the PEG grafting density decreased, reaching the maximum attachment at medium PEG densities. The results demonstrate that, at certain PEG surface coverages, mammalian cell attachment can be tuned with the potential to optimise their behaviour with controlled serum protein adsorption.

  1. Variation in bacterial ATP concentration during rapid changes in extracellular pH and implications for the activity of attached bacteria.

    Science.gov (United States)

    Albert, Lynal S; Brown, Derick G

    2015-08-01

    In this study we investigated the relationship between a rapid change in extracellular pH and the alteration of bacterial ATP concentration. This relationship is a key component of a hypothesis indicating that bacterial bioenergetics - the creation of ATP from ADP via a proton gradient across the cytoplasmic membrane - can be altered by the physiochemical charge-regulation effect, which results in a pH shift at the bacteria's surface upon adhesion to another surface. The bacterial ATP concentration was measured during a rapid change in extracellular pH from a baseline pH of 7.2 to pH values between 3.5 and 10.5. Experiments were conducted with four neutrophilic bacterial strains, including the Gram-negative Escherichia coli and Pseudomonas putida and the Gram-positive Bacillus subtilis and Staphylococcus epidermidis. A change in bulk pH produced an immediate response in bacterial ATP, demonstrating a direct link between changes in extracellular pH and cellular bioenergetics. In general, the shifts in ATP were similar across the four bacterial strains, with results following an exponential relationship between the extracellular pH and cellular ATP concentration. One exception occurred with S. epidermidis, where there was no variation in cellular ATP at acidic pH values, and this finding is consistent with this species' ability to thrive under acidic conditions. These results provide insight into obtaining a desired bioenergetic response in bacteria through (i) the application of chemical treatments to vary the local pH and (ii) the selection and design of surfaces resulting in local pH modification of attached bacteria via the charge-regulation effect. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Bacterial attachment on titanium surfaces is dependent on topography and chemical changes induced by nonthermal atmospheric pressure plasma.

    Science.gov (United States)

    Jeong, Won-Seok; Kwon, Jae-Sung; Lee, Jung-Hwan; Uhm, Soo-Hyuk; Ha Choi, Eun; Kim, Kwang-Mahn

    2017-07-26

    Here, we investigated the antibacterial effects of chemical changes induced by nonthermal atmospheric pressure plasma (NTAPP) on smooth and rough Ti. The morphologies of smooth and rough surfaces of Ti were examined using scanning electron microscopy (SEM). Both Ti specimens were then treated for 10 min by NTAPP with nitrogen gas. The surface roughness, chemistry, and wettability were examined by optical profilometry, x-ray photoelectron spectroscopy, and water contact angle analysis, respectively. Bacterial attachment was measured by determining the number of colony forming units and by SEM analysis. The rough Ti showed irregular micropits, whereas smooth Ti had a relatively regular pattern on the surface. There were no differences in morphology between samples before and after NTAPP treatment. NTAPP treatment resulted in changes from hydrophobic to hydrophilic properties on rough and smooth Ti; rough Ti showed relatively higher hydrophilicity. Before NTAPP treatment, Streptococcus sanguinis (S. sanguinis) showed greater attachment on rough Ti, and after NTAPP treatment, there was a significant reduction in bacterial attachment. Moreover, the bacterial attachment rate was significantly lower on rough Ti, and the structure of S. sanguinis colonies were significantly changed on NTAPP-treated Ti. NTAPP treatment inhibited bacterial attachment surrounding titanium implants, regardless of surface topography. Therefore, NTAPP treatment on Ti is a next-generation tool for antibacterial applications in the orthopaedic and dental fields.

  3. Sonication reduces the attachment of Salmonella Typhimurium ATCC 14028 cells to bacterial cellulose-based plant cell wall models and cut plant material.

    Science.gov (United States)

    Tan, Michelle S F; Rahman, Sadequr; Dykes, Gary A

    2017-04-01

    This study investigated the removal of bacterial surface structures, particularly flagella, using sonication, and examined its effect on the attachment of Salmonella Typhimurium ATCC 14028 cells to plant cell walls. S. Typhimurium ATCC 14028 cells were subjected to sonication at 20 kHz to remove surface structures without affecting cell viability. Effective removal of flagella was determined by staining flagella of sonicated cells with Ryu's stain and enumerating the flagella remaining by direct microscopic counting. The attachment of sonicated S. Typhimurium cells to bacterial cellulose-based plant cell wall models and cut plant material (potato, apple, lettuce) was then evaluated. Varying concentrations of pectin and/or xyloglucan were used to produce a range of bacterial cellulose-based plant cell wall models. As compared to the non-sonicated controls, sonicated S. Typhimurium cells attached in significantly lower numbers (between 0.5 and 1.0 log CFU/cm 2 ) to all surfaces except to the bacterial cellulose-only composite without pectin and xyloglucan. Since attachment of S. Typhimurium to the bacterial cellulose-only composite was not affected by sonication, this suggests that bacterial surface structures, particularly flagella, could have specific interactions with pectin and xyloglucan. This study indicates that sonication may have potential applications for reducing Salmonella attachment during the processing of fresh produce. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Comparison of bacterial attachment to platelet bags with and without preconditioning with plasma.

    Science.gov (United States)

    Loza-Correa, M; Kalab, M; Yi, Q-L; Eltringham-Smith, L J; Sheffield, W P; Ramirez-Arcos, S

    2017-07-01

    Canadian Blood Services produces apheresis and buffy coat pooled platelet concentrates (PCs) stored in bags produced by two different manufacturers (A and B, respectively), both made of polyvinyl chloride-butyryl trihexyl citrate. This study was aimed at comparing Staphylococcus epidermidis adhesion to the inner surface of both bag types in the presence or absence of plasma factors. Sets (N = 2-6) of bags type A and B were left non-coated (control) or preconditioned with platelet-rich, platelet-poor or defibrinated plasma (PRP, PPP and DefibPPP, respectively). Each bag was inoculated with a 200-ml S. epidermidis culture adjusted to 0·5 colony-forming units/ml. Bags were incubated under platelet storage conditions for 7 days. After culture removal, bacteria attached to the plastic surface were either dislodged by sonication for bacterial quantification or examined in situ by scanning electron microscopy (SEM). Higher bacterial adhesion was observed to preconditioned PC bags than control containers for both bag types (P bags was confirmed by SEM. Bacteria adhered equally to both types of containers in the presence of PRP, PPP and DefibPPP residues (P > 0·05). By contrast, a significant increase in bacterial adherence was observed to type A bags compared with type B bags in the absence of plasma (P bags depends on the presence of plasma factors. Future efforts should be focused on reducing plasma proteins' attachment to platelet storage containers to decrease subsequent bacterial adhesion. © 2017 International Society of Blood Transfusion.

  5. Does circumcision alter the periurethral uropathogenic bacterial flora

    Directory of Open Access Journals (Sweden)

    Mushtaq Ahmad Laway

    2012-01-01

    Full Text Available Background: The aim of this study was to assess the pattern of periurethral bacterial flora in uncircumcised boys and to evaluate the effect of circumcision on alteration of periurethral uropathogenic bacterial flora. Materials and Methods: Pattern of periurethral bacterial flora before and after circumcision was studied prospectively in 124 boys. The results were analysed to compare change in bacterial colonisation before and after circumcision. Results: The age range was 6 weeks to 96 months. Most (94.3% of the boys had religious indication and 5.7% had medical indication for circumcision. E. coli, Proteus and Klebsiella were most common periurethral bacterial flora in uncircumcised subjects. Coagulase-negative staphylococcus and Staphylococcus aureus was most common periurethral bacterial flora in circumcised subjects. In 66.1% of circumcised subjects, no bacteria were grown from periurethral region. Conclusion: We conclude that presence of prepuce is associated with great quantity of periurethral bacteria, greater likelihood of the presence of high concentration of uropathogens and high incidence of urinary tract infection (UTI. This study provides circumstantial evidence supporting the idea that early circumcision may be beneficial for prevention of UTI.

  6. POLYSACCHARIDES AND eDNA AID BACTERIAL ATTACHMENT TO POLYMER BRUSH COATINGS (PLL-g-PEG)

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Ogaki, Ryosuke; Regina, Viduthalai R.

    measured the adsorption of peptides, polysaccharides and DNA to these coatings, as they represent bacterial adhesins with very different properties. While protein adsorption was minimized, we found considerable adsorption of polysaccharides, and exposure to DNA resulted in complete desorption...... of the conventional coating. These results explain why S. epidermidis, which produces polysaccharides and extracellular DNA, could successfully colonize the conventional PLL-g-PEG coatings. The ability of high-density PLL-g-PEG to resist polysaccharides, DNA, and bacterial adhesion of all strains is thus highly......Polymer brush coatings of poly(ethylene glycol) are considered the gold standard for nonfouling surfaces, but nevertheless, a few bacteria manage to attach and initiate biofilm formation on these coatings. To achieve robust resistance against bacterial adhesion and biofilm formation, grafting...

  7. Impaired bacterial attachment to light activated Ni-Ti alloy

    International Nuclear Information System (INIS)

    Chrzanowski, Wojciech; Valappil, Sabeel P.; Dunnill, Charles W.; Abou Neel, Ensanya A.; Lee, Kevin; Parkin, Ivan P.; Wilson, Michael; Armitage, David A.; Knowles, Jonathan C.

    2010-01-01

    Ni-Ti alloy due to its unique mechanical properties, is used for many types of implants. Failure of these implants can be attributed to many different factors; however infections are a common problem. In this paper, the attachment of the bacteria, Staphylococcus aureus, to the Ni-Ti surface modified by a range of processes with and without of light activation (used to elicit antimicrobial properties of materials) was assessed and related to different surface characteristics. Before the light activation the number of bacterial colony forming units was the greatest for the samples thermally oxidised at 600 deg. C. This sample and the spark oxidised samples showed the highest photocatalytic activity but only the thermally oxidised samples at 600 deg. C showed a significant drop of S. aureus attachment. The findings in this study indicate that light activation and treating samples at 600 deg. C is a promising method for Ni-Ti implant applications with inherent antimicrobial properties. Light activation was shown to be an effective way to trigger photocatalytic reactions on samples covered with relatively thick titanium dioxide via accumulation of photons in the surface and a possible increase in defects which may result in free oxygen. Moreover, light activation caused an increase in the total surface energy.

  8. Mechanisms of Bacterial (Serratia marcescens) Attachment to, Migration along, and Killing of Fungal Hyphae.

    Science.gov (United States)

    Hover, Tal; Maya, Tal; Ron, Sapir; Sandovsky, Hani; Shadkchan, Yana; Kijner, Nitzan; Mitiagin, Yulia; Fichtman, Boris; Harel, Amnon; Shanks, Robert M Q; Bruna, Roberto E; García-Véscovi, Eleonora; Osherov, Nir

    2016-05-01

    We have found a remarkable capacity for the ubiquitous Gram-negative rod bacterium Serratia marcescens to migrate along and kill the mycelia of zygomycete molds. This migration was restricted to zygomycete molds and several basidiomycete species. No migration was seen on any molds of the phylum Ascomycota. S. marcescens migration did not require fungal viability or surrounding growth medium, as bacteria migrated along aerial hyphae as well.S. marcescens did not exhibit growth tropism toward zygomycete mycelium. Bacterial migration along hyphae proceeded only when the hyphae grew into the bacterial colony. S. marcescens cells initially migrated along the hyphae, forming attached microcolonies that grew and coalesced to generate a biofilm that covered and killed the mycelium. Flagellum-defective strains of S. marcescens were able to migrate along zygomycete hyphae, although they were significantly slower than the wild-type strain and were delayed in fungal killing. Bacterial attachment to the mycelium does not necessitate type 1 fimbrial adhesion, since mutants defective in this adhesin migrated equally well as or faster than the wild-type strain. Killing does not depend on the secretion of S. marcescens chitinases, as mutants in which all three chitinase genes were deleted retained wild-type killing abilities. A better understanding of the mechanisms by which S. marcescens binds to, spreads on, and kills fungal hyphae might serve as an excellent model system for such interactions in general; fungal killing could be employed in agricultural fungal biocontrol. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  9. Bacterial resistance of self-assembled surfaces using PPOm-b-PSBMAn zwitterionic copolymer - concomitant effects of surface topography and surface chemistry on attachment of live bacteria.

    Science.gov (United States)

    Hsiao, Sheng-Wen; Venault, Antoine; Yang, Hui-Shan; Chang, Yung

    2014-06-01

    Three well-defined diblock copolymers made of poly(sulfobetaine methacrylate) (poly(SBMA)) and poly(propylene oxide) (PPO) groups were synthesized by atom transfer radical polymerization (ATRP) method. They were physically adsorbed onto three types of surfaces having different topography, including smooth flat surface, convex surface, and indented surface. Chemical state of surfaces was characterized by XPS while the various topographies were examined by SEM and AFM. Hydrophilicity of surfaces was dependent on both the surface chemistry and the surface topography, suggesting that orientation of copolymer brushes can be tuned in the design of surfaces aimed at resisting bacterial attachment. Escherichia coli, Staphylococcus epidermidis, Streptococcus mutans and Escherichia coli with green fluorescent protein (E. coli GFP) were used in bacterial tests to assess the resistance to bacterial attachment of poly(SBMA)-covered surfaces. Results highlighted a drastic improvement of resistance to bacterial adhesion with the increasing of poly(SBMA) to PPO ratio, as well as an important effect of surface topography. The chemical effect was directly related to the length of the hydrophilic moieties. When longer, more water could be entrapped, leading to improved anti-bacterial properties. The physical effect impacted on the orientation of the copolymer brushes, as well as on the surface contact area available. Convex surfaces as well as indented surfaces wafer presented the best resistance to bacterial adhesion. Indeed, bacterial attachment was more importantly reduced on these surfaces compared with smooth surfaces. It was explained by the non-orthogonal orientation of copolymer brushes, resulting in a more efficient surface coverage of zwitterionic molecules. This work suggests that not only the control of surface chemistry is essential in the preparation of surfaces resisting bacterial attachment, but also the control of surface topography and orientation of antifouling

  10. Bacterial cell numbers and community structures of seawater biofilms depend on the attachment substratum

    KAUST Repository

    Yap, Scott A.

    2018-02-02

    Seawater is increasingly being used as a source for various industrial applications. For such applications, biofilm growth creates various problems including but not limited to pipe biocorrosion. In this study, it is hypothesized that the material type is preferred by certain bacterial populations in the seawater to attach and establish biofilms. By comparing differences in the total cell counts and microbial communities attached to high-density polyethylene (HDPE), polycarbonate, stainless steel (SS316) and titanium, the appropriate material can be used to minimize biofilm growth. All four materials have hydrophilic surfaces, but polycarbonate exhibits higher surface roughness. There were no significant differences in the cell numbers attached to polycarbonate, HDPE and titanium. Instead, there were significantly fewer cells attached to SS316. However, there was a higher relative abundance of genera associated with opportunistic pathogens on SS316. Copy numbers of genes representing Desulfobacteraceae and Desulfobulbaceae, both of which are sulfate-reducing bacteria (SRB), were approximately 10-fold higher in biofilms sampled from SS316. The enrichment of SRB in the biofilm associated with SS316 indicates that this material may be prone to biocorrosion. This study highlights the need for industries to consider the choice of material used in seawater applications to minimize microbial-associated problems.

  11. Bacterial cell numbers and community structures of seawater biofilms depend on the attachment substratum

    KAUST Repository

    Yap, Scott A.; Scarascia, Giantommaso; Hong, Pei-Ying

    2018-01-01

    Seawater is increasingly being used as a source for various industrial applications. For such applications, biofilm growth creates various problems including but not limited to pipe biocorrosion. In this study, it is hypothesized that the material type is preferred by certain bacterial populations in the seawater to attach and establish biofilms. By comparing differences in the total cell counts and microbial communities attached to high-density polyethylene (HDPE), polycarbonate, stainless steel (SS316) and titanium, the appropriate material can be used to minimize biofilm growth. All four materials have hydrophilic surfaces, but polycarbonate exhibits higher surface roughness. There were no significant differences in the cell numbers attached to polycarbonate, HDPE and titanium. Instead, there were significantly fewer cells attached to SS316. However, there was a higher relative abundance of genera associated with opportunistic pathogens on SS316. Copy numbers of genes representing Desulfobacteraceae and Desulfobulbaceae, both of which are sulfate-reducing bacteria (SRB), were approximately 10-fold higher in biofilms sampled from SS316. The enrichment of SRB in the biofilm associated with SS316 indicates that this material may be prone to biocorrosion. This study highlights the need for industries to consider the choice of material used in seawater applications to minimize microbial-associated problems.

  12. A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts.

    Directory of Open Access Journals (Sweden)

    Tobias T Hägi

    Full Text Available There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a to establish a pocket model enabling mechanical removal of biofilm and b to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL fibroblasts.Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a hand-instrumentation with curettes (CUR, b ultrasonication (US, c subgingival air-polishing using erythritol (EAP and d subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX. The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz, the caused tooth substance-loss (thickness as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD.After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10. The lowest reduction was found after CUR (2 log10. Additionally, substance-loss was the highest when using CUR (128±40 µm in comparison with US (14±12 µm, EAP (6±7 µm and EAP-CHX (11±10 µm. Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts.The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air-polishing with erythritol prevents from substance-loss and results

  13. SURFACE FINISHES ON STAINLESS STEEL REDUCE BACTERIAL ATTACHMENT AND EARLY BIOFILM FORMATION: SCANNING ELECTRON AND ATOMIC FORCE MICROSCOPY STUDY

    Science.gov (United States)

    Three common finishing treatments of stainless steel that are used for equipment during poultry processing were tested for resistance to bacterial contamination. Methods were developed to measure attached bacteria and to identify factors that make surface finishes susceptible or ...

  14. Evaluation of penicylinders used in disinfectant testing: bacterial attachment and surface texture.

    Science.gov (United States)

    Cole, E C; Rutala, W A; Carson, J L

    1987-01-01

    Two possible deficiencies in the AOAC use-dilution method for registration of chemical disinfectants by the Environmental Protection Agency are examined: (1) the physical disparities among brands of penicylinders and (2) the variability of bacterial numbers on penicylinders depending upon test strain and penicylinder surface texture. Textural differences of 2 brands of stainless steel penicylinders, one brand of porcelain, and one brand of glass were assessed by scanning electron microscopy. A considerable variation in smoothness of both inner and outer surfaces of stainless steel and porcelain penicylinders was observed. Glass penicylinders were very smooth. Numbers of bacteria attached to a penicylinder were assessed by vortexing the penicylinders 30 s at No. 4 after using the AOAC method of bacterial inoculation and drying 40 min at 37 degrees C. With this methodology, stainless steel carriers retained the 3 AOAC-recommended bacterial test strains differentially: ca 10(7) for Pseudomonas aeruginosa, 5 X 10(6) for Staphylococcus aureus, and 10(6) for Salmonella choleraesuis; glass retained 10(6)-10(7) organisms of all 3 test strains; porcelain retained about that amount of S. aureus but 10(5)-10(6) P. aeruginosa and 10(3)-10(4) S. choleraesuis. These data suggest that disinfectants are not similarly challenged with the AOAC-recommended test bacteria and that an alternative method should be considered to ensure comparable numbers of bacteria on penicylinders.

  15. Osteopontin mediates Citrobacter rodentium-induced colonic epithelial cell hyperplasia and attaching-effacing lesions.

    Science.gov (United States)

    Wine, Eytan; Shen-Tu, Grace; Gareau, Mélanie G; Goldberg, Harvey A; Licht, Christoph; Ngan, Bo-Yee; Sorensen, Esben S; Greenaway, James; Sodek, Jaro; Zohar, Ron; Sherman, Philip M

    2010-09-01

    Although osteopontin (OPN) is up-regulated in inflammatory bowel diseases, its role in disease pathogenesis remains controversial. The objective of this study was to determine the role of OPN in host responses to a non-invasive bacterial pathogen, Citrobacter rodentium, which serves as a murine infectious model of colitis. OPN gene knockout and wild-type mice were infected orogastrically with either C. rodentium or Luria-Bertani (LB) broth. Mouse-derived OPN(+/+) and OPN(-/-) fibroblasts were incubated with C. rodentium and attaching-effacing lesions were demonstrated using transmission electron microscopy and immunofluorescence. Colonic expression of OPN was increased by C. rodentium infection of wild-type mice. Furthermore, colonic epithelial cell hyperplasia, the hallmark of C. rodentium infection, was reduced in OPN(-/-) mice, and spleen enlargement by infection was absent in OPN(-/-) mice. Rectal administration of OPN to OPN(-/-) mice restored these effects. There was an 8- to 17-fold reduction in bacterial colonization in OPN(-/-) mice, compared with wild-type mice, which was accompanied by reduced attaching-effacing lesions, both in infected OPN(-/-) mice and OPN(-/-) mouse fibroblasts. Moreover, adhesion pedestals were restored in OPN(-/-) cells complemented with human OPN. Therefore, lack of OPN results in decreased pedestal formation, colonization, and colonic epithelial cell hyperplasia responses to C. rodentium infection, indicating that OPN impacts disease pathogenesis through bacterial attachment and altered host immune responses.

  16. Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH

    Directory of Open Access Journals (Sweden)

    Yuting Zhang

    2017-07-01

    Full Text Available Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007–2014 of applying chemical nitrogen, phosphorus and potassium (NPK fertilizers, composted manure or their combination to acidic (pH 5.8, near-neutral (pH 6.8 or alkaline (pH 8.4 Eutric Regosol soil in a maize-vegetable rotation in southwest China. In alkaline soil, nutrient sources did not affect bacterial Operational Taxonomic Unit (OTU richness or Shannon diversity index, despite higher available N, P, K, and soil organic carbon in fertilized than in unfertilized soil. In contrast, bacterial OTU richness and Shannon diversity index were significantly lower in acidic and near-neutral soils under NPK than under manure or their combination, which corresponded with changes in soil pH. Permutational multivariate analysis of variance showed that bacterial community structure was significantly affected across these three soils, but the PCoA ordination patterns indicated the effect was less distinct among nutrient sources in alkaline than in acidic and near-neural soils. Distance-based redundancy analysis showed that bacterial community structures were significantly altered by soil pH in acidic and near-neutral soils, but not by any soil chemical properties in alkaline soil. The relative abundance (% of most bacterial phyla was higher in near-neutral than in acidic or alkaline soils. The most dominant phyla were Proteobacteria (24.6%, Actinobacteria (19.7%, Chloroflexi (15.3% and Acidobacteria (12.6%; the medium dominant phyla were Bacterioidetes (5.3%, Planctomycetes (4.8%, Gemmatimonadetes (4.5%, Firmicutes (3.4%, Cyanobacteria (2.1%, Nitrospirae (1.8%, and candidate division TM7 (1

  17. Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH.

    Science.gov (United States)

    Zhang, Yuting; Shen, Hong; He, Xinhua; Thomas, Ben W; Lupwayi, Newton Z; Hao, Xiying; Thomas, Matthew C; Shi, Xiaojun

    2017-01-01

    Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007-2014) of applying chemical nitrogen, phosphorus and potassium (NPK) fertilizers, composted manure or their combination to acidic (pH 5.8), near-neutral (pH 6.8) or alkaline (pH 8.4) Eutric Regosol soil in a maize-vegetable rotation in southwest China. In alkaline soil, nutrient sources did not affect bacterial Operational Taxonomic Unit (OTU) richness or Shannon diversity index, despite higher available N, P, K, and soil organic carbon in fertilized than in unfertilized soil. In contrast, bacterial OTU richness and Shannon diversity index were significantly lower in acidic and near-neutral soils under NPK than under manure or their combination, which corresponded with changes in soil pH. Permutational multivariate analysis of variance showed that bacterial community structure was significantly affected across these three soils, but the PCoA ordination patterns indicated the effect was less distinct among nutrient sources in alkaline than in acidic and near-neural soils. Distance-based redundancy analysis showed that bacterial community structures were significantly altered by soil pH in acidic and near-neutral soils, but not by any soil chemical properties in alkaline soil. The relative abundance (%) of most bacterial phyla was higher in near-neutral than in acidic or alkaline soils. The most dominant phyla were Proteobacteria (24.6%), Actinobacteria (19.7%), Chloroflexi (15.3%) and Acidobacteria (12.6%); the medium dominant phyla were Bacterioidetes (5.3%), Planctomycetes (4.8%), Gemmatimonadetes (4.5%), Firmicutes (3.4%), Cyanobacteria (2.1%), Nitrospirae (1.8%), and candidate division TM7 (1

  18. Canopy soil bacterial communities altered by severing host tree limbs

    Directory of Open Access Journals (Sweden)

    Cody R. Dangerfield

    2017-09-01

    Full Text Available Trees of temperate rainforests host a large biomass of epiphytic plants, which are associated with soils formed in the forest canopy. Falling of epiphytic material results in the transfer of carbon and nutrients from the canopy to the forest floor. This study provides the first characterization of bacterial communities in canopy soils enabled by high-depth environmental sequencing of 16S rRNA genes. Canopy soil included many of the same major taxonomic groups of Bacteria that are also found in ground soil, but canopy bacterial communities were lower in diversity and contained different operational taxonomic units. A field experiment was conducted with epiphytic material from six Acer macrophyllum trees in Olympic National Park, Washington, USA to document changes in the bacterial communities of soils associated with epiphytic material that falls to the forest floor. Bacterial diversity and composition of canopy soil was highly similar, but not identical, to adjacent ground soil two years after transfer to the forest floor, indicating that canopy bacteria are almost, but not completely, replaced by ground soil bacteria. Furthermore, soil associated with epiphytic material on branches that were severed from the host tree and suspended in the canopy contained altered bacterial communities that were distinct from those in canopy material moved to the forest floor. Therefore, the unique nature of canopy soil bacteria is determined in part by the host tree and not only by the physical environmental conditions associated with the canopy. Connection to the living tree appears to be a key feature of the canopy habitat. These results represent an initial survey of bacterial diversity of the canopy and provide a foundation upon which future studies can more fully investigate the ecological and evolutionary dynamics of these communities.

  19. Plasmid-dependent attachment of Agrobacterium tumefaciens to plant tissue culture cells.

    Science.gov (United States)

    Matthysse, A G; Wyman, P M; Holmes, K V

    1978-11-01

    Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells. Kinetic studies showed that virulent strains of A. tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells. Five Ti-plasmid-containing virulent Agrobacterium strains showed greater attachment to tobacco cells than did five avirulent strains. Light and scanning electron microscopic observations confirmed that virulent strains showed little attachment. Bacterial attachment was blocked by prior incubation of the plant cells with lipopolysaccharide extracted from A. tumefaciens, but not from A. radiobacter, suggesting that bacterial lipopolysaccharide is one of the components involved in the attachment process. At least one other bacterial product may be required for attachment in tissue culture because the virulent A. tumefaciens NT1, which lacks the Ti plasmid, does not itself attach to tobacco cells, but its lipopolysaccharide does inhibit the attachment of virulent strains.

  20. Long-term nitrogen amendment alters the diversity and assemblage of soil bacterial communities in tallgrass prairie.

    Directory of Open Access Journals (Sweden)

    Joseph D Coolon

    Full Text Available Anthropogenic changes are altering the environmental conditions and the biota of ecosystems worldwide. In many temperate grasslands, such as North American tallgrass prairie, these changes include alteration in historically important disturbance regimes (e.g., frequency of fires and enhanced availability of potentially limiting nutrients, particularly nitrogen. Such anthropogenically-driven changes in the environment are known to elicit substantial changes in plant and consumer communities aboveground, but much less is known about their effects on soil microbial communities. Due to the high diversity of soil microbes and methodological challenges associated with assessing microbial community composition, relatively few studies have addressed specific taxonomic changes underlying microbial community-level responses to different fire regimes or nutrient amendments in tallgrass prairie. We used deep sequencing of the V3 region of the 16S rRNA gene to explore the effects of contrasting fire regimes and nutrient enrichment on soil bacterial communities in a long-term (20 yrs experiment in native tallgrass prairie in the eastern Central Plains. We focused on responses to nutrient amendments coupled with two extreme fire regimes (annual prescribed spring burning and complete fire exclusion. The dominant bacterial phyla identified were Proteobacteria, Verrucomicrobia, Bacteriodetes, Acidobacteria, Firmicutes, and Actinobacteria and made up 80% of all taxa quantified. Chronic nitrogen enrichment significantly impacted bacterial community diversity and community structure varied according to nitrogen treatment, but not phosphorus enrichment or fire regime. We also found significant responses of individual bacterial groups including Nitrospira and Gammaproteobacteria to long-term nitrogen enrichment. Our results show that soil nitrogen enrichment can significantly alter bacterial community diversity, structure, and individual taxa abundance, which have

  1. ABCB1 (P-glycoprotein) reduces bacterial attachment to human gastrointestinal LS174T epithelial cells.

    Science.gov (United States)

    Crowe, Andrew; Bebawy, Mary

    2012-08-15

    The aim of this project was to show elevated P-glycoprotein (P-gp) expression decreasing bacterial association with LS174T human gastrointestinal cells, and that this effect could be reversed upon blocking functional P-gp efflux. Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Lactobacillus acidophilus and numerous strains of Escherichia coli, from commensal to enteropathogenic and enterohaemorrhagic strains (O157:H7) were fluorescently labelled and incubated on LS174T cultures either with or without P-gp amplification using rifampicin. PSC-833 was used as a potent functional P-gp blocking agent. Staphylococcus and Pseudomonas displayed the greatest association with the LS174T cells. Surprisingly, lactobacilli retained more fluorescence than enteropathogenic-E. coli in this system. Irrespective of attachment differences between the bacterial species, the increase in P-gp protein expression decreased bacterial fluorescence by 25-30%. This included the GFP-labelled E. coli, and enterohaemorrhagic E. coli (O157:H7). Blocking P-gp function through the co-administration of PSC-833 increased the amount of bacteria associated with P-gp expressing LS174T cells back to control levels. As most bacteria were affected to the same degree, irrespective of pathogenicity, it is unlikely that P-gp has a direct influence on adhesion of bacteria, and instead P-gp may be playing an indirect role by secreting a bank of endogenous factors or changing the local environment to one less suited to bacterial growth in general. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  2. Association of Antibiotic Resistance in Agricultural Escherichia coli Isolates with Attachment to Quartz▿

    OpenAIRE

    Liu, Ping; Soupir, Michelle L.; Zwonitzer, Martha; Huss, Bridgette; Jarboe, Laura R.

    2011-01-01

    Surface water can be contaminated by bacteria from various sources, including manure from agricultural facilities. Attachment of these bacteria to soil and organic particles contributes to their transport through the environment, though the mechanism of attachment is unknown. As bacterial attachment to human tissues is known to be correlated with antibiotic resistance, we have investigated here the relationship between bacterial attachment to environmental particles and antibiotic resistance ...

  3. Carbon nanomaterials alter plant physiology and soil bacterial community composition in a rice-soil-bacterial ecosystem.

    Science.gov (United States)

    Hao, Yi; Ma, Chuanxin; Zhang, Zetian; Song, Youhong; Cao, Weidong; Guo, Jing; Zhou, Guopeng; Rui, Yukui; Liu, Liming; Xing, Baoshan

    2018-01-01

    The aim of this study was to compare the toxicity effects of carbon nanomaterials (CNMs), namely fullerene (C 60 ), reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs), on a mini-ecosystem of rice grown in a loamy potted soil. We measured plant physiological and biochemical parameters and examined bacterial community composition in the CNMs-treated plant-soil system. After 30 days of exposure, all the three CNMs negatively affected the shoot height and root length of rice, significantly decreased root cortical cells diameter and resulted in shrinkage and deformation of cells, regardless of exposure doses (50 or 500 mg/kg). Additionally, at the high exposure dose of CNM, the concentrations of four phytohormones, including auxin, indoleacetic acid, brassinosteroid and gibberellin acid 4 in rice roots significantly increased as compared to the control. At the high exposure dose of MWCNTs and C 60 , activities of the antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD) in roots increased significantly. High-throughput sequencing showed that three typical CNMs had little effect on shifting the predominant soil bacterial species, but the presence of CNMs significantly altered the composition of the bacterial community. Our results indicate that different CNMs indeed resulted in environmental toxicity to rice and soil bacterial community in the rhizosphere and suggest that CNMs themselves and their incorporated products should be reasonably used to control their release/discharge into the environment to prevent their toxic effects on living organisms and the potential risks to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Bacterial production and growth rate estimation from [3H]thymidine incorporation for attached and free-living bacteria in aquatic systems

    International Nuclear Information System (INIS)

    Iriberri, J.; Unanue, M.; Ayo, B.; Barcina, I.; Egea, L.

    1990-01-01

    Production and specific growth rates of attached and free-living bacteria were estimated in an oligotrophic marine system, La Salvaje Beach, Vizcaya, Spain, and in a freshwater system having a higher nutrient concentration, Butron River, Vizcaya, Spain. Production was calculated from [methyl- 3 H]thymidine incorporation by estimating specific conversion factors (cells or micrograms of C produced per mole of thymidine incorporated) for attached and free-living bacteria, respectively, in each system. Conversion factors were not statistically different between attached and free-living bacteria: 6.812 x 10 11 and 8.678 x 10 11 μg of C mol -1 for free-living and attached bacteria in the freshwater system, and 1.276 x 10 11 and 1.354 x 10 11 μg of C mol -1 for free-living and attached bacteria in the marine system. Therefore, use of a unique conversion factor for the mixed bacterial population is well founded. However, conversion factors were higher in the freshwater system than in the marine system. This could be due to the different tropic conditions of the two systems. Free-living bacteria contributed the most to production in the two systems (85% in the marine system and 67% in the freshwater system) because of their greater contribution to total biomass. Specific growth rates calculated from production data and biomass data were similar for attached and free-living bacteria

  5. Mutations That Alter the Bacterial Cell Envelope Increase Lipid Production

    Energy Technology Data Exchange (ETDEWEB)

    Lemmer, Kimberly C.; Zhang, Weiping; Langer, Samantha J.; Dohnalkova, Alice; Hu, Dehong; Lemke, Rachelle A.; Piotrowski, Jeff S.; Orr, Galya; Noguera, Daniel R.; Donohue, Timothy J.

    2017-05-23

    ABSTRACT

    Lipids from microbes offer a promising source of renewable alternatives to petroleum-derived compounds. In particular, oleaginous microbes are of interest because they accumulate a large fraction of their biomass as lipids. In this study, we analyzed genetic changes that alter lipid accumulation inRhodobacter sphaeroides. By screening anR. sphaeroidesTn5mutant library for insertions that increased fatty acid content, we identified 10 high-lipid (HL) mutants for further characterization. These HL mutants exhibited increased sensitivity to drugs that target the bacterial cell envelope and changes in shape, and some had the ability to secrete lipids, with two HL mutants accumulating ~60% of their total lipids extracellularly. When one of the highest-lipid-secreting strains was grown in a fed-batch bioreactor, its lipid content was comparable to that of oleaginous microbes, with the majority of the lipids secreted into the medium. Based on the properties of these HL mutants, we conclude that alterations of the cell envelope are a previously unreported approach to increase microbial lipid production. We also propose that this approach may be combined with knowledge about biosynthetic pathways, in this or other microbes, to increase production of lipids and other chemicals.

    IMPORTANCEThis paper reports on experiments to understand how to increase microbial lipid production. Microbial lipids are often cited as one renewable replacement for petroleum-based fuels and chemicals, but strategies to increase the yield of these compounds are needed to achieve this goal. While lipid biosynthesis is often well understood, increasing yields of these compounds to industrially relevant levels is a challenge, especially since genetic, synthetic biology, or engineering approaches are not feasible in many microbes. We show that altering the bacterial cell envelope can be used to increase

  6. Phenotypes of non-attached Pseudomonas aeruginosa aggregates resemble surface attached biofilm.

    Directory of Open Access Journals (Sweden)

    Morten Alhede

    Full Text Available For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse conditions. However, microscopic investigations of samples isolated from sites of chronic infections seem to suggest that some bacteria do not need to be attached to surfaces in order to establish chronic infections. In this study we employed scanning electron microscopy, confocal laser scanning microscopy, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance and resistance to phagocytes were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both the physiological states of the aggregates and particular matrix components. Bacterial surface-attachment and subsequent biofilm formation are considered hallmarks of the capacity of microbes to cause persistent infections. We have observed non-attached aggregates in the lungs of cystic fibrosis patients; otitis media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non

  7. Supplemental Dietary Inulin of Variable Chain Lengths Alters Intestinal Bacterial Populations in Young Pigs123

    Science.gov (United States)

    Patterson, Jannine K.; Yasuda, Koji; Welch, Ross M.; Miller, Dennis D.; Lei, Xin Gen

    2010-01-01

    Previously, we showed that supplementation of diets with short-chain inulin (P95), long-chain inulin (HP), and a 50:50 mixture of both (Synergy 1) improved body iron status and altered expression of the genes involved in iron homeostasis and inflammation in young pigs. However, the effects of these 3 types of inulin on intestinal bacteria remain unknown. Applying terminal restriction fragment length polymorphism analysis, we determined the abundances of luminal and adherent bacterial populations from 6 segments of the small and large intestines of pigs (n = 4 for each group) fed an iron-deficient basal diet (BD) or the BD supplemented with 4% of P95, Synergy 1, or HP for 5 wk. Compared with BD, all 3 types of inulin enhanced (P inulin on bacterial populations in the lumen contents were found. Meanwhile, all 3 types of inulin suppressed the less desirable bacteria Clostridium spp. and members of the Enterobacteriaceae in the lumen and mucosa of various gut segments. Our findings suggest that the ability of dietary inulin to alter intestinal bacterial populations may partially account for its iron bioavailability-promoting effect and possibly other health benefits. PMID:20980641

  8. Acidic Conditions in the NHE2-/- Mouse Intestine Result in an Altered Mucosa-Associated Bacterial Population with Changes in Mucus Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Melinda A. Engevik

    2013-12-01

    Full Text Available Background: The mechanisms bacteria use to proliferate and alter the normal bacterial composition remain unknown. The ability to link changes in the intestinal micro-environment, such as ion composition and pH, to bacterial proliferation is clinically advantageous for diseases that involve an altered gut microbiota, such as Inflammatory Bowel Disease, obesity and diabetes. In human and mouse intestine, the apical Na+/H+ exchangers NHE2 and NHE3 affect luminal Na+, water, and pH. Loss of NHE2 results in acidic luminal pH. Since acid resistance systems in gram-positive bacteria are well documented, we hypothesize that gram-positive bacteria would increase in representation in the acidic NHE2-/- intestine. Methods: Intestinal ion composition was measured by fame photometry and chloridometry and pH measured electrochemically. DNA extracted from intestinal flushes or from mucosal scrapings was analyzed by qRT-PCR to examine luminal and mucosa-associated bacterial populations. Epithelial mucus oligosaccharide patterns were examined by histology with FIT-C labeled lectins. Results: Although total luminal and mucosa-associated bacteria were unchanged in NHE2-/- intestine, gram-positive bacterial phyla were increased in the mucosa-associated bacterial population in a region-specific manner. The genera Clostridium and Lactobacillus were increased in the cecum and colon which corresponded to changes in NHE2-/- mucus oligosaccharide composition of mannose, N-acetyglucosamine, N-acetygalactosamine and galactose. Conclusions: Together these data indicate that changes in ion transport induce region-specific bacterial changes, which alter host mucus oligosaccharide patterns. These host-bacterial interactions provide a possible mechanism of niche-development and shed insight on how certain groups proliferate in changing environments and maintain their proliferation by altering the host.

  9. Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria

    Directory of Open Access Journals (Sweden)

    Claudia D. Infante

    2018-05-01

    Full Text Available Background: Marine ecosystems contain benthic microalgae and bacterial species that are capable of secreting extracellular polymeric substances (EPS, suggesting that settlement of these microorganisms can occur on submerged surfaces, a key part of the first stage of biofouling. Currently, anti-fouling treatments that help control this phenomenon involve the use of biocides or antifouling paints that contain heavy metals, which over a long period of exposure can spread to the environment. The bacterium Alteromonas sp. Ni1-LEM has an inhibitory effect on the adhesion of Nitzschia ovalis, an abundant diatom found on submerged surfaces. Results: We evaluated the effect of the bioactive compound secreted by this bacterium on the EPS of biofilms and associated epiphytic bacteria. Three methods of EPS extraction were evaluated to determine the most appropriate and efficient methodology based on the presence of soluble EPS and the total protein and carbohydrate concentrations. Microalgae were cultured with the bacterial compound to evaluate its effect on EPS secretion and variations in its protein and carbohydrate concentrations. An effect of the bacterial supernatant on EPS was observed by assessing biofilm formation and changes in the concentration of proteins and carbohydrates present in the biofilm. Conclusions: These results indicate that a possible mechanism for regulating biofouling could be through alteration of biofilm EPS and alteration of the epiphytic bacterial community associated with the microalga.How to cite: Infante, C.D., Castillo, F., Pérez, V., et al. Inhibition of Nitzschia ovalis biofilm settlement by a bacterial bioactive compound through alteration of EPS and epiphytic bacteria. Electron J Biotechnol 2018;33 https://doi.org/10.1016/j.ejbt.2018.03.002. Keywords: Anti-fouling, Benthic microalgae, Biofilm, Biofouling, Epiphytic bacterial community, EPS, Marine ecosystems, Metagenomic, Nitzschia ovalis, Settlement inhibition

  10. Modulation of cell surface hydrophobicity and attachment of bacteria to abiotic surfaces and shrimp by Malaysian herb extracts.

    Science.gov (United States)

    Hui, Yew Woh; Dykes, Gary A

    2012-08-01

    The use of simple crude water extracts of common herbs to reduce bacterial attachment may be a cost-effective way to control bacterial foodborne pathogens, particularly in developing countries. The ability of water extracts of three common Malaysian herbs (Andrographis paniculata, Eurycoma longifolia, and Garcinia atroviridis) to modulate hydrophobicity and attachment to surfaces of five food-related bacterial strains (Bacillus cereus ATCC 14576, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 10145, Salmonella Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923) were determined. The bacterial attachment to hydrocarbon assay was used to determine bacterial hydrophobicity. Staining and direct microscopic counts were used to determine attachment of bacteria to glass and stainless steel. Plating on selective media was used to determine attachment of bacteria to shrimp. All extracts were capable of either significantly ( P 0.05) to bacterial attachment. For specific combinations of bacteria, surface material, and plant extract, significant correlations (R > 0.80) between hydrophobicity and attachment were observed. The highest of these was observed for S. aureus attachment to stainless steel and glass after treatment with the E. longifolia extract (R = 0.99, P < 0.01). The crude water herb extracts in this study were shown to have the potential to modulate specific bacterial and surface interactions and may, with further work, be useful for the simple and practical control of foodborne pathogens.

  11. Using Bacterial Extract along with Differential Gene Expression in Acropora millepora Larvae to Decouple the Processes of Attachment and Metamorphosis

    Science.gov (United States)

    Siboni, Nachshon; Abrego, David; Seneca, Francois; Motti, Cherie A.; Andreakis, Nikos; Tebben, Jan; Blackall, Linda L.; Harder, Tilmann

    2012-01-01

    Biofilms of the bacterium Pseudoalteromonas induce metamorphosis of acroporid coral larvae. The bacterial metabolite tetrabromopyrrole (TBP), isolated from an extract of Pseudoalteromonas sp. associated with the crustose coralline alga (CCA) Neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0–2%). To better understand the molecular events and mechanisms underpinning the induction of Acropora millepora larval metamorphosis, including cell proliferation, apoptosis, differentiation, migration, adhesion and biomineralisation, two novel coral gene expression assays were implemented. These involved the use of reverse-transcriptase quantitative PCR (RT-qPCR) and employed 47 genes of interest (GOI), selected based on putative roles in the processes of settlement and metamorphosis. Substantial differences in transcriptomic responses of GOI were detected following incubation of A. millepora larvae with a threshold concentration and 10-fold elevated concentration of TBP-containing extracts of Pseudoalteromonas sp. The notable and relatively abrupt changes of the larval body structure during metamorphosis correlated, at the molecular level, with significant differences (pmetamorphosis. The bacterial TBP-containing extract provided a unique opportunity to monitor the regulation of genes exclusively involved in the process of metamorphosis, contrasting previous gene expression studies that utilized cues, such as crustose coralline algae, biofilms or with GLW-amide neuropeptides that stimulate the entire onset of larval metamorphosis and attachment. PMID:22655067

  12. Endocytosis-inducer adhesins produced by enteropathogenic serogroups of Escherichia coli participate on bacterial attachment to infant enterocytes

    Directory of Open Access Journals (Sweden)

    João Ramos Costa Andrade

    1987-03-01

    Full Text Available Enteropathogenic E. coli (EPEC infection of Hep-2 cells preoceeds through bacterial attachment to cell surface and internalization of adhered bacteria. EPEC attachment is a prerequisite for cell infection and is mediated by adhesins that recognize carbohydrate-containing receptors on cell membrane. Such endocytosis-inducer adhesins (EIA also promote EPEC binding to infant enterocytes, suggesting that EIA may have an important role on EPEC gastroenteritis.A infecção de células Hep-2 por E. coli enteropatogênicas (ECEP implica na aderência bacteriana e posterior interiorização dos microrganismos aderidos por um mecanismo de endocitose. A aderência das ECEP é pré-requisito para a infecção e é mediada por adesinas que reconhecem receptores inibidos por certas oses na membrana celular. Tais "adesinas indutoras da endocitose" (AIE também promovem a ligação bacteriana a enterócitos obtidos do intestino delgado de lactente, sugerindo que as AIE possam desempenhar algum papel nas diarréias causadas por ECEP.

  13. Vizantin inhibits bacterial adhesion without affecting bacterial growth and causes Streptococcus mutans biofilm to detach by altering its internal architecture.

    Science.gov (United States)

    Takenaka, Shoji; Oda, Masataka; Domon, Hisanori; Ohsumi, Tatsuya; Suzuki, Yuki; Ohshima, Hayato; Yamamoto, Hirofumi; Terao, Yutaka; Noiri, Yuichiro

    2016-11-11

    An ideal antibiofilm strategy is to control both in the quality and quantity of biofilm while maintaining the benefits derived from resident microflora. Vizantin, a recently developed immunostimulating compound, has also been found to have antibiofilm property. This study evaluated the influence on biofilm formation of Streptococcus mutans in the presence of sulfated vizantin and biofilm development following bacterial adhesion on a hydroxyapatite disc coated with sulfated vizantin. Supplementation with sulfated vizantin up to 50 μM did not affect either bacterial growth or biofilm formation, whereas 50 μM sulfated vizantin caused the biofilm to readily detach from the surface. Sulfated vizantin at the concentration of 50 μM upregulated the expression of the gtfB and gtfC genes, but downregulated the expression of the gtfD gene, suggesting altered architecture in the biofilm. Biofilm development on the surface coated with sulfated vizantin was inhibited depending on the concentration, suggesting prevention from bacterial adhesion. Among eight genes related to bacterial adherence in S. mutans, expression of gtfB and gtfC was significantly upregulated, whereas the expression of gtfD, GbpA and GbpC was downregulated according to the concentration of vizantin, especially with 50 μM vizantin by 0.8-, 0.4-, and 0.4-fold, respectively. These findings suggest that sulfated vizantin may cause structural degradation as a result of changing gene regulation related to bacterial adhesion and glucan production of S. mutans. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Impervious Surfaces Alter Soil Bacterial Communities in Urban Areas: A Case Study in Beijing, China

    Directory of Open Access Journals (Sweden)

    Yinhong Hu

    2018-02-01

    Full Text Available The rapid expansion of urbanization has caused land cover change, especially the increasing area of impervious surfaces. Such alterations have significant effects on the soil ecosystem by impeding the exchange of gasses, water, and materials between soil and the atmosphere. It is unclear whether impervious surfaces have any effects on soil bacterial diversity and community composition. In the present study, we conducted an investigation of bacterial communities across five typical land cover types, including impervious surfaces (concrete, permeable pavement (bricks with round holes, shrub coverage (Buxus megistophylla Levl., lawns (Festuca elata Keng ex E. Alexeev, and roadside trees (Sophora japonica Linn. in Beijing, to explore the response of bacteria to impervious surfaces. The soil bacterial communities were addressed by high-throughput sequencing of the bacterial 16S rRNA gene. We found that Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Chloroflexi, and Firmicutes were the predominant phyla in urban soils. Soil from impervious surfaces presented a lower bacterial diversity, and differed greatly from other types of land cover. Soil bacterial diversity was predominantly affected by Zn, dissolved organic carbon (DOC, and soil moisture content (SMC. The composition of the bacterial community was similar under shrub coverage, roadside trees, and lawns, but different from beneath impervious surfaces and permeable pavement. Variance partitioning analysis showed that edaphic properties contributed to 12% of the bacterial community variation, heavy metal pollution explained 3.6% of the variation, and interaction between the two explained 33% of the variance. Together, our data indicate that impervious surfaces induced changes in bacterial community composition and decrease of bacterial diversity. Interactions between edaphic properties and heavy metals were here found to change the composition of the bacterial community and

  15. Aerobic bacterial microbiota of the conjunctiva in diabetic patients with normal and altered glycated hemoglobin levels in two regions in Brazil

    Directory of Open Access Journals (Sweden)

    Natalia Pimentel Moreno

    2014-12-01

    Full Text Available Purpose: To study the aerobic bacterial microbiota of the conjunctiva in diabetic patients with regard to the management of diabetes, assessed using glycated hemoglobin levels. Methods: A cross-sectional study was conducted using conjunctival smears of diabetic patients from both sexes and with different ages, residing in two different Brazilian cities (Sorocaba and Rio Branco. A control group of non-diabetic patients was also included. The diabetic patients were considered to have controlled diabetes when their glycated hemoglobin level was ≤7% and blood glucose level was ≤126 mg/dL. Patients with non-controlled diabetes were those with glycated hemoglobin levels >7% and blood glucose levels >126 mg/dL. The samples obtained were inoculated in Brain-Heart Infusion broth and in culture media for aerobic bacteria (blood and chocolate agars; bacterial growth was evaluated in a microbiology laboratory. Results: A total of 120 eyes of 120 patients were included in the present study. The percentage of cultures in which bacterial growth was observed was greater in diabetic patients, although the difference was not statistically significant (p=0.103. There was a greater trend toward bacterial growth in the conjunctiva of diabetic patients with altered fasting blood glucose. There was no difference in the frequency of bacterial growth on the conjunctiva between diabetic patients with normal or altered glycated hemoglobin levels. In Sorocaba, conjunctival bacterial growth was similar to that observed in Rio Branco. The microorganism most frequently detected in the present study was Staphylococcus epidermidis, followed by Staphylococcus aureus, Proteus mirabilis, and Escherichia coli. Conclusion: There was no difference between diabetic patients with normal or altered glycated hemoglobin levels. The microorganisms found were similar to those found in studies investigating the conjunctival bacterial flora of diabetic and non-diabetic patients.

  16. Evaluating the effects of variable water chemistry on bacterial transport during infiltration.

    Science.gov (United States)

    Zhang, Haibo; Nordin, Nahjan Amer; Olson, Mira S

    2013-07-01

    Bacterial infiltration through the subsurface has been studied experimentally under different conditions of interest and is dependent on a variety of physical, chemical and biological factors. However, most bacterial transport studies fail to adequately represent the complex processes occurring in natural systems. Bacteria are frequently detected in stormwater runoff, and may present risk of microbial contamination during stormwater recharge into groundwater. Mixing of stormwater runoff with groundwater during infiltration results in changes in local solution chemistry, which may lead to changes in both bacterial and collector surface properties and subsequent bacterial attachment rates. This study focuses on quantifying changes in bacterial transport behavior under variable solution chemistry, and on comparing the influences of chemical variability and physical variability on bacterial attachment rates. Bacterial attachment rate at the soil-water interface was predicted analytically using a combined rate equation, which varies temporally and spatially with respect to changes in solution chemistry. Two-phase Monte Carlo analysis was conducted and an overall input-output correlation coefficient was calculated to quantitatively describe the importance of physiochemical variation on the estimates of attachment rate. Among physical variables, soil particle size has the highest correlation coefficient, followed by porosity of the soil media, bacterial size and flow velocity. Among chemical variables, ionic strength has the highest correlation coefficient. A semi-reactive microbial transport model was developed within HP1 (HYDRUS1D-PHREEQC) and applied to column transport experiments with constant and variable solution chemistries. Bacterial attachment rates varied from 9.10×10(-3)min(-1) to 3.71×10(-3)min(-1) due to mixing of synthetic stormwater (SSW) with artificial groundwater (AGW), while bacterial attachment remained constant at 9.10×10(-3)min(-1) in a constant

  17. Attachment and entry of Chlamydia have distinct requirements for host protein disulfide isomerase.

    Directory of Open Access Journals (Sweden)

    Stephanie Abromaitis

    2009-04-01

    Full Text Available Chlamydia is an obligate intracellular pathogen that causes a wide range of diseases in humans. Attachment and entry are key processes in infectivity and subsequent pathogenesis of Chlamydia, yet the mechanisms governing these interactions are unknown. It was recently shown that a cell line, CHO6, that is resistant to attachment, and thus infectivity, of multiple Chlamydia species has a defect in protein disulfide isomerase (PDI N-terminal signal sequence processing. Ectopic expression of PDI in CHO6 cells led to restoration of Chlamydia attachment and infectivity; however, the mechanism leading to this recovery was not ascertained. To advance our understanding of the role of PDI in Chlamydia infection, we used RNA interference to establish that cellular PDI is essential for bacterial attachment to cells, making PDI the only host protein identified as necessary for attachment of multiple species of Chlamydia. Genetic complementation and PDI-specific inhibitors were used to determine that cell surface PDI enzymatic activity is required for bacterial entry into cells, but enzymatic function was not required for bacterial attachment. We further determined that it is a PDI-mediated reduction at the cell surface that triggers bacterial uptake. While PDI is necessary for Chlamydia attachment to cells, the bacteria do not appear to utilize plasma membrane-associated PDI as a receptor, suggesting that Chlamydia binds a cell surface protein that requires structural association with PDI. Our findings demonstrate that PDI has two essential and independent roles in the process of chlamydial infectivity: it is structurally required for chlamydial attachment, and the thiol-mediated oxido-reductive function of PDI is necessary for entry.

  18. Pyrosequencing analysis of free-living and attached bacterial communities in Meiliang Bay, Lake Taihu, a large eutrophic shallow lake in China.

    Science.gov (United States)

    Tang, Xiangming; Li, Linlin; Shao, Keqiang; Wang, Boweng; Cai, Xianlei; Zhang, Lei; Chao, Jianying; Gao, Guang

    2015-01-01

    To elucidate the relationship between particle-attached (PA, ≥ 5.0 μm) and free-living (FL, 0.2-5.0 μm) bacterial communities, samplings were collected seasonally from November 2011 to August 2012 in Meiliang Bay, Lake Taihu, China. We used 454 pyrosequencing of 16S rRNA genes to study bacterial diversity and structure of PA and FL communities. The analysis rendered 37,985 highly qualified reads, subsequently assigned to 1755 operational taxonomic units (97% similarity) for the 8 samples. Although 27 high-level taxonomic groups were obtained, the 3 dominant phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) comprised about 75.9% and 82.4% of the PA and FL fractions, respectively. Overall, we found no significant differences between community types, as indicated by ANOSIM R statistics (R = 0.063, P > 0.05) and the Parsimony test (P = 0.222). Dynamics of bacterial communities were correlated with changes in concentrations of total suspended solids (TSS) and total phosphorus (TP). In summer, a significant taxonomic overlap in the 2 size fractions was observed when Cyanobacteria, a major contributor of TSS and TP, dominated in the water, highlighting the potential rapid exchange between PA and FL bacterial populations in large shallow eutrophic lakes.

  19. Attachment of Salmonella strains to a plant cell wall model is modulated by surface characteristics and not by specific carbohydrate interactions.

    Science.gov (United States)

    Tan, Michelle Sze-Fan; Moore, Sean C; Tabor, Rico F; Fegan, Narelle; Rahman, Sadequr; Dykes, Gary A

    2016-09-15

    Processing of fresh produce exposes cut surfaces of plant cell walls that then become vulnerable to human foodborne pathogen attachment and contamination, particularly by Salmonella enterica. Plant cell walls are mainly composed of the polysaccharides cellulose, pectin and hemicelluloses (predominantly xyloglucan). Our previous work used bacterial cellulose-based plant cell wall models to study the interaction between Salmonella and the various plant cell wall components. We demonstrated that Salmonella attachment was favoured in the presence of pectin while xyloglucan had no effect on its attachment. Xyloglucan significantly increased the attachment of Salmonella cells to the plant cell wall model only when it was in association with pectin. In this study, we investigate whether the plant cell wall polysaccharides mediate Salmonella attachment to the bacterial cellulose-based plant cell wall models through specific carbohydrate interactions or through the effects of carbohydrates on the physical characteristics of the attachment surface. We found that none of the monosaccharides that make up the plant cell wall polysaccharides specifically inhibit Salmonella attachment to the bacterial cellulose-based plant cell wall models. Confocal laser scanning microscopy showed that Salmonella cells can penetrate and attach within the tightly arranged bacterial cellulose network. Analysis of images obtained from atomic force microscopy revealed that the bacterial cellulose-pectin-xyloglucan composite with 0.3 % (w/v) xyloglucan, previously shown to have the highest number of Salmonella cells attached to it, had significantly thicker cellulose fibrils compared to other composites. Scanning electron microscopy images also showed that the bacterial cellulose and bacterial cellulose-xyloglucan composites were more porous when compared to the other composites containing pectin. Our study found that the attachment of Salmonella cells to cut plant cell walls was not mediated by

  20. Comparison of cell-specific activity between free-living and attached bacteria using isolates and natural assemblages

    DEFF Research Database (Denmark)

    Grossart, H.P.; Tang, K.W.; Kiørboe, Thomas

    2007-01-01

    Marine snow aggregates are microbial hotspots that support high bacterial abundance and activities. We conducted laboratory experiments to compare cell-specific bacterial protein production (BPP) and protease activity between free-living and attached bacteria. Natural bacterial assemblages attached...... bacteria increasing their metabolism upon attachment to surfaces. In subsequent experiments, we used four strains of marine snow bacteria isolates to test the hypothesis that bacteria could up- and down-regulate their metabolism while on and off an aggregate. The protease activity of attached bacteria...... to model aggregates (agar spheres) had threefold higher BPP and two orders of magnitude higher protease activity than their free-living counterpart. These observations could be explained by preferential colonization of the agar spheres by bacteria with inherently higher metabolic activity and/or individual...

  1. Propulsion of liposomes using bacterial motors

    International Nuclear Information System (INIS)

    Zhang Zhenhai; Li Kejie; Li Zhifei; Yu Wei; Xie Zhihong; Shi Zhiguo

    2013-01-01

    Here we describe the utilization of flagellated bacteria as actuators to propel spherical liposomes by attaching bacteria to the liposome surface. Bacteria were stably attached to liposomes using a cross-linking antibody. The effect of the number of attached bacteria on propulsion speed was experimentally determined. The effects of bacterial propulsion on the bacteria–antibody–liposome complex were stochastic. We demonstrated that liposomal mobility increased when bacteria were attached, and the propulsion speed correlated with the number of bacteria. (paper)

  2. O antigen modulates insect vector acquisition of the bacterial plant pathogen Xylella fastidiosa.

    Science.gov (United States)

    Rapicavoli, Jeannette N; Kinsinger, Nichola; Perring, Thomas M; Backus, Elaine A; Shugart, Holly J; Walker, Sharon; Roper, M Caroline

    2015-12-01

    Hemipteran insect vectors transmit the majority of plant pathogens. Acquisition of pathogenic bacteria by these piercing/sucking insects requires intimate associations between the bacterial cells and insect surfaces. Lipopolysaccharide (LPS) is the predominant macromolecule displayed on the cell surface of Gram-negative bacteria and thus mediates bacterial interactions with the environment and potential hosts. We hypothesized that bacterial cell surface properties mediated by LPS would be important in modulating vector-pathogen interactions required for acquisition of the bacterial plant pathogen Xylella fastidiosa, the causative agent of Pierce's disease of grapevines. Utilizing a mutant that produces truncated O antigen (the terminal portion of the LPS molecule), we present results that link this LPS structural alteration to a significant decrease in the attachment of X. fastidiosa to blue-green sharpshooter foreguts. Scanning electron microscopy confirmed that this defect in initial attachment compromised subsequent biofilm formation within vector foreguts, thus impairing pathogen acquisition. We also establish a relationship between O antigen truncation and significant changes in the physiochemical properties of the cell, which in turn affect the dynamics of X. fastidiosa adhesion to the vector foregut. Lastly, we couple measurements of the physiochemical properties of the cell with hydrodynamic fluid shear rates to produce a Comsol model that predicts primary areas of bacterial colonization within blue-green sharpshooter foreguts, and we present experimental data that support the model. These results demonstrate that, in addition to reported protein adhesin-ligand interactions, O antigen is crucial for vector-pathogen interactions, specifically in the acquisition of this destructive agricultural pathogen. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. An Examination of Attachment Styles and Social Skills of University Students

    Science.gov (United States)

    Dereli, Esra; Karakus, Ozlem

    2011-01-01

    Introduction: Attachment organization across the lifespan and across generations, long-term predictions from attachment organization to later psychosocial functioning, and the possibility of altering attachment organization with intervention suggest that attachment theory may potentially shed valuable light on adult social development and deviant…

  4. Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material.

    Science.gov (United States)

    Tran, Phat; Arnett, Avery; Jarvis, Courtney; Mosley, Thomas; Tran, Khien; Hanes, Rob; Webster, Dan; Mitchell, Kelly; Dominguez, Leo; Hamood, Abdul; Reid, Ted W

    2017-09-01

    Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle. Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium-coated scleral buckles. The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells. Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture. This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

  5. Bacterial lipopolysaccharide-induced systemic inflammation alters perfusion of white matter-rich regions without altering flow in brain-irrigating arteries: Relationship to blood-brain barrier breakdown?

    Science.gov (United States)

    Dhaya, Ibtihel; Griton, Marion; Raffard, Gérard; Amri, Mohamed; Hiba, Bassem; Konsman, Jan Pieter

    2018-01-15

    To better understand brain dysfunction during sepsis, cerebral arterial blood flow was assessed with Phase Contrast Magnetic Resonance Imaging, perfusion with Arterial Spin Labeling and structure with diffusion-weighted Magnetic Resonance Imaging in rats after intraperitoneal administration of bacterial lipopolysaccharides. Although cerebral arterial flow was not altered, perfusion of the corpus callosum region and diffusion parallel to its fibers were higher after lipopolysaccharide administration as compared to saline injection. In parallel, lipopolysaccharide induced perivascular immunoglobulin-immunoreactivity in white matter. These findings indicate that systemic inflammation can result in increased perfusion, blood-brain barrier breakdown and altered water diffusion in white matter. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Effect of bovine manure on fecal coliform attachment to soil and soil particles of different sizes.

    Science.gov (United States)

    Guber, Andrey K; Pachepsky, Yakov A; Shelton, Daniel R; Yu, Olivia

    2007-05-01

    Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt fraction, and the clay fraction of loam and sandy clay loam soils were separated and used along with soil samples in batch attachment experiments with water-FC suspensions and water-manure-FC suspensions. In the absence of manure colloids, bacterial attachment to soil, silt, and clay particles was much higher than the attachment to sand particles having no organic coating. The attachment to the coated sand particles was similar to the attachment to silt and clay. Manure colloids in suspensions decreased bacterial attachment to soils, clay and silt fractions, and coated sand fractions, but did not decrease the attachment to sand fractions without the coating. The low attachment of bacteria to silt and clay particles in the presence of manure colloids may cause predominantly free-cell transport of manure-borne FC in runoff.

  7. Nano and Microscale Topographies for the Prevention of Bacterial Surface Fouling

    Directory of Open Access Journals (Sweden)

    Mary V. Graham

    2014-01-01

    Full Text Available Bacterial surface fouling is problematic for a wide range of applications and industries, including, but not limited to medical devices (implants, replacement joints, stents, pacemakers, municipal infrastructure (pipes, wastewater treatment, food production (food processing surfaces, processing equipment, and transportation (ship hulls, aircraft fuel tanks. One method to combat bacterial biofouling is to modify the topographical structure of the surface in question, thereby limiting the ability of individual cells to attach to the surface, colonize, and form biofilms. Multiple research groups have demonstrated that micro and nanoscale topographies significantly reduce bacterial biofouling, for both individual cells and bacterial biofilms. Antifouling strategies that utilize engineered topographical surface features with well-defined dimensions and shapes have demonstrated a greater degree of controllable inhibition over initial cell attachment, in comparison to undefined, texturized, or porous surfaces. This review article will explore the various approaches and techniques used by researches, including work from our own group, and the underlying physical properties of these highly structured, engineered micro/nanoscale topographies that significantly impact bacterial surface attachment.

  8. Association of Antibiotic Resistance in Agricultural Escherichia coli Isolates with Attachment to Quartz▿

    Science.gov (United States)

    Liu, Ping; Soupir, Michelle L.; Zwonitzer, Martha; Huss, Bridgette; Jarboe, Laura R.

    2011-01-01

    Surface water can be contaminated by bacteria from various sources, including manure from agricultural facilities. Attachment of these bacteria to soil and organic particles contributes to their transport through the environment, though the mechanism of attachment is unknown. As bacterial attachment to human tissues is known to be correlated with antibiotic resistance, we have investigated here the relationship between bacterial attachment to environmental particles and antibiotic resistance in agricultural isolates. We evaluated 203 Escherichia coli isolates collected from swine facilities for attachment to quartz, resistance to 13 antibiotics, and the presence of genes encoding 13 attachment factors. The genes encoding type I, EcpA, P pili, and Ag43 were detected, though none was significantly related to attachment. Quartz attachment was positively and significantly (P amoxicillin/streptomycin/tetracycline/sulfamethazine/tylosin/chlortetracycline and negatively and significantly (P < 0.0038) related to combined resistance to nalidixic acid/kanamycin/neomycin. These results provide clear evidence for a link between antibiotic resistance and attachment to quartz in agricultural isolates. We propose that this may be due to encoding by the responsible genes on a mobile genetic element. Further exploration of the relationship between antibiotic resistance and attachment to environmental particles will improve the understanding and modeling of environmental transport processes, with the goal of preventing human exposure to antibiotic-resistant or virulent microorganisms. PMID:21821756

  9. Association of antibiotic resistance in agricultural Escherichia coli isolates with attachment to quartz.

    Science.gov (United States)

    Liu, Ping; Soupir, Michelle L; Zwonitzer, Martha; Huss, Bridgette; Jarboe, Laura R

    2011-10-01

    Surface water can be contaminated by bacteria from various sources, including manure from agricultural facilities. Attachment of these bacteria to soil and organic particles contributes to their transport through the environment, though the mechanism of attachment is unknown. As bacterial attachment to human tissues is known to be correlated with antibiotic resistance, we have investigated here the relationship between bacterial attachment to environmental particles and antibiotic resistance in agricultural isolates. We evaluated 203 Escherichia coli isolates collected from swine facilities for attachment to quartz, resistance to 13 antibiotics, and the presence of genes encoding 13 attachment factors. The genes encoding type I, EcpA, P pili, and Ag43 were detected, though none was significantly related to attachment. Quartz attachment was positively and significantly (P amoxicillin/streptomycin/tetracycline/sulfamethazine/tylosin/chlortetracycline and negatively and significantly (P < 0.0038) related to combined resistance to nalidixic acid/kanamycin/neomycin. These results provide clear evidence for a link between antibiotic resistance and attachment to quartz in agricultural isolates. We propose that this may be due to encoding by the responsible genes on a mobile genetic element. Further exploration of the relationship between antibiotic resistance and attachment to environmental particles will improve the understanding and modeling of environmental transport processes, with the goal of preventing human exposure to antibiotic-resistant or virulent microorganisms.

  10. Inhibition of bacterial growth by iron oxide nanoparticles with and without attached drug: Have we conquered the antibiotic resistance problem?

    Science.gov (United States)

    Armijo, Leisha M.; Jain, Priyanka; Malagodi, Angelina; Fornelli, F. Zuly; Hayat, Allison; Rivera, Antonio C.; French, Michael; Smyth, Hugh D. C.; Osiński, Marek

    2015-03-01

    Pseudomonas aeruginosa is among the top three leading causative opportunistic human pathogens, possessing one of the largest bacterial genomes and an exceptionally large proportion of regulatory genes therein. It has been known for more than a decade that the size and complexity of the P. aeruginosa genome is responsible for the adaptability and resilience of the bacteria to include its ability to resist many disinfectants and antibiotics. We have investigated the susceptibility of P. aeruginosa bacterial biofilms to iron oxide (magnetite) nanoparticles (NPs) with and without attached drug (tobramycin). We also characterized the susceptibility of zero-valent iron NPs, which are known to inactivate microbes. The particles, having an average diameter of 16 nm were capped with natural alginate, thus doubling the hydrodynamic size. Nanoparticle-drug conjugates were produced via cross-linking drug and alginate functional groups. Drug conjugates were investigated in the interest of determining dosage, during these dosage-curve experiments, NPs unbound to drug were tested in cultures as a negative control. Surprisingly, we found that the iron oxide NPs inhibited bacterial growth, and thus, biofilm formation without the addition of antibiotic drug. The inhibitory dosages of iron oxide NPs were investigated and the minimum inhibitory concentrations are presented. These findings suggest that NP-drug conjugates may overcome the antibiotic drug resistance common in P. aeruginosa infections.

  11. Altering textural properties of fermented milk by using surface-engineered Lactococcus lactis.

    Science.gov (United States)

    Tarazanova, Mariya; Huppertz, Thom; Kok, Jan; Bachmann, Herwig

    2018-05-09

    Lactic acid bacteria are widely used for the fermentation of dairy products. While bacterial acidification rates, proteolytic activity and the production of exopolysaccharides are known to influence textural properties of fermented milk products, little is known about the role of the microbial surface on microbe-matrix interactions in dairy products. To investigate how alterations of the bacterial cell surface affect fermented milk properties, 25 isogenic Lactococcus lactis strains that differed with respect to surface charge, hydrophobicity, cell chaining, cell-clumping, attachment to milk proteins, pili expression and EPS production were used to produce fermented milk. We show that overexpression of pili increases surface hydrophobicity of various strains from 3-19% to 94-99%. A profound effect of different cell surface properties was an altered spatial distribution of the cells in the fermented product. Aggregated cells tightly fill the cavities of the protein matrix, while chaining cells seem to be localized randomly. A positive correlation was found between pili overexpression and viscosity and gel hardness of fermented milk. Gel hardness also positively correlated with clumping of cells in the fermented milk. Viscosity of fermented milk was also higher when it was produced with cells with a chaining phenotype or with cells that overexpress exopolysaccharides. Our results show that alteration of cell surface morphology affects textural parameters of fermented milk and cell localization in the product. This is indicative of a cell surface-dependent potential of bacterial cells as structure elements in fermented foods. © 2018 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  12. Influence of Natural Organic Matter on Attachment Kinetics of Salmonella Typhimurium

    Science.gov (United States)

    Chowdhury, I.; Zorlu, O.; Hill, J. E.; Walker, S. L.

    2011-12-01

    Salmonella enterica serovar Typhimurium is one of the most common and virulent bacterial pathogens, usually found in food and water. This waterborne pathogen has been attributed to causing gastroenteritis and typhoid fever, leading to 16 million cases and over half a million deaths worldwide each year. Natural organic matter (NOM) is ubiquitous in environment and previous work has shown NOM to enhance the stability and transport of bacteria cells; hence NOM will certainly interact with Salmonella and affect its transport in environment. The objective of this study was to investigate the influence of NOM (Suwannee River humic acid standard II, SRHA) on the attachment kinetics of a model Salmonella (Salmonella enterica serovar Typhimurium SA5983) to glass. The transport study was conducted in a parallel plate flow chamber using fluorescent microscope to visualize the bacterial cells, which were tagged with green fluorescent protein (GFP). The solution pH was unadjusted, and the flow rate through parallel plate channel was 0.1 mL/min to simulate groundwater conditions. Parameters varied in this study were NOM presence, ion valence (K+, Ca2+) as well as cell growth phase (mid-exponential and late-exponential growth phases). These parameters were chosen because ion valence may alter the NOM conformation and capacity for bridging, as well growth phase impacts the cellular surface chemistry. Extensive characterization of the bacterial cells was conducted including measurements of electrophoretic mobility, hydrophobicity, acidity, surface charge density and extracellular polymeric substance content. Additionally, electrokintic characterization was conducted for the glass. Preliminary results demonstrated the sensitivity of cell attachment to ionic valence and cell growth phase. Also the addition of NOM reduced the attachment of the Salmonella cells significantly under all of these conditions. Without NOM, attachment efficiencies (α) in KCl were similar at both growth

  13. Mercury alters the bacterial community structure and diversity in soil even at concentrations lower than the guideline values.

    Science.gov (United States)

    Mahbub, Khandaker Rayhan; Subashchandrabose, Suresh Ramraj; Krishnan, Kannan; Naidu, Ravi; Megharaj, Mallavarapu

    2017-03-01

    This study evaluated the effect of inorganic mercury (Hg) on bacterial community and diversity in different soils. Three soils-neutral, alkaline and acidic-were spiked with six different concentrations of Hg ranging from 0 to 200 mg kg -1 and aged for 90 days. At the end of the ageing period, 18 samples from three different soils were investigated for bacterial community structure and soil physicochemical properties. Illumina MiSeq-based 16s ribosomal RNA (rRNA) amplicon sequencing revealed the alteration in the bacterial community between un-spiked control soils and Hg-spiked soils. Among the bacterial groups, Actinobacteria (22.65%) were the most abundant phyla in all samples followed by Proteobacteria (21.95%), Bacteroidetes (4.15%), Firmicutes (2.9%) and Acidobacteria (2.04%). However, the largest group showing increased abundance with higher Hg doses was the unclassified group (45.86%), followed by Proteobacteria. Mercury had a considerable negative impact on key soil functional bacteria such as ammonium oxidizers and nitrifiers. Canonical correspondence analysis (CCA) indicated that among the measured soil properties, Hg had a major influence on bacterial community structure. Furthermore, nonlinear regression analysis confirmed that Hg significantly decreased soil bacterial alpha diversity in lower organic carbon containing neutral and alkaline soils, whereas in acidic soil with higher organic carbon there was no significant correlation. EC 20 values obtained by a nonlinear regression analysis indicated that Hg significantly decreased soil bacterial diversity in concentrations lower than several guideline values.

  14. Neural basis of attachment-caregiving systems interaction:insights from neuroimaging

    Directory of Open Access Journals (Sweden)

    Delia eLenzi

    2015-08-01

    Full Text Available The attachment and the caregiving system are complementary systems which are active simultaneously in infant and mother interactions. This ensures the infant survival and optimal social, emotional and cognitive development. In this brief review we first define the characteristics of these two behavioral systems and the theory that links them, according to what Bowlby called the attachment-caregiving social bond (Bowlby, 1969. We then follow with those neuroimaging studies that have focused on this particular issue, i.e. those which have studied the activation of the careging system in women (using infant stimuli and have explored how the individual attachment model (through the Adult Attachment Interview modulates its activity. Studies report altered activation in limbic and prefrontal areas and in basal ganglia and hypothalamus/pituitary regions. These altered activations are thought to be the neural substrate of the attachment-caregiving systems interaction.

  15. Attachment of Salmonella serovars and Listeria monocytogenes to stainless steel and plastic conveyor belts.

    Science.gov (United States)

    Veluz, G A; Pitchiah, S; Alvarado, C Z

    2012-08-01

    In poultry industry, cross-contamination due to processing equipment and contact surfaces is very common. This study examined the extent of bacterial attachment to 6 different types and design of conveyor belts: stainless steel-single loop, stainless steel-balance weave, polyurethane with mono-polyester fabric, acetal, polypropylene mesh top, and polypropylene. Clean conveyor belts were immersed separately in either a cocktail of Salmonella serovars (Salmonella Typhimurium and Salmonella Enteritidis) or Listeria monocytogenes strains (Scott A, Brie 1, ATCC 6744) for 1 h at room temperature. Soiled conveyor chips were dipped in poultry rinses contaminated with Salmonella or Listeria cocktail and incubated at 10°C for 48 h. The polyurethane with mono-polyester fabric conveyor belt and chip exhibited a higher (Pconveyor belt attached a lower (Pconveyor belts exhibited stronger bacterial adhesion compared with stainless steel. The result suggests the importance of selecting the design and finishes of conveyor belt materials that are most resistant to bacterial attachment.

  16. Role of Fimbriae, Flagella and Cellulose on the Attachment of Salmonella Typhimurium ATCC 14028 to Plant Cell Wall Models.

    Directory of Open Access Journals (Sweden)

    Michelle S F Tan

    Full Text Available Cases of foodborne disease caused by Salmonella are frequently associated with the consumption of minimally processed produce. Bacterial cell surface components are known to be important for the attachment of bacterial pathogens to fresh produce. The role of these extracellular structures in Salmonella attachment to plant cell walls has not been investigated in detail. We investigated the role of flagella, fimbriae and cellulose on the attachment of Salmonella Typhimurium ATCC 14028 and a range of isogenic deletion mutants (ΔfliC fljB, ΔbcsA, ΔcsgA, ΔcsgA bcsA and ΔcsgD to bacterial cellulose (BC-based plant cell wall models [BC-Pectin (BCP, BC-Xyloglucan (BCX and BC-Pectin-Xyloglucan (BCPX] after growth at different temperatures (28°C and 37°C. We found that all three cell surface components were produced at 28°C but only the flagella was produced at 37°C. Flagella appeared to be most important for attachment (reduction of up to 1.5 log CFU/cm2 although both cellulose and fimbriae also aided in attachment. The csgD deletion mutant, which lacks both cellulose and fimbriae, showed significantly higher attachment as compared to wild type cells at 37°C. This may be due to the increased expression of flagella-related genes which are also indirectly regulated by the csgD gene. Our study suggests that bacterial attachment to plant cell walls is a complex process involving many factors. Although flagella, cellulose and fimbriae all aid in attachment, these structures are not the only mechanism as no strain was completely defective in its attachment.

  17. Altered Bacterial Profiles in Saliva from Adults with Caries Lesions

    DEFF Research Database (Denmark)

    Belstrøm, D; Fiehn, N-E; Nielsen, C H

    2014-01-01

    -Whitney's test with Benjamini-Hochberg correction for multiple comparisons. Principal component analysis was used to visualize bacterial community profiles. A reduced bacterial diversity was observed in samples from subjects with dental caries. Five bacterial taxa (Veillonella parvula, Veillonella atypica......, Megasphaera micronuciformis, Fusobacterium periodontium and Achromobacter xylosoxidans) and one bacterial cluster (Leptotrichia sp. clones C3MKM102 and GT018_ot417/462) were less frequently found in the caries group (adjusted p value ... salivarius) and three bacterial clusters (Streptococcus parasanguinis I and II and sp. clone BE024_ot057/411/721, Streptococcus parasanguinis I and II and sinensis_ot411/721/767, Streptococcus salivarius and sp. clone FO042_ot067/755) were present at significantly higher levels (adjusted p value

  18. Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

    Energy Technology Data Exchange (ETDEWEB)

    Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu; Leone, Vanessa; Brulc, Jennifer; Mangatu, Thomas; Antonopoulos, Dionysios A.; Chang, Eugene B; Kahn, Stacy A.; Kirschner, Barbara S; Young, Glenn; DePaolo, R. William

    2016-01-13

    Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

  19. Bacterial endophytes enhance competition by invasive plants.

    Science.gov (United States)

    Rout, Marnie E; Chrzanowski, Thomas H; Westlie, Tara K; DeLuca, Thomas H; Callaway, Ragan M; Holben, William E

    2013-09-01

    Invasive plants can alter soil microbial communities and profoundly alter ecosystem processes. In the invasive grass Sorghum halepense, these disruptions are consequences of rhizome-associated bacterial endophytes. We describe the effects of N2-fixing bacterial strains from S. halepense (Rout and Chrzanowski, 2009) on plant growth and show that bacteria interact with the plant to alter soil nutrient cycles, enabling persistence of the invasive. • We assessed fluxes in soil nutrients for ∼4 yr across a site invaded by S. halepense. We assayed the N2-fixing bacteria in vitro for phosphate solubilization, iron chelation, and production of the plant-growth hormone indole-3-acetic acid (IAA). We assessed the plant's ability to recruit bacterial partners from substrates and vertically transmit endophytes to seeds and used an antibiotic approach to inhibit bacterial activity in planta and assess microbial contributions to plant growth. • We found persistent alterations to eight biogeochemical cycles (including nitrogen, phosphorus, and iron) in soils invaded by S. halepense. In this context, three bacterial isolates solubilized phosphate, and all produced iron siderophores and IAA in vitro. In growth chamber experiments, bacteria were transmitted vertically, and molecular analysis of bacterial community fingerprints from rhizomes indicated that endophytes are also horizontally recruited. Inhibiting bacterial activity with antibiotics resulted in significant declines in plant growth rate and biomass, with pronounced rhizome reductions. • This work suggests a major role of endophytes on growth and resource allocation of an invasive plant. Indeed, bacterial isolate physiology is correlated with invader effects on biogeochemical cycles of nitrogen, phosphate, and iron.

  20. The mechanics of adhesion polymers and their role in bacterial attachment

    OpenAIRE

    Zakrisson, Johan

    2015-01-01

    Bacterial resistance to antibiotics is increasing at a high rate in both developing and developed countries. To circumvent the problem of drug-resistant bacterial pathogens, we need to develop new effective methods, substances, and materials that can disarm and prevent them from causing infections. However, to do this we first need to find new possible targets in bacteria to approach and novel strategies to apply.Escherichia coli (E. coli) bacteria is a normal member of the intestinal microfl...

  1. Effects of Lectins on initial attachment of cariogenic Streptococcus mutans.

    Science.gov (United States)

    Ito, Takashi; Yoshida, Yasuhiro; Shiota, Yasuyoshi; Ito, Yuki; Yamamoto, Tadashi; Takashiba, Shogo

    2018-02-01

    Oral bacteria initiate biofilm formation by attaching to tooth surfaces via an interaction of a lectin-like bacterial protein with carbohydrate chains on the pellicle. This study aimed to find naturally derived lectins that inhibit the initial attachment of a cariogenic bacterial species, Streptococcus mutans (S. mutans), to carbohydrate chains in saliva in vitro. Seventy kinds of lectins were screened for candidate motifs that inhibit the attachment of S. mutans ATCC 25175 to a saliva-coated culture plate. The inhibitory effect of the lectins on attachment of the S. mutans to the plates was quantified by crystal violet staining, and the biofilm was observed under a scanning electron microscope (SEM). Surface plasmon resonance (SPR) analysis was performed to examine the binding of S. mutans to carbohydrate chains and the binding of candidate lectins to carbohydrate chains, respectively. Moreover, binding assay between the biotinylated-lectins and the saliva components was conducted to measure the lectin binding. Lectins recognizing a salivary carbohydrate chain, Galβ1-3GalNAc, inhibited the binding of S. mutans to the plate. In particular, Agaricus bisporus agglutinin (ABA) markedly inhibited the binding. This inhibition was confirmed by SEM observation. SPR analysis indicated that S. mutans strongly binds to Galβ1-3GalNAc, and ABA binds to Galβ1-3GalNAc. Finally, the biotinylated Galβ1-3GalNAc-binding lectins including ABA demonstrated marked binding to the saliva components. These results suggest that ABA lectin inhibited the attachment of S. mutans to Galβ1-3GalNAc in saliva and ABA can be useful as a potent inhibitor for initial attachment of oral bacteria and biofilm formation.

  2. High-grain diets altered rumen fermentation and epithelial bacterial community and resulted in rumen epithelial injuries of goats.

    Science.gov (United States)

    Zhang, Ruiyang; Ye, Huimin; Liu, Junhua; Mao, Shengyong

    2017-09-01

    This study evaluated the effects of high-grain diets on the rumen fermentation, epithelial bacterial community, morphology of rumen epithelium, and local inflammation of goats during high-grain feeding. Twelve 8-month-old goats were randomly assigned to two different diets, a hay diet or a high-grain diet (65% grain, HG). At the end of 7 weeks of treatment, samples of rumen content and rumen epithelium were collected. Rumen pH was lower (P rumen epithelial bacterial community, with an increase in the proportion of genus Prevotella and a decrease in the relative abundance of the genera Shuttleworthia and Fibrobacteres. PICRUSt analysis suggested that the HG-fed group had a higher (P rumen epithelial injury and upregulated (P rumen pH, LPS level, and rumen epithelial bacteria abundance. In conclusion, our results indicated that the alterations in the rumen environment and epithelial bacterial community which were induced by HG feeding may result in the damage and local inflammation in the rumen epithelium, warranting further study of rumen microbial-host interactions in the HG feeding model.

  3. Effects of Emotion Regulation Training on Attachment Style of Primiparous Pregnant Women with Insecure Attachment

    Directory of Open Access Journals (Sweden)

    Tayebeh Reyhani

    2016-04-01

    Full Text Available Background: Pregnant women with insecure attachment style are at high risk of psychiatric disorders. Since emotions are the first coordinators of attachment behavior, emotion regulation training can alter maternal attachment style. In this study, we aimed to evaluate the effects of emotion regulation training on the attachment styles of primiparous pregnant women with insecure attachment style. Aim: This study aimed to evaluate the effects of training programs on the headache of patients after spinal anesthesia. Method: This randomized, clinical trial on 40 primiparous pregnant women with age range of 30-34 years, who were referred to healthcare centers of Mashhad, Iran, during 2014. The data collection instrument was Revised Adult Attachment Scale (RAAS. The participants were assigned to intervention and control groups. A training program was implemented on emotion regulation based on dialectical behavior therapy (DBT for the intervention group. After delivery, RAAS was completed by the mothers again. The control group only received the routine care. To analyze the data, Chi-square and independent t-test were run using SPSS, version 15. Results: Mean ages of the mothers in the intervention and control groups were 26.9±4.04 and 27.5±3.5 years, respectively. According to the results of independent t-test, the difference between the groups was non-significant (P=0.77. The groups were analogous in terms of attachment style pre-intervention. After the intervention, independent t-test did not reflect any significant differences between the groups regarding avoidant (P=0.37 and anxious (P=0.11 attachment styles. However, mean score for secure attachment style was significantly enhanced (P=0.01. Implications for Practice: Our findings revealed that implementation of emotion regulation training increased secure attachment scores. Thus, implementing emotion regulation training program is recommended as part of a program for pre-natal care in healthcare

  4. Root bacterial endophytes alter plant phenotype, but not physiology

    DEFF Research Database (Denmark)

    Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.

    2016-01-01

    (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...... growth rate up to 137% relative to non-inoculated control plants, evidence that plants respond to bacteria by modifying morphology. However, endophyte inoculation had no influence on total plant biomass and photosynthetic traits (net photosynthesis, chlorophyll content). In sum, bacterial inoculation did......Plant traits, such as root and leaf area, influence how plants interact with their environment and the diverse microbiota living within plants can influence plant morphology and physiology. Here, we explored how three bacterial strains isolated from the Populus root microbiome, influenced plant...

  5. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy

    DEFF Research Database (Denmark)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H

    2017-01-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analy...

  6. Non-invasive vibrational SFG spectroscopy reveals that bacterial adhesion can alter the conformation of grafted "brush" chains on SAM.

    Science.gov (United States)

    Bulard, Emilie; Guo, Ziang; Zheng, Wanquan; Dubost, Henri; Fontaine-Aupart, Marie-Pierre; Bellon-Fontaine, Marie-Noëlle; Herry, Jean-Marie; Briandet, Romain; Bourguignon, Bernard

    2011-04-19

    Understanding bacterial adhesion on a surface is a crucial step to design new materials with improved properties or to control biofilm formation and eradication. Sum Frequency Generation (SFG) vibrational spectroscopy has been employed to study in situ the conformational response of a self-assembled monolayer (SAM) of octadecanethiol (ODT) on a gold film to the adhesion of hydrophilic and hydrophobic ovococcoid model bacteria. The present work highlights vibrational SFG spectroscopy as a powerful and unique non-invasive biophysical technique to probe and control bacteria interaction with ordered surfaces. Indeed, the SFG vibrational spectral changes reveal different ODT SAM conformations in air and upon exposure to aqueous solution or bacterial adhesion. Furthermore, this effect depends on the bacterial cell surface properties. The SFG spectral modeling demonstrates that hydrophobic bacteria flatten the ODT SAM alkyl chain terminal part, whereas the hydrophilic ones raise this ODT SAM terminal part. Microorganism-induced alteration of grafted chains can thus affect the desired interfacial functionality, a result that should be considered for the design of new reactive materials. © 2011 American Chemical Society

  7. Bacterial pathogen manipulation of host membrane trafficking.

    Science.gov (United States)

    Asrat, Seblewongel; de Jesús, Dennise A; Hempstead, Andrew D; Ramabhadran, Vinay; Isberg, Ralph R

    2014-01-01

    Pathogens use a vast number of strategies to alter host membrane dynamics. Targeting the host membrane machinery is important for the survival and pathogenesis of several extracellular, vacuolar, and cytosolic bacteria. Membrane manipulation promotes bacterial replication while suppressing host responses, allowing the bacterium to thrive in a hostile environment. This review provides a comprehensive summary of various strategies used by both extracellular and intracellular bacteria to hijack host membrane trafficking machinery. We start with mechanisms used by bacteria to alter the plasma membrane, delve into the hijacking of various vesicle trafficking pathways, and conclude by summarizing bacterial adaptation to host immune responses. Understanding bacterial manipulation of host membrane trafficking provides insights into bacterial pathogenesis and uncovers the molecular mechanisms behind various processes within a eukaryotic cell.

  8. Exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring.

    Directory of Open Access Journals (Sweden)

    Bas ter Braak

    Full Text Available Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-competent hemocytes. One possibility is that immune priming with microbial elicitors could stimulate immune protection against subsequent bacterial infections, as has been observed in several other insect systems. To address this hypothesis we challenged aphids with bacterial immune elicitors twenty-four hours prior to live bacterial pathogen infections and then compared their survival rates to aphids that were not pre-exposed to bacterial signals. Using two aphid genotypes, we found no evidence for immune protection conferred by immune priming during infections with either Serratia marcescens or with Escherichia coli. Immune priming was not altered by the presence of facultative, beneficial symbionts in the aphids. In the absence of inducible immune protection, aphids may allocate energy towards other defense traits, including production of offspring with wings that could escape deteriorating conditions. To test this, we monitored the ratio of winged to unwinged offspring produced by adult mothers of a single clone that had been exposed to bacterial immune elicitors, to live E. coli infections or to no challenge. We found no correlation between immune challenge and winged offspring production, suggesting that this mechanism of defense, which functions upon exposure to fungal pathogens, is not central to aphid responses to bacterial infections.

  9. Effect of Extracellular Polymeric Substances on Surface Properties and Attachment Behavior of Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Qian Li

    2016-09-01

    Full Text Available Bacterial contact leaching of ores is more effective than non-contact leaching. Adhesion is the first step for leaching bacteria to form a biofilm on a mineral surface. Extracellular polymeric substances (EPS are pivotal for mediating bacterial adhesion to a substratum. In order to clarify the role of EPS, we measured the adhesion forces between chalcopyrite-, sulfur- or FeSO4·7H2O-grown cells of Acidithiobacillus ferrooxidans and chalcopyrite by an atomic force microscope (AFM before and after EPS removal. Surface properties of these cells were assessed by measurements of the contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR and acid-base titration. Bacterial attachment to chalcopyrite was monitored for 140 min. The results indicate that the EPS control the surface properties of the cells. In addition, the surface properties are decisive for adhesion. The adhesion forces and the amounts of attached cells decreased dramatically after removing EPS, which was not dependent on the preculture.

  10. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina Lundgaard; Login, Frédéric H.; Jensen, Helene Halkjær

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacteria...

  11. Native arbuscular mycorrhizal symbiosis alters foliar bacterial community composition.

    Science.gov (United States)

    Poosakkannu, Anbu; Nissinen, Riitta; Kytöviita, Minna-Maarit

    2017-11-01

    The effects of arbuscular mycorrhizal (AM) fungi on plant-associated microbes are poorly known. We tested the hypothesis that colonization by an AM fungus affects microbial species richness and microbial community composition of host plant tissues. We grew the grass, Deschampsia flexuosa in a greenhouse with or without the native AM fungus, Claroideoglomus etunicatum. We divided clonally produced tillers into two parts: one inoculated with AM fungus spores and one without AM fungus inoculation (non-mycorrhizal, NM). We characterized bacterial (16S rRNA gene) and fungal communities (internal transcribed spacer region) in surface-sterilized leaf and root plant compartments. AM fungus inoculation did not affect microbial species richness or diversity indices in leaves or roots, but the AM fungus inoculation significantly affected bacterial community composition in leaves. A total of three OTUs in leaves belonging to the phylum Firmicutes positively responded to the presence of the AM fungus in roots. Another six OTUs belonging to the Proteobacteria (Alpha, Beta, and Gamma) and Bacteroidetes were significantly more abundant in NM plants when compared to AM fungus-inoculated plants. Further, there was a significant correlation between plant dry weight and leaf microbial community compositional shift. Also, there was a significant correlation between leaf bacterial community compositional shift and foliar nitrogen content changes due to AM fungus inoculation. The results suggest that AM fungus colonization in roots has a profound effect on plant physiology that is reflected in leaf bacterial community composition.

  12. Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition†

    Science.gov (United States)

    Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

    2010-01-01

    We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A + PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems. PMID:19707620

  13. Alteration of chromophoric dissolved organic matter by solar UV radiation causes rapid changes in bacterial community composition.

    Science.gov (United States)

    Piccini, Claudia; Conde, Daniel; Pernthaler, Jakob; Sommaruga, Ruben

    2009-09-01

    We evaluated the effect of photochemical alterations of chromophoric dissolved organic matter (CDOM) on bacterial abundance, activity and community composition in a coastal lagoon of the Atlantic Ocean with high dissolved organic carbon concentration. On two occasions during the austral summer, bacteria-free water of the lagoon was exposed to different regions of the solar spectrum (full solar radiation, UV-A+PAR, PAR) or kept in the dark. Subsequently, dilution cultures were established with bacterioplankton from the lagoon that were incubated in the pre-exposed water for 5 h in the dark. Cell abundance, activity, and community composition of bacterioplankton were assessed before and after incubation in the different treatments. Changes in absorption, fluorescence, and DOC concentration were used as proxies for CDOM photoalteration. We found a significant CDOM photobleaching signal, DOC loss, as well as a stimulation of bacterial activity in the treatments pre-exposed to UV radiation, suggesting increased bioavailability of DOM. Bacterial community analysis by fluorescence in situ hybridization revealed that this stimulation was mainly accompanied by the specific enrichment of Alpha- and Betaproteobacteria. Thus, our results suggest that CDOM photoalteration not only stimulates bacterioplankton growth, but also induces rapid changes in bacterioplankton composition, which can be of relevance for ecosystem functioning, particularly considering present and future changes in the input of terrestrial CDOM to aquatic systems.

  14. Modification and Assembly of a Versatile Lactonase for Bacterial Quorum Quenching

    Directory of Open Access Journals (Sweden)

    Melissa K. Rhoads

    2018-02-01

    Full Text Available This work sets out to provide a self-assembled biopolymer capsule activated with a multi-functional enzyme for localized delivery. This enzyme, SsoPox, which is a lactonase and phosphotriesterase, provides a means of interrupting bacterial communication pathways that have been shown to mediate pathogenicity. Here we demonstrate the capability to express, purify and attach SsoPox to the natural biopolymer chitosan, preserving its activity to “neutralize” long-chain autoinducer-1 (AI-1 communication molecules. Attachment is shown via non-specific binding and by engineering tyrosine and glutamine affinity ‘tags’ at the C-terminus for covalent linkage. Subsequent degradation of AI-1, in this case N-(3-oxododecanoyl-l-homoserine lactone (OdDHL, serves to “quench” bacterial quorum sensing (QS, silencing intraspecies communication. By attaching enzymes to pH-responsive chitosan that, in turn, can be assembled into various forms, we demonstrate device-based flexibility for enzyme delivery. Specifically, we have assembled quorum-quenching capsules consisting of an alginate inner core and an enzyme “decorated” chitosan shell that are shown to preclude bacterial QS crosstalk, minimizing QS mediated behaviors.

  15. Electrochemical characterization of the bacterial cell surface

    NARCIS (Netherlands)

    Wal, van der A.

    1996-01-01


    Bacterial cells are ubiquitous in natural environments and also play important roles in domestic and industrial processes. They are found either suspended in the aqueous phase or attached to solid particles. The adhesion behaviour of bacteria is influenced by the physico-chemical

  16. Helicobacter bilis Infection Alters Mucosal Bacteria and Modulates Colitis Development in Defined Microbiota Mice.

    Science.gov (United States)

    Atherly, Todd; Mosher, Curtis; Wang, Chong; Hostetter, Jesse; Proctor, Alexandra; Brand, Meghan W; Phillips, Gregory J; Wannemuehler, Michael; Jergens, Albert E

    2016-11-01

    Helicobacter bilis infection of C3H/HeN mice harboring the altered Schaedler flora (ASF) triggers progressive immune responsiveness and the development of colitis. We sought to investigate temporal alterations in community structure of a defined (ASF-colonized) microbiota in normal and inflamed murine intestines and to correlate microbiota changes to histopathologic lesions. The colonic mucosal microbiota of healthy mice and ASF mice colonized with H. bilis for 3, 6, or 12 weeks were investigated by fluorescence in situ hybridization targeting the 16S ribosomal RNA genes of total bacteria, group-specific organisms, and individual ASF bacterial species. Microbial profiling of ASF and H. bilis abundance was performed on cecal contents. Helicobacter bilis-colonized mice developed colitis associated with temporal changes in composition and spatial distribution of the mucosal microbiota. The number of total bacteria, ASF519, and helicobacter-positive bacteria were increased (P attachment, or by invasion, and this interaction is differentially expressed over time.

  17. God attachment, mother attachment, and father attachment in early and middle adolescence.

    Science.gov (United States)

    Sim, Tick Ngee; Yow, Amanda Shixian

    2011-06-01

    The present study examined the interplay of attachment to God, attachment to mother, and attachment to father with respect to adjustment (hope, self-esteem, depression) for 130 early and 106 middle adolescents in Singapore. Results showed that the parental attachments were generally linked (in expected directions) to adjustment. God attachment, however, had unique results. At the bivariate level, God attachment was only linked to early adolescents' self-esteem. When considered together with parental attachments (including interactions), God attachment did not emerge as the key moderator in attachment interactions and yielded some unexpected results (e.g., being positively linked to depression). These results are discussed viz-a-viz the secure base and safe haven functions that God and parental attachments may play during adolescence.

  18. Molecular Characterisation and Co-cultivation of Bacterial Biofilm Communities Associated with the Mat-Forming Diatom Didymosphenia geminata.

    Science.gov (United States)

    Brandes, Josephin; Kuhajek, Jeanne M; Goodwin, Eric; Wood, Susanna A

    2016-10-01

    Didymosphenia geminata (Lyngbye) M. Schmidt is a stalked freshwater diatom that is expanding its range globally. In some rivers, D. geminata forms thick and expansive polysaccharide-dominated mats. Like other stalked diatoms, D. geminata cells attach to the substratum with a pad of adhesive extracellular polymeric substance. Research on D. geminata and other diatoms suggests that bacterial biofilm composition may contribute to successful attachment. The aim of this study was to investigate the composition and role of bacterial biofilm communities in D. geminata attachment and survival. Bacterial biofilms were collected at four sites in the main stem of a river (containing D. geminata) and in four tributaries (free of D. geminata). Samples were characterised using automated rRNA intergenic spacer analysis and high-throughput sequencing (HTS). Mat-associated bacteria were isolated and their effect on the early establishment of D. geminata cells assessed using co-culturing experiments. ARISA and HTS data showed differences in bacterial communities between samples with and without D. geminata at two of the four sites. Samples with D. geminata had a higher relative abundance of Sphingobacteria (p geminata reduced survival (p geminata. Attachment was enhanced by Micrococcus sp. and Pseudomonas sp. (p geminata, and may partly explain observed distribution patterns.

  19. The bacterial communities of Drosophila suzukii collected from undamaged cherries

    Directory of Open Access Journals (Sweden)

    James Angus Chandler

    2014-07-01

    Full Text Available Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila.

  20. Significant relationship between soil bacterial community structure and incidence of bacterial wilt disease under continuous cropping system.

    Science.gov (United States)

    She, Siyuan; Niu, Jiaojiao; Zhang, Chao; Xiao, Yunhua; Chen, Wu; Dai, Linjian; Liu, Xueduan; Yin, Huaqun

    2017-03-01

    Soil bacteria are very important in biogeochemical cycles and play significant role in soil-borne disease suppression. Although continuous cropping is responsible for soil-borne disease enrichment, its effect on tobacco plant health and how soil bacterial communities change are yet to be elucidated. In this study, soil bacterial communities across tobacco continuous cropping time-series fields were investigated through high-throughput sequencing of 16S ribosomal RNA genes. The results showed that long-term continuous cropping could significantly alter soil microbial communities. Bacterial diversity indices and evenness indices decreased over the monoculture span and obvious variations for community structures across the three time-scale tobacco fields were detected. Compared with the first year, the abundances of Arthrobacter and Lysobacter showed a significant decrease. Besides, the abundance of the pathogen Ralstonia spp. accumulated over the monoculture span and was significantly correlated with tobacco bacterial wilt disease rate. Moreover, Pearson's correlation demonstrated that the abundance of Arthrobacter and Lysobacter, which are considered to be beneficial bacteria had significant negative correlation with tobacco bacterial wilt disease. Therefore, after long-term continuous cropping, tobacco bacterial wilt disease could be ascribed to the alteration of the composition as well as the structure of the soil microbial community.

  1. Nature, Nurture, and Attachment: Implications in Light of Expanding Definitions of Parenthood.

    Science.gov (United States)

    Junewicz, Alexandra; Billick, Stephen Bates

    2018-01-02

    Recent expansion of the legal definition of parenthood in New York State raises the question of whether the presence of a genetic relationship between a parent and child trumps environmental and interpersonal factors in the formation of a strong, secure attachment bond. The purpose of this paper is to emphasize that attachment between a child and secure attachment figure is inherently biological, and that such biological attachment supersedes the existence of a genetic parent-child relationship. First, the paper provides an overview of attachment and its biological basis. It then discusses the impact on attachment of environmental and interpersonal influences, which current research suggests have the power to alter brain biology. There is no clear evidence that a genetic relationship confers a significant advantage in terms of attachment. This paper proposes that the term "biological parent" be redefined to include anyone with whom a child shares a strong attachment bond.

  2. Chicken Juice Enhances Surface Attachment and Biofilm Formation of Campylobacter jejuni

    Science.gov (United States)

    Brown, Helen L.; Reuter, Mark; Salt, Louise J.; Cross, Kathryn L.; Betts, Roy P.

    2014-01-01

    The bacterial pathogen Campylobacter jejuni is primarily transmitted via the consumption of contaminated foodstuffs, especially poultry meat. In food processing environments, C. jejuni is required to survive a multitude of stresses and requires the use of specific survival mechanisms, such as biofilms. An initial step in biofilm formation is bacterial attachment to a surface. Here, we investigated the effects of a chicken meat exudate (chicken juice) on C. jejuni surface attachment and biofilm formation. Supplementation of brucella broth with ≥5% chicken juice resulted in increased biofilm formation on glass, polystyrene, and stainless steel surfaces with four C. jejuni isolates and one C. coli isolate in both microaerobic and aerobic conditions. When incubated with chicken juice, C. jejuni was both able to grow and form biofilms in static cultures in aerobic conditions. Electron microscopy showed that C. jejuni cells were associated with chicken juice particulates attached to the abiotic surface rather than the surface itself. This suggests that chicken juice contributes to C. jejuni biofilm formation by covering and conditioning the abiotic surface and is a source of nutrients. Chicken juice was able to complement the reduction in biofilm formation of an aflagellated mutant of C. jejuni, indicating that chicken juice may support food chain transmission of isolates with lowered motility. We provide here a useful model for studying the interaction of C. jejuni biofilms in food chain-relevant conditions and also show a possible mechanism for C. jejuni cell attachment and biofilm initiation on abiotic surfaces within the food chain. PMID:25192991

  3. Abundance of bacterial and diatom fouling on various surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi

    Abundance of bacterial and diatom fouling on aluminium, fibreglass and stainless steel were studied from Dona Paula waters of the Zuari Estuary. Both these forms were reversibly attached in large numbers to surfaces during the initial 24 hr...

  4. Pseudomonas aeruginosa cells attached to a surface display a typical proteome early as 20 minutes of incubation.

    Directory of Open Access Journals (Sweden)

    Marc Crouzet

    Full Text Available Biofilms are present in all environments and often result in negative effects due to properties of the biofilm lifestyle and especially antibiotics resistance. Biofilms are associated with chronic infections. Controlling bacterial attachment, the first step of biofilm formation, is crucial for fighting against biofilm and subsequently preventing the persistence of infection. Thus deciphering the underlying molecular mechanisms involved in attachment could allow discovering molecular targets from it would be possible to develop inhibitors against bacterial colonization and potentiate antibiotherapy. To identify the key components and pathways that aid the opportunistic pathogen Pseudomonas aeruginosa in attachment we performed for the first time a proteomic analysis as early as after 20 minutes of incubation using glass wool fibers as a surface. We compared the protein contents of the attached and unattached bacteria. Using mass spectrometry, 3043 proteins were identified. Our results showed that, as of 20 minutes of incubation, using stringent quantification criteria 616 proteins presented a modification of their abundance in the attached cells compared to their unattached counterparts. The attached cells presented an overall reduced gene expression and characteristics of slow-growing cells. The over-accumulation of outer membrane proteins, periplasmic folding proteins and O-antigen chain length regulators was also observed, indicating a profound modification of the cell envelope. Consistently the sigma factor AlgU required for cell envelope homeostasis was highly over-accumulated in attached cells. In addition our data suggested a role of alarmone (pppGpp and polyphosphate during the early attachment phase. Furthermore, almost 150 proteins of unknown function were differentially accumulated in the attached cells. Our proteomic analysis revealed the existence of distinctive biological features in attached cells as early as 20 minutes of

  5. Antimicrobial peptide coatings for hydroxyapatite:Electrostatic and covalent attachment of antimicrobial peptides to surfaces

    OpenAIRE

    Townsend, Leigh; Williams, Richard L.; Anuforom, Olachi; Berwick, Matthew R.; Halstead, Fenella; Hughes, Erik; Stamboulis, Artemis; Oppenheim, Beryl; Gough, Julie; Grover, Liam; Scott, Robert A H; Webber, Mark; Peacock, Anna F A; Belli, Antonio; Logan, Ann

    2017-01-01

    The interface between implanted devices and their host tissue is complex and is often optimized for maximal integration and cell adhesion. However, this also gives a surface suitable for bacterial colonization. We have developed a novel method of modifying the surface at the material-tissue interface with an antimicrobial peptide (AMP) coating to allowcell attachment while inhibiting bacterial colonization. The technology reported here is a dual AMP coating. The dual coating consists ofAMPs c...

  6. Recombinant bacterial hemoglobin alters metabolism of Aspergillus niger

    DEFF Research Database (Denmark)

    Hofmann, Gerald; Diano, Audrey; Nielsen, Jens

    2009-01-01

    , the fungus will produce various by-products like organic acids and polyols. In order to circumvent this problem we here study the effects of the expression of a bacterial hemoglobin protein on the metabolism of A. niger. We integrated the vgb gene from Vitreoscilla sp. into the genome at the pyrA locus...

  7. A short-time scale colloidal system reveals early bacterial adhesion dynamics.

    Directory of Open Access Journals (Sweden)

    Christophe Beloin

    2008-07-01

    Full Text Available The development of bacteria on abiotic surfaces has important public health and sanitary consequences. However, despite several decades of study of bacterial adhesion to inert surfaces, the biophysical mechanisms governing this process remain poorly understood, due, in particular, to the lack of methodologies covering the appropriate time scale. Using micrometric colloidal surface particles and flow cytometry analysis, we developed a rapid multiparametric approach to studying early events in adhesion of the bacterium Escherichia coli. This approach simultaneously describes the kinetics and amplitude of early steps in adhesion, changes in physicochemical surface properties within the first few seconds of adhesion, and the self-association state of attached and free-floating cells. Examination of the role of three well-characterized E. coli surface adhesion factors upon attachment to colloidal surfaces--curli fimbriae, F-conjugative pilus, and Ag43 adhesin--showed clear-cut differences in the very initial phases of surface colonization for cell-bearing surface structures, all known to promote biofilm development. Our multiparametric analysis revealed a correlation in the adhesion phase with cell-to-cell aggregation properties and demonstrated that this phenomenon amplified surface colonization once initial cell-surface attachment was achieved. Monitoring of real-time physico-chemical particle surface properties showed that surface-active molecules of bacterial origin quickly modified surface properties, providing new insight into the intricate relations connecting abiotic surface physicochemical properties and bacterial adhesion. Hence, the biophysical analytical method described here provides a new and relevant approach to quantitatively and kinetically investigating bacterial adhesion and biofilm development.

  8. Mathematical Modelling of Bacterial Populations in Bio-remediation Processes

    Science.gov (United States)

    Vasiliadou, Ioanna A.; Vayenas, Dimitris V.; Chrysikopoulos, Constantinos V.

    2011-09-01

    An understanding of bacterial behaviour concerns many field applications, such as the enhancement of water, wastewater and subsurface bio-remediation, the prevention of environmental pollution and the protection of human health. Numerous microorganisms have been identified to be able to degrade chemical pollutants, thus, a variety of bacteria are known that can be used in bio-remediation processes. In this study the development of mathematical models capable of describing bacterial behaviour considered in bio-augmentation plans, such as bacterial growth, consumption of nutrients, removal of pollutants, bacterial transport and attachment in porous media, is presented. The mathematical models may be used as a guide in designing and assessing the conditions under which areas contaminated with pollutants can be better remediated.

  9. Diazotrophic Bacterial Community of Degraded Pastures

    Directory of Open Access Journals (Sweden)

    João Tiago Correia Oliveira

    2017-01-01

    Full Text Available Pasture degradation can cause changes in diazotrophic bacterial communities. Thus, this study aimed to evaluate the culturable and total diazotrophic bacterial community, associated with regions of the rhizosphere and roots of Brachiaria decumbens Stapf. pastures in different stages of degradation. Samples of roots and rhizospheric soil were collected from slightly, partially, and highly degraded pastures. McCrady’s table was used to obtain the Most Probable Number (MPN of bacteria per gram of sample, in order to determine population density and calculate the Shannon-Weaver diversity index. The diversity of total diazotrophic bacterial community was determined by the technique of Denaturing Gradient Gel Electrophoresis (DGGE of the nifH gene, while the diversity of the culturable diazotrophic bacteria was determined by the Polymerase Chain Reaction (BOX-PCR technique. The increase in the degradation stage of the B. decumbens Stapf. pasture did not reduce the population density of the cultivated diazotrophic bacterial community, suggesting that the degradation at any degree of severity was highly harmful to the bacteria. The structure of the total diazotrophic bacterial community associated with B. decumbens Stapf. was altered by the pasture degradation stage, suggesting a high adaptive capacity of the bacteria to altered environments.

  10. Bacterial Cell Surface Damage Due to Centrifugal Compaction

    NARCIS (Netherlands)

    Peterson, Brandon W.; Sharma, Prashant K.; van der Mei, Henny C.; Busscher, Henk J.

    Centrifugal damage has been known to alter bacterial cell surface properties and interior structures, including DNA. Very few studies exist on bacterial damage caused by centrifugation because of the difficulty in relating centrifugation speed and container geometry to the damage caused. Here, we

  11. Enhanced bioleaching on attachment of indigenous acidophilic bacteria to pyrite surface

    Science.gov (United States)

    Wi, D. W.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

    2012-04-01

    In recent years, bioleaching has been widely applied on an industrial scale due to the advantages of low cost and environment friendliness. The direct contact mechanism of bioleaching assumes the action of a metal sulfide-attached cell oxidizing the mineral by an enzyme system with oxygen to sulfate and metal cations. Fundamental surface properties of sulfide particles and leaching-bacteria in bioleaching play the key role in the efficiency of this process. The aim of this work is to investigate of direct contact bioleaching mechanism on pyrite through attachment properties between indigenous acidophilic bacteria and pyrite surfaces. The bacteria were obtained from sulfur hot springs, Hatchobaru thermal electricity plant in Japan. And pyrite was collected from mine waste from Gwang-yang abandoned gold mines, Korea. In XRD analyses of the pyrite, x-ray diffracted d-value belong to pyrite was observed. The indigenous acidophilic bacteria grew well in a solution and over the course of incubation pH decreased and Eh increased. In relation to a bacterial growth-curve, the lag phase was hardly shown while the exponential phase was very fast. Bioleaching experiment result was showed that twenty days after the indigenous acidophilic bacteria were inoculated to a pyrite-leaching medium, the bacterial sample had a greater concentration of Fe and Zn than within the control sample. In SEM-EDS analyses, rod-shaped bacteria and round-shaped microbes were well attached to the surface of pyrite. The size of the rod-shaped bacteria ranged from 1.05~1.10 ? to 4.01~5.38 ?. Round-shaped microbes were more than 3.0 ? in diameter. Paired cells of rod-shaped bacteria were attached to the surface of pyrite linearly.

  12. Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

    Directory of Open Access Journals (Sweden)

    Ing-Marie Jonsson

    2010-12-01

    Full Text Available Ecs is an ATP-binding cassette (ABC transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s transported by Ecs is (are still unknown.In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine.Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

  13. Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

    Science.gov (United States)

    Jonsson, Ing-Marie; Juuti, Jarmo T; François, Patrice; AlMajidi, Rana; Pietiäinen, Milla; Girard, Myriam; Lindholm, Catharina; Saller, Manfred J; Driessen, Arnold J M; Kuusela, Pentti; Bokarewa, Maria; Schrenzel, Jacques; Kontinen, Vesa P

    2010-12-02

    Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown. In this study we mutated the ecsAB operon in two Staphylococcus aureus strains, Newman and LS-1. Phenotypic and functional characterization of these Ecs deficient mutants revealed a defect in growth, increased autolysis and lysostaphin sensitivity, altered composition of cell wall proteins including the precursor form of staphylokinase and an altered bacterial surface texture. DNA microarray analysis indicated that the Ecs deficiency changed expression of the virulence factor regulator protein Rot accompanied by differential expression of membrane transport proteins, particularly ABC transporters and phosphate-specific transport systems, protein A, adhesins and capsular polysaccharide biosynthesis proteins. Virulence of the ecs mutants was studied in a mouse model of hematogenous S. aureus infection. Mice inoculated with the ecs mutant strains developed markedly milder infections than those inoculated with the wild-type strains and had consequently lower mortality, less weight loss, milder arthritis and decreased persistence of staphylococci in the kidneys. The ecs mutants had higher susceptibility to ribosomal antibiotics and plant alkaloids chelerythrine and sanguinarine. Our results show that Ecs is essential for staphylococcal virulence and antimicrobial resistance probably since the transport function of Ecs is essential for the normal structure and function of the cell wall. Thus targeting Ecs may be a new approach in combating staphylococcal infection.

  14. Influence of Root Exudates and Soil on Attachment of Pasteuria penetrans to Meloidogyne arenaria.

    Science.gov (United States)

    Liu, Chang; Timper, Patricia; Ji, Pingsheng; Mekete, Tesfamariam; Joseph, Soumi

    2017-09-01

    The bacterium Pasteuria penetrans is a parasite of root-knot nematodes ( Meloidogyne spp.). Endospores of P. penetrans attach to the cuticle of second-stage juveniles (J2) and subsequently sterilize infected females. When encumbered by large numbers of spores, juveniles are less mobile and their ability to infect roots is reduced. This study looked at different factors that influence spore attachment of P. penetrans to the root-knot nematode Meloidogyne arenaria . Pretreatment of J2 with root exudates of eggplant ( Solanum melongena cv. Black beauty) reduced spore attachment compared with pretreatment with phosphate-buffered saline (PBS), suggesting that the nematode surface coat was altered or the spore recognition domains on the nematode surface were blocked. Spore attachment was equally reduced following exposure to root exudates from both host and nonhost plants for M. arenaria , indicating a common signal that affects spore attachment. Although phytohormones have been shown to influence the lipophilicity of the nematode surface coat, auxins and kinetins did not affect spore attachment compared with PBS. Root exudates reduced spore attachment more in sterilized soil than in natural soil. Sterilization may have eliminated microbes that consume root exudates, or altered the chemical components of the soil solution or root exudates. Root exudates caused a greater decrease in spore attachment in loamy sand than in a sandy loam soil. The sandy loam had higher clay content than the loamy sand, which may have resulted in more adsorption of compounds in the root exudates that affect spore attachment. The components of the root exudates could have also been modified by soil type. The results of this study demonstrate that root exudates can decrease the attachment of P. penetrans endospores to root-knot nematodes, indicating that when these nematodes enter the root zone their susceptibility to spore attachment may decrease.

  15. Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow

    DEFF Research Database (Denmark)

    Kristensen, M F; Zeng, G; Neu, T R

    2017-01-01

    caries or medical device-related infections. It further investigated if OPN's effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN......The bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental......, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN's effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion...

  16. Alien vs. predator: bacterial challenge alters coral microbiomes unless controlled by Halobacteriovorax predators

    Directory of Open Access Journals (Sweden)

    Rory M. Welsh

    2017-05-01

    consuming foreign or “alien” gram negative bacteria. Halobacteriovorax inoculation also altered the microbiome but to a lesser degree than V. coralliilyticus, and Halobacteriovorax were never detected after inoculation. Simultaneous challenge with both V. coralliilyticus and predatory Halobacteriovorax eliminated the increase in V. coralliilyticus, ameliorated changes to the rest of the coral microbiome, and prevented the secondary blooms of opportunistic Rhodobacterales and Cytophagales seen in the V. coralliilyticus challenge. These data suggest that, under certain circumstances, host-associated bacterial predators may mitigate the ability of other bacteria to destabilize the microbiome.

  17. Soil bacterial community and functional shifts in response to altered snowpack in moist acidic tundra of northern Alaska

    Science.gov (United States)

    Ricketts, Michael P.; Poretsky, Rachel S.; Welker, Jeffrey M.; Gonzalez-Meler, Miquel A.

    2016-09-01

    functional potential was inferred using ancestral state reconstruction to approximate functional gene abundance, revealing a decreased abundance of genes required for soil organic matter (SOM) decomposition in the organic layers of the deep snow accumulation zones. These results suggest that predicted climate change scenarios may result in altered soil bacterial community structure and function, and indicate a reduction in decomposition potential, alleviated temperature limitations on extracellular enzymatic efficiency, or both. The fate of stored C in Arctic soils ultimately depends on the balance between these mechanisms.

  18. Biofilm attachment reduction on bioinspired, dynamic, micro-wrinkling surfaces

    International Nuclear Information System (INIS)

    Epstein, Alexander K; Hong, Donggyoon; Kim, Philseok; Aizenberg, Joanna

    2013-01-01

    Most bacteria live in multicellular communities known as biofilms that are adherent to surfaces in our environment, from sea beds to plumbing systems. Biofilms are often associated with clinical infections, nosocomial deaths and industrial damage such as bio-corrosion and clogging of pipes. As mature biofilms are extremely challenging to eradicate once formed, prevention is advantageous over treatment. However, conventional surface chemistry strategies are either generally transient, due to chemical masking, or toxic, as in the case of leaching marine antifouling paints. Inspired by the nonfouling skins of echinoderms and other marine organisms, which possess highly dynamic surface structures that mechanically frustrate bio-attachment, we have developed and tested a synthetic platform based on both uniaxial mechanical strain and buckling-induced elastomer microtopography. Bacterial biofilm attachment to the dynamic substrates was studied under an array of parameters, including strain amplitude and timescale (1–100 mm s −1 ), surface wrinkle length scale, bacterial species and cell geometry, and growth time. The optimal conditions for achieving up to ∼ 80% Pseudomonas aeruginosa biofilm reduction after 24 h growth and ∼ 60% reduction after 48 h were combinatorially elucidated to occur at 20% strain amplitude, a timescale of less than ∼ 5 min between strain cycles and a topography length scale corresponding to the cell dimension of ∼ 1 μm. Divergent effects on the attachment of P. aeruginosa, Staphylococcus aureus and Escherichia coli biofilms showed that the dynamic substrate also provides a new means of species-specific biofilm inhibition, or inversely, selection for a desired type of bacteria, without reliance on any toxic or transient surface chemical treatments. (paper)

  19. Biofilm attachment reduction on bioinspired, dynamic, micro-wrinkling surfaces

    Science.gov (United States)

    Epstein, Alexander K.; Hong, Donggyoon; Kim, Philseok; Aizenberg, Joanna

    2013-09-01

    Most bacteria live in multicellular communities known as biofilms that are adherent to surfaces in our environment, from sea beds to plumbing systems. Biofilms are often associated with clinical infections, nosocomial deaths and industrial damage such as bio-corrosion and clogging of pipes. As mature biofilms are extremely challenging to eradicate once formed, prevention is advantageous over treatment. However, conventional surface chemistry strategies are either generally transient, due to chemical masking, or toxic, as in the case of leaching marine antifouling paints. Inspired by the nonfouling skins of echinoderms and other marine organisms, which possess highly dynamic surface structures that mechanically frustrate bio-attachment, we have developed and tested a synthetic platform based on both uniaxial mechanical strain and buckling-induced elastomer microtopography. Bacterial biofilm attachment to the dynamic substrates was studied under an array of parameters, including strain amplitude and timescale (1-100 mm s-1), surface wrinkle length scale, bacterial species and cell geometry, and growth time. The optimal conditions for achieving up to ˜ 80% Pseudomonas aeruginosa biofilm reduction after 24 h growth and ˜ 60% reduction after 48 h were combinatorially elucidated to occur at 20% strain amplitude, a timescale of less than ˜ 5 min between strain cycles and a topography length scale corresponding to the cell dimension of ˜ 1 μm. Divergent effects on the attachment of P. aeruginosa, Staphylococcus aureus and Escherichia coli biofilms showed that the dynamic substrate also provides a new means of species-specific biofilm inhibition, or inversely, selection for a desired type of bacteria, without reliance on any toxic or transient surface chemical treatments.

  20. An electrochemical impedance model for integrated bacterial biofilms

    International Nuclear Information System (INIS)

    Ben-Yoav, Hadar; Freeman, Amihay; Sternheim, Marek; Shacham-Diamand, Yosi

    2011-01-01

    Bacterial cells attachment onto solid surfaces and the following growth into mature microbial biofilms may result in highly antibiotic resistant biofilms. Such biofilms may be incidentally formed on tissues or implanted devices, or intentionally formed by directed deposition of microbial sensors on whole-cell bio-chip surface. A new method for electrical characterization of the later on-chip microbial biofilm buildup is presented in this paper. Measurement of impedance vs. frequency in the range of 100 mHz to 400 kHz of Escherichia coli cells attachment to indium-tin-oxide-coated electrodes was carried out while using optical microscopy estimating the electrode area coverage. We show that impedance spectroscopy measurements can be interpreted by a simple electrical equivalent model characterizing both attachment and growth of the biofilm. The correlation of extracted equivalent electrical lumped components with the visual biofilm parameters and their dependence on the attachment and growth phases is confirmed.

  1. Dynamic metabolic exchange governs a marine algal-bacterial interaction.

    Science.gov (United States)

    Segev, Einat; Wyche, Thomas P; Kim, Ki Hyun; Petersen, Jörn; Ellebrandt, Claire; Vlamakis, Hera; Barteneva, Natasha; Paulson, Joseph N; Chai, Liraz; Clardy, Jon; Kolter, Roberto

    2016-11-18

    Emiliania huxleyi is a model coccolithophore micro-alga that generates vast blooms in the ocean. Bacteria are not considered among the major factors influencing coccolithophore physiology. Here we show through a laboratory model system that the bacterium Phaeobacter inhibens , a well-studied member of the Roseobacter group, intimately interacts with E. huxleyi. While attached to the algal cell, bacteria initially promote algal growth but ultimately kill their algal host. Both algal growth enhancement and algal death are driven by the bacterially-produced phytohormone indole-3-acetic acid. Bacterial production of indole-3-acetic acid and attachment to algae are significantly increased by tryptophan, which is exuded from the algal cell. Algal death triggered by bacteria involves activation of pathways unique to oxidative stress response and programmed cell death. Our observations suggest that bacteria greatly influence the physiology and metabolism of E. huxleyi. Coccolithophore-bacteria interactions should be further studied in the environment to determine whether they impact micro-algal population dynamics on a global scale.

  2. Temperature increases from 55 to 75 C in a two-phase biogas reactor result in fundamental alterations within the bacterial and archaeal community structure

    Energy Technology Data Exchange (ETDEWEB)

    Rademacher, Antje [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik; Technische Univ. Berlin (Germany). Inst. fuer Technischen Umweltschutz; Nolte, Christine; Schoenberg, Mandy; Klocke, Michael [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abt. Bioverfahrenstechnik

    2012-10-15

    Agricultural biogas plants were operated in most cases below their optimal performance. An increase in the fermentation temperature and a spatial separation of hydrolysis/acetogenesis and methanogenesis are known strategies in improving and stabilizing biogas production. In this study, the dynamic variability of the bacterial and archaeal community was monitored within a two-phase leach bed biogas reactor supplied with rye silage and straw during a stepwise temperature increase from 55 to 75 C within the leach bed reactor (LBR), using TRFLP analyses. To identify the terminal restriction fragments that were obtained, bacterial and archaeal 16S rRNA gene libraries were constructed. Above 65 C, the bacterial community structure changed from being Clostridiales-dominated toward being dominated by members of the Bacteroidales, Clostridiales, and Thermotogales orders. Simultaneously, several changes occurred, including a decrease in the total cell count, degradation rate, and biogas yield along with alterations in the intermediate production. A bioaugmentation with compost at 70 C led to slight improvements in the reactor performance; these did not persist at 75 C. However, the archaeal community within the downstream anaerobic filter reactor (AF), operated constantly at 55 C, altered by the temperature increase in the LBR. At an LBR temperature of 55 C, members of the Methanobacteriales order were prevalent in the AF, whereas at higher LBR temperatures Methanosarcinales prevailed. Altogether, the best performance of this two-phase reactor was achieved at an LBR temperature of below 65 C, which indicates that this temperature range has a favorable effect on the microbial community responsible for the production of biogas. (orig.)

  3. Study on attachment of agrobacterium tumefanciens with citrus reticulata var. tankan hayata embryogenic cells

    International Nuclear Information System (INIS)

    Wang Shengbin; Yu Rangcai; Zou Weiquan; Huang Ziran

    2002-01-01

    32 P-NaH 2 PO 4 in LB medium had no negative effect on the growth of Agrobacterium tumefanciens when below the concentration of 1.169 x 10 5 Bq/ml, indicating that Agrobacterium tumefanciens could be radiolabeled with 32 P-NaH 2 PO 4 . The kinetic experiment showed that attachment of agrobacterium tumefanciens to citrus embryogenic cells was a dynamic binding. The number of bacteria attached to embryogenic cells was correlated with bacterial population and was not affected by Aceto-syringone (As) or Tween-20 in the co-cultivation medium

  4. A Molecular Genetic Basis Explaining Altered Bacterial Behavior in Space

    Data.gov (United States)

    National Aeronautics and Space Administration — Bacterial behavior has been observed to change during spaceflight. Higher final cell counts enhanced biofilm formation increased virulence and reduced susceptibility...

  5. All bonds are not alike: A psychoendocrine evaluation of infant attachment.

    Science.gov (United States)

    Gaudin, Sabrina; Chaillou, Elodie; Wycke, Marie-Anne; Cornilleau, Fabien; Moussu, Chantal; Calandreau, Ludovic; Lainé, Anne-Lyse; Nowak, Raymond

    2018-01-01

    Characteristics of attachment were assessed in peer- and object-reared lambs, and compared to mothered subjects by taking into consideration distress, proximity seeking, and exploration during two separation-reunion tests in both the familiar and a novel environment. Plasma cortisol and oxytocin were assayed as physiological indicators of stress and being comforted during the separation-reunion test. Rewarding properties of the familiar figures were also determined in a conditioned place preference-like paradigm. Between-group analysis revealed the existence of secure attachment with the mother, alteration of secure attachment with the peer and weaker attachment with the object. Weaker attachment was expressed by a lack of distress during separation in the home pen and no preference for the place conditioned with the familiar object. Elevated basal plasma oxytocin levels, but not cortisol, observed in maternally deprived lambs were more likely linked to the absence of a maternal figure rather than social comfort during reunion. © 2017 Wiley Periodicals, Inc.

  6. Surface contact stimulates the just-in-time deployment of bacterial adhesins.

    Science.gov (United States)

    Li, Guanglai; Brown, Pamela J B; Tang, Jay X; Xu, Jing; Quardokus, Ellen M; Fuqua, Clay; Brun, Yves V

    2012-01-01

    The attachment of bacteria to surfaces provides advantages such as increasing nutrient access and resistance to environmental stress. Attachment begins with a reversible phase, often mediated by surface structures such as flagella and pili, followed by a transition to irreversible attachment, typically mediated by polysaccharides. Here we show that the interplay between pili and flagellum rotation stimulates the rapid transition between reversible and polysaccharide-mediated irreversible attachment. We found that reversible attachment of Caulobacter crescentus cells is mediated by motile cells bearing pili and that their contact with a surface results in the rapid pili-dependent arrest of flagellum rotation and concurrent stimulation of polar holdfast adhesive polysaccharide. Similar stimulation of polar adhesin production by surface contact occurs in Asticcacaulis biprosthecum and Agrobacterium tumefaciens. Therefore, single bacterial cells respond to their initial contact with surfaces by triggering just-in-time adhesin production. This mechanism restricts stable attachment to intimate surface interactions, thereby maximizing surface attachment, discouraging non-productive self-adherence, and preventing curing of the adhesive. © 2011 Blackwell Publishing Ltd.

  7. Attachment of Escherichia coli and enterococci to particles in runoff.

    Science.gov (United States)

    Soupir, Michelle L; Mostaghimi, Saied; Dillaha, Theo

    2010-01-01

    Association of Escherichia coli and enterococci with particulates present in runoff from erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial movement to surface waters. Three soils with different textures were collected from the Ap horizon (silty loam, silty clay loam, and loamy fine sand), placed in portable box plots, treated with standard cowpats, and placed under a rainfall simulator. Rainfall was applied to the plots until saturation-excess flow occurred for 30 min, and samples were collected 10, 20, and 30 min after initiation of the runoff event. The attachment of E. coli and enterococci to particles present in runoff was determined by a screen filtration and centrifugation procedure. Percentage of E. coli and enterococci attached to particulates in runoff ranged from 28 to 49%, with few statistically significant differences in attachment among the three soils. Similar partitioning release patterns were observed between E. coli and enterococci from the silty loam (r = 0.57) and silty clay loam soils (r = 0.60). At least 60% of all attached E. coli and enterococci were associated particles within an 8- to 62-microm particle size category. The results indicate that the majority of fecal bacteria attach to and are transported with manure colloids in sediment-laden flow regardless of the soil texture.

  8. Bacterial Cell Mechanics.

    Science.gov (United States)

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  9. Subgingival bacteria in Ghanaian adolescents with or without progression of attachment loss

    Directory of Open Access Journals (Sweden)

    Gunnar Dahlén

    2014-05-01

    Full Text Available Objective: This study describes subgingival bacterial profiles associated with clinical periodontal status in Ghanaian adolescents with or without progression of attachment loss. Materials and methods: Among 500 adolescents included in a cohort study, 397 returned 2 years later for a periodontal re-examination, including full-mouth CAL measurements. At follow-up, a subgroup of 98 adolescents was also subjected to bacterial sampling with paper points at four periodontal sites (mesial aspect of 11, 26, 31, and 46 and analyzed with the checkerboard DNA–DNA hybridization technique against DNA-probes from nine periodontitis-associated bacterial species. Results: The 98 Ghanaian adolescents examined in the present study were similar to the entire group examined at the 2-year follow-up with respect to age, gender, and CAL ≥3 mm. A high detection frequency of Fusobacterium nucleatum and Prevotella intermedia (>99% using checkerboard analysis was found, while for Aggregatibacter actinomycetemcomitans the detection frequency was <50%. A strong correlation was found at the individual level between the presence of P. intermedia and the total CAL change, and P. intermedia and Porphyromonas gingivalis were strongly correlated with a change in CAL and probing pocket depth (PPD at the sampled sites. In a linear regression model, a significant discriminating factor for the total CAL change in the dentition during the 2-year follow-up period was obtained for P. intermedia and public school. Conclusion: This study indicates that subgingival bacterial species other than A. actinomycetemcomitans, for example, P. intermedia, have a significant association with periodontal breakdown (change in CAL in Ghanaian adolescents with progression of periodontal attachment loss.

  10. Selective pressures to maintain attachment site specificity of integrative and conjugative elements.

    Directory of Open Access Journals (Sweden)

    Kayla L Menard

    Full Text Available Integrative and conjugative elements (ICEs are widespread mobile genetic elements that are usually found integrated in bacterial chromosomes. They are important agents of evolution and contribute to the acquisition of new traits, including antibiotic resistances. ICEs can excise from the chromosome and transfer to recipients by conjugation. Many ICEs are site-specific in that they integrate preferentially into a primary attachment site in the bacterial genome. Site-specific ICEs can also integrate into secondary locations, particularly if the primary site is absent. However, little is known about the consequences of integration of ICEs into alternative attachment sites or what drives the apparent maintenance and prevalence of the many ICEs that use a single attachment site. Using ICEBs1, a site-specific ICE from Bacillus subtilis that integrates into a tRNA gene, we found that integration into secondary sites was detrimental to both ICEBs1 and the host cell. Excision of ICEBs1 from secondary sites was impaired either partially or completely, limiting the spread of ICEBs1. Furthermore, induction of ICEBs1 gene expression caused a substantial drop in proliferation and cell viability within three hours. This drop was dependent on rolling circle replication of ICEBs1 that was unable to excise from the chromosome. Together, these detrimental effects provide selective pressure against the survival and dissemination of ICEs that have integrated into alternative sites and may explain the maintenance of site-specific integration for many ICEs.

  11. Genes ycfR, sirA and yigG contribute to the surface attachment of Salmonella enterica Typhimurium and Saintpaul to fresh produce.

    Directory of Open Access Journals (Sweden)

    Joelle K Salazar

    Full Text Available Salmonella enterica is a frequent contaminant of minimally-processed fresh produce linked to major foodborne disease outbreaks. The molecular mechanisms underlying the association of this enteric pathogen with fresh produce remain largely unexplored. In our recent study, we showed that the expression of a putative stress regulatory gene, ycfR, was significantly induced in S. enterica upon exposure to chlorine treatment, a common industrial practice for washing and decontaminating fresh produce during minimal processing. Two additional genes, sirA involved in S. enterica biofilm formation and yigG of unknown function, were also found to be differentially regulated under chlorine stress. To further characterize the roles of ycfR, sirA, and yigG in S. enterica attachment and survival on fresh produce, we constructed in-frame deletions of all three genes in two different S. enterica serovars, Typhimurium and Saintpaul, which have been implicated in previous disease outbreaks linked to fresh produce. Bacterial attachment to glass and polystyrene microtiter plates, cell aggregation and hydrophobicity, chlorine resistance, and surface attachment to intact spinach leaf and grape tomato were compared among wild-type strains, single-gene deletion mutants, and their respective complementation mutants. The results showed that deletions of ycfR, sirA, and yigG reduced bacterial attachment to glass and polystyrene as well as fresh produce surface with or without chlorine treatment in both Typhimurium and Saintpaul. Deletion of ycfR in Typhimurium significantly reduced bacterial chlorine resistance and the attachment to the plant surfaces after chlorinated water washes. Deletions of ycfR in Typhimurium and yigG in Saintpaul resulted in significant increase in cell aggregation. Our findings suggest that ycfR, sirA, and yigG collectively contribute to S. enterica surface attachment and survival during post-harvest minimal processing of fresh produce.

  12. Nanoscale imaging of the growth and division of bacterial cells on planar substrates with the atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Van Der Hofstadt, M. [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Hüttener, M.; Juárez, A. [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Departament de Microbiologia, Universitat de Barcelona, Avinguda Diagonal 645, 08028 Barcelona (Spain); Gomila, G., E-mail: ggomila@ibecbarcelona.eu [Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 11-15, 08028 Barcelona (Spain); Departament d' Electronica, Universitat de Barcelona, C/ Marti i Franqués 1, 08028 Barcelona (Spain)

    2015-07-15

    With the use of the atomic force microscope (AFM), the Nanomicrobiology field has advanced drastically. Due to the complexity of imaging living bacterial processes in their natural growing environments, improvements have come to a standstill. Here we show the in situ nanoscale imaging of the growth and division of single bacterial cells on planar substrates with the atomic force microscope. To achieve this, we minimized the lateral shear forces responsible for the detachment of weakly adsorbed bacteria on planar substrates with the use of the so called dynamic jumping mode with very soft cantilever probes. With this approach, gentle imaging conditions can be maintained for long periods of time, enabling the continuous imaging of the bacterial cell growth and division, even on planar substrates. Present results offer the possibility to observe living processes of untrapped bacteria weakly attached to planar substrates. - Highlights: • Gelatine coatings used to weakly attach bacterial cells onto planar substrates. • Use of the dynamic jumping mode as a non-perturbing bacterial imaging mode. • Nanoscale resolution imaging of unperturbed single living bacterial cells. • Growth and division of single bacteria cells on planar substrates observed.

  13. Electrical conductivity measurements of bacterial nanowires from Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Maruthupandy, Muthusamy; Anand, Muthusamy; Beevi, Akbar Sait Hameedha; Priya, Radhakrishnan Jeeva; Maduraiveeran, Govindhan

    2015-01-01

    The extracellular appendages of bacteria (flagella) that transfer electrons to electrodes are called bacterial nanowires. This study focuses on the isolation and separation of nanowires that are attached via Pseudomonas aeruginosa bacterial culture. The size and roughness of separated nanowires were measured using transmission electron microscopy (TEM) and atomic force microscopy (AFM), respectively. The obtained bacterial nanowires indicated a clear image of bacterial nanowires measuring 16 nm in diameter. The formation of bacterial nanowires was confirmed by microscopic studies (AFM and TEM) and the conductivity nature of bacterial nanowire was investigated by electrochemical techniques. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), which are nondestructive voltammetry techniques, suggest that bacterial nanowires could be the source of electrons—which may be used in various applications, for example, microbial fuel cells, biosensors, organic solar cells, and bioelectronic devices. Routine analysis of electron transfer between bacterial nanowires and the electrode was performed, providing insight into the extracellular electron transfer (EET) to the electrode. CV revealed the catalytic electron transferability of bacterial nanowires and electrodes and showed excellent redox activities. CV and EIS studies showed that bacterial nanowires can charge the surface by producing and storing sufficient electrons, behave as a capacitor, and have features consistent with EET. Finally, electrochemical studies confirmed the development of bacterial nanowires with EET. This study suggests that bacterial nanowires can be used to fabricate biomolecular sensors and nanoelectronic devices. (paper)

  14. Enteropathogenic Escherichia coli translocate Tir and form an intimin-Tir intimate attachment to red blood cell membranes.

    Science.gov (United States)

    Shaw, Robert K; Daniell, Sarah; Frankel, Gad; Knutton, Stuart

    2002-05-01

    Type III secretion allows bacteria to inject effector proteins into host cells. In enteropathogenic Escherichia coli (EPEC) the type III secreted protein, Tir, is translocated to the host-cell plasma membrane where it functions as a receptor for the bacterial adhesin intimin, leading to intimate bacterial attachment and "attaching and effacing" (A/E) lesion formation. To study EPEC type III secretion the interaction of EPEC with monolayers of red blood cells (RBCs) has been exploited and in a recent study [Shaw, R. K., Daniell, S., Ebel, F., Frankel, G. & Knutton, S. (2001 ). Cell Microbiol 3, 213-222] it was shown that EPEC induced haemolysis of RBCs and translocation of EspD, a putative pore-forming type III secreted protein in the RBC membrane. Here it is demonstrated that EPEC are able to translocate and correctly insert Tir into the RBC membrane and produce an intimin-Tir intimate bacterial attachment, identical to that seen in A/E lesions. Following translocation Tir did not undergo any change in apparent molecular mass or become tyrosine-phosphorylated and there was no focusing of RBC cytoskeletal actin beneath intimately adherent bacteria, and no pedestal formation. This study, employing an RBC model of infection, has demonstrated that Tir translocation can be separated from host-cell-mediated Tir modifications; the data show that the EPEC type III protein translocation apparatus is sufficient to deliver and correctly insert Tir into host-cell membranes independent of eukaryotic cell functions.

  15. Enhanced bacterial affinity of PVDF membrane: its application as improved sea water sampling tool for environmental monitoring.

    Science.gov (United States)

    Kumar, Sweta Binod; Sharnagat, Preeti; Manna, Paramita; Bhattacharya, Amit; Haldar, Soumya

    2017-02-01

    Isolation of diversified bacteria from seawater is a major challenge in the field of environmental microbiology. In the present study, an attempt has been made to select specific membrane with improved property of attaching diversified bacteria. Initially, different concentrations (15, 18, and 20% W/W) of polysulfone (PSF) were used to check their affinity for the attachment of selected gram-positive (Bacillus subtilis) and gram-negative (Escherichia coli) bacteria. Among these, 20% W/W PSF showed maximum attachment. Therefore, membrane prepared with other materials such as polyvinylidene fluoride (PVDF) and polyether sulfone (PES) were used with the same concentration (20% W/W) to check their improved bacterial attachment property. Comparative study of bacterial attachment on three different membranes revealed that PVDF possessed the highest affinity towards both the groups of bacteria. This property was confirmed by different analytical methods viz. contact angle, atomic force microscopy, zeta potential, and flux study and further validated with seawater samples collected from seven sites of western coast and Lakshadweep island of India, using Biolog EcoPlate™. All the samples showed that bacterial richness and diversity was high in PVDF membrane in comparison to surrounding seawater samples. Interestingly, affinity for more diversified bacteria was reported to be higher in water sample with less turbidity and low bacteria load. This finding can facilitate the development of PVDF (20% W/W) membrane as a simple, cheap, and less labor intensive environmental sampling tool for the isolation of diversified bacteria from seawater sample wih different physiochemical properties. Graphical abstract ᅟ.

  16. Using ATTO dyes to probe bacterial interactions with the marine diatom Pseudo-nitzschia.

    Science.gov (United States)

    Mehic, S.; Sison-Mangus, M.

    2016-02-01

    Pseudo-nitzschia blooms are known to be highly toxic and detrimental to wildlife. The neurotoxin produced by the algae can ripple through the entire food web creating a direct impact on oceanic life and human-related industries. With coastal blooms increasing in both size and duration in recent years, it is crucial that we uncover more microbial interactions that may affect the toxicity of these blooms. Current harmful algal bloom studies have shown that different bacterial consortia can have a great impact Pseudo-nitzschia physiology. More specifically, research suggests that bacteria affect both growth rates and domoic acid concentrations of laboratory grown cultures. However, these studies do not explore the attachment patterns of these bacteria with the diatom. Bacterial attachment may dictate the different types of interactions between bacteria and the diatoms, a trait that is largely unexplored in the symbiotic interactions between the two organisms. In this study, we seek to identify direct and indirect interactions between four bacteria taxa from different phyla and three different species of Pseudo-nitzschia. Our preliminary scanning electron microscopy and DAPI staining experiments hint at distinct differences in attachment among bacterial taxa. To explore this work further, we aim to employ ATTO dyes and epifluorescent microscopy on both binary and multiple cultures to visualize patterns in attachment. By utilizing ATTO dyes with distinct wavelength emissions, we can perform a series experiment that highlights the interaction between bacteria and diatoms, without inserting a fluorescent reporter gene in the bacteria. Multiple cultures will be used to identify possible cooperative or negative interactive traits between bacteria that can affect diatom host physiology. Implications on both phytoplankton physiology and nutrient cycling will be subsequently discussed.

  17. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    Directory of Open Access Journals (Sweden)

    V Bianciotto

    2009-12-01

    Full Text Available Arbuscular mycorrhizal (AM fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR. We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium to AM roots and AM fungal structures. Mutants affected in extracellular polysaccharides (EPS have been tested in in vitro adhesion assays and shown to be strongly impaired in the attachment to both types of surfaces as well as to quartz fibers. Anchoring of rhizobacteria to AM fungal structures may have special ecological and biotechnological significance because it may facilitate colonisation of new rhizospheres by the bacteria, and may be an essential trait for the development of mixed inocula.

  18. Paternal Attachment, Parenting Beliefs and Children's Attachment

    Science.gov (United States)

    Howard, Kimberly S.

    2010-01-01

    Relationships between fathers' romantic attachment style, parenting beliefs and father-child attachment security and dependence were examined in a diverse sample of 72 fathers of young children. Paternal romantic attachment style was coded based on fathers' endorsement of a particular style represented in the Hazan and Shaver Three-Category…

  19. Influence of the nano-micro structure of the surface on bacterial adhesion

    Directory of Open Access Journals (Sweden)

    Carolina Díaz

    2007-03-01

    Full Text Available Biomaterials failures are frequently associated to the formation of bacterial biofilms on the surface. The aim of this work is to study the adhesion of non motile bacteria streptococci consortium and motile Pseudomonas fluorescens. Substrates with micro and nanopatterned topography were used. The influence of surface characteristics on bacterial adhesion was investigated using optical and epifluorescence microscopy, scanning electron microscopy (SEM and atomic force microscopy (AFM. Results showed an important influence of the substratum nature. On microrough surfaces, initial bacterial adhesion was less significant than on smooth surfaces. In contrast, nanopatterned samples showed more bacterial attachment than the smooth control. It was also noted a remarkable difference in morphology, orientation and distribution of bacteria between the smooth and the nanostructured substrate. The results show the important effect of substratum nature and topography on bacterial adhesion which depended on the relation between roughness characteristics dimensions and bacterial size.

  20. Attached and planktonic Listeria monocytogenes global proteomic responses and associated influence of strain genetics and temperature.

    Science.gov (United States)

    Mata, Marcia M; da Silva, Wladimir P; Wilson, Richard; Lowe, Edwin; Bowman, John P

    2015-02-06

    Contamination of industrial and domestic food usage environments by the attachement of bacterial food-borne pathogen Listeria monocytogenes has public health and economic implications. Comprehensive proteomics experiments using label-free liquid chromatography/tandem mass spectrometry were used to compare the proteomes of two different L. monocytogenes strains (Siliken_1/2c and F2365_4b), which show very different capacities to attach to surfaces. Growth temperature and strain type were highly influential on the proteomes in both attached and planktonic cells. On the basis of the proteomic data, it is highly unlikely that specific surface proteins play a direct role in adherence to inanimate surfaces. Instead, strain-dependent responses related to cell envelope polymer biosynthesis and stress response regulation likely contribute to a different ability to attach and also to survive external stressors. Collectively, the divergent proteome-level responses observed define strain- and growth-temperature-dependent differences relevant to attachment efficacy, highlight relevant proteins involved in stress protection in attached cells, and suggest that strain differences and growth conditions are important in relation to environmental persistence.

  1. Factors affecting the bacterial community composition and heterotrophic production of Columbia River estuarine turbidity maxima.

    Science.gov (United States)

    Herfort, Lydie; Crump, Byron C; Fortunato, Caroline S; McCue, Lee Ann; Campbell, Victoria; Simon, Holly M; Baptista, António M; Zuber, Peter

    2017-12-01

    Estuarine turbidity maxima (ETM) function as hotspots of microbial activity and diversity in estuaries, yet, little is known about the temporal and spatial variability in ETM bacterial community composition. To determine which environmental factors affect ETM bacterial populations in the Columbia River estuary, we analyzed ETM bacterial community composition (Sanger sequencing and amplicon pyrosequencing of 16S rRNA gene) and bulk heterotrophic production ( 3 H-leucine incorporation rates). We collected water 20 times to cover five ETM events and obtained 42 samples characterized by different salinities, turbidities, seasons, coastal regimes (upwelling vs. downwelling), locations, and particle size. Spring and summer populations were distinct. All May samples had similar bacterial community composition despite having different salinities (1-24 PSU), but summer non-ETM bacteria separated into marine, freshwater, and brackish assemblages. Summer ETM bacterial communities varied depending on coastal upwelling or downwelling conditions and on the sampling site location with respect to tidal intrusion during the previous neap tide. In contrast to ETM, whole (>0.2 μm) and free-living (0.2-3 μm) assemblages of non-ETM waters were similar to each other, indicating that particle-attached (>3 μm) non-ETM bacteria do not develop a distinct community. Brackish water type (ETM or non-ETM) is thus a major factor affecting particle-attached bacterial communities. Heterotrophic production was higher in particle-attached than free-living fractions in all brackish waters collected throughout the water column during the rise to decline of turbidity through an ETM event (i.e., ETM-impacted waters). However, free-living communities showed higher productivity prior to or after an ETM event (i.e., non-ETM-impacted waters). This study has thus found that Columbia River ETM bacterial communities vary based on seasons, salinity, sampling location, and particle size, with the

  2. Impact of Maternal Attachment Style on Mother to Infant Attachment

    Directory of Open Access Journals (Sweden)

    Moghaddam Hoseini V

    2011-08-01

    Full Text Available Background and Objectives: Maternal attachment has the potential to affect both child development and parenting. As such, mother-infant attachment has been considered an important topic in recent years. The aim of this study was to determine the relationship between maternal adult attachment style, the maternal obstetric and demographic characteristics and mother-infant attachment.Methods: In this descriptive-correlational study, 102 women who had referred to health centers in Mashhad in 2008 and who had inclusion criteriawere selected using stratified cluster sampling. After interview about obstetric and demographic characteristics, they were asked to complete the "Revised Adult Attachment Scale" and "Mother to Infant Attachment Inventory" for assessment of maternal attachment style and mother-infant attachment 4-5 weeks after delivery. Data were analyzed by Pearson Correlation, Kruskal-wallis and Mann-whitney statistical tests.Results: In this study, themean of mother-infant attachment was found to be 97.486.12 and the mean of secure adult attachment was higher than that of other styles (16.893.97. Although, there were negative significant relationship between maternal avoidant style and mother-infant attachment (p=0.037,r=-0/20, there were no relationship between maternal age and education, parity, type of delivery and mother-infant attachment.Conclusion: The results of this research show that maternal attachment style is one of the factors of mother -infant attachment.

  3. Seasonal to hour variation scales in abundance and production of total and particle-attached bacteria in the open NW Mediterranean Sea (0–1000 m

    Directory of Open Access Journals (Sweden)

    G. Mével

    2008-11-01

    Full Text Available We present the vertical and temporal dynamics of total vs. particle-attached bacterial abundance and activity over a 5 week period under summer to autumn transition in NW Mediterranean Sea. At a weekly time scale, total bacterial biomass and production in the euphotic layers was significantly correlated with phytoplanktonic biomass. At an hourly time scale, total bacterial biomass responded very rapidly to chlorophyll a fluctuations, suggesting a tight coupling between phytoplankton and bacteria for resource partitioning during the summer-autumn transition. In contrast, no influence of diel changes on bacterial parameters was detected. Episodic events such as coastal water intrusions had a significant positive effect on total bacterial abundance and production, whereas we could not detect any influence of short wind events whatever the magnitude. Finally, we show that particle-attached bacteria can represent a large proportion (up to 49% of the total bacterial activity in the euphotic layer but display rapid and sporadic changes at hourly time scales. In the mesopelagic layers, bacterial abundance and production linearly decreased with depth, except some production peaks at 400–750 m. This study underlines the value of large datasets covering different temporal scales to clarify the biogeochemical role of bacteria in the cycling of organic matter in open seawater.

  4. Bacterial community affects toxin production by Gymnodinium catenatum.

    Directory of Open Access Journals (Sweden)

    Maria E Albinsson

    Full Text Available The paralytic shellfish toxin (PST-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01 and grown with: 1 complex bacterial communities derived from each of the two parent cultures; 2 simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3 a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell of clonal offspring (134-197 fmol STX cell(-1 was similar to the parent cultures (169-206 fmol STX cell(-1, however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1 than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1. Specific toxin production rate (fmol STX day(-1 was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1 day(-1 did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

  5. Bacterial community affects toxin production by Gymnodinium catenatum.

    Science.gov (United States)

    Albinsson, Maria E; Negri, Andrew P; Blackburn, Susan I; Bolch, Christopher J S

    2014-01-01

    The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134-197 fmol STX cell(-1)) was similar to the parent cultures (169-206 fmol STX cell(-1)), however cultures grown with single bacterial types contained less toxin (134-146 fmol STX cell(-1)) than offspring or parent cultures grown with more complex mixed bacterial communities (152-176 fmol STX cell(-1)). Specific toxin production rate (fmol STX day(-1)) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell(-1) day(-1)) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX

  6. MECHANISM OF ACTION OF ANTIBIOTICS WHICH INHIBIT SYNTHESIS OF BACTERIAL CELL WALL

    Directory of Open Access Journals (Sweden)

    Indira Mujezinović

    2013-03-01

    Full Text Available Bacterial cell possess a cell wall, which is a main difference from mammalian cells. Its basic function is to provide the strength of bacteria, keeps its shape and provides an unusually high internal osmotic pressure. Synthesis of (construction of bacterial cell wall occurs in at least three phases. All of these three phases can be influence by a variety of antibiotics in way to inhibit its synthesis. The most important drugs that act in this manner are ß-lactam antibiotics (penicillins, cephalosporins, cephamycins and other ß-lactams. They interfere with the synthesis of the bacterial cell wall peptidoglycan. After attachment to penicillin binding proteins (PBP on bacteria, they inhibit the transpeptidation enzyme that cross-links the peptide chain attached to the backbone of the peptidoglycan. The final bactericidal event is the inactivation of an inhibitor of autolytic enzymes in the cell wall, wich leads to lysis of the bacteria. Vancomycin inhibits the release of the building block unit from the carrier, thus preventing its addition to the growing end of the peptidoglycan. Cycloserine, which is a structural analogue of D-alanine, prevents the addition of the two terminal alanine residue to the initial tripeptide side-chain on N-acetylmuramic acid by competitive inhibition. Bacitracin interferes with the regeneration of the lipid carrier by blocking its dephosphorylation. Key words: bacterial cell wall, paptidoglycan, antibiotics, ß-lactams

  7. Microplastic-associated bacterial assemblages in the intertidal zone of the Yangtze Estuary.

    Science.gov (United States)

    Jiang, Peilin; Zhao, Shiye; Zhu, Lixin; Li, Daoji

    2018-05-15

    Plastic trash is common in oceans. Terrestrial and marine ecosystem interactions occur in the intertidal zone where accumulation of plastic frequently occurs. However, knowledge of the plastic-associated microbial community (the plastisphere) in the intertidal zone is scanty. We used high-throughput sequencing to profile the bacterial communities attached to microplastic samples from intertidal locations around the Yangtze estuary in China. The structure and composition of plastisphere communities varied significantly among the locations. We found the taxonomic composition on microplastic samples was related to their sedimentary and aquatic origins. Correlation network analysis was used to identify keystone bacterial genera (e.g. Rhodobacterales, Sphingomonadales and Rhizobiales), which represented important microbial associations within the plastisphere community. Other species (i.e. potential pathogens) were considered as hitchhikers in the plastic attached microbial communities. Metabolic pathway analysis suggested adaptations of these bacterial assemblages to the plastic surface-colonization lifestyle. These adaptations included reduced "cell motility" and greater "xenobiotics biodegradation and metabolism." The findings illustrate the diverse microbial assemblages that occur on microplastic and increase our understanding of plastisphere ecology. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-10-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacterial colonies in infected host cells (Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy, Ernstsen et al., 2017 [1]). The infected cells were imaged with a 10× objective and number of intracellular bacterial colonies, their size distribution and the number of cell nuclei were automatically quantified using a spot detection-tool. The spot detection-output was exported to Excel, where data analysis was performed. In this article, micrographs and spot detection data are made available to facilitate implementation of the method.

  9. Lake Bacterial Assemblage Composition Is Sensitive to Biological Disturbance Caused by an Invasive Filter Feeder.

    Science.gov (United States)

    Denef, Vincent J; Carrick, Hunter J; Cavaletto, Joann; Chiang, Edna; Johengen, Thomas H; Vanderploeg, Henry A

    2017-01-01

    One approach to improve forecasts of how global change will affect ecosystem processes is to better understand how anthropogenic disturbances alter bacterial assemblages that drive biogeochemical cycles. Species invasions are important contributors to global change, but their impacts on bacterial community ecology are rarely investigated. Here, we studied direct impacts of invasive dreissenid mussels (IDMs), one of many invasive filter feeders, on freshwater lake bacterioplankton. We demonstrated that direct effects of IDMs reduced bacterial abundance and altered assemblage composition by preferentially removing larger and particle-associated bacteria. While this increased the relative abundances of many free-living bacterial taxa, some were susceptible to filter feeding, in line with efficient removal of phytoplankton cells of <2 μm. This selective removal of particle-associated and larger bacteria by IDMs altered inferred bacterial functional group representation, defined by carbon and energy source utilization. Specifically, we inferred an increased relative abundance of chemoorganoheterotrophs predicted to be capable of rhodopsin-dependent energy generation. In contrast to the few previous studies that have focused on the longer-term combined direct and indirect effects of IDMs on bacterioplankton, our study showed that IDMs act directly as a biological disturbance to which freshwater bacterial assemblages are sensitive. The negative impacts on particle-associated bacteria, which have been shown to be more active than free-living bacteria, and the inferred shifts in functional group representation raise the possibility that IDMs may directly alter bacterially mediated ecosystem functions. IMPORTANCE Freshwater bacteria play fundamental roles in global elemental cycling and are an intrinsic part of local food webs. Human activities are altering freshwater environments, and much has been learned regarding the sensitivity of bacterial assemblages to a variety of

  10. In vitro study of antibiotic effect on bacterial adherence to acrylic intraocular lenses.

    Science.gov (United States)

    Gaál, Valéria; Kilár, Ferenc; Acs, Barnabás; Szijjártó, Zsuzsanna; Kocsis, Béla; Kustos, Ildikó

    2005-11-10

    Implantation of artificial intraocular lenses into the eye during ophthalmic surgical procedures ensures an unliving surface on which bacterial pathogens may attach and form biofilms. Despite antibiotic treatment bacteria growing in biofilms might cause inflammation and serious complications. In this study the adhesive ability of 7 Staphylococcus aureus and 11 coagulase-negative Staphylococcus (CNS) strains to the surface of acrylic intraocular lenses had been examined by the ultrasonic method. In untreated cases adhesion of the S. aureus and CNS strains did not differ significantly. We could not demonstrate significant differences between the adhesive ability of the standard strains and the clinical isolates. In this study a single--60 min long--antibiotic (ciprofloxacin and tobramycin) treatment had been applied, that correlate well with the single or intermittant antibiotic prophylaxis of patients. Ciprofloxacin administration was able to reduce significantly the number of attached cells on the surface of acrylic lenses both in the case of S. aureus and CNS strains. Dependence of the effect from concentration could also be demonstrated. Tobramycin treatment was able to inhibit significantly the attachment of S. aureus cells. Despite the debate on antibiotic prophylaxis we presented in our experiments that a single antibiotic administration can decrease the attachment of bacterial cells to the surface of acrylic intraocular lenses, and might be effective in the prevention of postoperative endophthalmitis, that is a rare but serious complication of ophthalmic surgery.

  11. Bacterial adhesion capacity on food service contact surfaces.

    Science.gov (United States)

    Fink, Rok; Okanovič, Denis; Dražič, Goran; Abram, Anže; Oder, Martina; Jevšnik, Mojca; Bohinc, Klemen

    2017-06-01

    The aim of this study was to analyse the adhesion of E. coli, P. aeruginosa and S. aureus on food contact materials, such as polyethylene terephthalate, silicone, aluminium, Teflon and glass. Surface roughness, streaming potential and contact angle were measured. Bacterial properties by contact angle and specific charge density were characterised. The bacterial adhesion analysis using staining method and scanning electron microscopy showed the lowest adhesion on smooth aluminium and hydrophobic Teflon for most of the bacteria. However, our study indicates that hydrophobic bacteria with high specific charge density attach to those surfaces more intensively. In food services, safety could be increased by selecting material with low adhesion to prevent cross contamination.

  12. Impact of Maternal Attachment Style on Mother to Infant Attachment

    Directory of Open Access Journals (Sweden)

    V Moghaddam Hoseini

    2012-05-01

    Full Text Available

    Background and Objectives: Maternal attachment has the potential to affect both child development and parenting. As such, mother-infant attachment has been considered an important topic in recent years. The aim of this study was to determine the relationship between maternal adult attachment style, the maternal obstetric and demographic characteristics and mother-infant attachment.

     

    Methods: In this descriptive-correlational study, 102 women who had referred to health centers in Mashhad in 2008 and who had inclusion criteriawere selected using stratified cluster sampling. After interview about obstetric and demographic characteristics, they were asked to complete the "Revised Adult Attachment Scale" and "Mother to Infant Attachment Inventory" for assessment of maternal attachment style and mother-infant attachment 4-5 weeks after delivery. Data were analyzed by Pearson Correlation, Kruskal-wallis and Mann-whitney statistical tests.

     

    Results: In this study, themean of mother-infant attachment was found to be 97.48±6.12 and the mean of secure adult attachment was higher than that of other styles (16.89±3.97. Although, there were negative significant relationship between maternal avoidant style and mother-infant attachment (p=0.037,r=-0/20, there were no relationship between maternal age and education, parity, type of delivery and mother-infant attachment.

     

    Conclusion: The results of this research show that maternal attachment style is one of the factors of mother -infant attachment.

  13. Specific inflammatory response of Anemonia sulcata (Cnidaria) after bacterial injection causes tissue reaction and enzymatic activity alteration.

    Science.gov (United States)

    Trapani, M R; Parisi, M G; Parrinello, D; Sanfratello, M A; Benenati, G; Palla, F; Cammarata, M

    2016-03-01

    The evolution of multicellular organisms was marked by adaptations to protect against pathogens. The mechanisms for discriminating the ''self'' from ''non-self" have evolved into a long history of cellular and molecular strategies, from damage repair to the co-evolution of host-pathogen interactions. We investigated the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of substances that varied in type and dimension, and observed clear, strong and specific reactions, especially after injection of Escherichia coli and Vibrio alginolyticus. Moreover, we analyzed enzymatic activity of protease, phosphatase and esterase, showing how the injection of different bacterial strains alters the expression of these enzymes and suggesting a correlation between the appearance of the inflammatory reaction and the modification of enzymatic activities. Our study shows for the first time, a specific reaction and enzymatic responses following injection of bacteria in a cnidarian. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. No difference in portal and hepatic venous bacterial DNA in patients with cirrhosis undergoing transjugular intrahepatic portosystemic shunt insertion

    DEFF Research Database (Denmark)

    Mortensen, Christian; Karlsen, Stine; Grønbaek, Henning

    2013-01-01

    Bacterial translocation (BT) with immune activation may lead to hemodynamical alterations and poor outcomes in patients with cirrhosis.......Bacterial translocation (BT) with immune activation may lead to hemodynamical alterations and poor outcomes in patients with cirrhosis....

  15. Prevention of bacterial colonization of contact lenses with covalently attached selenium and effects on the rabbit cornea.

    Science.gov (United States)

    Mathews, Steven M; Spallholz, Julian E; Grimson, Mark J; Dubielzig, Richard R; Gray, Tracy; Reid, Ted W

    2006-08-01

    Although silicone hydrogel materials have produced many corneal health benefits to patients wearing contact lenses, bacteria that cause acute red eye or corneal ulcers are still a concern. A coating that inhibits bacterial colonization while not adversely affecting the cornea should improve the safety of contact lens wear. A covalent selenium (Se) coating on contact lenses was evaluated for safety using rabbits and prevention of bacterial colonization of the contact lenses in vitro. Contact lenses coated with Se were worn on an extended-wear schedule for up to 2 months by 10 New Zealand White rabbits. Corneal health was evaluated with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. Lenses worn by the rabbits were analyzed for protein and lipid deposits. In addition, the ability of Se to block bacterial colonization was tested in vitro by incubating lenses in a Pseudomonas aeruginosa broth followed by scanning electron microscopy of the contact lens surface. The covalent Se coating decreased bacterial colonization in vitro while not adversely affecting the corneal health of rabbits in vivo. The Se coating produced no noticeable negative effects as observed with slit-lamp biomicroscopy, pachymetry, electron microscopy, and histology. The Se coating did not affect protein or lipid deposition on the contact lenses. The data from this pilot study suggest that a Se coating on contact lenses might reduce acute red eye and bacterial ulceration because of an inhibition of bacterial colonization. In addition, our safety tests suggest that this positive effect can be produced without an adverse effect on corneal health.

  16. Electron attachment cross sections obtained from electron attachment spectroscopy

    International Nuclear Information System (INIS)

    Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.

    1988-01-01

    Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)

  17. Iodine susceptibility of pseudomonads grown attached to stainless steel surfaces

    Science.gov (United States)

    Pyle, B. H.; McFeters, G. A.

    1990-01-01

    Pseudomonads were adapted to grow in phosphate-buffered water and on stainless steel surfaces to study the iodine sensitivity of attached and planktonic cells. Cultures adapted to low nutrient growth were incubated at room temperature in a circulating reactor system with stainless steel coupons to allow biofilm formation on the metal surfaces. In some experiments, the reactor was partially emptied and refilled with buffer at each sampling time to simulate a "fill-and-draw" water system. Biofilms of attached bacteria, resuspended biofilm bacteria, and reactor suspension, were exposed to 1 mg l-1 iodine for 2 min. Attached bacterial populations which established on coupons within 3 to 5 days displayed a significant increase in resistance to iodine. Increased resistance was also observed for resuspended cells from the biofilm and planktonic bacteria in the system suspension. Generally, intact biofilms and resuspended biofilm cells were most resistant, followed by planktonic bacteria and phosphate buffer cultures. Thus, biofilm formation on stainless steel surfaces within water systems can result in significantly increased disinfection resistance of commonly-occurring water-borne bacteria that may enhance their ability to colonise water treatment and distribution systems.

  18. Modeling bacterial attachment to surfaces as an early stage of biofilm development.

    Science.gov (United States)

    El Moustaid, Fadoua; Eladdadi, Amina; Uys, Lafras

    2013-06-01

    Biofilms are present in all natural, medical and industrial surroundings where bacteria live. Biofilm formation is a key factor in the growth and transport of both beneficial and harmful bacteria. While much is known about the later stages of biofilm formation, less is known about its initiation which is an important first step in the biofilm formation. In this paper, we develop a non-linear system of partial differential equations of Keller-Segel type model in one-dimensional space, which couples the dynamics of bacterial movement to that of the sensing molecules. In this case, bacteria perform a biased random walk towards the sensing molecules. We derive the boundary conditions of the adhesion of bacteria to a surface using zero-Dirichlet boundary conditions, while the equation describing sensing molecules at the interface needed particular conditions to be set. The numerical results show the profile of bacteria within the space and the time evolution of the density within the free-space and on the surface. Testing different parameter values indicate that significant amount of sensing molecules present on the surface leads to a faster bacterial movement toward the surface which is the first step of biofilm initiation. Our work gives rise to results that agree with the biological description of the early stages of biofilm formation.

  19. Bacterial strategies of resistance to antimicrobial peptides.

    Science.gov (United States)

    Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

    2016-05-26

    Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

  20. Bacterial infection increases risk of carcinogenesis by targeting mitochondria

    DEFF Research Database (Denmark)

    Strickertsson, Jesper A.B.; Desler, Claus; Rasmussen, Lene Juel

    2017-01-01

    pathways, and compares the impact of the bacterial alteration of mitochondrial function to that of cancer. Bacterial virulence factors have been demonstrated to induce mutations of mitochondrial DNA (mtDNA) and to modulate DNA repair pathways of the mitochondria. Furthermore, virulence factors can induce...... or impair the intrinsic apoptotic pathway. The effect of bacterial targeting of mitochondria is analogous to behavior of mitochondria in a wide array of tumours, and this strongly suggests that mitochondrial targeting of bacteria is a risk factor for carcinogenesis....

  1. Ammonia produced by bacterial colonies promotes growth of ampicillin-sensitive Serratia sp. by means of antibiotic inactivation.

    Science.gov (United States)

    Cepl, Jaroslav; Blahůšková, Anna; Cvrčková, Fatima; Markoš, Anton

    2014-05-01

    Volatiles produced by bacterial cultures are known to induce regulatory and metabolic alterations in nearby con-specific or heterospecific bacteria, resulting in phenotypic changes including acquisition of antibiotic resistance. We observed unhindered growth of ampicillin-sensitive Serratia rubidaea and S. marcescens on ampicillin-containing media, when exposed to volatiles produced by dense bacterial growth. However, this phenomenon appeared to result from pH increase in the medium caused by bacterial volatiles rather than alterations in the properties of the bacterial cultures, as alkalization of ampicillin-containing culture media to pH 8.5 by ammonia or Tris exhibited the same effects, while pretreatment of bacterial cultures under the same conditions prior to antibiotic exposure did not increase ampicillin resistance. Ampicillin was readily inactivated at pH 8.5, suggesting that observed bacterial growth results from metabolic alteration of the medium, rather than an active change in the target bacterial population (i.e. induction of resistance or tolerance). However, even such seemingly simple mechanism may provide a biologically meaningful basis for protection against antibiotics in microbial communities growing on semi-solid media. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  2. Modeling the integration of bacterial rRNA fragments into the human cancer genome.

    Science.gov (United States)

    Sieber, Karsten B; Gajer, Pawel; Dunning Hotopp, Julie C

    2016-03-21

    Cancer is a disease driven by the accumulation of genomic alterations, including the integration of exogenous DNA into the human somatic genome. We previously identified in silico evidence of DNA fragments from a Pseudomonas-like bacteria integrating into the 5'-UTR of four proto-oncogenes in stomach cancer sequencing data. The functional and biological consequences of these bacterial DNA integrations remain unknown. Modeling of these integrations suggests that the previously identified sequences cover most of the sequence flanking the junction between the bacterial and human DNA. Further examination of these reads reveals that these integrations are rich in guanine nucleotides and the integrated bacterial DNA may have complex transcript secondary structures. The models presented here lay the foundation for future experiments to test if bacterial DNA integrations alter the transcription of the human genes.

  3. Attachment and Psychopathology

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Ustundag

    2011-06-01

    Full Text Available The type of attachment defined in the early stages of life and thought to be continuous, is a phenomenon that shapes the pattern of how a person makes contact with others. The clinical appearance of every type of attachment is different and each one has prospective and retrospective phenomenological reflections. In all stages of life and in close relationships, it can be observed if a person gets in close contact with someone else and if this relation bears supportive and protective qualities. According to attachment theorists, once it is defined as safe or unsafe during nursing period, it shows little change. Starting from Bowlby’s work, unsafe attachment type is considered as the determining factor of psychopathology in the later periods of life, while safe attachment is considered as in relation with healthy processes. The nature’s original model is safe attachment. Anxious/indecisive attachment, an unsafe attachment type, is associated with anxiety disorders and depressive disorder, while avoidant attachment is associated with behavior disorder and other extroverted pathologies. Disorganized/disoriented attachment is considered to be together with dissociative disorder. The aim of this paper is to review attachment theory and the relation between attachment and psychopathology.

  4. Application of photostable quantum dots for indirect immunofluorescent detection of specific bacterial serotypes on small marine animals

    International Nuclear Information System (INIS)

    Decho, Alan W; Beckman, Erin M; Chandler, G Thomas; Kawaguchi, Tomohiro

    2008-01-01

    An indirect immunofluorescence approach was developed using semiconductor quantum dot nanocrystals to label and detect a specific bacterial serotype of the bacterial human pathogen Vibrio parahaemolyticus, attached to small marine animals (i.e. benthic harpacticoid copepods), which are suspected pathogen carriers. This photostable labeling method using nanotechnology will potentially allow specific serotypes of other bacterial pathogens to be detected with high sensitivity in a range of systems, and can be easily applied for sensitive detection to other Vibrio species such as Vibrio cholerae

  5. Attachment and prejudice.

    Science.gov (United States)

    Carnelley, Katherine B; Boag, Elle M

    2018-04-16

    There is a paucity of research that examines prejudice from an attachment theory perspective. Herein we make theoretical links between attachment patterns and levels of prejudice. Perceptions of outgroup threat, which activate the attachment system, are thought to lead to fear and prejudice for those high in attachment anxiety, and to distancing and prejudice for those high in attachment avoidance. We review the literature that examines the associations between attachment patterns and prejudice; evidence from attachment priming studies suggests a causal role of attachment security in reducing prejudice. We identify several mediators of these links: empathy, negative emotions, trust, social dominance orientation, romanticism, and contact quality. Future research should manipulate potential mediators and use psychophysiological assessments of threat. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Manipulation of host membranes by bacterial effectors.

    Science.gov (United States)

    Ham, Hyeilin; Sreelatha, Anju; Orth, Kim

    2011-07-18

    Bacterial pathogens interact with host membranes to trigger a wide range of cellular processes during the course of infection. These processes include alterations to the dynamics between the plasma membrane and the actin cytoskeleton, and subversion of the membrane-associated pathways involved in vesicle trafficking. Such changes facilitate the entry and replication of the pathogen, and prevent its phagocytosis and degradation. In this Review, we describe the manipulation of host membranes by numerous bacterial effectors that target phosphoinositide metabolism, GTPase signalling and autophagy.

  7. Direct analysis by time-of-flight secondary ion mass spectrometry reveals action of bacterial laccase-mediator systems on both hardwood and softwood samples.

    Science.gov (United States)

    Goacher, Robyn E; Braham, Erick J; Michienzi, Courtney L; Flick, Robert M; Yakunin, Alexander F; Master, Emma R

    2017-12-29

    The modification and degradation of lignin play a vital role in carbon cycling as well as production of biofuels and bioproducts. The possibility of using bacterial laccases for the oxidation of lignin offers a route to utilize existing industrial protein expression techniques. However, bacterial laccases are most frequently studied on small model compounds that do not capture the complexity of lignocellulosic materials. This work studied the action of laccases from Bacillus subtilis and Salmonella typhimurium (EC 1.10.3.2) on ground wood samples from yellow birch (Betula alleghaniensis) and red spruce (Picea rubens). The ability of bacterial laccases to modify wood can be facilitated by small molecule mediators. Herein, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), gallic acid and sinapic acid mediators were tested. Direct analysis of the wood samples was achieved by time-of-flight secondary ion mass spectrometry (ToF-SIMS), a surface sensitive mass spectrometry technique that has characteristic peaks for H, G and S lignin. The action of the bacterial laccases on both wood samples was demonstrated and revealed a strong mediator influence. The ABTS mediator led to delignification, evident in an overall increase of polysaccharide peaks in the residual solid, along with equal loss of G and S-lignin peaks. The gallic acid mediator demonstrated minimal laccase activity. Meanwhile, the sinapic acid mediator altered the S/G peak ratio consistent with mediator attaching to the wood solids. The current investigation demonstrates the action of bacterial laccase-mediator systems directly on woody materials, and the potential of using ToF-SIMS to uncover the fundamental and applied role of bacterial enzymes in lignocellulose conversion. © 2017 Scandinavian Plant Physiology Society.

  8. The Arbuscular Mycorrhizal Fungus Funneliformis mosseae Alters Bacterial Communities in Subtropical Forest Soils during Litter Decomposition

    Directory of Open Access Journals (Sweden)

    Heng Gui

    2017-06-01

    Full Text Available Bacterial communities and arbuscular mycorrhizal fungi (AMF co-occur in the soil, however, the interaction between these two groups during litter decomposition remains largely unexplored. In order to investigate the effect of AMF on soil bacterial communities, we designed dual compartment microcosms, where AMF (Funneliformis mosseae was allowed access (AM to, or excluded (NM from, a compartment containing forest soil and litterbags. Soil samples from this compartment were analyzed at 0, 90, 120, 150, and 180 days. For each sample, Illumina sequencing was used to assess any changes in the soil bacterial communities. We found that most of the obtained operational taxonomic units (OTUs from both treatments belonged to the phylum of Proteobacteria, Acidobacteria, and Actinobacteria. The community composition of bacteria at phylum and class levels was slightly influenced by both time and AMF. In addition, time and AMF significantly affected bacterial genera (e.g., Candidatus Solibacter, Dyella, Phenylobacterium involved in litter decomposition. Opposite to the bacterial community composition, we found that overall soil bacterial OTU richness and diversity are relatively stable and were not significantly influenced by either time or AMF inoculation. OTU richness at phylum and class levels also showed consistent results with overall bacterial OTU richness. Our study provides new insight into the influence of AMF on soil bacterial communities at the genus level.

  9. Bacterial adherence to polymethylmethacrylate posterior chamber IOLs

    Directory of Open Access Journals (Sweden)

    Tyagi Shalini

    2001-01-01

    Full Text Available Purpose: Bacterial adherence to intraocular lenses (IOLs has been incriminated in the pathogenesis of postoperative endophthalmitis. Staphylococcus epidermidis is the most common organism isolated. We studied the in-vitro adhesion of Staphylococcus epidermidis to Polymethylmethacrylate (PMMA IOLs and the effect of duration of exposure to adherence. Methods: Two groups of 10 IOLs each were incubated in Staphylococcus epidermidis suspension for 2 minutes and 20 minutes respectively. Adhesion of bacterial cells was determined by counting the number of viable bacteria attached to IOLs. Results: The mean bacterial adherence with 2 minutes incubation was 12,889 ± 7,150 bacteria / IOL and with 20 minutes incubation was 84,226 ± 35,024 bacteria/IOL (P< 0.01. Conclusion: Our results show that Staphylococcus epidermidis adheres to PMMA IOLs in vitro and the degree of adherence is less for shorter duration of exposure. We conclude that viable bacteria irreversibly adherent to IOLs may play a role in the pathogenesis of postoperative endophthalmitis. Shorter duration of operative manipulation and exposure to contaminating sources may decrease the chances of postoperative endophthalmitis.

  10. Carbon nanotubes as in vivo bacterial probes.

    Science.gov (United States)

    Bardhan, Neelkanth M; Ghosh, Debadyuti; Belcher, Angela M

    2014-09-17

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F'-positive and F'-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F'-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  11. Carbon nanotubes as in vivo bacterial probes

    Science.gov (United States)

    Bardhan, Neelkanth M.; Ghosh, Debadyuti; Belcher, Angela M.

    2014-09-01

    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F‧-positive and F‧-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F‧-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  12. Present and future etiological treatment of bacterial pneumonia 3. The antibacterial drugs under development

    Directory of Open Access Journals (Sweden)

    A.A. Abaturov

    2017-08-01

    Full Text Available The rapid spread of antibiotic-resistant bacterial strains necessitates the development of new antibacterial agents and a review of the guidelines for etiological treatment of bacterial infections, including pneumonia. Currently, new antibacterial agents are being developed that disrupt the biosynthesis of peptidoglycan, teichoic and lipoteichoic acids, and also block the attachment of virulent factors to the bacterial wall. New molecules of old classes of antibiotics and representatives of new classes of antibiotics with their targets (lipid II and III, teichoic and lipoteichoic acids, alanine racemase, and sortase A will become practical tools in clinical practice in the very near future. The goals and mechanisms of action of new antibacterial compounds predetermine their clinical prospects in future strategies for the treatment of infectious bacterial diseases.

  13. Cell surface physico chemistry alters biofilm development of Pseudomonas aeruginosa lipopolysaccharide mutants

    NARCIS (Netherlands)

    Flemming, CA; Palmer, RJ; Arrage, AA; van der Mei, H.C.; White, DC

    1999-01-01

    The hydrophobic and electrostatic characteristics of bacterial cell surfaces were compared with attachment proclivity and biomass accumulation over time between wildtype Pseudomonas aeruginosa serotype O6 (possesses A and B band LPS), and three LPS-deficient mutants, vi;. A28 (A(+)B(-)), R5

  14. Cryo-electron tomography of bacterial viruses

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Ferreira, Ricardo C. [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children' s Healthcare of Atlanta, Atlanta, GA 30322 (United States); Wright, Elizabeth R., E-mail: erwrigh@emory.edu [Division of Pediatric Infectious Diseases, Emory University School of Medicine, Children' s Healthcare of Atlanta, Atlanta, GA 30322 (United States)

    2013-01-05

    Bacteriophage particles contain both simple and complex macromolecular assemblages and machines that enable them to regulate the infection process under diverse environmental conditions with a broad range of bacterial hosts. Recent developments in cryo-electron tomography (cryo-ET) make it possible to observe the interactions of bacteriophages with their host cells under native-state conditions at unprecedented resolution and in three-dimensions. This review describes the application of cryo-ET to studies of bacteriophage attachment, genome ejection, assembly and egress. Current topics of investigation and future directions in the field are also discussed.

  15. Maternal antenatal depression and infant disorganized attachment at 12 months.

    Science.gov (United States)

    Hayes, Lisa J; Goodman, Sherryl H; Carlson, Elizabeth

    2013-01-01

    Although high rates of attachment disorganization have been observed in infants of depressed mothers, little is known about the role of antenatal depression as a precursor to infant attachment disorganization. The primary aim of this study was to examine associations between maternal antenatal depression and infant disorganization at 12 months in a sample of women (N = 79) at risk for perinatal depression. A secondary aim was to test the roles of maternal postpartum depression and maternal parenting quality as potential moderators of this predicted association. Among women with histories of major depressive episodes, maternal depressive symptoms were assessed at multiple times during pregnancy and the first year postpartum, maternal parenting quality was measured at three months postpartum, and attachment disorganization was assessed at 12 months postpartum. Results revealed that infants classified as disorganized had mothers with higher levels of depressive symptoms during pregnancy compared to infants classified as organized. Maternal parenting quality moderated this association, as exposure to higher levels of maternal depressive symptoms during pregnancy was only associated with higher rates of infant disorganized attachment when maternal parenting at three months was less optimal. These findings suggest that enhancing maternal parenting behaviors during this early period in development has the potential to alter pathways to disorganized attachment among infants exposed to antenatal maternal depressive symptoms, which could have enduring consequences for child wellbeing.

  16. Drought consistently alters the composition of soil fungal and bacterial communities in grasslands from two continents.

    Science.gov (United States)

    Ochoa-Hueso, Raúl; Collins, Scott L; Delgado-Baquerizo, Manuel; Hamonts, Kelly; Pockman, William T; Sinsabaugh, Robert L; Smith, Melinda D; Knapp, Alan K; Power, Sally A

    2018-03-05

    The effects of short-term drought on soil microbial communities remain largely unexplored, particularly at large scales and under field conditions. We used seven experimental sites from two continents (North America and Australia) to evaluate the impacts of imposed extreme drought on the abundance, community composition, richness, and function of soil bacterial and fungal communities. The sites encompassed different grassland ecosystems spanning a wide range of climatic and soil properties. Drought significantly altered the community composition of soil bacteria and, to a lesser extent, fungi in grasslands from two continents. The magnitude of the fungal community change was directly proportional to the precipitation gradient. This greater fungal sensitivity to drought at more mesic sites contrasts with the generally observed pattern of greater drought sensitivity of plant communities in more arid grasslands, suggesting that plant and microbial communities may respond differently along precipitation gradients. Actinobateria, and Chloroflexi, bacterial phyla typically dominant in dry environments, increased their relative abundance in response to drought, whereas Glomeromycetes, a fungal class regarded as widely symbiotic, decreased in relative abundance. The response of Chlamydiae and Tenericutes, two phyla of mostly pathogenic species, decreased and increased along the precipitation gradient, respectively. Soil enzyme activity consistently increased under drought, a response that was attributed to drought-induced changes in microbial community structure rather than to changes in abundance and diversity. Our results provide evidence that drought has a widespread effect on the assembly of microbial communities, one of the major drivers of soil function in terrestrial ecosystems. Such responses may have important implications for the provision of key ecosystem services, including nutrient cycling, and may result in the weakening of plant-microbial interactions and a

  17. Role of Gamma Radiation and Some Natural Products in Alteration of Bacterial Outer Membrane Porins Permeability for Uptake of Certain Antibiotics

    International Nuclear Information System (INIS)

    El-Bastawisy, H.S.

    2015-01-01

    Membrane permeability is the first step involved in resistance of bacteria to an antibiotic. The bacterial outer membrane proteins (OMPs) that constitute porins play role in the definition of intrinsic resistance in Gram negative bacilli that is altered under antibiotic pressure. It has been noted that the response to prolonged exposure to increasing levels of antibiotic cause major changes in the permeability of the bacterium due to down regulation of porins and over expression of efflux pumps. In this study a total of 92 bacterial isolates of different species were isolated from different sites of cancer and non cancer patients; the microorganisms were identified using API system. The susceptibility test was carried out for all the isolates to detect the multidrug resistant isolates; from this test eleven strains were selected for further studies. Antimicrobial susceptibility of the eleven strains against some selected antibiotics acting on the inhibition of cell wall synthesis before and after in vitro gamma irradiation was carried out. The obtained results showed a clear increase in the number of resistant isolates after irradiation as compared to those before irradiation. The efficacy of the citrus fruits (Citrus limon, Citrus paradise, Citrus reticulate and Citrus sinensis) was tested to improve the performance of the tested antibiotics by increasing its permeability through the porin channels. The dried crushed citrus fruits peels were decontaminated by gamma irradiation at 700 Gray; then the aqueous extract of the citrus fruits were prepared to test its antimicrobial activity against the selected bacterial strains. The obtained results revealed that the aqueous extracts of different citrus fruits peels did not show any antibacterial activities against six bacterial isolates (Acinetobacter calcoaceticus 44, Enterbacter cloacae 51, Escherichia coli 52, Pseudomonas fluorescens 64, Klebsiella pneumoniae 78 and Pseudomonas aeruginosa 90). Therefore, these six

  18. 'Adoption and attachment theory' the attachment models of adoptive mothers and the revision of attachment patterns of their late-adopted children.

    Science.gov (United States)

    Pace, C S; Zavattini, G C

    2011-01-01

    This study examined the attachment patterns of late-adopted children (aged 4-7) and their adoptive mothers during the first 7- to 8-month period after adoption and aimed to evaluate the effect of adoptive mothers' attachment security on the revision of the attachment patterns of their late-adopted children. We assessed attachment patterns in 20 adoptive dyads and 12 genetically related dyads at two different times: T1 (time 1) within 2 months of adoption and T2 (time 2) 6 months after T1. The children's behavioural attachment patterns were assessed using the Separation-Reunion Procedure and the children's representational (verbal) attachment patterns using the Manchester Child Attachment Story Task. The attachment models of the adoptive mothers were classified using the Adult Attachment Interview. We found that there was a significant enhancement of the late-adopted children's attachment security across the time period considered (P= 0.008). Moreover, all the late-adopted children who showed a change from insecurity to security had adoptive mothers with secure attachment models (P= 0.044). However, the matching between maternal attachment models and late-adopted children's attachment patterns (behaviours and representations) was not significant. Our data suggest that revision of the attachment patterns in the late-adopted children is possible but gradual, and that the adoptive mothers' attachment security makes it more likely to occur. © 2010 Blackwell Publishing Ltd.

  19. Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

    Science.gov (United States)

    Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H

    2011-02-17

    Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

  20. Alterations in Helicobacter pylori triggered by contact with gastric epithelial cells

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Johnson

    2012-02-01

    Full Text Available Helicobacter pylori lives within the mucus layer of the human stomach, in close proximity to gastric epithelial cells. While a great deal is known about the effects of H. pylori on human cells and the specific bacterial products that mediate these effects, relatively little work has been done to investigate alterations in H. pylori that may be triggered by bacterial contact with human cells. In this review, we discuss the spectrum of changes in bacterial physiology and morphology that occur when H. pylori is in contact with gastric epithelial cells. Several studies have reported that cell contact causes alterations in H. pylori gene transcription. In addition, H. pylori contact with gastric epithelial cells promotes the formation of pilus-like structures at the bacteria-host cell interface. The formation of these structures requires multiple genes in the cag pathogenicity island, and these structures are proposed to have an important role in the type IV secretion system-dependent process through which CagA enters host cells. Finally, H. pylori contact with epithelial cells can promote bacterial replication and the formation of microcolonies, phenomena that are facilitated by the acquisition of iron and other nutrients from infected cells. In summary, the gastric epithelial cell surface represents an important niche for H. pylori, and upon entry into this niche, the bacteria alter their behavior in a manner that optimizes bacterial proliferation and persistent colonization of the host.

  1. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    International Nuclear Information System (INIS)

    Möller, Jens; Emge, Philippe; Vizcarra, Ima Avalos; Kollmannsberger, Philip; Vogel, Viola

    2013-01-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length. (paper)

  2. Bacterial filamentation accelerates colonization of adhesive spots embedded in biopassive surfaces

    Science.gov (United States)

    Möller, Jens; Emge, Philippe; Avalos Vizcarra, Ima; Kollmannsberger, Philip; Vogel, Viola

    2013-12-01

    Sessile bacteria adhere to engineered surfaces and host tissues and pose a substantial clinical and economical risk when growing into biofilms. Most engineered and biological interfaces are of chemically heterogeneous nature and provide adhesive islands for bacterial attachment and growth. To mimic either defects in a surface coating of biomedical implants or heterogeneities within mucosal layers (Peyer's patches), we embedded micrometre-sized adhesive islands in a poly(ethylene glycol) biopassive background. We show experimentally and computationally that filamentation of Escherichia coli can significantly accelerate the bacterial surface colonization under physiological flow conditions. Filamentation can thus provide an advantage to a bacterial population to bridge non-adhesive distances exceeding 5 μm. Bacterial filamentation, caused by blocking of bacterial division, is common among bacterial species and can be triggered by environmental conditions or antibiotic treatment. While great awareness exists that the build-up of antibiotic resistance serves as intrinsic survival strategy, we show here that antibiotic treatment can actually promote surface colonization by triggering filamentation, which in turn prevents daughter cells from being washed away. Our combined microfabrication and computational approaches provide quantitative insights into mechanisms that enable biofouling of biopassive surfaces with embedded adhesive spots, even for spot distances that are multiples of the bacterial length.

  3. Cellular reprogramming by gram-positive bacterial components: a review.

    LENUS (Irish Health Repository)

    Buckley, Julliette M

    2012-02-03

    LPS tolerance has been the focus of extensive scientific and clinical research over the last several decades in an attempt to elucidate the sequence of changes that occur at a molecular level in tolerized cells. Tolerance to components of gram-positive bacterial cell walls such as bacterial lipoprotein and lipoteichoic acid is a much lesser studied, although equally important, phenomenon. This review will focus on cellular reprogramming by gram-positive bacterial components and examines the alterations in cell surface receptor expression, changes in intracellular signaling, gene expression and cytokine production, and the phenomenon of cross-tolerance.

  4. The attachment system in fledgling relationships: an activating role for attachment anxiety.

    Science.gov (United States)

    Eastwick, Paul W; Finkel, Eli J

    2008-09-01

    Is it sensible to study attachment dynamics between potential romantic partners before they share a full-fledged attachment bond? The present data indicate that such an approach may reveal novel insights about initial attraction processes. Four studies suggest that the state-like experience of attachment anxiety has functional implications within fledgling (i.e., desired or undeveloped) romantic relationships, well before the formation of an attachment bond. Studies 1 and 3 reveal that attachment anxiety directed toward a particular romantic interest is elevated before (in comparison with after) participants report being in an established relationship. Studies 2 and 3 demonstrate that such partner-specific attachment anxiety predicts attachment-relevant outcomes in fledgling relationships, including proximity seeking, safe haven, secure base, passionate love, and other approach behaviors. These associations were reliable above and beyond (and were typically as strong as or stronger than) the effect of sexual desire. Finally, Study 4 presents evidence that partner-specific attachment anxiety may cause several of these attachment-relevant outcomes. Attachment anxiety seems to be a normative experience and may signal the activation of the attachment system during the earliest stages of romantic relationships.

  5. Blade attachment assembly

    Science.gov (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

    2016-05-03

    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  6. Surface-attached cells, biofilms and biocide susceptibility: implications for hospital cleaning and disinfection.

    Science.gov (United States)

    Otter, J A; Vickery, K; Walker, J T; deLancey Pulcini, E; Stoodley, P; Goldenberg, S D; Salkeld, J A G; Chewins, J; Yezli, S; Edgeworth, J D

    2015-01-01

    Microbes tend to attach to available surfaces and readily form biofilms, which is problematic in healthcare settings. Biofilms are traditionally associated with wet or damp surfaces such as indwelling medical devices and tubing on medical equipment. However, microbes can survive for extended periods in a desiccated state on dry hospital surfaces, and biofilms have recently been discovered on dry hospital surfaces. Microbes attached to surfaces and in biofilms are less susceptible to biocides, antibiotics and physical stress. Thus, surface attachment and/or biofilm formation may explain how vegetative bacteria can survive on surfaces for weeks to months (or more), interfere with attempts to recover microbes through environmental sampling, and provide a mixed bacterial population for the horizontal transfer of resistance genes. The capacity of existing detergent formulations and disinfectants to disrupt biofilms may have an important and previously unrecognized role in determining their effectiveness in the field, which should be reflected in testing standards. There is a need for further research to elucidate the nature and physiology of microbes on dry hospital surfaces, specifically the prevalence and composition of biofilms. This will inform new approaches to hospital cleaning and disinfection, including novel surfaces that reduce microbial attachment and improve microbial detachment, and methods to augment the activity of biocides against surface-attached microbes such as bacteriophages and antimicrobial peptides. Future strategies to address environmental contamination on hospital surfaces should consider the presence of microbes attached to surfaces, including biofilms. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. Transitions in sensitive period attachment learning in infancy: the role of corticosterone.

    Science.gov (United States)

    Sullivan, Regina M; Holman, Parker J

    2010-05-01

    Survival of altricial infants, including humans and rats, depends on attachment to the caregiver - a process that requires infants to recognize, learn, and remember their attachment figure. The demands of a dynamic environment combined with a maturing organism require frequent neurobehavioral reorganization. This restructuring of behavior and its supporting neural circuitry can be viewed through the unique lens of attachment learning in rats in which preference learning is enhanced and aversion learning is attenuated. Behavioral restructuring is well adapted to securing the crucial infant-caregiver relationship regardless of the quality of care. With maturation and the end of the infant-caregiver attachment learning period, the complex interplay of neural structures, hormones, and social behavior coordinates the developing rat's eventual transition to life outside of the nest. Nevertheless, early-life environmental and physiological stressors can alter the resilient nature of this system, particularly with respect to the amygdala, and these changes may provide important clues to understanding the lasting effects of early stress. (c) 2009 Elsevier Ltd. All rights reserved.

  8. Bacterial transport in heterogeneous porous media: Observations from laboratory experiments

    Science.gov (United States)

    Silliman, S. E.; Dunlap, R.; Fletcher, M.; Schneegurt, M. A.

    2001-11-01

    Transport of bacteria through heterogeneous porous media was investigated in small-scale columns packed with sand and in a tank designed to allow the hydraulic conductivity to vary as a two-dimensional, lognormally distributed, second-order stationary, exponentially correlated random field. The bacteria were Pseudomonas ftuorescens R8, a strain demonstrating appreciable attachment to surfaces, and strain Ml, a transposon mutant of strain R8 with reduced attachment ability. In bench top, sand-filled columns, transport was determined by measuring intensity of fluorescence of stained cells in the effluent or by measuring radiolabeled cells that were retained in the sand columns. Results demonstrated that strain Ml was transported more efficiently than strain R8 through columns packed with either a homogeneous silica sand or a more heterogeneous sand with iron oxide coatings. Two experiments conducted in the tank involved monitoring transport of bacteria to wells via sampling from wells and sample ports in the tank. Bacterial numbers were determined by direct plate count. At the end of the first experiment, the distribution of the bacteria in the sediment was determined by destructive sampling and plating. The two experiments produced bacterial breakthrough curves that were quite similar even though the similarity between the two porous media was limited to first- and second-order statistical moments. This result appears consistent with the concept of large-scale, average behavior such as has been observed for the transport of conservative chemical tracers. The transported bacteria arrived simultaneously with a conservative chemical tracer (although at significantly lower normalized concentration than the tracer). However, the bacterial breakthrough curves showed significant late time tailing. The concentrations of bacteria attached to the sediment surfaces showed considerably more spatial variation than did the concentrations of bacteria in the fluid phase. This

  9. Influence of microorganisms on the alteration of glasses; Influence des microorganismes sur l'alteration des verres

    Energy Technology Data Exchange (ETDEWEB)

    Besnainou, B; Libert, M F [CEA Cadarache, 13 - Saint Paul lez Durance (France). Dept. d' Entreposage et de Stockage des Dechets

    1997-07-01

    Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

  10. Characterization of bovine ruminal epithelial bacterial communities using 16S rRNA sequencing, PCR-DGGE, and qRT-PCR analysis.

    Science.gov (United States)

    Li, Meiju; Zhou, Mi; Adamowicz, Elizabeth; Basarab, John A; Guan, Le Luo

    2012-02-24

    Currently, knowledge regarding the ecology and function of bacteria attached to the epithelial tissue of the rumen wall is limited. In this study, the diversity of the bacterial community attached to the rumen epithelial tissue was compared to the rumen content bacterial community using 16S rRNA gene sequencing, PCR-DGGE, and qRT-PCR analysis. Sequence analysis of 2785 randomly selected clones from six 16S rDNA (∼1.4kb) libraries showed that the community structures of three rumen content libraries clustered together and were separated from the rumen tissue libraries. The diversity index of each library revealed that ruminal content bacterial communities (4.12/4.42/4.88) were higher than ruminal tissue communities (2.90/2.73/3.23), based on 97% similarity. The phylum Firmicutes was predominant in the ruminal tissue communities, while the phylum Bacteroidetes was predominant in the ruminal content communities. The phyla Fibrobacteres, Planctomycetes, and Verrucomicrobia were only detected in the ruminal content communities. PCR-DGGE analysis of the bacterial profiles of the rumen content and ruminal epithelial tissue samples from 22 steers further confirmed that there is a distinct bacterial community that inhibits the rumen epithelium. The distinctive epimural bacterial communities suggest that Firmicutes, together with other epithelial-specific species, may have additional functions other than food digestion. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Smoking cessation alters subgingival microbial recolonization.

    Science.gov (United States)

    Fullmer, S C; Preshaw, P M; Heasman, P A; Kumar, P S

    2009-06-01

    Smoking cessation improves the clinical manifestations of periodontitis; however, its effect on the subgingival biofilm, the primary etiological agent of periodontitis, is unclear. The purpose of this study was to investigate, longitudinally, if smoking cessation altered the composition of the subgingival microbial community, by means of a quantitative, cultivation-independent assay for bacterial profiling. Subgingival plaque was collected at baseline, and 3, 6, and 12 months post-treatment from smokers who received root planing and smoking cessation counseling. The plaque was analyzed by terminal restriction fragment length polymorphism (t-RFLP). Microbial profiles differed significantly between smokers and quitters at 6 and 12 months following smoking cessation. The microbial community in smokers was similar to baseline, while quitters demonstrated significantly divergent profiles. Changes in bacterial levels contributed to this shift. These findings reveal a critical role for smoking cessation in altering the subgingival biofilm and suggest a mechanism for improved periodontal health associated with smoking cessation.

  12. Electron-attachment processes

    International Nuclear Information System (INIS)

    Christophorou, L.G.; McCorkle, D.L.; Christodoulides, A.A.

    1982-01-01

    Topics covered include: (1) modes of production of negative ions, (2) techniques for the study of electron attachment processes, (3) dissociative electron attachment to ground-state molecules, (4) dissociative electron attachment to hot molecules (effects of temperature on dissociative electron attachment), (5) molecular parent negative ions, and (6) negative ions formed by ion-pair processes and by collisions of molecules with ground state and Rydberg atoms

  13. Long-term nickel exposure altered the bacterial community composition but not diversity in two contrasting agricultural soils.

    Science.gov (United States)

    Li, Jing; Hu, Hang-Wei; Ma, Yi-Bing; Wang, Jun-Tao; Liu, Yu-Rong; He, Ji-Zheng

    2015-07-01

    Nickel pollution imposes deleterious effects on soil ecosystem. The responses of soil microorganisms to long-term nickel pollution under field conditions remain largely unknown. Here, we used high-throughput sequencing to elucidate the impacts of long-term nickel pollution on soil bacterial communities in two contrasting agricultural soils. Our results found that the soil microbial biomass carbon consistently decreased along the nickel gradients in both soils. Nickel pollution selectively favored or impeded the prevalence of several dominant bacterial guilds, in particular, Actinobacteria showed tolerance, while Acidobacteria and Planctomycetes displayed sensitivity. Despite the apparent shifts in the bacterial community composition, no clear tendency in the bacterial diversity and abundance was identified along the nickel gradients in either soil. Collectively, we provide evidence that long-term nickel pollution shifted the soil bacterial communities, resulting in the decrease of microbial biomass although the bacterial diversity was not significantly changed.

  14. Bacterial biofilm and associated infections

    Directory of Open Access Journals (Sweden)

    Muhsin Jamal

    2018-01-01

    Full Text Available Microscopic entities, microorganisms that drastically affect human health need to be thoroughly investigated. A biofilm is an architectural colony of microorganisms, within a matrix of extracellular polymeric substance that they produce. Biofilm contains microbial cells adherent to one-another and to a static surface (living or non-living. Bacterial biofilms are usually pathogenic in nature and can cause nosocomial infections. The National Institutes of Health (NIH revealed that among all microbial and chronic infections, 65% and 80%, respectively, are associated with biofilm formation. The process of biofilm formation consists of many steps, starting with attachment to a living or non-living surface that will lead to formation of micro-colony, giving rise to three-dimensional structures and ending up, after maturation, with detachment. During formation of biofilm several species of bacteria communicate with one another, employing quorum sensing. In general, bacterial biofilms show resistance against human immune system, as well as against antibiotics. Health related concerns speak loud due to the biofilm potential to cause diseases, utilizing both device-related and non-device-related infections. In summary, the understanding of bacterial biofilm is important to manage and/or to eradicate biofilm-related diseases. The current review is, therefore, an effort to encompass the current concepts in biofilm formation and its implications in human health and disease.

  15. Candida albicans and bacterial microbiota interactions in the cecum during recolonization following broad-spectrum antibiotic therapy.

    Science.gov (United States)

    Mason, Katie L; Erb Downward, John R; Mason, Kelly D; Falkowski, Nicole R; Eaton, Kathryn A; Kao, John Y; Young, Vincent B; Huffnagle, Gary B

    2012-10-01

    Candida albicans is a normal member of the gastrointestinal (GI) tract microbiota of healthy humans, but during host immunosuppression or alterations in the bacterial microbiota, C. albicans can disseminate and cause life-threatening illness. The bacterial microbiome of the GI tract, including lactic acid bacteria (LAB), plays a vital role in preventing fungal invasion. However, little is known about the role of C. albicans in shaping the bacterial microbiota during antibiotic recovery. We investigated the fungal burdens in the GI tracts of germfree mice and mice with a disturbed microbiome to demonstrate the role of the microbiota in preventing C. albicans colonization. Histological analysis demonstrated that colonization with C. albicans during antibiotic treatment does not trigger overt inflammation in the murine cecum. Bacterial diversity is reduced long term following cefoperazone treatment, but the presence of C. albicans during antibiotic recovery promoted the recovery of bacterial diversity. Cefoperazone diminishes Bacteroidetes populations long term in the ceca of mice, but the presence of C. albicans during cefoperazone recovery promoted Bacteroidetes population recovery. However, the presence of C. albicans resulted in a long-term reduction in Lactobacillus spp. and promoted Enterococcus faecalis populations. Previous studies have focused on the ability of bacteria to alter C. albicans; this study addresses the ability of C. albicans to alter the bacterial microbiota during nonpathogenic colonization.

  16. In vitro chondrogenesis with lysozyme susceptible bacterial cellulose as a scaffold.

    Science.gov (United States)

    Yadav, Vikas; Sun, Lin; Panilaitis, Bruce; Kaplan, David L

    2015-12-01

    A current focus of tissue engineering is the use of adult human mesenchymal stem cells (hMSCs) as an alternative to autologous chondrocytes for cartilage repair. Several natural and synthetic polymers (including cellulose) have been explored as a biomaterial scaffold for cartilage tissue engineering. While bacterial cellulose (BC) has been used in tissue engineering, its lack of degradability in vivo and high crystallinity restricts widespread applications in the field. Recently we reported the formation of a novel bacterial cellulose that is lysozyme-susceptible and -degradable in vivo from metabolically engineered Gluconacetobacter xylinus. Here we report the use of this modified bacterial cellulose (MBC) for cartilage tissue engineering using hMSCs. MBC's glucosaminoglycan-like chemistry, combined with in vivo degradability, suggested opportunities to exploit this novel polymer in cartilage tissue engineering. We have observed that, like BC, MBC scaffolds support cell attachment and proliferation. Chondrogenesis of hMSCs in the MBC scaffolds was demonstrated by real-time RT-PCR analysis for cartilage-specific extracellular matrix (ECM) markers (collagen type II, aggrecan and SOX9) as well as histological and immunohistochemical evaluations of cartilage-specific ECM markers. Further, the attachment, proliferation, and differentiation of hMSCs in MBC showed unique characteristics. For example, after 4 weeks of cultivation, the spatial cell arrangement and collagen type-II and ACAN distribution resembled those in native articular cartilage tissue, suggesting promise for these novel in vivo degradable scaffolds for chondrogenesis. Copyright © 2013 John Wiley & Sons, Ltd.

  17. Measurement of glucose utilization by Pseudomonas fluorescens that are free-living and that are attached to surfaces

    International Nuclear Information System (INIS)

    Fletcher, M.

    1986-01-01

    The assimilation and respiration of glucose by attached and free-living Pseudomonas fluorescens were compared. The attachment surfaces were polyvinylidene fluoride, polyethylene, and glass. Specific uptake of [ 1 C]glucose was determined after bacterial biomass was measured by (1) microscopic counts or (2) prelabelling of cells by providing [ 3 H]leucine as substrate, followed by dual-labelling scintillation counting. The glucose concentration was 1.4, 3.5, 5.5, 7.6, or 9.7 μM. Glucose assimilation by cells which became detached from the surfaces during incubation with glucose was also measured after the detached cells were collected by filtration. The composition of the substratum had no effect on the amount of glucose assimilated by attached cells. Glucose assimilation by attached cells exceeded that by free-living cells by a factor of between 2 and 5 or more, and respiration of glucose by surface-associated cells was greater than that by free-living bacteria. Glucose assimilation by detached cells was greater than that by attached bacteria. Measurements of biomass by microscopic counts gave more consistent results than those obtained with dual-labelling, but in general, results obtained by both methods were corroborative

  18. Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

    Science.gov (United States)

    Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G

    2012-11-01

    Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

  19. Role of a bacillus Calmette-Guérin fibronectin attachment protein in BCG-induced antitumor activity.

    Science.gov (United States)

    Zhao, W; Schorey, J S; Bong-Mastek, M; Ritchey, J; Brown, E J; Ratliff, T L

    2000-04-01

    Intravesical Mycobacterium bovis bacillus Calmette-Gu*erin (BCG) is the treatment of choice for superficial bladder cancer. Previous studies showed that attachment of BCG to fibronectin within the bladder was necessary for mediation of the antitumor response. Further studies identified a bacterial receptor, fibronectin attachment protein (FAP), as an important mediator of BCG attachment to fibronectin. In vitro studies showed that a stable BCG/fibronectin interaction was dependent on FAP binding to fibronectin; however, no role for FAP in the attachment of BCG in vivo has been characterized. We now report the cloning of the M. bovis BCG FAP (FAP-B) and demonstrate an important role for FAP in the in vivo attachment of BCG to the bladder wall and in the induction of BCG-mediated antitumor activity. The predicted amino acid sequence for FAP-B shows 61% and 71% homology, respectively, with Mycobacterium avium FAP (FAP-A) and Mycobacterium leprae FAP (FAP-L). Rabbit polyclonal antibodies against Mycobacterium vaccae FAP (FAP-V) reacted with all 3 recombinant FAP proteins on Western blots. Functional studies show FAP-B to bind fibronectin via the highly conserved attachment regions previously identified for FAP-A and FAP-L and also to competitively inhibit attachment of BCG to matrix fibronectin. In vivo studies show FAP to be a necessary protein for the stable attachment of BCG to the bladder wall. Moreover, stable binding of BCG via FAP was shown to be necessary for the expression of BCG-induced antitumor activity. Our results demonstrate a biological role for FAP in the mediation of BCG-induced antitumor activity.

  20. Attachment and social networks.

    Science.gov (United States)

    Gillath, Omri; C Karantzas, Gery; Lee, Juwon

    2018-02-21

    The current review covers two lines of research linking attachment and social networks. One focuses on attachment networks (the people who fulfill one's attachment needs), examining composition and age-related differences pertaining to these networks. The other line integrates attachment with social network analysis to investigate how individual differences in adult attachment are associated with the management and characteristics (e.g., density, multiplexity, and centrality) of people's social networks. We show that most people's attachment networks are small and hierarchical, with one figure being the primary attachment figure (often a mother or romantic partner, depending on age). Furthermore, attachment style predicts network characteristics and management, such that insecurity is associated with less closeness, multiplexity, centrality, and poorer management (less maintenance, more dissolution). Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Brood size modifications affect plumage bacterial assemblages of European starlings.

    Science.gov (United States)

    Lucas, Françoise S; Moureau, Benoit; Jourdie, Violaine; Heeb, Philipp

    2005-02-01

    During reproduction, birds face trade-offs between time and energy devoted to parental effort and traits associated with self-maintenance. We manipulated brood sizes to investigate the effects of such trade-offs on feather bacterial densities and the structure of bacterial assemblages on feathers in adult European starlings, Sturnus vulgaris, and in vitro feather degradation. As predicted by a trade-off between parental effort and self-maintenance, we found that birds with enlarged broods had more free-living bacteria on their feathers than birds with reduced broods. Furthermore, we found a significant interaction between brood manipulation and original brood size on free-living bacterial densities suggesting that the trade-off is mediated by the adults' initial reproductive investment. In contrast, brood size manipulations had no significant effect on densities of attached bacteria. Using ribosomal intergenic spacer analysis (RISA), we demonstrated that brood manipulations significantly modified the structure (band pattern) of feather-degrading bacterial assemblages, but had no significant effect on their richness (number of bands) or the in vitro feather degradation. In vitro feather degradation varied in relation to the premanipulation brood size and positively with the richness of the feather degrading bacterial community. Besides brood manipulation effect, we found that ecological factors and individual traits, such as the age, the nest location or the capture date, shaped bacterial assemblages and feather degradation capacities.

  2. Viii. Attachment and sleep among toddlers: disentangling attachment security and dependency.

    Science.gov (United States)

    Bélanger, Marie-Ève; Bernier, Annie; Simard, Valérie; Bordeleau, Stéphanie; Carrier, Julie

    2015-03-01

    Many scholars have proposed that parent-child attachment security should favor child sleep. Research has yet, however, to provide convincing support for this hypothesis. The current study used objective measures of sleep and attachment to assess the longitudinal links between mother-child attachment security and subsequent sleep, controlling for child dependency. Sixty-two middle-class families (30 girls) were met twice, when children were 15 months (Wave 1; W1) and 2 years of age (Wave 2; W2). At W1, mother-child attachment was assessed with the observer version of the Attachment Q-Sort. At W2, children wore an actigraph monitor for 72 hr. Results indicated that children more securely attached to their mothers subsequently slept more at night and had higher sleep efficiency, and these predictions were not confounded by child dependency. These findings suggest a unique role for secure attachment relationships in the development of young children's sleep regulation, while addressing methodological issues that have long precluded consensus in this literature. © 2015 The Society for Research in Child Development, Inc.

  3. DNA repair in bacterial cultures and plasmid DNA exposed to infrared laser for treatment of pain

    International Nuclear Information System (INIS)

    Canuto, K S; Sergio, L P S; Marciano, R S; Guimarães, O R; Polignano, G A C; Geller, M; Fonseca, A S; Paoli, F

    2013-01-01

    Biostimulation of tissues by low intensity lasers has been described on a photobiological basis and clinical protocols are recommended for treatment of various diseases, but their effects on DNA are controversial. The objective of this work was to evaluate effects of low intensity infrared laser exposure on survival and bacterial filamentation in Escherichia coli cultures, and induction of DNA lesions in bacterial plasmids. In E. coli cultures and plasmids exposed to an infrared laser at fluences used to treat pain, bacterial survival and filamentation and DNA lesions in plasmids were evaluated by electrophoretic profile. Data indicate that the infrared laser (i) increases survival of E. coli wild type in 24 h of stationary growth phase, (ii) induces bacterial filamentation, (iii) does not alter topological forms of plasmids and (iv) does not alter the electrophoretic profile of plasmids incubated with exonuclease III or formamidopyrimidine DNA glycosylase. A low intensity infrared laser at the therapeutic fluences used to treat pain can alter survival of E. coli wild type, induce filamentation in bacterial cells, depending on physiologic conditions and DNA repair, and induce DNA lesions other than single or double DNA strand breaks or alkali-labile sites, which are not targeted by exonuclease III or formamidopyrimidine DNA glycosylase. (letter)

  4. Bacterial Extracellular Polysaccharides Involved in Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Elena P. Ivanova

    2009-07-01

    Full Text Available Extracellular polymeric substances (EPS produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids and humic substances. EPS make up the intercellular space of microbial aggregates and form the structure and architecture of the biofilm matrix. The key functions of EPS comprise the mediation of the initial attachment of cells to different substrata and protection against environmental stress and dehydration. The aim of this review is to present a summary of the current status of the research into the role of EPS in bacterial attachment followed by biofilm formation. The latter has a profound impact on an array of biomedical, biotechnology and industrial fields including pharmaceutical and surgical applications, food engineering, bioremediation and biohydrometallurgy. The diverse structural variations of EPS produced by bacteria of different taxonomic lineages, together with examples of biotechnological applications, are discussed. Finally, a range of novel techniques that can be used in studies involving biofilm-specific polysaccharides is discussed.

  5. A computer investigation of chemically mediated detachment in bacterial biofilms.

    Science.gov (United States)

    Hunt, Stephen M; Hamilton, Martin A; Sears, John T; Harkin, Gary; Reno, Jason

    2003-05-01

    A three-dimensional computer model was used to evaluate the effect of chemically mediated detachment on biofilm development in a negligible-shear environment. The model, BacLAB, combines conventional diffusion-reaction equations for chemicals with a cellular automata algorithm to simulate bacterial growth, movement and detachment. BacLAB simulates the life cycle of a bacterial biofilm from its initial colonization of a surface to the development of a mature biofilm with cell areal densities comparable to those in the laboratory. A base model founded on well established transport equations that are easily adaptable to investigate conjectures at the biological level has been created. In this study, the conjecture of a detachment mechanism involving a bacterially produced chemical detachment factor in which high local concentrations of this detachment factor cause the bacteria to detach from the biofilm was examined. The results show that the often observed 'mushroom'-shaped structure can occur if detachment events create voids so that the remaining attached cells look like mushrooms.

  6. Effects of the Adult Attachment Projective Picture System on oxytocin and cortisol blood levels in mothers

    Directory of Open Access Journals (Sweden)

    Sabrina Krause

    2016-12-01

    Full Text Available Oxytocin, a small neuropeptide of nine amino acids, has been characterized as the hormone of affiliation and is stimulated, for instance, in mothers when interacting with their offspring. Variations in maternal oxytocin levels were reported to predict differences in the quality of care provided by mothers. In this study, the Adult Attachment Projective Picture System (AAP as a valid measure to assess attachment representations was used as an activating attachment-related stimulus. We investigated whether the AAP induces a release of oxytocin in mothers with a secure attachment representation and a stress-related cortisol response in mothers with an insecure attachment representation. Therefore, pre-post effects of AAP administration on plasma oxytocin and serum cortisol levels were investigated in n = 44 mothers 3 months after parturition. Oxytocin levels increased from pre to post by the significant majority of 73% participants (p = .004 and cortisol decreased by the significant majority of 73% participants (p = .004. Interestingly, no association between alterations in oxytocin and cortisol were found; this suggests taking a model of two independent processes into considerations. These results show that the AAP test procedure induces an oxytocin response. Concerning the results within the four AAP representation subgroups, our hypothesis of a particularly strong increase in oxytocin in secure mothers was not confirmed; however, in secure mothers we observed a particularly strong decrease in cortisol, consistent with our hypotheses. Effect sizes are reported, allowing the replication of results in a larger study with sufficient sample size to draw final conclusions with respect to differences in OT and cortisol alterations depending on attachment representation. When interpreting the results, one should keep in mind that this study investigated lactating mothers. Thus, the generalizability of results is limited and future studies should

  7. Effects of the Adult Attachment Projective Picture System on Oxytocin and Cortisol Blood Levels in Mothers.

    Science.gov (United States)

    Krause, Sabrina; Pokorny, Dan; Schury, Katharina; Doyen-Waldecker, Cornelia; Hulbert, Anna-Lena; Karabatsiakis, Alexander; Kolassa, Iris-Tatjana; Gündel, Harald; Waller, Christiane; Buchheim, Anna

    2016-01-01

    Oxytocin, a small neuropeptide of nine amino acids, has been characterized as the "hormone of affiliation" and is stimulated, for instance, in mothers when interacting with their offspring. Variations in maternal oxytocin levels were reported to predict differences in the quality of care provided by mothers. In this study, the Adult Attachment Projective Picture System (AAP) as a valid measure to assess attachment representations was used as an activating attachment-related stimulus. We investigated whether the AAP induces a release of oxytocin in mothers with a secure attachment representation and a stress-related cortisol response in mothers with an insecure attachment representation. Therefore, pre-post effects of AAP administration on plasma oxytocin and serum cortisol levels were investigated in n = 44 mothers 3 months after parturition. Oxytocin levels increased from pre to post in the significant majority of 73% participants ( p = 0.004) and cortisol decreased in the significant majority of 73% participants ( p = 0.004). Interestingly, no association between alterations in oxytocin and cortisol were found; this suggests taking a model of two independent processes into considerations. These results show that the AAP test procedure induces an oxytocin response. Concerning the results within the four AAP representation subgroups, our hypothesis of a particularly strong increase in oxytocin in secure mothers was not confirmed; however, in secure mothers we observed a particularly strong decrease in cortisol. Effect sizes are reported, allowing the replication of results in a larger study with sufficient sample size to draw final conclusions with respect to differences in OT and cortisol alterations depending on attachment representation. When interpreting the results, one should keep in mind that this study investigated lactating mothers. Thus, the generalizability of results is limited and future studies should investigate non-lactating healthy females as well

  8. An experimental evaluation of the State Adult Attachment Measure: The Influence of Attachment Primes on the Content of State Attachment Representations

    OpenAIRE

    Bosmans, Guy; Bowles, David, P.; Dewitte, Marieke; De Winter, Simon; Braet, Caroline

    2014-01-01

    Attachment theory predicts cross-contextual stability of attachment representations, but research findings are rather mixed. Recently, it has been suggested that these mixed findings reflect the existence of both state and trait attachment components. The development of the State Adult Attachment Measure (SAAM) has enabled an investigation of this hypothesis. The current study aimed to evaluate the extent to which the SAAM is a useful instrument for studying such state attachment hypotheses. ...

  9. Attachment over Time.

    Science.gov (United States)

    Lewis, Michael; Feiring, Candice; Rosenthal, Saul

    2000-01-01

    Examined continuity in attachment classification from infancy through adolescence and related it to autobiographical memories of childhood, divorce, and maladjustment in white middle-class children. Found no continuity in attachment classification from 1 to 18 years and no relation between infant attachment status and adolescent adjustment.…

  10. [Bacterial biofilms as a natural form of existence of bacteria in the environment and host organism].

    Science.gov (United States)

    Romanova, Iu M; Gintsburg, A L

    2011-01-01

    Advances in microscopic analysis and molecular genetics research methods promoted the acquisition of evidence that natural bacteria populations exist predominately as substrate attached biofilms. Bacteria in biofilms are able to exchange signals and display coordinated activity that is inherent to multicellular organisms. Formation of biofilm communities turned out to be one of the main survival strategies of bacteria in their ecological niche. Bacteria in attached condition in biofilm are protected from the environmental damaging factors and effects of antibacterial substances in the environment and host organism during infection. According to contemporary conception, biofilm is a continuous layer of bacterial cells that are attached to a surface and each other, and contained in a biopolymer matrix. Such bacterial communities may be composed of bacteria of one or several species, and composed of actively functioning cells as well as latent and uncultured forms. Particular attention has recently been paid to the role of biofilms in the environment and host organism. Microorganisms form biofilm on any biotic and abiotic surfaces which creates serious problems in medicine and various areas of economic activity. Currently, it is established that biofilms are one of the pathogenetic factors of chronic inflection process formation. The review presents data on ubiquity of bacteria existence as biofilms, contemporary methods of microbial community analysis, structural-functional features of bacterial biofilms. Particular attention is paid to the role of biofilm in chronic infection process formation, heightened resistance to antibiotics of bacteria in biofilms and possible mechanisms of resistance. Screening approaches for agents against biofilms in chronic infections are discussed.

  11. Low childhood subjective social status and telomere length in adulthood: The role of attachment orientations.

    Science.gov (United States)

    Murdock, Kyle W; Seiler, Annina; Chirinos, Diana A; Garcini, Luz M; Acebo, Sally L; Cohen, Sheldon; Fagundes, Christopher P

    2018-04-01

    Low subjective social status (SSS) in childhood places one at greater risk of a number of health problems in adulthood. Theoretical and empirical evidence indicates that exposure to supportive parenting may buffer the negative effects of low childhood SSS on adult health. Given the importance of supportive caregivers and close others for the development of attachment orientations throughout the lifespan, attachment theory may be important for understanding why some individuals are resilient to the negative effects of low childhood SSS on adult health while others are not. We examined if attachment anxiety and attachment avoidance altered the association between childhood subjective social status (SSS) and length of telomeres in white blood cells in adulthood. Shorter telomere length is associated with increased risk of age-related diseases including cancer, type 2 diabetes, and cardiovascular disease. Participants (N = 128) completed self-report measures of childhood SSS and attachment orientations, as well as a blood draw. We found that among those with low childhood SSS, low attachment anxiety was associated with longer telomere length in white blood cells in comparison to high attachment anxiety controlling for participant age, sex, race, body mass index, and adult SSS. Among those with high childhood SSS, low attachment anxiety was associated with a slight decrease in telomere length. Attachment avoidance was unrelated to length of telomeres. Such findings provide further evidence for the role that close relationships may have on buffering SSS related health disparities. © 2018 Wiley Periodicals, Inc.

  12. Application of Colloidal Filtration Theory on Textile Fibrous Media: Effect of Fiber Orientation on Bacterial Removal Efficiency and Attachment

    Science.gov (United States)

    Roy, Sukumar; Ghosh, Subrata; Bhowmick, Niranjan

    2018-05-01

    A mechanism to remove the Pseudomonas bacteria from contaminated water by using textile fibrous media has been proposed in this article. The attachment of Pseudomonas bacteria on nylon fibrous media was studied in laboratory column experiment. A systematic study was carried out to investigate the attachment of bacteria on the fibrous material as a function of fiber orientation to the direction of the liquid flow. Three types of textiles media with different orientation fiber were selected for the experiment (i.e. 0°, 45° and 90°). It was found that the bacteria removal efficiency was comparatively higher at 90° orientation as compared to that of 45° and 0° orientation of fibrous media, suggesting that the removal efficiency of bacteria (1 - Fp) was depended on fiber orientation. The removal trends were explained on the basis of colloidal filtration theory. This is due to the higher single collector contact efficiency and attachment/collision efficiency as observed from the experimental data of removal efficiency.

  13. Altered membrane permeability in multidrug resistant Escherichia ...

    African Journals Online (AJOL)

    The study was conducted with the objective of examining the outer membrane proteins and their involvement during the transport of β - lactams in multidrug resistant Escherichia coli isolated from extra-intestinal infections. Also, the response of gram negative bacterial biomembrane alteration was studied using extended ...

  14. Systemic therapy and attachment narratives: Attachment Narrative Therapy.

    Science.gov (United States)

    Dallos, Rudi; Vetere, Arlene

    2014-10-01

    This article outlines an integration of attachment theory with narrative theory and systemic theory and practice: Attachment Narrative Therapy (ANT). This integration offers a more powerful explanatory formulation of the development and maintenance of human distress in relationships, families and communities, and gives direction to psychotherapeutic intervention. © The Author(s) 2014.

  15. Bacterial Flora Changes in Conjunctiva of Rats with Streptozotocin-Induced Type I Diabetes.

    Science.gov (United States)

    Yang, Chao; Fei, Yuda; Qin, Yali; Luo, Dan; Yang, Shufei; Kou, Xinyun; Zi, Yingxin; Deng, Tingting; Jin, Ming

    2015-01-01

    The microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ)-induced type I diabetes. A high dose of STZ (60 mg/kg, i.p.) was injected into Sprague-Dawley (SD) rats to induce type I diabetes mellitus (T1DM). The diabetic rats were raised in the animal laboratory and at 8 months post-injection of STZ swab samples were taken from the bulbar conjunctiva for cultivation of aerobic bacteria. The bacterial isolates were identified by Gram staining and biochemical features. The identified bacteria from both diabetic and healthy rats were then compared. The diabetic and healthy rats had different bacterial flora present in their bulbar conjunctiva. In total, 10 and 8 bacterial species were found in the STZ and control groups, respectively, with only three species (Enterococcus faecium, Enterococcus gallinarum and Escherichia coli) shared between the two groups. Gram-positive bacteria were common in both groups and the most abundant was Enterococcus faecium. However, after the development of T1DM, the bacterial flora in the rat bulbar conjunctiva changed considerably, with a reduced complexity evident. STZ-induced diabetes caused alterations of bacterial flora in the bulbar conjunctiva in rats, with some bacterial species disappearing and others emerging. Our results indicate that the conjunctival bacterial flora in diabetic humans should be surveyed for potential diagnostic markers or countermeasures to prevent eye infections in T1DM patients.

  16. Infant attachment, adult attachment, and maternal sensitivity: revisiting the intergenerational transmission gap.

    Science.gov (United States)

    Behrens, Kazuko Y; Haltigan, John D; Bahm, Naomi I Gribneau

    2016-08-01

    This study investigated the intergenerational transmission of attachment, utilizing the Adult Attachment Interview (AAI), the Strange Situation Procedure (SSP), and the Maternal Behavioral Q-Set (MBQS). We revisited fundamental questions in attachment theory and research by examining: (1) the level of intergenerational agreement between maternal attachment representations and infant attachment security, and (2) whether maternal sensitivity serves as an intergenerational mediator between adult and infant attachment security. Significant categorical matches between the AAI and the SSP as well as mean differences for MBQS scores between adult attachment secure-insecure groups were found. Consistent with earlier intergenerational research, maternal sensitivity only partially mediated the AAI-SSP link, indicating the transmission gap remains. Consistent with recent mediation studies, using more contemporary analytical techniques, it was confirmed that maternal sensitivity did mediate the direct pathway between AAI security and SSP security. Thus, the transmission gap appears somewhat different depending on the statistical method used to measure mediation. Post hoc analyses considered mothers' childhood experiences of separation/divorce and this helped make sense of intergenerational mismatches.

  17. Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

    Directory of Open Access Journals (Sweden)

    Eva Vandevivere

    Full Text Available Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information.

  18. Bacterial communities of two ubiquitous Great Barrier Reef corals reveals both site- and species-specificity of common bacterial associates.

    Directory of Open Access Journals (Sweden)

    E Charlotte E Kvennefors

    Full Text Available BACKGROUND: Coral-associated bacteria are increasingly considered to be important in coral health, and altered bacterial community structures have been linked to both coral disease and bleaching. Despite this, assessments of bacterial communities on corals rarely apply sufficient replication to adequately describe the natural variability. Replicated data such as these are crucial in determining potential roles of bacteria on coral. METHODOLOGY/PRINCIPAL FINDINGS: Denaturing Gradient Gel Electrophoresis (DGGE of the V3 region of the 16S ribosomal DNA was used in a highly replicated approach to analyse bacterial communities on both healthy and diseased corals. Although site-specific variations in the bacterial communities of healthy corals were present, host species-specific bacterial associates within a distinct cluster of gamma-proteobacteria could be identified, which are potentially linked to coral health. Corals affected by "White Syndrome" (WS underwent pronounced changes in their bacterial communities in comparison to healthy colonies. However, the community structure and bacterial ribotypes identified in diseased corals did not support the previously suggested theory of a bacterial pathogen as the causative agent of the syndrome. CONCLUSIONS/SIGNIFICANCE: This is the first study to employ large numbers of replicated samples to assess the bacterial communities of healthy and diseased corals, and the first culture-independent assessment of bacterial communities on WS affected Acroporid corals on the GBR. Results indicate that a minimum of 6 replicate samples are required in order to draw inferences on species, spatial or health-related changes in community composition, as a set of clearly distinct bacterial community profiles exist in healthy corals. Coral bacterial communities may be both site and species specific. Furthermore, a cluster of gamma-proteobacterial ribotypes may represent a group of specific common coral and marine

  19. High-grain diet feeding altered the composition and functions of the rumen bacterial community and caused the damage to the laminar tissues of goats.

    Science.gov (United States)

    Zhang, R Y; Jin, W; Feng, P F; Liu, J H; Mao, S Y

    2018-03-19

    In the current intensive production system, ruminants are often fed high-grain (HG) diets. However, this feeding pattern often causes rumen metabolic disorders and may further trigger laminitis, the exact mechanism is not clear. This study investigated the effect of HG diet feeding on fermentative and microbial changes in the rumen and on the expression of pro-inflammatory cytokines and matrix metalloproteinases (MMPs) in the lamellar tissue. In all, 12 male goats were fed a hay diet (0% grain; n=6) or an HG diet (56.5% grain; n=6). On day 50 of treatment, samples of blood, rumen content, and lamellar tissue of hooves of goats were collected. The data showed that compared with the hay group, HG-fed goats had lower (Pdiet feeding altered the composition of rumen bacterial community, and correspondingly, the results suggested that their functions in the HG group were also altered. HG diet feeding increased (Pbacterial community, and lead to higher levels of LPS in the peripheral blood, and further activated the inflammatory response in lamellar tissues, which may progress to the level of laminar damage.

  20. Bacterial Community Shift Drives Antibiotic Resistance Promotion during Drinking Water Chlorination.

    Science.gov (United States)

    Jia, Shuyu; Shi, Peng; Hu, Qing; Li, Bing; Zhang, Tong; Zhang, Xu-Xiang

    2015-10-20

    For comprehensive insights into the effects of chlorination, a widely used disinfection technology, on bacterial community and antibiotic resistome in drinking water, this study applied high-throughput sequencing and metagenomic approaches to investigate the changing patterns of antibiotic resistance genes (ARGs) and bacterial community in a drinking water treatment and distribution system. At genus level, chlorination could effectively remove Methylophilus, Methylotenera, Limnobacter, and Polynucleobacter, while increase the relative abundance of Pseudomonas, Acidovorax, Sphingomonas, Pleomonas, and Undibacterium in the drinking water. A total of 151 ARGs within 15 types were detectable in the drinking water, and chlorination evidently increased their total relative abundance while reduced their diversity in the opportunistic bacteria (p < 0.05). Residual chlorine was identified as the key contributing factor driving the bacterial community shift and resistome alteration. As the dominant persistent ARGs in the treatment and distribution system, multidrug resistance genes (mainly encoding resistance-nodulation-cell division transportation system) and bacitracin resistance gene bacA were mainly carried by chlorine-resistant bacteria Pseudomonas and Acidovorax, which mainly contributed to the ARGs abundance increase. The strong correlation between bacterial community shift and antibiotic resistome alteration observed in this study may shed new light on the mechanism behind the chlorination effects on antibiotic resistance.

  1. The Attachment Imperative

    DEFF Research Database (Denmark)

    Navne, Laura Emdal; Svendsen, Mette Nordahl; Gammeltoft, Tine

    2017-01-01

    on social relations and point to the productive aspects of practices of distance and detachment. We show that while the NICU upholds an imperative of attachment independently of the infant's chances of survival, for parents, attachment is contingent on certain hesitations in relation to their infant. We...... argue that there are nuances in practices of relationmaking in need of more attention (i.e., the nexus of attachment and detachment). Refraining from touching, holding, and feeding their infants during critical periods, the parents enact detachment as integral to their practices of attachment....... Such “cuts” in parent–infant relations become steps on the way to securing the infant's survival and making kin(ship). We conclude that although infants may be articulated as “maybe‐lives” by staff, in the NICU as well as in Danish society, the ideal of attachment appears to leave little room for “maybe‐parents.”...

  2. Three-dimensional visualization of nanostructured surfaces and bacterial attachment using Autodesk® Maya®

    Science.gov (United States)

    Boshkovikj, Veselin; Fluke, Christopher J.; Crawford, Russell J.; Ivanova, Elena P.

    2014-02-01

    There has been a growing interest in understanding the ways in which bacteria interact with nano-structured surfaces. As a result, there is a need for innovative approaches to enable researchers to visualize the biological processes taking place, despite the fact that it is not possible to directly observe these processes. We present a novel approach for the three-dimensional visualization of bacterial interactions with nano-structured surfaces using the software package Autodesk Maya. Our approach comprises a semi-automated stage, where actual surface topographic parameters, obtained using an atomic force microscope, are imported into Maya via a custom Python script, followed by a `creative stage', where the bacterial cells and their interactions with the surfaces are visualized using available experimental data. The `Dynamics' and `nDynamics' capabilities of the Maya software allowed the construction and visualization of plausible interaction scenarios. This capability provides a practical aid to knowledge discovery, assists in the dissemination of research results, and provides an opportunity for an improved public understanding. We validated our approach by graphically depicting the interactions between the two bacteria being used for modeling purposes, Staphylococcus aureus and Pseudomonas aeruginosa, with different titanium substrate surfaces that are routinely used in the production of biomedical devices.

  3. The process of developing and changing of infant-teacher attachment : A study on an infant whose attachment to the first attachment figure is insecure

    OpenAIRE

    上田, 七生

    2003-01-01

    Toward infants whose attachment to their first attachment figures (mainly their mothers) is insecure, how can we intervene in them? To reveal it, an observation was carried out regularly once a week, over a period of 9 months. The subjects were an infant who has insecure attachment and comparative one who has secure attachment. And the attachment behaviors they exhibited toward nursery school teachers, strangers, and an observer were counted. The amount of the attachment behaviors of the infa...

  4. The relation of infant attachment to attachment and cognitive and behavioural outcomes in early childhood.

    Science.gov (United States)

    Ding, Yan-hua; Xu, Xiu; Wang, Zheng-yan; Li, Hui-rong; Wang, Wei-ping

    2014-09-01

    In China, research on the relation of mother-infant attachment to children's development is scarce. This study sought to investigate the relation of mother-infant attachment to attachment, cognitive and behavioural development in young children. This study used a longitudinal study design. The subjects included healthy infants (n=160) aged 12 to 18 months. Ainsworth's "Strange Situation Procedure" was used to evaluate mother-infant attachment types. The attachment Q-set (AQS) was used to evaluate the attachment between young children and their mothers. The Bayley scale of infant development-second edition (BSID-II) was used to evaluate cognitive developmental level in early childhood. Achenbach's child behaviour checklist (CBCL) for 2- to 3-year-olds was used to investigate behavioural problems. In total, 118 young children (73.8%) completed the follow-up; 89.7% of infants with secure attachment and 85.0% of infants with insecure attachment still demonstrated this type of attachment in early childhood (κ=0.738, pInfants with insecure attachment collectively exhibited a significantly lower mental development index (MDI) in early childhood than did infants with secure attachment, especially the resistant type. In addition, resistant infants were reported to have greater social withdrawal, sleep problems and aggressive behaviour in early childhood. There is a high consistency in attachment development from infancy to early childhood. Secure mother-infant attachment predicts a better cognitive and behavioural outcome; whereas insecure attachment, especially the resistant attachment, may lead to a lower cognitive level and greater behavioural problems in early childhood. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Bacteriophages as Weapons Against Bacterial Biofilms in the Food Industry.

    Science.gov (United States)

    Gutiérrez, Diana; Rodríguez-Rubio, Lorena; Martínez, Beatriz; Rodríguez, Ana; García, Pilar

    2016-01-01

    Microbiological contamination in the food industry is often attributed to the presence of biofilms in processing plants. Bacterial biofilms are complex communities of bacteria attached to a surface and surrounded by an extracellular polymeric material. Their extreme resistance to cleaning and disinfecting processes is related to a unique organization, which implies a differential bacterial growth and gene expression inside the biofilm. The impact of biofilms on health, and the economic consequences, has promoted the development of different approaches to control or remove biofilm formation. Recently, successful results in phage therapy have boosted new research in bacteriophages and phage lytic proteins for biofilm eradication. In this regard, this review examines the environmental factors that determine biofilm development in food-processing equipment. In addition, future perspectives for the use of bacteriophage-derived tools as disinfectants are discussed.

  6. Sentence-Level Attachment Prediction

    Science.gov (United States)

    Albakour, M.-Dyaa; Kruschwitz, Udo; Lucas, Simon

    Attachment prediction is the task of automatically identifying email messages that should contain an attachment. This can be useful to tackle the problem of sending out emails but forgetting to include the relevant attachment (something that happens all too often). A common Information Retrieval (IR) approach in analyzing documents such as emails is to treat the entire document as a bag of words. Here we propose a finer-grained analysis to address the problem. We aim at identifying individual sentences within an email that refer to an attachment. If we detect any such sentence, we predict that the email should have an attachment. Using part of the Enron corpus for evaluation we find that our finer-grained approach outperforms previously reported document-level attachment prediction in similar evaluation settings.

  7. Long term repeated fire disturbance alters soil bacterial diversity but not the abundance in an Australian wet sclerophyll forest.

    Science.gov (United States)

    Shen, Ju-pei; Chen, C R; Lewis, Tom

    2016-01-20

    Effects of fire on biogeochemical cycling in terrestrial ecosystem are widely acknowledged, while few studies have focused on the bacterial community under the disturbance of long-term frequent prescribed fire. In this study, three treatments (burning every two years (B2), burning every four years (B4) and no burning (B0)) were applied for 38 years in an Australian wet sclerophyll forest. Results showed that bacterial alpha diversity (i.e. bacterial OTU) in the top soil (0-10 cm) was significantly higher in the B2 treatment compared with the B0 and B4 treatments. Non-metric multidimensional analysis (NMDS) of bacterial community showed clear separation of the soil bacterial community structure among different fire frequency regimes and between the depths. Different frequency fire did not have a substantial effect on bacterial composition at phylum level or bacterial 16S rRNA gene abundance. Soil pH and C:N ratio were the major drivers for bacterial community structure in the most frequent fire treatment (B2), while other factors (EC, DOC, DON, MBC, NH4(+), TC and TN) were significant in the less frequent burning and no burning treatments (B4 and B0). This study suggested that burning had a dramatic impact on bacterial diversity but not abundance with more frequent fire.

  8. Impacts of Alterations of Organic Inputs on the Bacterial Community within the sediments of Wind Cave, South Dakota, USA

    Directory of Open Access Journals (Sweden)

    Chelius Marisa K.

    2009-01-01

    Full Text Available Wind Cave (WICA in the Black Hills of South Dakota, like many mostly dry caves in temperate regions is an energy-starved system.The biotic communities that reside in these systems are low in diversity and simple in structure, and sensitive to changes in externalinputs of organic matter. Caves open to tourist traffic offer an opportunity to study the impacts of organic matter amendments in theform of human and rodent hair and dander, clothing lint, material from rodent activity (nesting materials and feces, and algal growthin and around artificial lighting. This study reports on the impacts of carbon amendments from humans and rodents on the bacterialand archaeal communities within the sediments of WICA from annual surveys and from a manipulative study that added lint (‘L’;cellulose plus rodent dander and rodent hair, rodent feces (‘F’, and a combination of both (‘LF’. The survey confirmed that bacterialbiomass was higher in regions of the cave with the highest rates of lint (hair and natural clothing fibers input. The manipulative studyfound that organic amendments in the forms of lint (L and rodent feces (F altered the WICA bacterial community structure in bothabundance and diversity, with the combined lint and feces (LF amendment having the most significant response. The high similarityof the LF and L communities suggests that the cave bacterial community is more carbon than nitrogen limited. The implication ofcave development to management practices is immediate and practical. Even small amounts of lint and organic matter foreign tocave bacteria significantly compromise the integrity of the endemic community resulting in the replacement of undescribed speciesby assemblages with at best, unknown impacts to natural cave features.

  9. Plumage bacterial assemblages in a breeding wild passerine: relationships with ecological factors and body condition.

    Science.gov (United States)

    Saag, Pauli; Tilgar, Vallo; Mänd, Raivo; Kilgas, Priit; Mägi, Marko

    2011-05-01

    Microorganisms have been shown to play an important role in shaping the life histories of animals, and it has recently been suggested that feather-degrading bacteria influence the trade-off between parental effort and self-preening behavior in birds. We studied a wild breeding population of great tits (Parus major) to explore habitat-, seasonal-, and sex-related variation in feather-degrading and free-living bacteria inhabiting the birds' yellow ventral feathers and to investigate associations with body condition. The density and species richness of bacterial assemblages was studied using flow cytometry and ribosomal intergenic spacer analysis. The density of studied bacteria declined between the nest-building period and the first brood. The number of bacterial phylotypes per bird was higher in coniferous habitat, while bacterial densities were higher in deciduous habitat. Free-living bacterial density was positively correlated with female mass; conversely, there was a negative correlation between attached bacterial density and female mass during the period of peak reproductive effort. Bacterial species richness was sex dependent, with more diverse bacterial assemblages present on males than females. Thus, this study revealed that bacterial assemblages on the feathers of breeding birds are affected both by life history and ecological factors and are related to body condition.

  10. Belt attachment and system

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Abraham D.; Davidson, Erick M.

    2018-03-06

    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  11. Changes in bacterial community after application of three different herbicides.

    Science.gov (United States)

    Moretto, Jéssica Aparecida Silva; Altarugio, Lucas Miguel; Andrade, Pedro Avelino; Fachin, Ana Lúcia; Andreote, Fernando Dini; Stehling, Eliana Guedes

    2017-07-06

    The native soil microbiota is very important to maintain the quality of that environment, but with the intensive use of agrochemicals, changes in microbial biomass and formation of large quantities of toxic waste were observed in soil, groundwater and surface water. Thereby, the goal of this study was to evaluate if the selective pressure exerted by the presence of the herbicides atrazine, diuron and 2,4-D changes the bacterial community structure of an agricultural soil, using denaturing gradient gel electrophoresis technique. According to PERMANOVA analysis, a greater effect of the herbicide persistence time in the soil, the effect of the herbicide class and the effect of interaction between these two factors (persistence time and herbicide class) were observed. In conclusion, the results showed that the selective pressure exerted by the presence of these herbicides altered the composition of the local microbiota, being atrazine and diuron that most significantly affected the bacterial community in soil, and the herbicide 2,4-D was the one that less altered the microbial community and that bacterial community was reestablished first. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Clinical decision - making review on magnetic attachments versus mechanical attachments in dental prosthetics

    Directory of Open Access Journals (Sweden)

    Francesca Fabiano

    2017-11-01

    Full Text Available Background Conventional dentures in edentulous patients show some limitations due to the lack of retention, support and stability thus resulting in difficulty to chew. The modern implantology allows to use different implant overdentures and different attachment systems. The selection of the attachment by practitioners is mainly influenced by the clinical experience or technical preferences. Aims The aim of the present review is to provide an adequate background to the clinicians, in order to select the prosthetic attachments according to the current literature. The mechanical attachments have been compared to the magnetic devices, with the aim to guide the decision of the practitioners. Methods Articles topics selection was based on the use of magnetic attachments in dentistry and the comparison between them and mechanical connectors. The databases used were PubMed/MEDLINE, Google Scholar and ISI Web of Science. A critical evaluation of the selected paper has been made to choose the ones that matched the inclusion criteria. Results Nowadays, few studies have compared different attachments in a manner useful for clinical decision-making. The main problem limiting long-term durability of magnetic attachments in the oral fluid is the poor corrosion resistance of permanent magnets and the consequent leaching of cytotoxic ions. Conclusion Magnetic attachments in comparison with other attaching systems can be useful in patients with special needs, in patients with limited interocclusal space, or in patients with neuromuscular limitations, thanks to the automatic reseating properties. However, it’s important to highlight that the mechanical attachments still represent the best choice in common conditions requiring dental prostheses.

  13. Chemical silicon surface modification and bioreceptor attachment to develop competitive integrated photonic biosensors.

    Science.gov (United States)

    Escorihuela, Jorge; Bañuls, María José; García Castelló, Javier; Toccafondo, Veronica; García-Rupérez, Jaime; Puchades, Rosa; Maquieira, Ángel

    2012-12-01

    Methodology for the functionalization of silicon-based materials employed for the development of photonic label-free nanobiosensors is reported. The studied functionalization based on organosilane chemistry allowed the direct attachment of biomolecules in a single step, maintaining their bioavailability. Using this immobilization approach in probe microarrays, successful specific detection of bacterial DNA is achieved, reaching hybridization sensitivities of 10 pM. The utility of the immobilization approach for the functionalization of label-free nanobiosensors based on photonic crystals and ring resonators was demonstrated using bovine serum albumin (BSA)/anti-BSA as a model system.

  14. ATTACHMENT AND TRANSFER

    OpenAIRE

    Pasare, Daniela

    2011-01-01

    Bowlby's concept of attachment and Freud's concept of transference are two of the most influential theories of how we construct mental representations of human relationships. The attachment’s theory offers one more strategy for the therapeutic approach. Factors that lead to a secure attachment between mother and child may also be applied to the relationship between patient and psychotherapist. Psychotherapy may help a patient create himself new attachment and relationship patterns. Creating a...

  15. The salivary microbiome is altered in the presence of a high salivary glucose concentration.

    Directory of Open Access Journals (Sweden)

    J Max Goodson

    Full Text Available Type II diabetes (T2D has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects.We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175 and those with low salivary glucose (LSG, glucose concentration < 0.1 mg/dL n = 2,537.HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83% of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64% were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness.HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence of hyperglycemia.

  16. Oxytocin receptor antagonist treatments alter levels of attachment to mothers and central dopamine activity in pre-weaning mandarin vole pups.

    Science.gov (United States)

    He, Zhixiong; Hou, Wenjuan; Hao, Xin; Dong, Na; Du, Peirong; Yuan, Wei; Yang, Jinfeng; Jia, Rui; Tai, Fadao

    2017-10-01

    Oxytocin (OT) is known to be important in mother-infant bonding. Although the relationship between OT and filial attachment behavior has been studied in a few mammalian species, the effects on infant social behavior have received little attention in monogamous species. The present study examined the effects of OT receptor antagonist (OTA) treatment on attachment behavior and central dopamine (DA) activity in male and female pre-weaning mandarin voles (Microtus mandarinus). Our data showed that OTA treatments decreased the attachment behavior of pups to mothers, measured using preference tests at postnatal day 14, 16, 18 and 20. OTA treatments reduced serum OT concentration in pre-weaning pups and decreased tyrosine hydroxylase (TH) levels in the ventral tegmental area (VTA), indicating a decrease in central DA activity. In male and female pups, OTA reduced DA levels, DA 1-type receptor (D1R) and DA 2-type receptor (D2R) protein expression in the nucleus accumbens (NAcc). Our results indicate that OTA treatment inhibits the attachment of pre-weaning pups to mothers. This inhibition is possibly associated with central DA activity and levels of two types of dopamine receptor in the NAcc. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Attachment is a dynamic system

    Directory of Open Access Journals (Sweden)

    Zlatka Cugmas

    2003-04-01

    Full Text Available On the basis of the study of recent scientific literature about the development of attachment, the author answers the following questions: which are the postulates the theory of attachment has about the stability of the patterns of attachment, which level of stability in the patterns of attachment from infancy to adulthood these studies illuminate and which factors significantly influence the (instability of the patterns of attachment in time. The theory of attachment assumes that normal circumstances elicit stability. Changes, however, can be the result of important events influencing the sensitivity of the object of attachment. Agreement has not yet been reached regarding the percentage of stability in the patterns of attachment. There is more agreement regarding attachment in adulthood than that in childhood. The results depend on the size and characteristics of the subjects of the research, the measuring instruments, type of data analysis etc. The author concludes that attachment is a dynamic system influenced by significant changes in life (the cognitive development of the child, external care, parents' divorce, different stressful situations. As the influence of stressful events on the individual person' s quality of attachment is examined, it is necessary to consider also his/her temperamental characteristics, role of other people in their lives, etc.

  18. Direct analysis of bacterial viability in endotracheal tube biofilm from a pig model of methicillin-resistant Staphylococcus aureus pneumonia following antimicrobial therapy.

    Science.gov (United States)

    Fernández-Barat, Laia; Li Bassi, Gianluigi; Ferrer, Miquel; Bosch, Anna; Calvo, Maria; Vila, Jordi; Gabarrús, Albert; Martínez-Olondris, Pilar; Rigol, Montse; Esperatti, Mariano; Luque, Néstor; Torres, Antoni

    2012-07-01

    Confocal laser scanning microscopy (CLSM) helps to observe the biofilms formed in the endotracheal tube (ETT) of ventilated subjects and to determine its structure and bacterial viability using specific dyes. We compared the effect of three different treatments (placebo, linezolid, and vancomycin) on the bacterial biofilm viability captured by CLSM. Eight pigs with pneumonia induced by methicillin-resistant Staphylococcus aureus (MRSA) were ventilated up to 96 h and treated with linezolid, vancomycin, or placebo (controls). ETT images were microscopically examined after staining with the live/dead(®) BacLight(™) Kit (Invitrogen, Barcelona, Spain) with a confocal laser scanning microscope. We analyzed 127 images obtained by CLSM. The median ratio of live/dead bacteria was 0.51, 0.74, and 1 for the linezolid, vancomycin, and control groups, respectively (P = 0.002 for the three groups); this ratio was significantly lower for the linezolid group, compared with the control group (P = 0.001). Images showed bacterial biofilm attached and non-attached to the ETT surface but growing within secretions accumulated inside ETT. Systemic treatment with linezolid is associated with a higher proportion of dead bacteria in the ETT biofilm of animals with MRSA pneumonia. Biofilm clusters not necessarily attach to the ETT surface. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  19. The abundance of health-associated bacteria is altered in PAH polluted soils-Implications for health in urban areas?

    Directory of Open Access Journals (Sweden)

    Anirudra Parajuli

    Full Text Available Long-term exposure to polyaromatic hydrocarbons (PAHs has been connected to chronic human health disorders. It is also well-known that i PAH contamination alters soil bacterial communities, ii human microbiome is associated with environmental microbiome, and iii alteration in the abundance of members in several bacterial phyla is associated with adverse or beneficial human health effects. We hypothesized that soil pollution by PAHs altered soil bacterial communities that had known associations with human health. The rationale behind our study was to increase understanding and potentially facilitate reconsidering factors that lead to health disorders in areas characterized by PAH contamination. Large containers filled with either spruce forest soil, pine forest soil, peat, or glacial sand were left to incubate or contaminated with creosote. Biological degradation of PAHs was monitored using GC-MS, and the bacterial community composition was analyzed using 454 pyrosequencing. Proteobacteria had higher and Actinobacteria and Bacteroidetes had lower relative abundance in creosote contaminated soils than in non-contaminated soils. Earlier studies have demonstrated that an increase in the abundance of Proteobacteria and decreased abundance of the phyla Actinobacteria and Bacteroidetes are particularly associated with adverse health outcomes and immunological disorders. Therefore, we propose that pollution-induced shifts in natural soil bacterial community, like in PAH-polluted areas, can contribute to the prevalence of chronic diseases. We encourage studies that simultaneously address the classic "adverse toxin effect" paradigm and our novel "altered environmental microbiome" hypothesis.

  20. Bacterial leaching of pyritic gold ores

    Energy Technology Data Exchange (ETDEWEB)

    Gagliardi, F.M.; Cashion, J.D.; Brown, L.J. [Monash Univ., Clayton, VIC (Australia). Dept. of Physics; Jay, W.H. [Monash Univ., Clayton, VIC (Australia). Chemical Engineering Department

    1996-12-31

    The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. {sup 57}Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS{sub 2}, and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

  1. Bacterial leaching of pyritic gold ores

    International Nuclear Information System (INIS)

    Gagliardi, F.M.; Cashion, J.D.; Brown, L.J.; Jay, W.H.

    1996-01-01

    The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. 57 Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS 2 , and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

  2. The Multimodal Assessment of Adult Attachment Security: Developing the Biometric Attachment Test.

    Science.gov (United States)

    Parra, Federico; Miljkovitch, Raphaële; Persiaux, Gwenaelle; Morales, Michelle; Scherer, Stefan

    2017-04-06

    Attachment theory has been proven essential for mental health, including psychopathology, development, and interpersonal relationships. Validated psychometric instruments to measure attachment abound but suffer from shortcomings common to traditional psychometrics. Recent developments in multimodal fusion and machine learning pave the way for new automated and objective psychometric instruments for adult attachment that combine psychophysiological, linguistic, and behavioral analyses in the assessment of the construct. The aim of this study was to present a new exposure-based, automatic, and objective adult-attachment assessment, the Biometric Attachment Test (BAT), which exposes participants to a short standardized set of visual and music stimuli, whereas their immediate reactions and verbal responses, captured by several computer sense modalities, are automatically analyzed for scoring and classification. We also aimed to empirically validate two of its assumptions: its capacity to measure attachment security and the viability of using themes as placeholders for rotating stimuli. A total of 59 French participants from the general population were assessed using the Adult Attachment Questionnaire (AAQ), the Adult Attachment Projective Picture System (AAP), and the Attachment Multiple Model Interview (AMMI) as ground truth for attachment security. They were then exposed to three different BAT stimuli sets, whereas their faces, voices, heart rate (HR), and electrodermal activity (EDA) were recorded. Psychophysiological features, such as skin-conductance response (SCR) and Bayevsky stress index; behavioral features, such as gaze and facial expressions; as well as linguistic and paralinguistic features, were automatically extracted. An exploratory analysis was conducted using correlation matrices to uncover the features that are most associated with attachment security. A confirmatory analysis was conducted by creating a single composite effects index and by testing it

  3. Reduction of rainbow trout spleen size by splenectomy does not alter resistance against bacterial cold water disease

    Science.gov (United States)

    In lower vertebrates, the contribution of the spleen to anti-bacterial immunity is poorly understood. Researchers have previously reported a phenotypic and genetic correlation between resistance to Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD) and spleen so...

  4. Measuring Patients’ Attachment Avoidance in Psychotherapy: Development of the Attachment Avoidance in Therapy Scale (AATS

    Directory of Open Access Journals (Sweden)

    András Láng

    2012-11-01

    Full Text Available A new scale measuring patient-therapist attachment avoidance was developed. Attachment Avoidance in Therapy Scale is a new measure based on the Bartholomew model of adult attachment (Bartholomew & Horowitz, 1991 and the Experience in Close Relationships Scale (Brennan, Clark, & Shaver, 1998 to measure patients’ attachment avoidance towards therapists. With 112 patient-therapist dyads participating in the study, validation of a preliminary scale – measuring both attachment anxiety and attachment avoidance in therapy – took place using therapists’ evaluations of patients’ relational behavior and patients’ self-reports about their attitude toward psychotherapy. Analysis of the data revealed six underlying scales. Results showed all six scales to be reliable. Validation of scales measuring attachment anxiety failed. The importance of Attachment Avoidance in Therapy Scale and its subscales is discussed.

  5. Mitigation of membrane biofouling by d-amino acids: Effect of bacterial cell-wall property and d-amino acid type.

    Science.gov (United States)

    Wang, Si-Yu; Sun, Xue-Fei; Gao, Wen-Jing; Wang, Yi-Fu; Jiang, Bei-Bei; Afzal, Muhammad Zaheer; Song, Chao; Wang, Shu-Guang

    2018-04-01

    Development of novel approaches for biofouling mitigation is of crucial importance for membrane-based technologies. d-amino acids (d-AAs) have been proposed as a potential strategy to mitigate biofouling. However, the effect of bacterial cell-wall properties and d-AAs type on biofouling mitigation remains unclear. This study assesses the effect of d-AAs type on membrane biofouling control, towards Gram positive (G+) and Gram negative (G-) bacteria. Three kinds of d-AAs were found to inhibit both G+ and G- bacterial attachment in short-term attachment and dead-end filtration experiments. The existence of d-AAs reduces extracellular polysaccharides and proteins on the membrane, which may decrease membrane biofouling. Cross-flow filtration tests further indicated that d-AAs could effectively reduce membrane biofouling. The permeate flux recovery post chemical cleaning, improved for both P. aeruginosa and B. subtilis treated with d-AAs. The results obtained from this study enable better understanding of the role of d-AAs species on bacterial adhesion and biofilm formation. This may provide a new way to regulate biofilm formation by manipulating the species of d-AAs membrane systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Demodex-associated bacterial proteins induce neutrophil activation.

    LENUS (Irish Health Repository)

    2012-02-01

    Background: Patients with rosacea demonstrate a higher density of Demodex mites in their skin than controls. A bacterium isolated from a Demodex mite from a patient with papulopustular rosacea (PPR) was previously shown to provoke an immune response in patients with PPR or ocular rosacea thus suggesting a possible role for bacterial proteins in the etiology of this condition. Objectives: To examine the response of neutrophils to proteins derived from a bacterium isolated from a Demodex mite. Methods: Bacterial cells were lysed and proteins were partially purified by AKTA-FPLC. Isolated neutrophils were exposed to bacterial proteins and monitored for alterations in migration, degranulation and cytokine production. Results: Neutrophils exposed to proteins from Bacillus cells demonstrated increased levels of migration and elevated release of MMP-9, an enzyme known to degrade collagen and cathelicidin, an antimicrobial peptide. In addition neutrophils exposed to the bacterial proteins demonstrated elevated rates of Il-8 and TNF-alpha production. Conclusions: Proteins produced by a bacterium isolated from a Demodex mite have the ability to increase the migration, degranulation and cytokine production abilities of neutrophils. These results suggest that bacteria may play a role in the inflammatory erythema associated with rosacea.

  7. Special Attachments. Module 19.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on special attachments, one in a series dealing with industrial sewing machines, their attachments, and operation, covers four topics: gauges; cording attachment; zipper foot; and hemming, shirring, and binding. For each topic these components are provided: an introduction, directions, an objective, learning activities, student…

  8. Correlation of open cell-attached and excised patch clamp techniques.

    Science.gov (United States)

    Filipovic, D; Hayslett, J P

    1995-11-01

    The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

  9. Antibiotic use during pregnancy alters the commensal vaginal microbiota

    DEFF Research Database (Denmark)

    Stokholm, J.; Schjørring, S.; Eskildsen, Carl Emil Aae

    2014-01-01

    Antibiotics may induce alterations in the commensal microbiota of the birth canal in pregnant women. Therefore, we studied the effect of antibiotic administration during pregnancy on commensal vaginal bacterial colonization at gestational week 36. Six hundred and sixty-eight pregnant women from...

  10. From security to attachment : Mary Ainsworth's contribution to attachment theory

    NARCIS (Netherlands)

    Rosmalen, Lenette (Lenny) van

    2015-01-01

    Even though John Bowlby (1907-1990) is generally regarded as the founder of attachment theory, Mary Ainsworth’s (1913-1999) contribution is considerable and goes beyond the design of the Strange Situation Procedure and the introduction of maternal sensitivity as decisive for a secure attachment

  11. Use of atomic force microscopy and transmission electron microscopy for correlative studies of bacterial capsules.

    Science.gov (United States)

    Stukalov, Oleg; Korenevsky, Anton; Beveridge, Terry J; Dutcher, John R

    2008-09-01

    Bacteria can possess an outermost assembly of polysaccharide molecules, a capsule, which is attached to their cell wall. We have used two complementary, high-resolution microscopy techniques, atomic force microscopy (AFM) and transmission electron microscopy (TEM), to study bacterial capsules of four different gram-negative bacterial strains: Escherichia coli K30, Pseudomonas aeruginosa FRD1, Shewanella oneidensis MR-4, and Geobacter sulfurreducens PCA. TEM analysis of bacterial cells using different preparative techniques (whole-cell mounts, conventional embeddings, and freeze-substitution) revealed capsules for some but not all of the strains. In contrast, the use of AFM allowed the unambiguous identification of the presence of capsules on all strains used in the present study, including those that were shown by TEM to be not encapsulated. In addition, the use of AFM phase imaging allowed the visualization of the bacterial cell within the capsule, with a depth sensitivity that decreased with increasing tapping frequency.

  12. Bacterial lipoproteins; biogenesis, sorting and quality control.

    Science.gov (United States)

    Narita, Shin-Ichiro; Tokuda, Hajime

    2017-11-01

    Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane. Most lipoproteins are anchored to the inner leaflet of the outer membrane with their protein moiety in the periplasm. However, recent studies indicated that some lipoproteins further undergo topology change in the outer membrane, and play critical roles in the biogenesis and quality control of the outer membrane. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Sexuality examined through the lens of attachment theory: attachment, caregiving, and sexual satisfaction.

    Science.gov (United States)

    Péloquin, Katherine; Brassard, Audrey; Lafontaine, Marie-France; Shaver, Phillip R

    2014-01-01

    Attachment researchers have proposed that the attachment, caregiving, and sexual behavioral systems are interrelated in adult love relationships (Mikulincer & Shaver, 2007 ). This study examined whether aspects of partners' caregiving (proximity, sensitivity, control, compulsive caregiving) mediated the association between their attachment insecurities (anxiety and avoidance) and each other's sexual satisfaction in two samples of committed couples (Study 1: 126 cohabiting or married couples from the general community; Study 2: 55 clinically distressed couples). Partners completed the Experiences in Close Relationships measure (Brennan, Clark, & Shaver, 1998 ), the Caregiving Questionnaire (Kunce & Shaver, 1994 ), and the Global Measure of Sexual Satisfaction (Lawrance & Byers, 1998 ). Path analyses based on the actor-partner interdependence model (APIM) revealed that caregiving proximity mediated the association between low attachment avoidance and partners' sexual satisfaction in distressed and nondistressed couples. Sensitivity mediated this association in nondistressed couples only. Control mediated the association between men's insecurities (attachment-related avoidance and anxiety) and their partners' low sexual satisfaction in nondistressed couples. Attachment anxiety predicted compulsive caregiving, but this caregiving dimension was not a significant mediator. These results are discussed in light of attachment theory and their implications for treating distressed couples.

  14. Influence of microorganisms on the alteration of glasses

    International Nuclear Information System (INIS)

    Besnainou, B.; Libert, M.F.

    1997-01-01

    Under specific conditions, microorganisms may enhance the alteration process of basaltic glass. However bacterial activity in the near field of a glass container would be possible only in environmental conditions provide nutrients and energetic substrates for bacterial growth. Depending of these conditions, microorganisms can: - modify the pH or the medium, - consume or produce soluble organic acids. To qualify the long term behaviour of glass, in presence of microorganisms, a qualitative and quantitative estimation of microbial activity potentialities and their consequences is needed. This must be achieved in studying the availability of the chemical species in the environment. (authors)

  15. Temperature-driven adaptation of the bacterial community in peat measured by using thymidine and leucine incorporation

    OpenAIRE

    Ranneklev, Sissel Brit; Bååth, Erland

    2001-01-01

    The temperature-driven adaptation of the bacterial community in peat was studied, by altering temperature to simulate self-heating and a subsequent return to mesophilic conditions. The technique used consisted of extracting the bacterial community from peat using homogenization-centrifugation and measuring the rates of thymidine (TdR) or leucine (Leu) incorporation by the extracted bacterial community at different temperatures. Increasing the peat incubation temperature from 25°C to 35, 45, o...

  16. Influence of substrate mineralogy on bacterial mineralization of calcium carbonate: implications for stone conservation.

    Science.gov (United States)

    Rodriguez-Navarro, Carlos; Jroundi, Fadwa; Schiro, Mara; Ruiz-Agudo, Encarnación; González-Muñoz, María Teresa

    2012-06-01

    The influence of mineral substrate composition and structure on bacterial calcium carbonate productivity and polymorph selection was studied. Bacterial calcium carbonate precipitation occurred on calcitic (Iceland spar single crystals, marble, and porous limestone) and silicate (glass coverslips, porous sintered glass, and quartz sandstone) substrates following culturing in liquid medium (M-3P) inoculated with different types of bacteria (Myxococcus xanthus, Brevundimonas diminuta, and a carbonatogenic bacterial community isolated from porous calcarenite stone in a historical building) and direct application of sterile M-3P medium to limestone and sandstone with their own bacterial communities. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), and 2-dimensional XRD (2D-XRD) analyses revealed that abundant highly oriented calcite crystals formed homoepitaxially on the calcitic substrates, irrespective of the bacterial type. Conversely, scattered spheroidal vaterite entombing bacterial cells formed on the silicate substrates. These results show that carbonate phase selection is not strain specific and that under equal culture conditions, the substrate type is the overruling factor for calcium carbonate polymorph selection. Furthermore, carbonate productivity is strongly dependent on the mineralogy of the substrate. Calcitic substrates offer a higher affinity for bacterial attachment than silicate substrates, thereby fostering bacterial growth and metabolic activity, resulting in higher production of calcium carbonate cement. Bacterial calcite grows coherently over the calcitic substrate and is therefore more chemically and mechanically stable than metastable vaterite, which formed incoherently on the silicate substrates. The implications of these results for technological applications of bacterial carbonatogenesis, including building stone conservation, are discussed.

  17. Influence of bacterial interactions on pneumococcal colonization of the nasopharynx.

    Science.gov (United States)

    Shak, Joshua R; Vidal, Jorge E; Klugman, Keith P

    2013-03-01

    Streptococcus pneumoniae (the pneumococcus) is a common commensal inhabitant of the nasopharynx and a frequent etiologic agent in serious diseases such as pneumonia, otitis media, bacteremia, and meningitis. Multiple pneumococcal strains can colonize the nasopharynx, which is also home to many other bacterial species. Intraspecies and interspecies interactions influence pneumococcal carriage in important ways. Co-colonization by two or more pneumococcal strains has implications for vaccine serotype replacement, carriage detection, and pneumonia diagnostics. Interactions between the pneumococcus and other bacterial species alter carriage prevalence, modulate virulence, and affect biofilm formation. By examining these interactions, this review highlights how the bacterial ecosystem of the nasopharynx changes the nature and course of pneumococcal carriage. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. What exactly distinguishes aggressive from chronic periodontitis: is it mainly a difference in the degree of bacterial invasiveness?

    Science.gov (United States)

    Van der Velden, Ubele

    2017-10-01

    At the International Workshop for Classification of Periodontal Diseases and Conditions in 1999, the classification of aggressive and chronic periodontitis that is presently used was introduced. A literature review of papers published in 2015 and having aggressive periodontitis in the title revealed that most studies use this terminology but it is questionable whether all established criteria were really applied correctly. Review of the literature showed no qualitative differences between aggressive and chronic periodontitis regarding bacterial and viral aspects. It is also unlikely that that there are major immunologic differences between aggressive and chronic periodontitis. Neutrophil function can be compromised in both conditions but may be more genetically related in aggressive periodontitis and be associated more with lifestyle factors in chronic periodontitis. In general, genetics plays a more important role in aggressive periodontitis than in chronic periodontitis. It is likely that periodontitis progresses by recurrent acute episodes during which invasion of bacteria into the connective tissue may occur. Two cases are presented for which invasive periodontitis is treated with systemic antibiotics, showing remarkable periodontal healing in terms of probing attachment gain, as well as radiographic bone gain. Periodontitis in an active state with bacterial invasion is probably accompanied with a significant increase in subgingival temperature. It is hypothesized that elevated subgingival temperature may help to distinguish between bacterial and nonbacterial invasive periodontitis. Scaling and root planing during a burst of disease activity may result in removal of connective tissue fiber attachment and down-growth of epithelium, thereby preventing the reattachment of connective tissue. Because the burst of disease is accompanied by an increase of temperature, assessment of the temperature may help in deciding whether or not to prescribe systemic antibiotics

  19. Structural Interfaces and Attachments in Biology

    CERN Document Server

    Birman, Victor; Genin, Guy

    2013-01-01

    Attachment of dissimilar materials in engineering and surgical practice is a perennial challenge. Bimaterial attachment sites are common locations for injury, repeated injury, and mechanical failure. Nature presents several highly effective solutions to the challenge of bimaterial attachment that differ from those found in engineering practice. Structural Interfaces and Attachments in Biology describes the attachment of dissimilar materials from multiple perspectives. The text will simultaneously elucidate natural bimaterial attachments and outline engineering principles underlying successful attachments to the communities of tissue engineers and surgeons. Included an in-depth analysis of the biology of attachments in the body and mechanisms by which robust attachments are formed, a review of current concepts of attaching dissimilar materials in surgical practice and a discussion of bioengineering approaches that are currently being developed. This book also: Provides the first comprehensive treatment of phys...

  20. Persistence in a single species CSTR model with suspended flocs and wall attached biofilms.

    Science.gov (United States)

    Mašić, Alma; Eberl, Hermann J

    2012-04-01

    We consider a mathematical model for a bacterial population in a continuously stirred tank reactor (CSTR) with wall attachment. This is a modification of the Freter model, in which we model the sessile bacteria as a microbial biofilm. Our analysis indicates that the results of the algebraically simpler original Freter model largely carry over. In a computational simulation study, we find that the vast majority of bacteria in the reactor will eventually be sessile. However, we also find that suspended biomass is relatively more efficient in removing substrate from the reactor than biofilm bacteria.

  1. Attachment and psychosis

    NARCIS (Netherlands)

    Korver, N.

    2014-01-01

    The main goal of this thesis was to further our understanding of current psychosocial models by introducing attachment as a relevant developmental framework. Firstly, attachment theory provides a psychosocial model for a developmental pathway to psychosis. Secondly, after expression of psychotic

  2. Effect of Attachment-Based Therapy on Behavioral Disorders in Girls with Attachment Problems

    Directory of Open Access Journals (Sweden)

    Marzieh Jahanbakhsh

    2014-09-01

    Full Text Available Background: Multidimensional and complex nature of children`s behavioral disorders requires assessment and usage of modern treatments. The present study investigated the effects of attachment-based therapy on behavioral disorders (depression, over anxiety and oppositional defiant in girl students of primary school who had attachment problems. Materials and Methods: This study is an empirical plan with pretest-posttest and control group. The target samples were 34 individuals of 388 second and fourth grade students of primary school that had highest scores on attachment problems and behavioral disorders (depression, over anxiety and oppositional defiant. Evaluation implemented using Randolph attachment disorder questionnaire (RADQ and Ontario mental health test. Mothers were presented in 10 group sessions of attachment-based intervention and its effects investigated in their girl`s behavioral disorders (depression, over anxiety and oppositional defiant. Results: Reduction rate of behavioral disorders general scores (depression, over anxiety and oppositional defiant of experimental group compared with control group showed significant decreases in posttest and three months follow up. Conclusion: The attachment based therapy offered for mothers of the girls with attachment problems was effective to reduction of behavioral disorders (depression, over anxiety and oppositional defiant symptoms in their children and the mother`s continues attention to interventional methods showed more improvement in follow up evaluation.

  3. Associations among Adult Attachment Presentations, Maternal Sensitivity, and Infant-Mother Attachment in a Sample of Adolescent Mothers.

    Science.gov (United States)

    Ward, Mary J.; Carlson, Elizabeth A.

    1995-01-01

    Associations among adolescent attachment organization, maternal sensitivity, and infant attachment organization were examined prospectively in 72 teenaged mother-infant dyads. Pregnant teenagers' attachment organizations predicted both sensitivity and infant-mother attachments. Associations between maternal sensitivity and infant attachment were…

  4. Attachment to the Romantic Partner and Sibling: Attachment Hierarchies of Twins and Non-Twin Siblings

    Directory of Open Access Journals (Sweden)

    Sascha Schwarz

    2015-12-01

    Full Text Available Previous studies have shown that romantic partners and siblings are important attachment figures. This study compares the attachment to the romantic partner with the attachment to the sibling as a function of the participant’s sibling type among monozygotic (MZ twins, dizygotic (DZ twins, and non-twin (NT siblings. The results show that MZ twins prefer their sibling to their romantic partner whereas DZ twins are equally attached to their sibling and romantic partner. In contrast, NT siblings are more attached to their romantic partner compared to their sibling. These results indicate that genetic relatedness has profound impact on a person’s attachment hierarchy and the relative rank of the romantic partner and the sibling.

  5. Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour

    Directory of Open Access Journals (Sweden)

    Roxanne D. Hawkins

    2017-05-01

    Full Text Available Attachment to pets has an important role in children’s social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life and pets (such as humane treatment. This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood.

  6. Gonococcal attachment to eukaryotic cells

    International Nuclear Information System (INIS)

    James, J.F.; Lammel, C.J.; Draper, D.L.; Brown, D.A.; Sweet, R.L.; Brooks, G.F.

    1983-01-01

    The attachment of Neisseria gonorrhoeae to eukaryotic cells grown in tissue culture was analyzed by use of light and electron microscopy and by labeling of the bacteria with [ 3 H]- and [ 14 C]adenine. Isogenic piliated and nonpiliated N. gonorrhoeae from opaque and transparent colonies were studied. The results of light microscopy studies showed that the gonococci attached to cells of human origin, including Flow 2000, HeLa 229, and HEp 2. Studies using radiolabeled gonococci gave comparable results. Piliated N. gonorrhoeae usually attached in larger numbers than nonpiliated organisms, and those from opaque colonies attached more often than isogenic variants from transparent colonies. Day-to-day variation in rate of attachment was observed. Scanning electron microscopy studies showed the gonococcal attachment to be specific for microvilli of the host cells. It is concluded that more N. gonorrhoeae from opaque colonies, as compared with isogenic variants from transparent colonies, attach to eukaryotic cells grown in tissue culture

  7. Concordance of attachment representations in preschool siblings assessed by the attachment story completion task

    OpenAIRE

    Werner, Helene; Zahn, Salome; Titze, Karl; Walitza, Susanne; Zulauf Logoz, Marina

    2015-01-01

    Several studies have indicated only a modest concordance of attachment security in siblings in infancy. Until now, very little was known about the concordance of siblings’ attachment security beyond infancy, as assessed by the attachment story completion task. This cross-sectional study aims to examine the concordance of attachment representations of 38 first-born (4–7 years) and 38 second-born (3–5 years) siblings living in middle-class two-parent families. Personality factors and the level ...

  8. [The interpretation of attachment in the Szondi test and in the questionnaire processes of attachment theory].

    Science.gov (United States)

    Török I, András; Vincze, Gábor

    2011-01-01

    [corrected] The Szondi-test is widely applied in clinical diagnostics in Hungary too, and the evidence resulting from the theory is that we can get information about attachment during its interpreting. Its validity is proven by empirical research and clinical experiences. By analyzing the modern attachment theory more thoroughly, it becomes clear in what ways the Szondi-test constellations regarding attachment are different from the classificationbased on questionnaires, allowing the discrete measurement of the attachment style. With the Szondi-test the classification to attachment style is more insecure, but if it is completed with exploration, it is more informative in vector C (vector of relation, attachment information), while short questionnaires make the classification to attachment style possible. In our empirical analysis we represent the integration of the above mentioned clinical and theoretical experiences. In the present analysis we compare the vector C and S constellation of the two-profile Szondi-test of 80 persons with the dimensions of ECR-R questionnaire and with Collins and Read's questionnaire classification regarding attachment style. The statistical results refer to the fact that there is a legitimacy to compare questionnaire processes allowing the discrete classification of attachment and the Szondi-test's information content regarding attachment. With applying the methods together, we get a unique, complementary section of the information relating to attachment. Comparing the two methods (projective and questionnaire) establishes the need of theoretical integration as well. We also make an attempt to explain Fraley's evolutionary non-adaptivity of avoidant attachment, in the case of whose presence adaptivity of early attachment, counterbalancing the exploration and security need, and providing closeness--farness loses its balance.

  9. Attachment theory: progress and future directions.

    Science.gov (United States)

    Fearon, R M Pasco; Roisman, Glenn I

    2017-06-01

    Attachment is a key subfield in the area of parenting and parent-child relationships research. In this brief overview, we summarise what we consider to be the state-of-the-art of attachment research, focusing primarily on the nature and significance of attachment in infancy and early childhood. We review 4 major topics that are central issues in the scientific literature on attachment: (1) the role of the environment in the development of attachment, (2) the intergenerational transmission of patterns of attachment, (3) the stability of attachment patterns through early adulthood, and (4) the role of attachment in adjustment and maladjustment. We conclude by highlighting several critical unresolved issues and priorities for future research. Copyright © 2017. Published by Elsevier Ltd.

  10. Attachment icebergs: Maternal and child health nurses' evaluation of infant-caregiver attachment.

    Science.gov (United States)

    Bryant, Edith; Ridgway, Lael; Lucas, Sandra

    2016-05-01

    Secure attachment of infants to their caregiver is important when promoting the emotional wellbeing and mental health of infants. Maternal and child health (MCH) nurses are well positioned to observe the quality of interactions between infants and caregivers and to assess and intervene. However, as yet there are no approved methods to assess the emotional and mental health of infants in community settings. A qualitative descriptive study of 12 MCH nurses in Victoria, Australia, using semi-structured interviews, was thematically analysed. The data revealed that nurses used many skills to identify and manage attachment difficulties. Key among these were observations of interactions, collaboration with caregivers and reflective practice. Assessments and interventions are also influenced by nurses' emotions, attitudes and workplace factors. An unexpected finding was that attachment markers can be likened to an 'iceberg': warning indicators at the tip can be easily observed by the nurse, while the less obvious underlying factors need to be explored in order to support attachment and improve infant mental health outcomes. Education for nurses should include concepts of attachment and link behaviours with emotional wellbeing.

  11. Attachment Patterns in the Psychotherapy Relationship: Development of the Client Attachment to Therapist Scale.

    Science.gov (United States)

    Mallinckrodt, Brent; And Others

    1995-01-01

    Describes development of an instrument, the Client Attachment to Therapist Scale (CATS). CATS factors correlated in expected directions with survey measures of object relations, client-rated working alliance, social self-efficacy, and adult attachment. Cluster analysis revealed four types of client attachment. Discusses implications of attachment…

  12. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-08-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analyzing size and number of intracellular bacterial colonies in infected tissue culture cells. Cells are seeded in 48-well plates and infected with a GFP-expressing bacterial pathogen. Following gentamicin treatment to remove extracellular pathogens, cells are fixed and cell nuclei stained. This is followed by automated microscopy and subsequent semi-automated spot detection to determine the number of intracellular bacterial colonies, their size distribution, and the average number per host cell. Multiple 48-well plates can be processed sequentially and the procedure can be completed in one working day. As a model we quantified intracellular bacterial colonies formed by uropathogenic Escherichia coli (UPEC) during infection of human kidney cells (HKC-8). Urinary tract infections caused by UPEC are among the most common bacterial infectious diseases in humans. UPEC can colonize tissues of the urinary tract and is responsible for acute, chronic, and recurrent infections. In the bladder, UPEC can form intracellular quiescent reservoirs, thought to be responsible for recurrent infections. In the kidney, UPEC can colonize renal epithelial cells and pass to the blood stream, either via epithelial cell disruption or transcellular passage, to cause sepsis. Intracellular colonies are known to be clonal, originating from single invading UPEC. In our experimental setup, we found UPEC CFT073 intracellular bacterial colonies to be heterogeneous in size and present in nearly one third of the HKC-8 cells. This high-throughput experimental format substantially reduces experimental time and enables fast screening of the intracellular bacterial load and cellular distribution of multiple

  13. Attachment at (not to) work: applying attachment theory to explain individual behavior in organizations.

    Science.gov (United States)

    Richards, David A; Schat, Aaron C H

    2011-01-01

    In this article, we report the results of 2 studies that were conducted to investigate whether adult attachment theory explains employee behavior at work. In the first study, we examined the structure of a measure of adult attachment and its relations with measures of trait affectivity and the Big Five. In the second study, we examined the relations between dimensions of attachment and emotion regulation behaviors, turnover intentions, and supervisory reports of counterproductive work behavior and organizational citizenship behavior. Results showed that anxiety and avoidance represent 2 higher order dimensions of attachment that predicted these criteria (except for counterproductive work behavior) after controlling for individual difference variables and organizational commitment. The implications of these results for the study of attachment at work are discussed.

  14. Adult Attachment Style and Suicidality.

    Science.gov (United States)

    Miniati, Mario; Callari, Antonio; Pini, Stefano

    2017-09-01

    There is evidence in the literature that adverse early attachment experiences and subsequent attachment insecurities during adulthood would lead to pessimism, low self-esteem, hopelessness and, ultimately, to suicide risk. This paper aims to review finding on the link between attachment style and suicidality. We searched the literature using the database of the U.S. National Center for Biotechnology Information (NCBI)-MedLine/Pubmed system from January 1992 until December 2016. We started with 1992 because, as far as we know, there are no published studies exploring the relationship between suicide and insecure attachment before that year. We considered reports published on the relationship between attachment style and suicidality. We applied several combinations of the following search terms: attachment, adult attachment style and suicidality, suicide, suicidal ideation, suicidal behavior or suicidal thoughts, and suicide attempts. We selected only English language studies. Research suggests that insecure attachment style, mostly anxious, and unresolved traumas are associated with an increased suicide risk. Few studies prospectively examined clinical course, comorbid psychiatric disorders, familial suicidality or other psychosocial factors. Further research is needed to highlight the nature of the link between attachment and suicidality. The presence of suicidal ideation and attempts might be a consequence of an underlying interaction between the emergence of psychiatrics symptoms, and the long-lasting presence of inadequate patterns of attachment. Within this context, Separation Anxiety Disorder, categorized in the DSM-5 as a condition not confined to childhood but as an anxiety disorder that may occur through the entire lifespan, might be the a key for the comprehension of this link. From a neurobiological point of view, the role of oxytocin remains unclear.

  15. Attachment behavior and mother-child conversations as predictors of attachment representations in middle childhood: a longitudinal study.

    Science.gov (United States)

    Dubois-Comtois, Karine; Cyr, Chantal; Moss, Ellen

    2011-07-01

    This study examines longitudinal links between mother-child conversations and attachment patterns in early childhood and later attachment representations. It also tests the role of conversations as mediators in the association between behavioral security and attachment representations. Mother-child conversations (snack-time) and attachment behaviors (Separation-Reunion procedure) were assessed for 83 5.5-year-olds while attachment representations (attachment narratives) were measured at 8.5 years of age. Results showed correspondence between attachment behaviors and representations for secure-confident, ambivalent-preoccupied, and disorganized/controlling-frightened groups. Affective quality of mother-child conversations predicted both child attachment behaviors and representations. Secure and confident children showed greater integration of affective information, ambivalent and preoccupied children more affect exaggeration, and disorganized/controlling and frightened children more chaotic conversations. Avoidant children tended to show more affect minimization in conversations. Finally, mother-child conversations centered on the sharing of emotions and thoughts mediated the relation between behavioral and representational attachment security, which underscores the importance of mother-child conversations in the development of attachment representations in childhood.

  16. In Azospirillum brasilense, mutations in flmA or flmB genes affect polar flagellum assembly, surface polysaccharides, and attachment to maize roots.

    Science.gov (United States)

    Rossi, Fernando Ariel; Medeot, Daniela Beatriz; Liaudat, Juan Pablo; Pistorio, Mariano; Jofré, Edgardo

    2016-09-01

    Azospirillum brasilense is a soil bacterium capable of promoting plant growth. Several surface components were previously reported to be involved in the attachment of A. brasilense to root plants. Among these components are the exopolysaccharide (EPS), lipopolysaccharide (LPS) and the polar flagellum. Flagellin from polar flagellum is glycosylated and it was suggested that genes involved in such a posttranslational modification are the same ones involved in the biosynthesis of sugars present in the O-antigen of the LPS. In this work, we report on the characterization of two homologs present in A. brasilense Cd, to the well characterized flagellin modification genes, flmA and flmB, from Aeromonas caviae. We show that mutations in either flmA or flmB genes of A. brasilense resulted in non-motile cells due to alterations in the polar flagellum assembly. Moreover, these mutations also affected the capability of A. brasilense cells to adsorb to maize roots and to produce LPS and EPS. By generating a mutant containing the polar flagellum affected in their rotation, we show the importance of the bacterial motility for the early colonization of maize roots. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. The Adult Attachment Projective Picture System: integrating attachment into clinical assessment.

    Science.gov (United States)

    George, Carol; West, Malcolm

    2011-01-01

    This article summarizes the development and validation of the Adult Attachment Projective System (AAP), a measure we developed from the Bowlby-Ainsworth developmental tradition to assess adult attachment status. The AAP has demonstrated excellent concurrent validity with the Adult Attachment Interview (George, Kaplan, & Main, 1984/1985/1996; Main & Goldwyn, 1985-1994; Main, Goldwyn, & Hesse, 2003), interjudge reliability, and test-retest reliability, with no effects of verbal intelligence or social desirability. The AAP coding and classification system and application in clinical and community samples are summarized. Finally, we introduce the 3 other articles that are part of this Special Section and discuss the use of the AAP in therapeutic assessment and treatment.

  18. Father attachment, father emotion expression, and children's attachment to fathers: The role of marital conflict.

    Science.gov (United States)

    Bi, Shuang; Haak, Eric A; Gilbert, Lauren R; El-Sheikh, Mona; Keller, Peggy S

    2018-06-01

    The current study examined relations between father attachment to spouses and child attachment to fathers in middle childhood, focusing on father emotion expressions in father-child interactions as mediators and marital conflict as a moderator of relations. Participants were 199 children between 6 and 12 years of age and their fathers. Fathers completed questionnaires about their attachment to their spouses, and both fathers and mothers reported on their marital conflict. Fathers also discussed a difficult topic with their children for 5 min, and fathers' positive and negative emotion expression during the discussions were coded. Children completed questionnaires through an interview about their attachment to their father. Father insecure attachment interacted with marital conflict in predicting more negative emotions and less positive emotions during father-child interactions. Specifically, in the context of higher marital conflict in this community sample, fathers who reported greater preoccupied attachment to their spouses exhibited more negative emotions and less positive emotions when interacting with their children. In turn, more father negative emotions and less positive emotions were associated with children's less secure attachment to fathers. In contrast, father fearful attachment interacted with marital conflict to predict less negative emotion and more positive emotion during interactions with children. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  19. Attachment within life history theory: an evolutionary perspective on individual differences in attachment.

    Science.gov (United States)

    Szepsenwol, Ohad; Simpson, Jeffry A

    2018-03-15

    In this article, we discuss theory and research on how individual differences in adult attachment mediate the adaptive calibration of reproductive strategies, cognitive schemas, and emotional expression and regulation. We first present an integration of attachment theory and life history theory. Then, we discuss how early harsh and/or unpredictable environments may promote insecure attachment by hampering parents' ability to provide sensitive and reliable care to their children. Finally, we discuss how, in the context of harsh and/or unpredictable environments, different types of insecure attachment (i.e. anxiety and avoidance) may promote evolutionary adaptive reproductive strategies, cognitive schemas, and emotional expression and regulation profiles. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. The effects of a low-intensity red laser on bacterial growth, filamentation and plasmid DNA

    International Nuclear Information System (INIS)

    Roos, C; Santos, J N; Guimarães, O R; Geller, M; Fonseca, A S; Paoli, F

    2013-01-01

    Exposure of nonphotosynthesizing microorganisms to light could increase cell division in cultures, a phenomenon denominated as biostimulation. However, data concerning the importance of the genetic characteristics of cells on this effect are as yet scarce. The aim of this work was to evaluate the effects of a low-intensity red laser on the growth, filamentation and plasmids in Escherichia coli cells proficient and deficient in DNA repair. E. coli cultures were exposed to a laser (658 nm, 10 mW, 1 and 8 J cm −2 ) to study bacterial growth and filamentation. Also, bacterial cultures hosting pBSK plasmids were exposed to the laser to study DNA topological forms from the electrophoretic profile in agarose gels. Data indicate the low-intensity red laser: (i) had no effect on the growth of E. coli wild type and exonuclease III deficient cells; (ii) induced bacterial filamentation, (iii) led to no alteration in the electrophoretic profile of plasmids from exonuclease III deficient cells, but plasmids from wild type cells were altered. A low-intensity red laser at the low fluences used in phototherapy has no effect on growth, but induces filamentation and alters the topological forms of plasmid DNA in E. coli cultures depending on the DNA repair mechanisms. (paper)

  1. Host-Specificity and Dynamics in Bacterial Communities Associated with Bloom-Forming Freshwater Phytoplankton

    Science.gov (United States)

    Bagatini, Inessa Lacativa; Eiler, Alexander; Bertilsson, Stefan; Klaveness, Dag; Tessarolli, Letícia Piton; Vieira, Armando Augusto Henriques

    2014-01-01

    Many freshwater phytoplankton species have the potential to form transient nuisance blooms that affect water quality and other aquatic biota. Heterotrophic bacteria can influence such blooms via nutrient regeneration but also via antagonism and other biotic interactions. We studied the composition of bacterial communities associated with three bloom-forming freshwater phytoplankton species, the diatom Aulacoseira granulata and the cyanobacteria Microcystis aeruginosa and Cylindrospermopsis raciborskii. Experimental cultures incubated with and without lake bacteria were sampled in three different growth phases and bacterial community composition was assessed by 454-Pyrosequencing of 16S rRNA gene amplicons. Betaproteobacteria were dominant in all cultures inoculated with lake bacteria, but decreased during the experiment. In contrast, Alphaproteobacteria, which made up the second most abundant class of bacteria, increased overall during the course of the experiment. Other bacterial classes responded in contrasting ways to the experimental incubations causing significantly different bacterial communities to develop in response to host phytoplankton species, growth phase and between attached and free-living fractions. Differences in bacterial community composition between cyanobacteria and diatom cultures were greater than between the two cyanobacteria. Despite the significance, major differences between phytoplankton cultures were in the proportion of the OTUs rather than in the absence or presence of specific taxa. Different phytoplankton species favoring different bacterial communities may have important consequences for the fate of organic matter in systems where these bloom forming species occur. The dynamics and development of transient blooms may also be affected as bacterial communities seem to influence phytoplankton species growth in contrasting ways. PMID:24465807

  2. A Bioinformatic Strategy for the Detection, Classification and Analysis of Bacterial Autotransporters

    Science.gov (United States)

    Celik, Nermin; Webb, Chaille T.; Leyton, Denisse L.; Holt, Kathryn E.; Heinz, Eva; Gorrell, Rebecca; Kwok, Terry; Naderer, Thomas; Strugnell, Richard A.; Speed, Terence P.; Teasdale, Rohan D.; Likić, Vladimir A.; Lithgow, Trevor

    2012-01-01

    Autotransporters are secreted proteins that are assembled into the outer membrane of bacterial cells. The passenger domains of autotransporters are crucial for bacterial pathogenesis, with some remaining attached to the bacterial surface while others are released by proteolysis. An enigma remains as to whether autotransporters should be considered a class of secretion system, or simply a class of substrate with peculiar requirements for their secretion. We sought to establish a sensitive search protocol that could identify and characterize diverse autotransporters from bacterial genome sequence data. The new sequence analysis pipeline identified more than 1500 autotransporter sequences from diverse bacteria, including numerous species of Chlamydiales and Fusobacteria as well as all classes of Proteobacteria. Interrogation of the proteins revealed that there are numerous classes of passenger domains beyond the known proteases, adhesins and esterases. In addition the barrel-domain-a characteristic feature of autotransporters-was found to be composed from seven conserved sequence segments that can be arranged in multiple ways in the tertiary structure of the assembled autotransporter. One of these conserved motifs overlays the targeting information required for autotransporters to reach the outer membrane. Another conserved and diagnostic motif maps to the linker region between the passenger domain and barrel-domain, indicating it as an important feature in the assembly of autotransporters. PMID:22905239

  3. Studies on the process of attachment of diazotroph alcaligenes faecalis and its Tn5 mutants to rice roots using 15N-labelling technique

    International Nuclear Information System (INIS)

    Fang Xuanjun; Lin Min; You Chongbiao

    1993-09-01

    By using 15 N-labelling technique and Tn5-induced mutants the attachment of associative diazotroph Alcaligenes faecalis to intact rice plants was examined in vitro. Three distinguished modes of attachment of Alcaligenes faecalis: adsorption, anchoring and colonization were proposed by using 15 N-labelling bacterial cells and Tn5-induced mutants. Che - mutants affected on adsorption, but not on anchoring. Exo - Che - mutant is defective in both adsorption and anchoring. Exo - or exo ++ mutants are only defective in anchoring. Effective colonization is benefit for establishment on the associative system. The data also indicated that EPS (exopolysaccharide) play rather important roles in the association between the host plant and bacteria

  4. Activating Attachments Reduces Memories of Traumatic Images.

    Directory of Open Access Journals (Sweden)

    Richard A Bryant

    Full Text Available Emotional memories, and especially intrusive memories, are a common feature of many psychological disorders, and are overconsolidated by stress. Attachment theory posits that activation of mental representations of attachment figures can reduce stress and boost coping. This study tested the proposition that attachment activation would reduce consolidation of emotional and intrusive memories. Sixty-seven undergraduate students viewed subliminal presentations of traumatic and neutral images, which were preceded by subliminal presentations of either attachment-related images or non-attachment-related images; free recall and intrusive memories were assessed two days later. Participants with low avoidant attachment tendencies who received the attachment primes recalled fewer memories and reported fewer intrusions than those who received the non-attachment primes. Unexpectedly, those with high anxious attachment tendencies reported fewer memories. These findings generally accord with attachment theory, and suggest that consolidation of emotional memories can be moderated by activation of attachment representations.

  5. Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS)

    International Nuclear Information System (INIS)

    Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

    2012-01-01

    Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature. - Highlights: ► Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS) was developed to study electron attachment reaction. ► The rate constants of electron attachment to CCl 4 and CHCl 3 were determined. ► The present experimental results are in good agreement with the previously reported data.

  6. Interferences in place attachment: implications for wilderness

    Science.gov (United States)

    Erin K. Sharpe; Alan W. Ewert

    2000-01-01

    Previous research on place attachment has tended to focus on attachment formation, with relatively little attention given to factors that disrupt or interfere with formed place attachments. Interferences to attachments are a worthy research area for two reasons: 1) The factors of place attachment are often more salient when being disrupted, and 2) place attachment...

  7. Alteration in fuel processing at Tokai Works of Mitsubishi Nuclear Fuel Co., Ltd

    International Nuclear Information System (INIS)

    1977-01-01

    The report of the Committee on Examination of Nuclear Fuel Safety to the Atomic Energy Commission of Japan concerning the alteration is given, which is attached to the reply from the commission to the prime minister, and its safety was confirmed. The alterations are installation of the storage for transport containers containing fuel assemblies, construction of radiation control and other buildings; and improvement and installation of the facilities for chemical-processing, pellet fabrication, fuel assembling, and storage. (Mori, K.)

  8. Using attachment theory in mentoring.

    Science.gov (United States)

    Miles, Kerri

    Attachment theory is a useful way to understand the bond between children and the people with whom they have emotional ties--usually caregivers. The theory can also help us to understand any adult relationship that provides closeness and a sense of attachment, especially in times of stress or need. Understanding the nature, cause and effect of the role and function of attachment from a training and development perspective, and different styles of attachment, may improve the quality of the mentoring experience for both mentors and mentees.

  9. Attachment and Dyadic Regulation Processes.

    Science.gov (United States)

    Overall, Nickola C; Simpson, Jeffry A

    2015-02-01

    Insecurely attached people have relatively unhappy and unstable romantic relationships, but the quality of their relationships depends on how their partners regulate them. Some partners find ways to regulate the emotional and behavioral reactions of insecurely attached individuals, which promotes greater relationship satisfaction and security. We discuss attachment theory and interdependence dilemmas, and then explain how and why certain responses by partners assuage the cardinal concerns of insecure individuals in key interdependent situations. We then review recent studies illustrating how partners can successfully regulate the reactions of anxiously and avoidantly attached individuals, yielding more constructive interactions. We finish by considering how these regulation processes can create a more secure dyadic environment, which helps to improve relationships and attachment security across time.

  10. Attachment Theory: Progress and Future Directions

    OpenAIRE

    Fearon, R. M. P.; Roisman, G. I.

    2017-01-01

    Attachment is a key subfield in the area of parenting and parent-child relationships research. In this brief overview, we summarise what we consider to be the state-of-the-art of attachment research, focusing primarily on the nature and significance of attachment in infancy and early childhood. We review 4 major topics that are central issues in the scientific literature on attachment: (1) the role of the environment in the development of attachment, (2) the intergenerational transmission of ...

  11. PGE2 suppresses intestinal T cell function in thermal injury: a cause of enhanced bacterial translocation.

    Science.gov (United States)

    Choudhry, M A; Fazal, N; Namak, S Y; Haque, F; Ravindranath, T; Sayeed, M M

    2001-09-01

    Increased gut bacterial translocation in burn and trauma patients has been demonstrated in a number of previous studies, however, the mechanism for such an increased gut bacterial translocation in injured patients remains poorly understood. Utilizing a rat model of burn injury, in the present study we examined the role of intestinal immune defense by analyzing the T cell functions. We investigated if intestinal T cells dysfunction contributes to bacterial translocation after burn injury. Also our study determined if burn-mediated alterations in intestinal T cell functions are related to enhanced release of PGE2. Finally, we examined whether or not burn-related alterations in intestinal T cell function are due to inappropriate activation of signaling molecule P59fyn, which is required for T cell activation and proliferation. The results presented here showed an increase in gut bacterial accumulation in mesenteric lymph nodes after thermal injury. This was accompanied by a decrease in the intestinal T cell proliferative responses. Furthermore, the treatments of burn-injured animals with PGE2 synthesis blocker (indomethacin or NS398) prevented both the decrease in intestinal T cell proliferation and enhanced bacterial translocation. Finally, our data suggested that the inhibition of intestinal T cell proliferation could result via PGE2-mediated down-regulation of the T cell activation-signaling molecule P59fyn. These findings support a role of T cell-mediated immune defense against bacterial translocation in burn injury.

  12. Assessing Attachment in Psychotherapy

    DEFF Research Database (Denmark)

    Talia, Alessandro; Miller-Bottome, Madeleine; Daniel, Sarah I.F.

    2017-01-01

    The authors present and validate the Patient Attachment Coding System (PACS), a transcript-based instrument that assesses clients' in-session attachment based on any session of psychotherapy, in multiple treatment modalities. One-hundred and sixty clients in different types of psychotherapy...... (cognitive–behavioural, cognitive–behavioural-enhanced, psychodynamic, relational, supportive) and from three different countries were administered the Adult Attachment Interview (AAI) prior to treatment, and one session for each client was rated with the PACS by independent coders. Results indicate strong...... inter-rater reliability, and high convergent validity of the PACS scales and classifications with the AAI. These results present the PACS as a practical alternative to the AAI in psychotherapy research and suggest that clinicians using the PACS can assess clients' attachment status on an ongoing basis...

  13. The effects of stainless steel finish on Salmonella Typhimurium attachment, biofilm formation and sensitivity to chlorine.

    Science.gov (United States)

    Schlisselberg, Dov B; Yaron, Sima

    2013-08-01

    Bacterial colonization and biofilm formation on stainless steel (SS) surfaces can be sources for cross contamination in food processing facilities, possessing a great threat to public health and food quality. Here the aim was to demonstrate the influence of surface finish of AISI 316 SS on colonization, biofilm formation and susceptibility of Salmonella Typhimurium to disinfection. Initial attachment of S. Typhimurium on surfaces of SS was four times lower, when surface was polished by Bright-Alum (BA) or Electropolishing (EP), as compared to Mechanical Sanded (MS) or the untreated surface (NT). The correlation between roughness and initial bacterial attachment couldn't account on its own to explain differences seen. Biofilms with similar thickness (15-18 μm) were developed on all surfaces 1-day post inoculation, whereas EP was the least covered surface (23%). Following 5-days, biofilm thickness was lowest on EP and MS (30 μm) and highest on NT (62 μm) surfaces. An analysis of surface composition suggested a link between surface chemistry and biofilm development, where the higher concentrations of metal ions in EP and MS surfaces correlated with limited biofilm formation. Interestingly, disinfection of biofilms with chlorine was up to 130 times more effective on the EP surface (0.005% surviving) than on the other surfaces. Overall these results suggest that surface finish should be considered carefully in a food processing plant. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Evaluation of bacterial run and tumble motility parameters through trajectory analysis

    Science.gov (United States)

    Liang, Xiaomeng; Lu, Nanxi; Chang, Lin-Ching; Nguyen, Thanh H.; Massoudieh, Arash

    2018-04-01

    In this paper, a method for extraction of the behavior parameters of bacterial migration based on the run and tumble conceptual model is described. The methodology is applied to the microscopic images representing the motile movement of flagellated Azotobacter vinelandii. The bacterial cells are considered to change direction during both runs and tumbles as is evident from the movement trajectories. An unsupervised cluster analysis was performed to fractionate each bacterial trajectory into run and tumble segments, and then the distribution of parameters for each mode were extracted by fitting mathematical distributions best representing the data. A Gaussian copula was used to model the autocorrelation in swimming velocity. For both run and tumble modes, Gamma distribution was found to fit the marginal velocity best, and Logistic distribution was found to represent better the deviation angle than other distributions considered. For the transition rate distribution, log-logistic distribution and log-normal distribution, respectively, was found to do a better job than the traditionally agreed exponential distribution. A model was then developed to mimic the motility behavior of bacteria at the presence of flow. The model was applied to evaluate its ability to describe observed patterns of bacterial deposition on surfaces in a micro-model experiment with an approach velocity of 200 μm/s. It was found that the model can qualitatively reproduce the attachment results of the micro-model setting.

  15. Carbon transformations in deep granitic groundwater by attached bacterial populations characterized with 16S-rRNA gene sequencing technique and scanning electron microscopy

    International Nuclear Information System (INIS)

    Ekendahl, S.; Arlinger, J.; Staahl, F.; Pedersen, K.

    1993-10-01

    This report presents molecular characterization of attached bacterial populations growing in slowly flowing (1-3 mm s -1 ) artesian groundwater from deep crystalline bed-rock of the Stripa research mine, south central Sweden. The assimilation rate of CO 2 and lactate, and the lactate respiration rates were also determined. The bacteria studied grew in anoxic, high pH, 9-10, and low redox artesian groundwater flowing up through tubings from two levels of a borehole designated V2, 812-820 m and 970-1240 m below ground. The major groups of bacteria were found. Signature bases placed them in the appropriate systematic groups. All belonged to the Proteobacterial groups beta and gamma. One group was found only at the 812-820 m level, where it constituted 63% of the sequenced clones, whereas the second group existed almost exclusively and constituted 85% of the sequenced clones at the 970-1240 m level. The third group was equally distributed between the levels. A few other bacteria were also found. None of the 16S-rRNA genes from the dominating bacteria resembled any of the other by more than 90% similarity, and none of them resembled anything in the database by more than 96%. Temperature did not seem to have any effect on species composition at the deeper level. SEM images showed rods appearing in microcolonies. The difference in population diversity between the two levels studied presumably reflect the different environments. The earlier proposed presence of sulphate reducing bacteria could no be confirmed

  16. Marine bacterial transparent exopolymer particles (TEP) and TEP precursors: Characterization and RO fouling potential

    KAUST Repository

    Li, Sheng

    2015-10-31

    This paper investigated the characteristics and membrane fouling potential of bacterial transparent exopolymer particles (TEP)/TEP precursors released from two marine bacteria, Pseudidiomarina homiensis (P. homiensis) and Pseudoalteromonas atlantica (P. atlantica), isolated from the Red Sea. Results showed that both bacteria grew at the similar rate, but the production of TEP/TEP precursors from P. atlantica was higher than that from P. homiensis. During the 168. h of incubation time, production rates of TEP/TEP precursors from P. atlantica and P. homiensis were 0.30 and 0.08 xanthan gum eq. mg/L-h, respectively. Isolated bacterial TEP precursors were mainly biopolymer, and P. atlantica produced a significantly higher concentration of biopolymer than that produced by P. homiensis. TEP/TEP precursors from both marine bacteria possessed protein-like material and were very similar in composition to previously reported foulants isolated from a fouled reverse osmosis (RO) membrane. Bacterial TEP/TEP precursors mostly consisted of aliphatic hydrocarbon from amino acids and amide group carbon of proteins (around 55%). Bacterial TEP precursors caused obvious fouling on RO membranes, which may create an ideal environment for bacteria attachment and promote to biofouling.

  17. Bioconvection as a Consequence of Bio-Stratification in Bacterial Populations

    Science.gov (United States)

    Shoup, Daniel; Strickland, Benjamin; Hoeger, Kentaro; Ursell, Tristan

    The collective motion of bacterial populations in solution can generate convective currents that significantly alter fluid motion and material transport. Known as bioconvection, this process is highly influenced by stimuli such as nutrients and toxins that can attract or repel bacteria via chemotaxis. Despite its prevalence in natural environments, ranging from the ocean floor to fluid in the human gut, this dynamic process and the physical and biological factors that influence it remain largely unexplored. To close this gap, we measure and analyze spontaneous bioconvection arising from the collective movement of dense populations of bacteria, such as Escherichia coli and Bacillus subtilis. By combining microscopy and image analysis, we find that modulations of the fluid volume geometry, erasure of the air-liquid interface, chemical perturbations like nutrients or antibiotics all alter the development of these dense bacterial masses and in turn the bio-convective currents and corresponding transport phenomena they generate. Our work suggests biophysical principles of material and organismal transport that apply to a broad range of systems where organisms can sense gradients and move within their environments.

  18. Nonleachable Imidazolium-Incorporated Composite for Disruption of Bacterial Clustering, Exopolysaccharide-Matrix Assembly, and Enhanced Biofilm Removal.

    Science.gov (United States)

    Hwang, Geelsu; Koltisko, Bernard; Jin, Xiaoming; Koo, Hyun

    2017-11-08

    Surface-grown bacteria and production of an extracellular polymeric matrix modulate the assembly of highly cohesive and firmly attached biofilms, making them difficult to remove from solid surfaces. Inhibition of cell growth and inactivation of matrix-producing bacteria can impair biofilm formation and facilitate removal. Here, we developed a novel nonleachable antibacterial composite with potent antibiofilm activity by directly incorporating polymerizable imidazolium-containing resin (antibacterial resin with carbonate linkage; ABR-C) into a methacrylate-based scaffold (ABR-modified composite; ABR-MC) using an efficient yet simplified chemistry. Low-dose inclusion of imidazolium moiety (∼2 wt %) resulted in bioactivity with minimal cytotoxicity without compromising mechanical integrity of the restorative material. The antibiofilm properties of ABR-MC were assessed using an exopolysaccharide-matrix-producing (EPS-matrix-producing) oral pathogen (Streptococcus mutans) in an experimental biofilm model. Using high-resolution confocal fluorescence imaging and biophysical methods, we observed remarkable disruption of bacterial accumulation and defective 3D matrix structure on the surface of ABR-MC. Specifically, the antibacterial composite impaired the ability of S. mutans to form organized bacterial clusters on the surface, resulting in altered biofilm architecture with sparse cell accumulation and reduced amounts of EPS matrix (versus control composite). Biofilm topology analyses on the control composite revealed a highly organized and weblike EPS structure that tethers the bacterial clusters to each other and to the surface, forming a highly cohesive unit. In contrast, such a structured matrix was absent on the surface of ABR-MC with mostly sparse and amorphous EPS, indicating disruption in the biofilm physical stability. Consistent with lack of structural organization, the defective biofilm on the surface of ABR-MC was readily detached when subjected to low shear

  19. Attachment style and adjustment to divorce.

    Science.gov (United States)

    Yárnoz-Yaben, Sagrario

    2010-05-01

    Divorce is becoming increasingly widespread in Europe. In this study, I present an analysis of the role played by attachment style (secure, dismissing, preoccupied and fearful, plus the dimensions of anxiety and avoidance) in the adaptation to divorce. Participants comprised divorced parents (N = 40) from a medium-sized city in the Basque Country. The results reveal a lower proportion of people with secure attachment in the sample group of divorcees. Attachment style and dependence (emotional and instrumental) are closely related. I have also found associations between measures that showed a poor adjustment to divorce and the preoccupied and fearful attachment styles. Adjustment is related to a dismissing attachment style and to the avoidance dimension. Multiple regression analysis confirmed that secure attachment and the avoidance dimension predict adjustment to divorce and positive affectivity while preoccupied attachment and the anxiety dimension predicted negative affectivity. Implications for research and interventions with divorcees are discussed.

  20. A study of the efficacy of fathers’ attachment training on paternal-fetal attachment and parental anxiety

    Directory of Open Access Journals (Sweden)

    Sara Setodeh

    2017-12-01

    Full Text Available Background . Attachment behaviors play an important role in accepting the identity of the fathers, the pleasant outcome of pregnancy and the child’s growth and development in the future. Objectives . This study aimed to investigate the effect of father’s attachment training (awaiting a child on paternal-fetal attachment and parental anxiety. Material and methods . This clinical trial was conducted on 150 spouses of eligible pregnant women. In the intervention group, four 90-minute training sessions were designed on maternal-fetal attachment, while the control group received routine prenatal care. The questionnaire of paternal-fetal attachment was completed both before and after intervention in both cases and control groups. Data analysis was done in SPSS software using a paired t-test and independent t-test (the significant level was 0.05. Results . The mean score of attachment was reported as 56.61 ± 6.05 and 64.53 ± 6.94 both before and after intervention, respectively. According to the paired t-test, there was a significant difference in the attachment score after intervention (p < 0.001. According to the independent t-test applied a month after intervention, the comparison of fathers’ anxiety scores before and after intervention showed a significant difference between the control and intervention groups (p < 0.001. Conclusions . Training fathers about attachment skills leads to increased paternal-fetal attachment and a lower anxiety score. Therefore, it seems necessary to include education of fathers in prenatal care.

  1. Experimental Study of Bacterial Penetration into Chalk Rock: Mechanisms and Effect on Permeability

    DEFF Research Database (Denmark)

    Halim, Amalia Yunita; Shapiro, Alexander; Eliasson Lantz, Anna

    2014-01-01

    Bacterial selective plugging is one of the mechanisms through which microorganisms can be applied for enhanced oil recovery, as bacteria can plug the water-swept zones of a reservoir, thus altering the flow paths and improving sweep efficiency. However, complete understanding of the penetration...... behavior of bacteria is lacking, especially in chalk formations where characteristic pore throat sizes are comparable with the sizes of bacterial cells. In this study, two bacterial strains, Bacillus licheniformis 421 (spore-forming) and Pseudomonas putida K12 (non-spore forming) were used to investigate...... the penetration of bacteria into chalk and its effect on permeability reduction. The core plugs were produced from Stevns Klint outcrop with low permeability (2–4 mD) and with pore sizes comparable to bacterial sizes. Both types of bacteria were able to penetrate and to be transported through the cores to some...

  2. Place attachment and natural environmental risk

    DEFF Research Database (Denmark)

    Bonaiuto, Marino; Alves, Susana; De Dominicis, Stefano

    2016-01-01

    Little is known about place attachment affecting natural environmental risk perception and coping. A systematic search of social science databases revealed 31 works (1996–2016) directly addressing place attachment in relation to different types of natural hazard risks (e.g., seismic, volcanic, etc.......). Across different contexts, the research shows: (a) positive and/or negative relationships between place attachment and natural environmental risk perception; (b) positive and/or negative relationships between place attachment and risk coping; and (c) mediating and moderating relationships. In particular......, results show that: (a) highly attached individuals perceive natural environmental risks but underestimate their potential effects; (b) highly attached individuals are unwilling to relocate when facing natural environmental risks and more likely to return to risky areas after a natural environmental...

  3. Understanding the Relationships between Attachment Styles, Locus of Control, School Maladaptation, and Depression Symptoms among Students in Foster Care

    Science.gov (United States)

    Jankowska, Anna M.; Lewandowska-Walter, A.; Chalupa, A. A.; Jonak, Jolanta; Duszynski, Ramzia; Mazurkiewicz, N.

    2015-01-01

    Altered family experiences place children in foster care at risk for school adjustment difficulties. This study focuses on exploring the differences in school adaptation, locus of control, depression symptoms, and attachment styles among children in foster care and children raised by their biological parents. Sixty children completed self-report…

  4. Kaempferol Inhibits the Primary Attachment Phase of Biofilm Formation in Staphylococcus aureus.

    Science.gov (United States)

    Ming, Di; Wang, Dacheng; Cao, Fengjiao; Xiang, Hua; Mu, Dan; Cao, Junjie; Li, Bangbang; Zhong, Ling; Dong, Xiaoyun; Zhong, Xiaobo; Wang, Lin; Wang, Tiedong

    2017-01-01

    The ability to form biofilms on surfaces makes Staphylococcus aureus the main pathogenic factor in implanted medical device infections. The aim of this study was to discover a biofilm inhibitor distinct from the antibiotics used to prevent infections resulting from S. aureus biofilms. Here, we describe kaempferol, a small molecule with anti-biofilm activity that specifically inhibited the formation of S. aureus biofilms. Crystal violet (CV) staining and fluorescence microscopy clearly showed that 64 μg/ml kaempferol inhibited biofilm formation by 80%. Meanwhile, the minimum inhibitory concentration (MIC) and growth curve results indicated that kaempferol had no antibacterial activity against the tested bacterial strain. Kaempferol inhibited the primary attachment phase of biofilm formation, as determined by a fibrinogen-binding assay. Moreover, a fluorescence resonance energy transfer (FRET) assay and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analyses revealed that kaempferol reduced the activity of S. aureus sortaseA (SrtA) and the expression of adhesion-related genes. Based on these results, kaempferol provides a starting point for the development of novel anti-biofilm drugs, which may decrease the risk of bacterial drug resistance, to prevent S. aureus biofilm-related infections.

  5. Attachment styles and contingencies of self-worth.

    Science.gov (United States)

    Park, Lora E; Crocker, Jennifer; Mickelson, Kristin D

    2004-10-01

    Previous research on attachment theory has focused on mean differences in level of self-esteem among people with different attachment styles. The present study examines the associations between attachment styles and different bases of self-esteem, or contingencies of self-worth, among a sample of 795 college students. Results showed that attachment security was related to basing self-worth on family support. Both the preoccupied attachment style and fearful attachment style were related to basing self-worth on physical attractiveness. The dismissing attachment style was related to basing self-worth less on others' approval, family support, and God's love.

  6. Site-specific mouth rinsing can improve oral odor by altering bacterial counts. Blind crossover clinical study.

    Science.gov (United States)

    Alqumber, Mohammed A; Arafa, Khaled A

    2014-11-01

    To determine whether site-specific mouth rinsing with oral disinfectants can improve oral odor beyond the traditional panoral mouth disinfection with mouth rinses by targeting specifically oral malodor implicated anaerobic bacteria. Twenty healthy fasting subjects volunteered for a blinded prospective, descriptive correlational crossover cross-section clinical trial conducted during the month of Ramadan between July and August 2013 in Albaha province in Saudi Arabia involving the application of Listerine Cool Mint mouth rinse by either the traditional panoral rinsing method, or a site-specific disinfection method targeting the subgingival and supragingival plaque and the posterior third of the tongue dorsum, while avoiding the remaining locations within the oral cavity. The viable anaerobic and aerobic bacterial counts, volatile sulfur compounds (VSCs) levels, organoleptic assessment of oral odor, and the tongue-coating index were compared at baseline, one, 5, and 9 hours after the treatment. The site-specific disinfection method reduced the VSCs and anaerobic bacterial loads while keeping the aerobic bacterial numbers higher than the traditional panoral rinsing method. Site-specific disinfection can more effectively maintain a healthy oral cavity by predominantly disinfecting the niches of anaerobic bacteria within the oral cavity.

  7. Decreased Bacterial Attachment and Protein Adsorption to Coatings Produced by Low Enegy Plasma Polymerization

    DEFF Research Database (Denmark)

    Andersen, T.E.; Kingshott, Peter; Benter, M.

    .figure) .and E. coli grown on uncoated silicone compared to PP-PVP coated silicone (right figure). Results from the flow chamber analysis shows PP-PVP to be very good at preventing E. coli colonization during prolonged growth in flow chamber. At this point other surfaces and bacteria remains to be tested...... adsorption and bacteria attachment/colonization. This is emphasized by the fact that long dwelling urinary catheters, which is a typical silicone medical device, causes 5% per day incidence of urinary tract infection [1,2]. A demand therefore exists for surface modifications providing the silicone material......-coated crystals were then treated with one of the plasma polymerized coatings. Adsorption of fibrinogen, human serum albumin or immunoglobulin G was measured using a QCM-D instrument [5] (model E4, Q-Sense AB, Vastra Frolunda, Sweden) using a solution of 50llg/1 protein in PBS buffer. Results and Discussion: Our...

  8. Introduction: attachment theory and psychotherapy.

    Science.gov (United States)

    Levy, Kenneth N

    2013-11-01

    In this introduction to the JCLP: In Session 69(11) issue on attachment theory and psychotherapy, the key points of attachment theory (Bowlby, , , 1981) and its relevance to psychotherapy are briefly described. The aim of this issue is to provide case illustrations of how an attachment theory perspective and principles can expand our understanding of psychotherapy practice. © 2013 Wiley Periodicals, Inc.

  9. Are bacterial volatile compounds poisonous odors to a fungal pathogen Botrytis cinerea, alarm signals to Arabidopsis seedlings for eliciting induced resistance, or both?

    Directory of Open Access Journals (Sweden)

    Choong-Min eRyu

    2016-02-01

    Full Text Available Biological control (biocontrol agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR. Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 hours post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen

  10. Everything You Want To Know about Attachment.

    Science.gov (United States)

    Honig, Alice Sterling

    This paper discusses infant attachment, which it defines as a long-lasting emotional bond revealed when a child under stress seeks out and tries to stay close to a specific figure. The paper addresses: (1) What is attachment? Who are the pioneers in attachment theory?; (2) How do we notice attachment in action?; (3) Is attachment the only…

  11. Phenotypes of Non-Attached Pseudomonas aeruginosa Aggregates Resemble Surface Attached Biofilm

    DEFF Research Database (Denmark)

    Alhede, Morten; Kragh, Kasper Nørskov; Qvortrup, Klaus

    2011-01-01

    For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse......, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently...... were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both...

  12. Association Between Insecure Attachment and ADHD

    DEFF Research Database (Denmark)

    Storebø, Ole Jakob; Rasmussen, Pernille Darling; Simonsen, Erik

    2016-01-01

    OBJECTIVE: Psychological theories have postulated an association between insecure attachment and ADHD. The objective of this study is to investigate possible association between insecure attachment and ADHD in children and adults. METHOD: Review of literature was performed using the Psyc......INFO, Medline, and EMBASE databases. RESULTS: Twenty-nine studies were included in the review. Overall, the studies showed that parental attachment problems and environmental mediating factors were significantly associated with childhood ADHD. Adults with ADHD had a much higher incidence of insecure attachment...... styles than reported in the general population. CONCLUSION: There seems to be a clear association between ADHD and insecure attachment. It is likely that early intervention in the form of parent training and pharmacological treatment may prevent development of attachment problems. But such studies have...

  13. Priming the Secure Attachment Schema Affects the Emotional Face Processing Bias in Attachment Anxiety: An fMRI Research

    Directory of Open Access Journals (Sweden)

    Xu Chen

    2017-04-01

    Full Text Available Our study explored how priming with a secure base schema affects the processing of emotional facial stimuli in individuals with attachment anxiety. We enrolled 42 undergraduate students between 18 and 27 years of age, and divided them into two groups: attachment anxiety and attachment secure. All participants were primed under two conditions, the secure priming using references to the partner, and neutral priming using neutral references. We performed repeated attachment security priming combined with a dual-task paradigm and functional magnetic resonance imaging. Participants’ reaction times in terms of responding to the facial stimuli were also measured. Attachment security priming can facilitate an individual’s processing of positive emotional faces; for instance, the presentation of the partner’s name was associated with stronger activities in a wide range of brain regions and faster reaction times for positive facial expressions in the subjects. The current finding of higher activity in the left-hemisphere regions for secure priming rather than neutral priming is consistent with the prediction that attachment security priming triggers the spread of the activation of a positive emotional state. However, the difference in brain activity during processing of both, positive and negative emotional facial stimuli between the two priming conditions appeared in the attachment anxiety group alone. This study indicates that the effect of attachment secure priming on the processing of emotional facial stimuli could be mediated by chronic attachment anxiety. In addition, it highlights the association between higher-order processes of the attachment system (secure attachment schema priming and early-stage information processing system (attention, given the increased attention toward the effects of secure base schema on the processing of emotion- and attachment-related information among the insecure population. Thus, the following study has

  14. Fire modifies the phylogenetic structure of soil bacterial co-occurrence networks.

    Science.gov (United States)

    Pérez-Valera, Eduardo; Goberna, Marta; Faust, Karoline; Raes, Jeroen; García, Carlos; Verdú, Miguel

    2017-01-01

    Fire alters ecosystems by changing the composition and community structure of soil microbes. The phylogenetic structure of a community provides clues about its main assembling mechanisms. While environmental filtering tends to reduce the community phylogenetic diversity by selecting for functionally (and hence phylogenetically) similar species, processes like competitive exclusion by limiting similarity tend to increase it by preventing the coexistence of functionally (and phylogenetically) similar species. We used co-occurrence networks to detect co-presence (bacteria that co-occur) or exclusion (bacteria that do not co-occur) links indicative of the ecological interactions structuring the community. We propose that inspecting the phylogenetic structure of co-presence or exclusion links allows to detect the main processes simultaneously assembling the community. We monitored a soil bacterial community after an experimental fire and found that fire altered its composition, richness and phylogenetic diversity. Both co-presence and exclusion links were more phylogenetically related than expected by chance. We interpret such a phylogenetic clustering in co-presence links as a result of environmental filtering, while that in exclusion links reflects competitive exclusion by limiting similarity. This suggests that environmental filtering and limiting similarity operate simultaneously to assemble soil bacterial communities, widening the traditional view that only environmental filtering structures bacterial communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  15. Pathogenic Leptospira species express surface-exposed proteins belonging to the bacterial immunoglobulin superfamily

    Science.gov (United States)

    Matsunaga, James; Barocchi, Michele A.; Croda, Julio; Young, Tracy A.; Sanchez, Yolanda; Siqueira, Isadora; Bolin, Carole A.; Reis, Mitermayer G.; Riley, Lee W.; Haake, David A.; Ko, Albert I.

    2005-01-01

    Summary Proteins with bacterial immunoglobulin-like (Big) domains, such as the Yersinia pseudotuberculosis invasin and Escherichia coli intimin, are surface-expressed proteins that mediate host mammalian cell invasion or attachment. Here, we report the identification and characterization of a new family of Big domain proteins, referred to as Lig (leptospiral Ig-like) proteins, in pathogenic Leptospira. Screening of L. interrogans and L. kirschneri expression libraries with sera from leptospirosis patients identified 13 lambda phage clones that encode tandem repeats of the 90 amino acid Big domain. Two lig genes, designated ligA and ligB, and one pseudo-gene, ligC, were identified. The ligA and ligB genes encode amino-terminal lipoprotein signal peptides followed by 10 or 11 Big domain repeats and, in the case of ligB, a unique carboxy-terminal non-repeat domain. The organization of ligC is similar to that of ligB but contains mutations that disrupt the reading frame. The lig sequences are present in pathogenic but not saprophytic Leptospira species. LigA and LigB are expressed by a variety of virulent leptospiral strains. Loss of Lig protein and RNA transcript expression is correlated with the observed loss of virulence during culture attenuation of pathogenic strains. High-pressure freeze substitution followed by immunocytochemical electron microscopy confirmed that the Lig proteins were localized to the bacterial surface. Immunoblot studies with patient sera found that the Lig proteins are a major antigen recognized during the acute host infection. These observations demonstrate that the Lig proteins are a newly identified surface protein of pathogenic Leptospira, which by analogy to other bacterial immunoglobulin superfamily virulence factors, may play a role in host cell attachment and invasion during leptospiral pathogenesis. PMID:12890019

  16. Observational attachment theory-based parenting measures predict children's attachment narratives independently from social learning theory-based measures.

    Science.gov (United States)

    Matias, Carla; O'Connor, Thomas G; Futh, Annabel; Scott, Stephen

    2014-01-01

    Conceptually and methodologically distinct models exist for assessing quality of parent-child relationships, but few studies contrast competing models or assess their overlap in predicting developmental outcomes. Using observational methodology, the current study examined the distinctiveness of attachment theory-based and social learning theory-based measures of parenting in predicting two key measures of child adjustment: security of attachment narratives and social acceptance in peer nominations. A total of 113 5-6-year-old children from ethnically diverse families participated. Parent-child relationships were rated using standard paradigms. Measures derived from attachment theory included sensitive responding and mutuality; measures derived from social learning theory included positive attending, directives, and criticism. Child outcomes were independently-rated attachment narrative representations and peer nominations. Results indicated that Attachment theory-based and Social Learning theory-based measures were modestly correlated; nonetheless, parent-child mutuality predicted secure child attachment narratives independently of social learning theory-based measures; in contrast, criticism predicted peer-nominated fighting independently of attachment theory-based measures. In young children, there is some evidence that attachment theory-based measures may be particularly predictive of attachment narratives; however, no single model of measuring parent-child relationships is likely to best predict multiple developmental outcomes. Assessment in research and applied settings may benefit from integration of different theoretical and methodological paradigms.

  17. Next Steps in Attachment Theory.

    Science.gov (United States)

    Bell, David C

    2012-12-01

    Thanks to the phenomenal success of attachment theory, great progress has been made in understanding child and adult relationships. The success of attachment theory opens the way to new research directions that can extend its successes even further. In particular, more work on the fundamental nature of attachment that respects recent biological research is important, as is concentrated effort on the related caregiving system.

  18. Next Steps in Attachment Theory

    OpenAIRE

    Bell, David C.

    2012-01-01

    Thanks to the phenomenal success of attachment theory, great progress has been made in understanding child and adult relationships. The success of attachment theory opens the way to new research directions that can extend its successes even further. In particular, more work on the fundamental nature of attachment that respects recent biological research is important, as is concentrated effort on the related caregiving system.

  19. Genetic and caregiving-based contributions to infant attachment: unique associations with distress reactivity and attachment security.

    Science.gov (United States)

    Raby, K Lee; Cicchetti, Dante; Carlson, Elizabeth A; Cutuli, J J; Englund, Michelle M; Egeland, Byron

    2012-09-01

    In the longitudinal study reported here, we examined genetic and caregiving-based contributions to individual differences in infant attachment classifications. For 154 mother-infant pairs, we rated mothers' responsiveness to their 6-month-old infants during naturalistic interactions and classified infants' attachment organization at 12 and 18 months using the Strange Situation procedure. These infants were later genotyped with respect to the serotonin-transporter-linked polymorphic region (5-HTTLPR). Maternal responsiveness uniquely predicted infants' attachment security. Infants' 5-HTTLPR variation uniquely predicted their subtype of attachment security at 12 months and their subtype of attachment insecurity at 12 and 18 months. The short allele for 5-HTTLPR was associated with attachment classifications characterized by higher emotional distress. These findings suggest that 5-HTTLPR variation contributes to infants' emotional reactivity and that the degree to which caregivers are responsive influences how effectively infants use their caregivers for emotion regulation. Theoretical implications for the study of genetic and caregiving influences are discussed.

  20. Attachment Security and Pain

    DEFF Research Database (Denmark)

    Andersen, Tonny Elmose; Lahav, Yael; Defrin, Ruth

    2015-01-01

    The present study assesses for the first time, the possible disruption effect of posttraumatic stress symptoms (PTSS) with regard to the protective role of attachment on pain, among ex-POWs. While secure attachment seems to serve as a buffer, decreasing the perception of pain, this function may...

  1. Attachment and Temperament Revisited: Infant Distress, Attachment Disorganization, and the Serotonin Transporter Polymorphism.

    Science.gov (United States)

    Brumariu, Laura E; Bureau, Jean-François; Nemoda, Zsofia; Sasvari-Szekely, Maria; Lyons-Ruth, Karlen

    This study's aim was to evaluate whether infant disorganized attachment and infant proneness to distress exhibited differential relations to infant genetic factors as indexed by the serotonin transporter polymorphism. The role of the short allele of the serotonin transporter polymorphism (5-HTTLPR) in enhancing sensitivity to fearful and negative affect has been well-established (Canli & Lesch, 2007). In the current study, we used this known property of the short allele to provide a test of an important postulate of attachment theory, namely that infant attachment security or disorganization is not a function of the infant's proneness to distress. Participants were 39 parents and infants assessed between 12 and 18 months in the Strange Situation procedure. Genotype categories for the 5-HTTLPR (and rs25531) were created by both the original and the reclassified grouping system; infant proneness to distress was assessed directly in the Strange Situation Procedure. We also assessed maternal behavior at 18 months to evaluate whether any observed genetic effect indicated a passive effect through the mother. Consistent with previous findings, the 5-HTTLPR short allele was significantly related to the infant's wariness and distress, but was not related to attachment security or attachment disorganization. In addition, maternal disrupted interaction with the infant was not related to infant genotype or infant distress. Results support the concept that infant proneness to distress is associated with serotonergic factors while infant attachment security or disorganization is not a function of either 5-HTTLPR or behaviorally rated proneness to distress.

  2. Structural, Surface, in vitro Bacterial Adhesion and Biofilm Formation Analysis of Three Dental Restorative Composites

    Directory of Open Access Journals (Sweden)

    Maria T. Azam

    2015-06-01

    Full Text Available This study was conducted to investigate the relationship between dental materials and bacterial adhesion on the grounds of their chemical composition and physical properties. Three commercially available dental restorative materials (Filtek™Z350, Filtek™P90 and Spectrum®TPH® were structurally analyzed and their wettability and surface roughness were evaluated by using Fourier Transform Infrared Spectroscopy, Contact Angle Measurement and Atomic Force Microscopy, respectively. These materials were molded into discs and tested with three bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia for microbial attachment. The bacterial adhesion was observed at different time intervals, i.e., 0 h, 8 h, 24 h, 48 h and 72 h, along with Colony Forming Unit Count and Optical Density measurement of the media. It was found that all materials showed a degree of conversion with time intervals, i.e., 0 h, 8 h, 24 h, 48 h and 72 h, which led to the availability of functional groups (N–H and C–H that might promote adhesion. The trend in difference in the extent of bacterial adhesion can be related to particle size, chemical composition and surface wettability of the dental materials.

  3. Acute exposure to crystalline silica reduces macrophage activation in response to bacterial lipoproteins

    Directory of Open Access Journals (Sweden)

    Gillian Lee Beamer

    2016-02-01

    Full Text Available Numerous studies have examined the relationship between alveolar macrophages (AM and crystalline silica (SiO2 using in vitro and in vivo immunotoxicity models; however, exactly how exposure to SiO2 alters the functionality of AM and the potential consequences for immunity to respiratory pathogens remains largely unknown. Because recognition and clearance of inhaled particulates and microbes is largely mediated by pattern recognition receptors (PRR on the surface of AM, we hypothesized that exposure to SiO2 limits the ability of AM to respond to bacterial challenge by altering PRR expression. Alveolar and bone marrow-derived macrophages downregulate TLR2 expression following acute SiO2 exposure (e.g. 4 hours. Interestingly, these responses were dependent upon interactions between SiO2 and the class A scavenger receptor CD204, but not MARCO. Furthermore, SiO2 exposure decreased uptake of fluorescently labeled Pam2CSK4 and Pam3CSK4, resulting in reduced secretion of IL-1β, but not IL-6. Collectively, our data suggest that SiO2 exposure alters AM phenotype, which in turn affects their ability to uptake and respond to bacterial lipoproteins.

  4. Post-splenectomy infections in chronic schistosomiasis as a consequence of bacterial translocation

    Directory of Open Access Journals (Sweden)

    Kedma de Magalhães Lima

    2015-06-01

    Full Text Available INTRODUCTION : Bacterial translocation is the invasion of indigenous intestinal bacteria through the gut mucosa to normally sterile tissues and internal organs. Schistosomiasis may cause alterations in the immune system and damage to the intestines, portal system and mesenteric lymph nodes. This study investigated bacterial translocation and alterations in the intestinal microbiota and mucosa in schistosomiasis and splenectomized mice. METHODS : Forty female 35-day-old Swiss Webster mice were divided into the following four groups with 10 animals each: schistosomotic (ESF, splenectomized schistosomotic (ESEF, splenectomized (EF and control (CF. Infection was achieved by introduction of 50 Schistosoma mansoni (SLM cercariae through the skin. At 125 days after birth, half of the parasitized and unparasitized mice were subjected to splenectomy. Body weights were recorded for one week after splenectomy; then, the mice were euthanized to study bacterial translocation, microbiota composition and intestinal morphometry. RESULTS : We observed significant reductions in the weight increases in the EF, ESF and ESEF groups. There were increases of at least 1,000 CFU of intestinal microbiota bacteria in these groups compared with the CF. The EF, ESF and ESEF mice showed decreases in the heights and areas of villi and the total villus areas (perimeter. We observed frequent co-infections with various bacterial genera. CONCLUSIONS : The ESEF mice showed a higher degree of sepsis. This finding may be associated with a reduction in the immune response associated with the absence of the spleen and a reduction in nutritional absorption strengthened by both of these factors (Schistosoma infection and splenectomy.

  5. The bacterial community of entomophilic nematodes and host beetles.

    Science.gov (United States)

    Koneru, Sneha L; Salinas, Heilly; Flores, Gilberto E; Hong, Ray L

    2016-05-01

    Insects form the most species-rich lineage of Eukaryotes and each is a potential host for organisms from multiple phyla, including fungi, protozoa, mites, bacteria and nematodes. In particular, beetles are known to be associated with distinct bacterial communities and entomophilic nematodes. While entomopathogenic nematodes require symbiotic bacteria to kill and reproduce inside their insect hosts, the microbial ecology that facilitates other types of nematode-insect associations is largely unknown. To illuminate detailed patterns of the tritrophic beetle-nematode-bacteria relationship, we surveyed the nematode infestation profiles of scarab beetles in the greater Los Angeles area over a five-year period and found distinct nematode infestation patterns for certain beetle hosts. Over a single season, we characterized the bacterial communities of beetles and their associated nematodes using high-throughput sequencing of the 16S rRNA gene. We found significant differences in bacterial community composition among the five prevalent beetle host species, independent of geographical origin. Anaerobes Synergistaceae and sulphate-reducing Desulfovibrionaceae were most abundant in Amblonoxia beetles, while Enterobacteriaceae and Lachnospiraceae were common in Cyclocephala beetles. Unlike entomopathogenic nematodes that carry bacterial symbionts, insect-associated nematodes do not alter the beetles' native bacterial communities, nor do their microbiomes differ according to nematode or beetle host species. The conservation of Diplogastrid nematodes associations with Melolonthinae beetles and sulphate-reducing bacteria suggests a possible link between beetle-bacterial communities and their associated nematodes. Our results establish a starting point towards understanding the dynamic interactions between soil macroinvertebrates and their microbiota in a highly accessible urban environment. © 2016 John Wiley & Sons Ltd.

  6. Temperament and attachment: one construct or two?

    Science.gov (United States)

    Mangelsdorf, S C; Frosch, C A

    1999-01-01

    In this chapter we described the constructs of temperament and attachment and have discussed similarities and differences between the two. We addressed the issue of whether temperament contributes to overall attachment security or to the specific type of attachment that children display. We conclude that although temperament may influence the type of secure and insecure attachment relationship children form with their parent, temperament alone will not determine if a child is classified as securely or insecurely attached. We presented evidence suggesting that certain dimensions of temperament, specifically negative emotionality, may be associated with infants' behavior during the Strange Situation, such as proneness-to-distress during separations. However, we noted that these temperament dimensions do not predict overall security of attachment. It is likely that although no single temperament characteristic, such as proneness-to-distress, in and of itself determines overall attachment security, it is possible that a constellation of temperament characteristics may be more strongly related to attachment security. The examination of constellations of temperament characteristics may be particularly useful for furthering our understanding of individual differences within attachment classifications. Such an approach may elucidate the reasons why infants are classified into one subgroup of secure, insecure-avoidant, or insecure-resistant attachment versus another subgroup. Furthermore, we suggest that the collection of findings regarding temperament and attachment not only underscores the importance of a transactional approach to early social-emotional development, but emphasizes that temperament and attachment can make unique and interactive contributions to children's social-emotional functioning. That is, the goodness-of-fit between infant and parent characteristics may best predict security of attachment. Although child characteristics clearly contribute to the

  7. Cyanuric acid biodegradation by a mixed bacterial culture of Agrobacterium tumefaciens and Acinetobacter sp. in a packed bed biofilm reactor.

    Science.gov (United States)

    Galíndez-Nájera, S P; Llamas-Martínez, M A; Ruiz-Ordaz, N; Juárez-Ramírez, C; Mondragón-Parada, M E; Ahuatzi-Chacón, D; Galíndez-Mayer, J

    2009-02-01

    Cyanuric acid (1,3,5-triazine-2,4,6-triol [OOOT]) is a common biodegradation byproduct of triazinic herbicides, frequently accumulated in soils or water when supplementary carbon sources are absent. A binary bacterial culture able to degrade OOOT was selected through a continuous selection process accomplished in a chemostat fed with a mineral salt (MS) medium containing cyanuric acid as the sole carbon and nitrogen source. By sequence comparison of their 16S rDNA amplicons, bacterial strains were identified as Agrobacterium tumefaciens, and Acinetobacter sp. When the binary culture immobilized in a packed bed reactor (PBR) was fed with MS medium containing OOOT (50 mg L(-1)), its removal efficiencies were about 95%; when it was fed with OOOT plus glucose (120 mg L(-1)) as a supplementary carbon source, its removal efficiencies were closer to 100%. From sessile cells, attached to PBR porous support, or free cells present in the outflowing medium, DNA was extracted and used for Random Amplification of Polymorphic DNA analysis. Electrophoretic patterns obtained were compared to those of pure bacterial strains, a clear predominance of A. tumefaciens in PBR was observed. Although in continuous suspended cell culture, a stable binary community could be maintained, the attachment capability of A. tumefaciens represented a selective advantage over Acinetobacter sp. in the biofilm reactor, favoring its predominance in the porous stone support.

  8. Sequential binding of calcium ions to the B-repeat domain of SdrD from Staphylococcus aureus.

    Science.gov (United States)

    Roman, Andrei Yu; Devred, François; Lobatchov, Vladimir M; Makarov, Alexander A; Peyrot, Vincent; Kubatiev, Aslan A; Tsvetkov, Philipp O

    2016-02-01

    Biofilms of live bacteria forming on medical devices and implants contribute significantly to bacterial blood dissemination and to the spread of nosocomial infections. Cell surface SdrD protein plays a key role in the attachment of Staphylococcus aureus to the extracellular matrix (ECM) and in the formation of biofilm. SdrD binds calcium ions using its B1-B5 region bearing EF-hand Ca-binding sites, leading to conformational changes in the structure of SdrD. This alters the distance between the bacterial surface and the ECM-interacting domain of SdrD in a spring-like fashion, participating in bacterial attachment. In this study we investigated calcium binding to EF-hand sites of SdrD using isothermal titration calorimetry and determined the impact of this process on SdrD's thermodynamic stability. This allowed us to propose a model of B1-B5 reorganization upon binding of calcium and to get new insight into the molecular mechanism of SdrD's action.

  9. To attach or not to attach? The effect of carrier surface morphology and topography on attachment of phoretic deutonymphs of Uropoda orbicularis (Acari)

    Science.gov (United States)

    Bajerlein, Daria; Adamski, Zbigniew; Kacalak, Wojciech; Tandecka, Katarzyna; Wiesner, Maciej; Jurga, Stefan

    2016-08-01

    Previous studies on preferences of phoretic deutonymphs of Uropodina for attachment sites have shown that they frequently select smooth and hydrophobic surfaces. The aim of our study was to provide the detailed morphological and topographical characteristics of beetle body surfaces to which deutonymphs frequently attach and to verify how the presence of setae and surface sculpture affects deutonymph attachment. The study was conducted on Uropoda orbicularis (Müller, 1776) and its common beetle carriers: Aphodius prodromus (Brahm, 1790), Aphodius fimetarius (Linnaeus, 1758), Onthophagus nuchicornis (Linnaeus, 1758) and Margarinotus carbonarius (Hoffmann, 1803). Morphology and topography of elytra, femora, propygidia and pygidia of beetles were analysed mainly using SEM methods supported with CLSM and AFM techniques. The hypothesis that deutonymphs may attach to surfaces covered with setae, if seta density is low enough not to disturb mite movement, was tested. The study revealed that deutonymphs attach to surfaces of various types as follows: (i) smooth, (ii) hairy, i.e., covered with setae, (iii) flat and (iv) sculptured. Smooth body parts and body parts covered with setae of low density were most frequently and intensively occupied with deutonymphs. Surfaces of high seta density were avoided by mites. Within elytra of Aphodius beetles, deutonymphs definitely preferred flat surfaces of elytral intervals. On the contrary, densely punctuated propygidium and pygidium in M. carbonarius were heavily infested with deutonymphs. We conclude that carrier surface morphology and topography are important for Uropodina deutonymph attachment, but these two factors cannot fully explain the observed relation.

  10. Attachment Theory and Mindfulness

    Science.gov (United States)

    Snyder, Rose; Shapiro, Shauna; Treleaven, David

    2012-01-01

    We initiate a dialog between two central areas in the field of psychology today: attachment theory/research and mindfulness studies. The impact of the early mother-infant relationship on child development has been well established in the literature, with attachment theorists having focused on the correlation between a mother's capacity for…

  11. Breastfeeding, Parenting, and Infant Attachment Behaviors.

    Science.gov (United States)

    Gibbs, Benjamin G; Forste, Renata; Lybbert, Emily

    2018-04-01

    Objectives Infants and toddlers need secure attachments in order to develop the social competence required to successfully navigate later peer and adult relationships. Breastfeeding is a parenting factor that has been associated with child emotional development-specifically the attachment between children and their mothers. Yet, this link may simply be the result of other parenting behaviors that are associated with breastfeeding. Thus, our objective is to examine whether the link between infant attachment behaviors and breastfeeding endures when accounting for a broad array of in-depth measures of parenting. Methods We use the Early Childhood Longitudinal Study of children from 9 months to 2 years of age collected by the National Center for Education Statistics. Using Ordinary Least Squares regression, data analyses examine the association between the Toddler Attachment Sort-45 (TAS-45) measures of toddler-parent attachment (infant attachment security and temperamental dependency) and breastfeeding practices. We also examine individual items of the TAS-45 to isolate specific attachment behaviors that have the strongest associations with breastfeeding. Results We find an enduring link between children who are predominantly breastfed for six or more months and infant attachment security. However, we find no evidence that breastfeeding is linked to a child's temperamental dependency. Of the nine items used to examine infant attachment behaviors, we find that breastfed children are rated as having slightly higher scores on two measures ("warm and cuddly," "cooperative") and lower scores on one measure ("demanding/angry"). Conclusions for Practice Breastfeeding has an important link to the child's use of their caregiver as a secure base for exploration and a place of comfort when distressed (infant attachment security). Yet, breastfeeding does not appear to reduce a child's temperamental dependency or level of clinginess as measured by how demanding, fussy or

  12. Adolescents' multiple versus single primary attachment figures, reorganization of attachment hierarchy, and adjustments: the important people interview approach.

    Science.gov (United States)

    Umemura, Tomotaka; Lacinová, Lenka; Kraus, Jakub; Horská, Eliška; Pivodová, Lenka

    2018-04-20

    Using 212 adolescents from a central-European country (mean age = 14.02, SD = 2.05, ranged from 11 to 18 years; females = 54%) and a multi-informant method to measure adolescents' behavioral and emotional adjustments, the present study explored three aspects regarding the attachment hierarchy. (1) The three types of behavioral systems of Rosenthal and Kobak's important people interview (IPI) were initially validated using an exploratory factor analysis with a US sample. Using a confirmatory factor analysis with a Czech sample, we replicated these three behavioral systems: attachment bond, support seeking, and affiliation. (2) We found that adolescents who developed attachment bond to multiple primary attachment figures were likely to score lower on both teacher-rated and parent-rated internalizing problems compared to those who had a single primary attachment figure. These multiple primary attachment figures tended to be family members (not peers). (3) Early adolescents who placed parents low in their attachment hierarchy scored higher on self-reported negative affect and lower on self-reported positive affect compared to early adolescents who placed parents high. The present study highlights multiple (vs. single) primary attachment figures as a protective factor and the premature reorganization of attachment hierarchy as a risk factor for adolescents' emotional and affective adjustments.

  13. Unique neurobiology during the sensitive period for attachment produces distinctive infant trauma processing

    Science.gov (United States)

    Opendak, Maya; Sullivan, Regina M.

    2016-01-01

    Background Trauma has neurobehavioral effects when experienced at any stage of development, but trauma experienced in early life has unique neurobehavioral outcomes related to later life psychiatric sequelae. Recent evidence has further highlighted the context of infant trauma as a critical variable in determining its immediate and enduring consequences. Trauma experienced from an attachment figure, such as occurs in cases of caregiver child maltreatment, is particularly detrimental. Methods Using data primarily from rodent models, we review the literature on the interaction between trauma and attachment in early life, which highlights the role of the caregiver’s presence in engagement of attachment brain circuitry and suppressing threat processing by the amygdala. We then consider how trauma with and without the caregiver produces long-term changes in emotionality and behavior, and suggest that these experiences initiate distinct pathways to pathology. Results Together these data suggest that infant trauma processing and its enduring effects are impacted by both the immaturity of brain areas for processing trauma and the unique functioning of the early-life brain, which is biased toward processing information within the attachment circuitry. Conclusion An understanding of developmental differences in trauma processing as well as the critical role of the caregiver in further altering early life brain processing of trauma is important for developing age-relevant treatment and interventions. Highlights of this article Trauma experienced in early life has been linked with life-long outcomes for mental health through a mechanism that remains unclear. Trauma experienced in the presence of a caregiver has unique consequences. The infant brain is predisposed toward processing information using attachment circuitry rather than threat circuitry. Data from rodent models suggest that repeated trauma in the presence of a caregiver prematurely engages brain areas important

  14. PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.

    2011-01-19

    Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), and measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work supports further development of metal titanates as a novel class of antibacterials.

  15. Cell shape can mediate the spatial organization of the bacterial cytoskeleton

    Science.gov (United States)

    Wang, Siyuan; Wingreen, Ned

    2013-03-01

    The bacterial cytoskeleton guides the synthesis of cell wall and thus regulates cell shape. Since spatial patterning of the bacterial cytoskeleton is critical to the proper control of cell shape, it is important to ask how the cytoskeleton spatially self-organizes in the first place. In this work, we develop a quantitative model to account for the various spatial patterns adopted by bacterial cytoskeletal proteins, especially the orientation and length of cytoskeletal filaments such as FtsZ and MreB in rod-shaped cells. We show that the combined mechanical energy of membrane bending, membrane pinning, and filament bending of a membrane-attached cytoskeletal filament can be sufficient to prescribe orientation, e.g. circumferential for FtsZ or helical for MreB, with the accuracy of orientation increasing with the length of the cytoskeletal filament. Moreover, the mechanical energy can compete with the chemical energy of cytoskeletal polymerization to regulate filament length. Notably, we predict a conformational transition with increasing polymer length from smoothly curved to end-bent polymers. Finally, the mechanical energy also results in a mutual attraction among polymers on the same membrane, which could facilitate tight polymer spacing or bundling. The predictions of the model can be verified through genetic, microscopic, and microfluidic approaches.

  16. Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis

    Directory of Open Access Journals (Sweden)

    Cheng-Yen Kao

    2016-02-01

    Full Text Available Helicobacter pylori pathogenesis and disease outcomes are mediated by a complex interplay between bacterial virulence factors, host, and environmental factors. After H. pylori enters the host stomach, four steps are critical for bacteria to establish successful colonization, persistent infection, and disease pathogenesis: (1 Survival in the acidic stomach; (2 movement toward epithelium cells by flagella-mediated motility; (3 attachment to host cells by adhesins/receptors interaction; (4 causing tissue damage by toxin release. Over the past 20 years, the understanding of H. pylori pathogenesis has been improved by studies focusing on the host and bacterial factors through epidemiology researches and molecular mechanism investigations. These include studies identifying the roles of novel virulence factors and their association with different disease outcomes, especially the bacterial adhesins, cag pathogenicity island, and vacuolating cytotoxin. Recently, the development of large-scale screening methods, including proteomic, and transcriptomic tools, has been used to determine the complex gene regulatory networks in H. pylori. In addition, a more available complete genomic database of H. pylori strains isolated from patients with different gastrointestinal diseases worldwide is helpful to characterize this bacterium. This review highlights the key findings of H. pylori virulence factors reported over the past 20 years.

  17. Markers of immunity and bacterial translocation in cirrhosis

    DEFF Research Database (Denmark)

    Mortensen, Christian

    2015-01-01

    to be correlated to portal hypertension, a clinically relevant haemodynamic alteration, and appeared to be associated with increased mortality. To assess the consequences of BT on immunity, we developed an assay for the detection of bacterial DNA (bDNA), a novel marker of BT. Using the assay in the second study......Bacterial translocation (BT), the migration of enteric bacteria to extraintestinal sites, is related to immune stimulation and haemodynamic changes in experimental cirrhosis. These changes may be highly relevant to patients with cirrhosis, where changes in the circulation cause serious......, in 38 patients with ascites, we found no association between bDNA and immunity, in contrast to some previous findings. In the final paper, exploring one possible translocation route, we hypothesized a difference in bDNA levels between the blood from the veins draining the gut on one hand and the liver...

  18. Attachment theory: A review of research

    Directory of Open Access Journals (Sweden)

    Polovina Nada

    2005-01-01

    Full Text Available Research of attachment is numerous and versatile. They differ according to problems addressed, methodology applied (longitudinal studies, studies with horizontal designs, different instruments used, different methods of data analysis, and characteristics of samples involved (concerning age socio/economic status, family ecology. The research is commonly relied on the core assumptions of the theory itself, and the shared characteristic is orientation to explore complex phenomena of human experience and functioning. From the vast variety of research only those who most directly test the basic assumptions of the attachment theory are focused and addressed in the paper: representation of patterns of attachment in the childhood and adulthood, stability and change of attachment security from infancy to early adulthood, transgenerational transmission of attachment characteristics, the place and the role of attachment behavioral system in the personality development. The aim of the paper is to highlight the basic research and theory issues and directions, and illustrate them with concrete research date.

  19. Attachment style and interpersonal trauma in refugees.

    Science.gov (United States)

    Morina, Naser; Schnyder, Ulrich; Schick, Matthis; Nickerson, Angela; Bryant, Richard A

    2016-12-01

    Refugees can suffer many experiences that threaten their trust in others. Although models of refugee mental health have postulated that attachment securities may be damaged by refugee experiences, this has yet to be empirically tested. This study aimed to understand the relationship between the nature of traumatic experiences sustained by refugees and attachment styles. In a cross-sectional study, treatment-seeking refugees (N = 134) were assessed for traumatic exposure using the Harvard Trauma Questionnaire and Posttraumatic Diagnostic Scale. Attachment style was assessed using the Experiences in Close Relationship Scale. Whereas gender and severity of interpersonal traumatic events predicted avoidant attachment style (accounting for 11% of the variance), neither these factors nor non-interpersonal trauma predicted anxious attachment. Exposure to interpersonal traumatic events, including torture, is associated with enduring avoidant attachment tendencies in refugees. This finding accords with attachment theories that prior adverse interpersonal experiences can undermine secure attachment systems, and may promote avoidance of attachment seeking. This finding may point to an important process maintaining poor psychological health in refugees affected by interpersonal trauma. © The Royal Australian and New Zealand College of Psychiatrists 2016.

  20. Attachment representation in institutionalized children: a preliminary study using the child attachment interview.

    Science.gov (United States)

    Zaccagnino, Maria; Cussino, Martina; Preziosa, Alessandra; Veglia, Fabio; Carassa, Antonella

    2015-01-01

    The experience of being removed from one's home and the transition to a residential care system pose enormous challenges for a child. Substantial evidence has been found regarding severe developmental effects due to early exposition to extreme psychosocial and affective deprivation. The research on Bowlby's theoretical proposals has highlighted the link between insecure, disorganized and atypical attachment patterns and children both living in foster care facilities and adopted out of those institutions. The goal of this pilot study is to investigate the attachment representation in an Italian sample of children in middle childhood (9-13 years old) who have been removed from their homes. Two compared groups of children participated in this study. The first group was composed of 24 Italian children who had been removed from their homes. The second group, considered as the control group, was composed of 35 Italian children who had never been in foster care placement. The quality of children's attachment to their primary caregivers was assessed by the Child Attachment Interview, an innovative semi-structured interview that seeks to bridge the measurement gap identified in middle childhood The children in foster care placement show a higher percentage of insecure and disorganized attachment representations and lower scores on the Child Reflective Functioning Scale. The clinical implications and enhancements to effective intervention for foster children's caretaking are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Host imprints on bacterial genomes--rapid, divergent evolution in individual patients.

    Directory of Open Access Journals (Sweden)

    Jaroslaw Zdziarski

    Full Text Available Bacteria lose or gain genetic material and through selection, new variants become fixed in the population. Here we provide the first, genome-wide example of a single bacterial strain's evolution in different deliberately colonized patients and the surprising insight that hosts appear to personalize their microflora. By first obtaining the complete genome sequence of the prototype asymptomatic bacteriuria strain E. coli 83972 and then resequencing its descendants after therapeutic bladder colonization of different patients, we identified 34 mutations, which affected metabolic and virulence-related genes. Further transcriptome and proteome analysis proved that these genome changes altered bacterial gene expression resulting in unique adaptation patterns in each patient. Our results provide evidence that, in addition to stochastic events, adaptive bacterial evolution is driven by individual host environments. Ongoing loss of gene function supports the hypothesis that evolution towards commensalism rather than virulence is favored during asymptomatic bladder colonization.

  2. What do we know about maternal-fetal attachment?

    Science.gov (United States)

    Shieh, C; Kravitz, M; Wang, H H

    2001-09-01

    A review of the literature suggests that there are three critical attributes related to the concept of maternal-fetal attachment, including cognitive, affective, and altruistic attachment. Cognitive attachment is the desire to know the baby. Affective attachment is the pleasure associated with thoughts of or interaction with the fetus. Altruistic attachment refers to a desire to protect the unborn child. Existing measurements on maternal-fetal attachment are developed based on low-risk and white pregnant women and previous research has not yet resulted in a consistent theoretical model. Future research should focus on development of culturally sensitive instruments and combining qualitative and quantitative measures to broaden theoretical understanding of the concept. Nursing assessment of maternal-fetal attachment is an on-going process. The nurse's role is to reassure those who have developed attachment to their fetuses and to motivate those who are unaware of or unconcerned about their attachment to their fetuses. Collecting data from different attributes of attachment helps nurses identify each woman's attachment patterns and areas of concern.

  3. Bacteriocidal activity of sanitizers against Enterococcus faecium attached to stainless steel as determined by plate count and impedance methods.

    Science.gov (United States)

    Andrade, N J; Bridgeman, T A; Zottola, E A

    1998-07-01

    Enterococcus faecium attached to stainless steel chips (100 mm2) was treated with the following sanitizers: sodium hypochlorite, peracetic acid (PA), peracetic acid plus an organic acid (PAS), quaternary ammonium, organic acid, and anionic acid. The effectiveness of sanitizer solutions on planktonic cells (not attached) was evaluated by the Association of Official Analytical Chemists (AOAC) suspension test. The number of attached cells was determined by impedance measurement and plate count method after vortexing. The decimal reduction (DR) in numbers of the E. faecium population was determined for the three methods and was analyzed by analysis of variance (P plate count method after vortexing, and impedance measurement, respectively. Plate count and impedance methods showed a difference (P measurement was the best method to measure adherent cells. Impedance measurement required the development of a quadratic regression. The equation developed from 82 samples is as follows: log CFU/chip = 0.2385T2-0.96T + 9.35, r2 = 0.92, P plate count method after vortexing. These data suggest that impedance measurement is the method of choice when evaluating the number of bacterial cells adhered to a surface.

  4. Xylella fastidiosa outer membrane vesicles modulate plant colonization by blocking attachment to surfaces.

    Science.gov (United States)

    Ionescu, Michael; Zaini, Paulo A; Baccari, Clelia; Tran, Sophia; da Silva, Aline M; Lindow, Steven E

    2014-09-16

    Outer membrane vesicles (OMVs) of Gram-negative bacteria have been studied intensively in recent years, primarily in their role in delivering virulence factors and antigens during pathogenesis. However, the near ubiquity of their production suggests that they may play other roles, such as responding to envelope stress or trafficking various cargoes to prevent dilution or degradation by other bacterial species. Here we show that OMVs produced by Xylella fastidiosa, a xylem-colonizing plant pathogenic bacterium, block its interaction with various surfaces such as the walls of xylem vessels in host plants. The release of OMVs was suppressed by the diffusible signal factor-dependent quorum-sensing system, and a X. fastidiosa ΔrpfF mutant in which quorum signaling was disrupted was both much more virulent to plants and less adhesive to glass and plant surfaces than the WT strain. The higher virulence of the ΔrpfF mutant was associated with fivefold higher numbers of OMVs recovered from xylem sap of infected plants. The frequency of attachment of X. fastidiosa to xylem vessels was 20-fold lower in the presence of OMVs than in their absence. OMV production thus is a strategy used by X. fastidiosa cells to adjust attachment to surfaces in its transition from adhesive cells capable of insect transmission to an "exploratory" lifestyle for systemic spread within the plant host which would be hindered by attachment. OMV production may contribute to the movement of other bacteria in porous environments by similarly reducing their contact with environmental constituents.

  5. Dual partitioning and attachment effects of rhamnolipid on pyrene biodegradation under bioavailability restrictions

    International Nuclear Information System (INIS)

    Congiu, Eleonora; Parsons, John R.; Ortega-Calvo, José-Julio

    2015-01-01

    We investigated the effects of different bioavailability scenarios on the rhamnolipid-enhanced biodegradation of pyrene by the representative polycyclic aromatic hydrocarbon degrader Mycobacterium gilvum VM552. This biosurfactant enhanced biodegradation when pyrene was provided in the form of solid crystals; no effect was observed when the same amount of the chemical was preloaded on polydimethylsiloxane (PDMS). An enhanced effect was observed when pyrene was sorbed into soil but not with the dissolved compound. Synchronous fluorescence spectrophotometry and liquid scintillation were used to determine the phase exchange of pyrene. We also investigated the phase distribution of bacteria. Our results suggest that the rhamnolipid can enhance the biodegradation of pyrene by micellar solubilization and increase diffusive uptake. These mechanisms increase substrate acquisition by bacterial cells at exposure concentrations well above the half-saturation constant for active uptake. The moderate solubilization of pyrene from PDMS by the rhamnolipid and the prevention of cell attachment may explain the lack of enhancement for pyrene-preloaded PDMS. - Highlights: • Rhamnolipid biosurfactant can enhance the biodegradation of pyrene. • The enhancement depends on how the bacteria are exposed to the pollutant. • Rhamnolipid stimulates if pyrene is provided by dissolution from crystals. • No effect is observed if pyrene is provided by partitioning from a silicone polymer. • This lack of effect is due to the balance between enhanced dissolution and decreased cell attachment. - Rhamnolipid-enhanced biodegradation of pyrene may depend on the exposure regime. Moderate solubilization from difficult matrices and prevention of cell attachment may have no effect

  6. Land-based salmon aquacultures change the quality and bacterial degradation of riverine dissolved organic matter

    DEFF Research Database (Denmark)

    Kamjunke, Norbert; Nimptsch, Jorge; Harir, Mourad

    2017-01-01

    characterization of aquaculture DOM quality and its bacterial degradation using four salmon aquacultures in Chile. Fluorescence measurements, ultrahigh-resolution mass spectrometry, and nuclear magnetic resonance spectroscopy of the DOM revealed specific and extensive molecular alterations caused by aquacultures...

  7. 蔬菜连作改为蓝莓种植后土壤细菌群落多样性变化的分析%Changes in Soil Bacterial Community Diversity Caused by Cropping System Alteration from Vegetable Continuous Cropping to Blueberry Planting

    Institute of Scientific and Technical Information of China (English)

    祁石刚; 田畅; 却枫; 徐志胜; 王枫; 熊爱生

    2016-01-01

    基于第二代Illumina Miseq高通量测序平台,利用16S rDNA技术分析了江苏省宿迁市蔬菜连作改为蓝莓种植后土壤细菌多样性的分布和细菌群落多样性的变化。结果表明:Kaistobacter、假交替单胞菌属( Pseud oaltre omno as)、硫杆状菌属( Thiobacillus)、Rubritalea、浮霉菌属( Planctomyces)、Lysobacter、纤维弧菌属( Cellvibrio)、噬氢菌属( Hdy roeg nohp a-ga )、鞘脂单胞菌属( Sphingomona s)和热单胞菌属( Thermomonas)为蔬菜连作改为蓝莓种植后土壤细菌的主要类群; Spo-rosarcina、Alicyclobacillus、氨氧化古细菌( Candidatus nitrososphaera)和P ontibatc er是蔬菜连作土壤细菌的主要类群;蔬菜连作改为种植蓝莓后,土壤细菌多样性和丰度降低,优势菌群也出现了显著的变化。%Based on the second-generation high-throughput sequencing platform Illumina Miseq , using the 16S rDNA gene sequencing technology, the author analyzed the changes in soil bacterial community diversity caused by the cropping system altera-tion from vegetable continuous cropping to blueberry planting in Suqian city of Jiangsu province .The results showed that:Kaisto-bacter, Pseudoalteromonas, Thiobacillus, Rubrti alea, Planctomyces, Lysobacter, Cellvibrio, Hydrogenophaga, Sphingomonas and Thermomonas were the dominant bacterial populations in the soil after cropping system alteration from vegetable continuous crop-ping to blueberry planting;Sporosarcina, Alicyclobacillus, Cand idatus nitrososphaera and Pontbi acter were the dominant bacterial populations in the soil of continuous-cropping vegetable field;after the alteration from vegetable continuous cropping to blueberry planting, the diversity and abundance of soil bacteria were reduced , and the dominant bacterial community also changed obvious-ly.

  8. Attachment Styles of Dermatological Patients in Europe

    DEFF Research Database (Denmark)

    Szabó, Csanád; Altmayer, Anita; Lien, Lars

    2017-01-01

    Attachment styles of dermatological outpatients and satisfaction with their dermatologists were investigated within the framework of a multicentre study conducted in 13 European countries, organized by the European Society for Dermatology and Psychiatry. Attachment style was assessed with the Adult......, and experienced similar rates of anxiety in relationships as did the controls. Participants who had secure attachment styles reported stressful life events during the last 6 months significantly less often than those who had insecure attachment styles. Patients with secure attachment styles tended to be more...... satisfied with their dermatologist than did insecure patients. These results suggest that secure attachment of dermatological outpatients may be a protective factor in the management of stress....

  9. Application of quercetin and its bio-inspired nanoparticles as anti-adhesive agents against Bacillus subtilis attachment to surface

    Energy Technology Data Exchange (ETDEWEB)

    Raie, Diana S., E-mail: raiediana@yahoo.com [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); Mhatre, Eisha [Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena (FSU), Jena (Germany); Thiele, Matthias [Nanobiophotonic Department, Leibniz Institute of Photonic Technology Jena (IPHT), Jena (Germany); Labena, A. [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); El-Ghannam, Gamal [National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza (Egypt); Farahat, Laila A. [Process Design and Development Department, Egyptian Petroleum Research Institute (EPRI), Nasr City, Cairo (Egypt); Youssef, Tareq [National Institute of Laser Enhanced Sciences (NILES), Cairo University, Giza (Egypt); Fritzsche, Wolfgang [Nanobiophotonic Department, Leibniz Institute of Photonic Technology Jena (IPHT), Jena (Germany); Kovács, Ákos T., E-mail: akos-tibor.kovacs@uni-jena.de [Terrestrial Biofilms Group, Institute of Microbiology, Friedrich Schiller University Jena (FSU), Jena (Germany)

    2017-01-01

    The aim of this study was directed to reveal the repulsive effect of coated glass slides by quercetin and its bio-inspired titanium oxide and tungsten oxide nanoparticles on physical surface attachment of Bacillus subtilis as an ab-initio step of biofilm formation. Nanoparticles were successfully synthesized using sol–gel and acid precipitation methods for titanium oxide and tungsten oxide, respectively (in the absence or presence of quercetin). The anti-adhesive impact of the coated-slides was tested through the physical attachment of B. subtilis after 24 h using Confocal Laser Scanning Microscopy (CLSM). Here, quercetin was presented as a bio-route for the synthesis of tungsten mixed oxides nano-plates at room temperature. In addition, quercetin had an impact on zeta potential and adsorption capacity of both bio-inspired amorphous titanium oxide and tungsten oxide nano-plates. Interestingly, our experiments indicated a contrary effect of quercetin as an anti-adhesive agent than previously reported. However, its bio-inspired metal oxide proved their repulsive efficiency. In addition, quercetin-mediated nano-tungsten and quercetin-mediated amorphous titanium showed anti-adhesive activity against B. subtilis biofilm. - Highlights: • Novel quercetin-mediated nanoparticles were tested for anti-adhesion against attachment of cells forming biofilms. • Quercetin showed a low-grade of protection level against bacterial attachment. • Bio-inspired nano-anatase showed a lower efficiency than amorphous titanium. • Thermally treated bio-inspired nano-tungsten gets an improved anti-adhesive activity.

  10. Comparison of the role of attachment, aggregation and internalisation of microorganisms in UVC and UVA (solar) disinfection.

    Science.gov (United States)

    Bichai, Françoise; Léveillé, Simon; Barbeau, Benoit

    2011-01-01

    In this comparative study, the impact of two microbial protective mechanisms against simulated UVA disinfection was assessed by using protocols previously developed for UVC disinfection assays. (i) The impact of natural microorganism aggregation and attachment to particles was assessed by targeting total coliform bacteria in natural surface water samples. (ii) The impact of bacteria internalisation by zooplankton was assessed by using C. elegans nematodes as a model host and E. coli as a bacterial target for UVA inactivation. Dispersion of natural aggregates by blending prior to UVA exposure was shown to enhance the inactivation rate of total coliforms as compared to untreated raw water. Removal of particles by an 8-microm membrane filtration did not improve UVA disinfection efficiency. Twenty-four per cent of the highest applied UVA fluence was found to reach internalised E. coli in nematodes. Both aggregation and internalisation showed similar impact as protective mechanisms against UVA and UVC bacterial inactivation.

  11. Within-person variation in security of attachment: a self-determination theory perspective on attachment, need fulfillment, and well-being.

    Science.gov (United States)

    La Guardia, J G; Ryan, R M; Couchman, C E; Deci, E L

    2000-09-01

    Attachment research has traditionally focused on individual differences in global patterns of attachment to important others. The current research instead focuses primarily on within-person variability in attachments across relational partners. It was predicted that within-person variability would be substantial, even among primary attachment figures of mother, father, romantic partner, and best friend. The prediction was supported in three studies. Furthermore, in line with self-determination theory, multilevel modeling and regression analyses showed that, at the relationship level, individuals' experience of fulfillment of the basic needs for autonomy, competence, and relatedness positively predicted overall attachment security, model of self, and model of other. Relations of both attachment and need satisfaction to well-being were also explored.

  12. Fuel rod attachment system

    International Nuclear Information System (INIS)

    Christiansen, D.W.

    1982-01-01

    A reusable system for removably attaching a nuclear reactor fuel rod to a support member. A locking cap is secured to the fuel rod and a locking strip is fastened to the support member or vice versa. The locking cap has two opposing fingers and shaped to form a socket having a body portion. The locking strip has an extension shaped to rigidly attach to the socket's body portion. The locking cap's fingers are resiliently deflectable. For attachment, the locking cap is longitudinally pushed onto the locking strip causing the extension to temporarily deflect open the fingers to engage the socket's body portion. For removal, the process is reversed. In an alternative embodiment, the cap is rigid and the strip is transversely resiliently compressible. (author)

  13. It takes two to talk: longitudinal associations among infant-mother attachment, maternal attachment representations, and mother-child emotion dialogues.

    Science.gov (United States)

    Hsiao, Celia; Koren-Karie, Nina; Bailey, Heidi; Moran, Greg

    2015-01-01

    Research on the attachment-dialogue link has largely focused on infant-mother attachment. This study investigated longitudinal associations between infant-mother attachment and maternal attachment representations and subsequent mother-child emotion dialogues (N = 50). Maternal attachment representations were assessed using the Adult Attachment Interview when children were 3 months, infant-mother attachment was assessed using the Strange Situation Procedure at 13 months, and mother-child emotion dialogues were assessed using the Autobiographical Emotional Events Dialogue at 3.5 years. Consistent with past research, the three organized categories of infant-mother attachment relationships were associated with later mother-child emotion dialogues. Disorganized attachment relationships were associated with a lack of consistent and coherent strategy during emotion dialogues. Autonomous mothers co-constructed coherent narratives with their children; Dismissing and Preoccupied mothers created stories that were less narratively organized. Although the Unresolved category was unrelated to classifications of types of mother-child discourse, mothers' quality of contribution to the dialogues was marginally lower compared to the quality of their children's contributions to the emotion discussion. Secure children showed highest levels of child cooperation and exploration. Autonomous mothers displayed highest levels of maternal sensitive guidance during emotion dialogues. We provide preliminary evidence for role reversal in dialogues between Preoccupied and Unresolved mothers and their children.

  14. Insecure attachment behavior and partner violence: incorporating couple perceptions of insecure attachment and relational aggression.

    Science.gov (United States)

    Oka, Megan; Sandberg, Jonathan G; Bradford, Angela B; Brown, Andrew

    2014-10-01

    Intimate partner violence and insecure attachment are therapeutically relevant concepts when working with couples. The link between attachment and intimate partner violence has been examined in the literature, but an area of aggression that often goes unexamined is relational aggression, or using third parties as a means of being aggressive toward a partner. We asked how participants' attachment behaviors were related to their own and partners' relational and physical aggression. We used structural equation modeling to estimate actor-partner interdependence among these relationships in 644 heterosexual couples. Results indicated significant partner paths from attachment to relational aggression, as well as significant actor paths between relational aggression and physical aggression. Implications were discussed. Data for this study were collected from the RELATE assessment. © 2014 American Association for Marriage and Family Therapy.

  15. Genetic manipulation of structural color in bacterial colonies

    DEFF Research Database (Denmark)

    Johansen, Villads Egede; Catón, Laura; Hamidjaja, Raditijo

    2018-01-01

    analysis, we obtained a detailed correlation of how genetic modifications alter structural color in bacterial colonies. Understanding of genotype and phenotype relations in this system opens the way to genetic engineering of on-demand living optical materials, for use as paints and living sensors.......Naturally occurring photonic structures are responsible for the bright and vivid coloration in a large variety of living organisms. Despite efforts to understand their biological functions, development, and complex optical response, little is known of the underlying genes involved...

  16. Bio-alteration of metallurgical wastes by Pseudomonas aeruginosa in a semi flow-through reactor.

    Science.gov (United States)

    van Hullebusch, Eric D; Yin, Nang-Htay; Seignez, Nicolas; Labanowski, Jérôme; Gauthier, Arnaud; Lens, Piet N L; Avril, Caroline; Sivry, Yann

    2015-01-01

    Metallurgical activities can generate a huge amount of partially vitrified waste products which are either landfilled or recycled. Lead Blast Furnace (LBF) slags are often disposed of in the vicinity of metallurgical plants, and are prone to weathering, releasing potentially toxic chemical components into the local environment. To simulate natural weathering in a slag heap, bioweathering of these LBF slags was studied in the presence of a pure heterotrophic bacterial strain (Pseudomonas aeruginosa) and in a semi-flow through reactor with intermittent leachate renewal. The evolution of water chemistry, slag composition and texture were monitored during the experiments. The cumulative bulk release of dissolved Fe, Si, Ca and Mg doubled in the presence of bacteria, probably due to the release of soluble complexing organic molecules (e.g. siderophores). In addition, bacterial biomass served as the bioadsorbent for Pb, Fe and Zn as 70-80% of Pb and Fe, 40-60% of Zn released are attached to and immobilized by the bacterial biomass. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Attachment-based interventions for families with young children.

    Science.gov (United States)

    Woodhouse, Susan S

    2018-05-21

    Given a large body of research indicating links between child attachment and later mental health outcomes, interventions that promote children's secure attachment to their caregivers have the potential to contribute to prevention of psychopathology and promotion of well-being. A number of attachment-based interventions have been developed to support parents, enhance caregiving quality, and promote children's attachment security with the aim of improving children's mental health. There is now a growing evidence base to support the efficacy of a number of these interventions. The present literature review and introduction to the special issue on attachment-based interventions for families with young children describes key aspects of attachment theory and research that form the theoretical and empirical background for attachment-based interventions, and introduces seven case studies illustrating five different attachment-based interventions. The case studies represent a variety of attachment-based models, including both group and individual treatments, and show applications across a range of caregiver contexts. © 2018 Wiley Periodicals, Inc.

  18. Impact of bacterial ice nucleating particles on weather predicted by a numerical weather prediction model

    Science.gov (United States)

    Sahyoun, Maher; Korsholm, Ulrik S.; Sørensen, Jens H.; Šantl-Temkiv, Tina; Finster, Kai; Gosewinkel, Ulrich; Nielsen, Niels W.

    2017-12-01

    Bacterial ice-nucleating particles (INP) have the ability to facilitate ice nucleation from super-cooled cloud droplets at temperatures just below the melting point. Bacterial INP have been detected in cloud water, precipitation, and dry air, hence they may have an impact on weather and climate. In modeling studies, the potential impact of bacteria on ice nucleation and precipitation formation on global scale is still uncertain due to their small concentration compared to other types of INP, i.e. dust. Those earlier studies did not account for the yet undetected high concentration of nanoscale fragments of bacterial INP, which may be found free or attached to soil dust in the atmosphere. In this study, we investigate the sensitivity of modeled cloud ice, precipitation and global solar radiation in different weather scenarios to changes in the fraction of cloud droplets containing bacterial INP, regardless of their size. For this purpose, a module that calculates the probability of ice nucleation as a function of ice nucleation rate and bacterial INP fraction was developed and implemented in a numerical weather prediction model. The threshold value for the fraction of cloud droplets containing bacterial INP needed to produce a 1% increase in cloud ice was determined at 10-5 to 10-4. We also found that increasing this fraction causes a perturbation in the forecast, leading to significant differences in cloud ice and smaller differences in convective and total precipitation and in net solar radiation reaching the surface. These effects were most pronounced in local convective events. Our results show that bacterial INP can be considered as a trigger factor for precipitation, but not an enhancement factor.

  19. The importance of shared environment in infant-father attachment: A behavioral genetic study of the Attachment Q-Sort

    NARCIS (Netherlands)

    Bakermans-Kranenburg, M.J.; van IJzendoorn, M.H.; Bokhorst, C.L.; Schuengel, C.

    2004-01-01

    In this first behavior genetic study on infant-father attachment, we estimated genetic and environmental influences on infant-father attachment behaviors and on temperamental dependency, both assessed with the Attachment Q-Sort (AQS; B. E.Vaughn & E. Waters, 1990; E. Waters, 1995). Mothers of mono-

  20. Attachment Competences in Children With ADHD During the Social-Skills Training and Attachment (SOSTRA) Randomized Clinical Trial

    DEFF Research Database (Denmark)

    Storebø, Ole Jakob; Skoog, Maria Annette Annelie; Darling Rasmussen, Pernille

    2014-01-01

    % confidence interval = [0.31, 3.58], p = .91). In total, 17 children (36%) changed their entry status, 1 (2%) from secure to insecure attachment, while 16 (34%) changed from insecure to secure attachment. Conclusion: The experimental treatment does not seem to affect attachment competences compared......Objective: To investigate the effects of social-skills training and a parental training program on children with ADHD as measured by the children's attachment competences. Method: The SOSTRA trial is a randomized, parallel-group, outcome-assessor-blinded, superiority trial evaluating 8 weeks social......-skills training and parental training plus standard treatment versus standard treatment alone for 8- to 12-year old children with ADHD. Results: There were no significant differences in attachment competences at 6 months between the experimental (n = 25) and the control (n = 22) groups (odds ratio = 1.06, 95...

  1. The Relationship between Maternal-Fetal Attachment and Mother-Infant Attachment Behaviors in Primiparous Women Referring to Mashhad Health Care Centers

    Directory of Open Access Journals (Sweden)

    Mahin Taffazoli

    2015-04-01

    Full Text Available Background & aim: Mother-infant bonding and interactions after childbirth are shaped by maternal-fetal attachment during pregnancy. Although many studies have shown the positive correlation between maternal-fetal attachment and mother-infant attachment behaviors, some controversial studies have shown otherwise. Therefore, this study aimed to evaluate the correlation between maternal-fetal attachment and mother-infant attachment behaviors in primiparous women. Methods:This descriptive correlational study was conducted on 100 primiparous women, referring to the selected heath care centers of Mashhad. Data were collected using Cranley's maternal–fetal attachment scale, Avant’s mother-infant attachment tool, Edinburgh postnatal depression scale, and a demographic/obstetric questionnaire including demographic data, obstetric information, delivery outcomes, and postpartum data. Pregnant women with a gestational age of 35-41 weeks, who met the inclusion criteria, completed Cranley's questionnaire, as well as the demographic/obstetric questionnaire. Four and eight weeks after delivery, the subjects were asked to complete the Edinburgh questionnaire and postpartum information; then, they were asked to breastfeed their infants on a chair in a quiet place for 15 minutes. The researcher observed the mothers’ behaviors toward their neonates. For data analysis, descriptive and analytical tests were performed, using SPSS version 16. Results: There was a direct positive relationship between maternal-fetal attachment and mothers’ emotional behaviors toward infants four and eight weeks after delivery. However, four and eight weeks after childbirth, no significant correlation was found between maternal-fetal attachment and mothers’ caring behaviors. Conclusion: According to the findings, maternal-fetal attachment is one of the most important factors for mother-infant attachment. These findings could be applied for enriching mother-infant attachment

  2. Ecomorphology of parasite attachment: experiments with feather lice.

    Science.gov (United States)

    Bush, Sarah E; Sohn, Edward; Clayton, Dale H

    2006-02-01

    The host specificity of some parasites can be reinforced by morphological specialization for attachment to mobile hosts. For example, ectoparasites with adaptations for attaching to hosts of a particular size might not be able to remain attached to larger or smaller hosts. This hypothesis is suggested by the positive correlation documented between the body sizes of many parasites and their hosts. We adopted an ecomorphological approach to test the attachment hypothesis. We tested the ability of host-specific feather lice (Phthiraptera: Ischnocera) to attach to 6 novel species of pigeons and doves that vary in size by nearly 2 orders of magnitude. Surprisingly, Rock Pigeon lice (Columbicola columbae) remained attached equally well to all 6 novel host species. We tested the relative importance of 3 factors that could facilitate louse attachment: whole-body insertion, tarsal claw use, and mandible use. Insertion, per se, was not necessary for attachment. However, insertion on coarse feathers of large hosts allowed lice to access feather barbules with their mandibles. Mandible use was a key component of attachment regardless of feather size. Attachment constraints do not appear to reinforce host specificity in this system.

  3. Antifouling effect of bioactive compounds from marine sponge Acanthella elongata and different species of bacterial film on larval attachment of Balanus amphitrite (cirripedia, crustacea

    Directory of Open Access Journals (Sweden)

    Viswambaran Ganapiriya

    2012-06-01

    Full Text Available The antifouling activity of bioactive compounds from marine sponge Acanthella elongata (Dendy and five species of bacterial biofilm were studied. Larvae of Balanus amphitrite (Cyprids and nauplii were used to monitor the settlement inhibition and the extent to which inhibition was due to toxicity. The crude extract and partially purified fractions of A.elongata showed significant inhibition over the settlement individually, and with the interaction of bacterial species. No bacterial film stimulated the barnacle settlement. The high but variable levels of antifouling activity in combination with less amount of toxicity showed the potential of these metabolites in environmentally-friendly antifouling preparations.

  4. Wait Up!: Attachment and Sovereign Power.

    Science.gov (United States)

    Duschinsky, Robbie; Greco, Monica; Solomon, Judith

    2015-09-01

    Sociologists and feminist scholars have, over many decades, characterised attachment as a social construction that functions to support political and gender conservatism. We accept that attachment theory has seen use to these ends and consider recent deployments of attachment theory as justification for a minimal State within conservative political discourse in the UK since 2009. However, we contest that attachment is reducible to its discursive construction. We consider Judith Butler's depiction of the infant attached to an abusive caregiver as a foundation and parallel to the position of the adult citizen subjected to punitive cultural norms and political institutions. We develop and qualify Butler's account, drawing on the insights offered by the work of Lauren Berlant. We also return to Foucault's Psychiatric Power lectures, in which familial relations are situated as an island of sovereign power within the sea of modern disciplinary institutions. These reflections help advance analysis of three important issues: the social and political implications of attachment research; the relationship between disciplinary and sovereign power in the affective dynamic of subjection; and the political and ethical status of professional activity within the psy disciplines.

  5. Persistence of bacterial proteolytic enzymes in lake ecosystems.

    Science.gov (United States)

    Kiersztyn, Bartosz; Siuda, Waldemar; Chróst, Ryszard J

    2012-04-01

    This study analyzes proteolytic enzyme persistence and the role of dead (or metabolically inactive) aquatic bacteria in organic matter cycling. Samples from four lakes of different trophic status were used. Irrespective of the trophic status of the examined lakes, bacterial aminopeptidases remained active even 72 h after the death of the bacteria that produced them. The total pool of proteolytic enzymes in natural lake water samples was also stable. We found that the rates of amino acid enzymatic release from proteinaceous matter added to preserved lake water sample were constant for at least 96 h (r(2)  = 0.99, n = 17, P ≤ 0.0001, V(max)  = 84.6 nM h(-1) ). We also observed that proteases built into bacterial cell debris fragments remained active for a long time, even after the total destruction of cells. Moreover, during 24 h of incubation time, about 20% of these enzymatically active fragments adsorbed onto natural seston particles, becoming a part of the 'attached enzymes system' that is regarded as the 'hot-spot' of protein degradation in aquatic ecosystems. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  6. Adult attachment style and anxiety

    DEFF Research Database (Denmark)

    Nielsen, Sara Kerstine Kaya; Lønfeldt, Nicole Nadine; Wolitzky-Taylor, Kate

    2017-01-01

    Although there is substantial evidence for the role of emotion regulation in the etiology and maintenance of anxiety disorders, knowledge about what contributes to emotion dysregulation is sparse. Attachment style is related to emotion regulation and anxiety symptoms, but these variables have rar...... knowledge to examine the mediating role of emotion regulation between attachment dimensions (avoidance and anxiety) and anxiety symptoms.......Although there is substantial evidence for the role of emotion regulation in the etiology and maintenance of anxiety disorders, knowledge about what contributes to emotion dysregulation is sparse. Attachment style is related to emotion regulation and anxiety symptoms, but these variables have...... rarely been examined together. Examining emotion dysregulation within the context of anxiety disorders through an attachment theory framework will lead to a better understanding of the etiology and maintenance of anxiety disorders. In the present study we combined theoretically and empirically derived...

  7. Sine-Bar Attachment For Machine Tools

    Science.gov (United States)

    Mann, Franklin D.

    1988-01-01

    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  8. Overdenture locator attachments for atrophic mandible

    Directory of Open Access Journals (Sweden)

    Neerja Mahajan

    2013-01-01

    Full Text Available Implant-supported overdentures provide a good opportunity for dentists to improve oral health and quality-of-life of patients. Atrophic mandible poses a significant challenge to successful oral rehabilitation with dental implants. In this article, the fabrication of lower overdenture by two narrow platform implants is described with dual retentive, resilient, self-locating locator attachment system. The locator attachment system has the lowest profile in comparison with the ball and bar attachments and is versatile up to 40΀ of divergence between two implants. By using locators as attachments, we can meet functional, economic and social expectation of patients with ease and satisfaction.

  9. Streptomyces sporulation - Genes and regulators involved in bacterial cell differentiation

    OpenAIRE

    Larsson, Jessica

    2010-01-01

    Streptomycetes are Gram-positive bacteria with a complex developmental life cycle. They form spores on specialized cells called aerial hyphae, and this sporulation involves alterations in growth, morphogenesis and cell cycle processes like cell division and chromosome segregation. Understanding the developmental mechanisms that streptomycetes have evolved for regulating for example cell division is of general interest in bacterial cell biology. It can also be valuable in the design of new dru...

  10. Does penile tourniquet application alter bacterial adhesion to rat urethral cells: an in vitro study.

    Science.gov (United States)

    Boybeyi-Turer, Ozlem; Kacmaz, Birgul; Arat, Esra; Atasoy, Pınar; Kisa, Ucler; Gunal, Yasemin Dere; Aslan, Mustafa Kemal; Soyer, Tutku

    2018-04-01

    To investigate the effects of penile tourniquet (PT) application on bacterial adhesion to urothelium. Fifty-six rats were allocated into control group (CG), sham group (SG), PT group (PTG). No intervention was applied in CG. A 5mm-length urethral repair was performed in SG and PTG. In PTG, a 10-min duration of PT was applied during the procedure and the tissue oxygenation monitor was used to adjust the same degree of ischemia in all subjects. Samples were examined for wound healing parameters and tissue levels of inflammatory markers, eNOS, e-selectin, and ICAM-1antibodies. The adhesion of Escherichia coli to urothelium was investigated with in vitro adhesion assay. Inflammation was higher and wound healing was worse in SG than CG and in PTG in comparison to CG and SG (pcaused endothelial corruption and prevented cell proliferation in cell culture. The PT application does not improve wound healing and increases bacterial adhesion molecules in penile tissue. The in vitro assays showed that PT causes severe endothelial damage and inhibits endothelial cell proliferation. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Insecure attachment and anxiety in student athletes.

    Science.gov (United States)

    Han, D H; Kim, S M; Zaichkowsky, L

    2013-06-01

    The main purpose of our research was to examine attachment type and competition anxiety in high school student athletes and general high school students. We recruited 465 student athletes and 543 general students to participate in our study. The Revised Korean version of the Experiences in Close Relationships Scale (K-ECRS) and the Competitive State Anxiety Inventory-2 (CSAI-2) were given to all students. In χ2 tests, athletes showed attachment types in the following order of prevalence: fearful, dismissive, and preoccupied, compared to the fearful, preoccupied, and dismissive order observed in general students. In parametric, independent t-tests, athletes reported significantly higher cognitive anxiety scores, relative to general students. Further, athletes with insecure attachment compared to those with secure attachment reported higher cognitive anxiety scores and self-confidence scores. In both the athletes with insecure attachment and general students with insecure attachment groups, the K-ECRS anxiety subscale was significantly correlated with CSAI-2 total score. In post hoc analysis in the athletes with insecure attachment group, the K-ECRS anxiety subscale was also significantly correlated with the CSAI-2 cognitive anxiety subscale. These results suggest that anxious athletes with an insecure attachment style tend to exaggerate threats from both external and internal sources, which negatively affect their performances.

  12. Sibling rivalry: related bacterial small RNAs and their redundant and non-redundant roles.

    Science.gov (United States)

    Caswell, Clayton C; Oglesby-Sherrouse, Amanda G; Murphy, Erin R

    2014-01-01

    Small RNA molecules (sRNAs) are now recognized as key regulators controlling bacterial gene expression, as sRNAs provide a quick and efficient means of positively or negatively altering the expression of specific genes. To date, numerous sRNAs have been identified and characterized in a myriad of bacterial species, but more recently, a theme in bacterial sRNAs has emerged: the presence of more than one highly related sRNAs produced by a given bacterium, here termed sibling sRNAs. Sibling sRNAs are those that are highly similar at the nucleotide level, and while it might be expected that sibling sRNAs exert identical regulatory functions on the expression of target genes based on their high degree of relatedness, emerging evidence is demonstrating that this is not always the case. Indeed, there are several examples of bacterial sibling sRNAs with non-redundant regulatory functions, but there are also instances of apparent regulatory redundancy between sibling sRNAs. This review provides a comprehensive overview of the current knowledge of bacterial sibling sRNAs, and also discusses important questions about the significance and evolutionary implications of this emerging class of regulators.

  13. Sibling rivalry: Related bacterial small RNAs and their redundant and non-redundant roles

    Directory of Open Access Journals (Sweden)

    Clayton eCaswell

    2014-10-01

    Full Text Available Small RNA molecules (sRNAs are now recognized as key regulators controlling bacterial gene expression, as sRNAs provide a quick and efficient means of positively or negatively altering the expression of specific genes. To date, numerous sRNAs have been identified and characterized in a myriad of bacterial species, but more recently, a theme in bacterial sRNAs has emerged: the presence of more than one highly related sRNAs produced by a given bacterium, here termed sibling sRNAs. Sibling sRNAs are those that are highly similar at the nucleotide level, and while it might be expected that sibling sRNAs exert identical regulatory functions on the expression of target genes based on their high degree of relatedness, emerging evidence is demonstrating that this is not always the case. Indeed, there are several examples of bacterial sibling sRNAs with non-redundant regulatory functions, but there are also instances of apparent regulatory redundancy between sibling sRNAs. This review provides a comprehensive overview of the current knowledge of bacterial sibling sRNAs, and also discusses important questions about the significance and evolutionary implications of this emerging class of regulators.

  14. Universal precision sine bar attachment

    Science.gov (United States)

    Mann, Franklin D. (Inventor)

    1989-01-01

    This invention relates to an attachment for a sine bar which can be used to perform measurements during lathe operations or other types of machining operations. The attachment can be used for setting precision angles on vises, dividing heads, rotary tables and angle plates. It can also be used in the inspection of machined parts, when close tolerances are required, and in the layout of precision hardware. The novelty of the invention is believed to reside in a specific versatile sine bar attachment for measuring a variety of angles on a number of different types of equipment.

  15. Bacterial dynamics in intestines of the black tiger shrimp and the Pacific white shrimp during Vibrio harveyi exposure.

    Science.gov (United States)

    Rungrassamee, Wanilada; Klanchui, Amornpan; Maibunkaew, Sawarot; Karoonuthaisiri, Nitsara

    2016-01-01

    The intestinal microbiota play important roles in health of their host, contributing to maintaining the balance and resilience against pathogen. To investigate effects of pathogen to intestinal microbiota, the bacterial dynamics upon a shrimp pathogen, Vibrio harveyi, exposures were determined in two economically important shrimp species; the black tiger shrimp (BT) and the Pacific white shrimp (PW). Both shrimp species were reared under the same diet and environmental conditions. Shrimp survival rates after the V. harveyi exposure revealed that the PW shrimp had a higher resistance to the pathogen than the BT shrimp. The intestinal bacterial profiles were determined by denaturing gradient gel electrophoresis (DGGE) and barcoded pyrosequencing of the 16S rRNA sequences under no pathogen challenge control and under pathogenic V. harveyi challenge. The DGGE profiles showed that the presence of V. harveyi altered the intestinal bacterial patterns in comparison to the control in BT and PW intestines. This implies that bacterial balance in shrimp intestines was disrupted in the presence of V. harveyi. The barcoded pyrosequencing analysis showed the similar bacterial community structures in intestines of BT and PW shrimp under a normal condition. However, during the time course exposure to V. harveyi, the relative abundance of bacteria belong to Vibrio genus was higher in the BT intestines at 12h after the exposure, whereas relative abundance of vibrios was more stable in PW intestines. The principle coordinates analysis based on weighted-UniFrac analysis showed that intestinal bacterial population in the BT shrimp lost their ability to restore their bacterial balance during the 72-h period of exposure to the pathogen, while the PW shrimp were able to reestablish their bacterial population to resemble those seen in the unexposed control group. This observation of bacterial disruption might correlate to different mortality rates observed between the two shrimp species

  16. Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

    2011-04-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

  17. Emergency Face-Mask Removal Effectiveness: A Comparison of Traditional and Nontraditional Football Helmet Face-Mask Attachment Systems

    Science.gov (United States)

    Swartz, Erik E.; Belmore, Keith; Decoster, Laura C.; Armstrong, Charles W.

    2010-01-01

    Abstract Context: Football helmet face-mask attachment design changes might affect the effectiveness of face-mask removal. Objective: To compare the efficiency of face-mask removal between newly designed and traditional football helmets. Design: Controlled laboratory study. Setting: Applied biomechanics laboratory. Participants: Twenty-five certified athletic trainers. Intervention(s): The independent variable was face-mask attachment system on 5 levels: (1) Revolution IQ with Quick Release (QR), (2) Revolution IQ with Quick Release hardware altered (QRAlt), (3) traditional (Trad), (4) traditional with hardware altered (TradAlt), and (5) ION 4D (ION). Participants removed face masks using a cordless screwdriver with a back-up cutting tool or only the cutting tool for the ION. Investigators altered face-mask hardware to unexpectedly challenge participants during removal for traditional and Revolution IQ helmets. Participants completed each condition twice in random order and were blinded to hardware alteration. Main Outcome Measure(s): Removal success, removal time, helmet motion, and rating of perceived exertion (RPE). Time and 3-dimensional helmet motion were recorded. If the face mask remained attached at 3 minutes, the trial was categorized as unsuccessful. Participants rated each trial for level of difficulty (RPE). We used repeated-measures analyses of variance (α  =  .05) with follow-up comparisons to test for differences. Results: Removal success was 100% (48 of 48) for QR, Trad, and ION; 97.9% (47 of 48) for TradAlt; and 72.9% (35 of 48) for QRAlt. Differences in time for face-mask removal were detected (F4,20  =  48.87, P  =  .001), with times ranging from 33.96 ± 14.14 seconds for QR to 99.22 ± 20.53 seconds for QRAlt. Differences were found in range of motion during face-mask removal (F4,20  =  16.25, P  =  .001), with range of motion from 10.10° ± 3.07° for QR to 16.91° ± 5.36° for TradAlt. Differences also were detected

  18. Emergency face-mask removal effectiveness: a comparison of traditional and nontraditional football helmet face-mask attachment systems.

    Science.gov (United States)

    Swartz, Erik E; Belmore, Keith; Decoster, Laura C; Armstrong, Charles W

    2010-01-01

    Football helmet face-mask attachment design changes might affect the effectiveness of face-mask removal. To compare the efficiency of face-mask removal between newly designed and traditional football helmets. Controlled laboratory study. Applied biomechanics laboratory. Twenty-five certified athletic trainers. The independent variable was face-mask attachment system on 5 levels: (1) Revolution IQ with Quick Release (QR), (2) Revolution IQ with Quick Release hardware altered (QRAlt), (3) traditional (Trad), (4) traditional with hardware altered (TradAlt), and (5) ION 4D (ION). Participants removed face masks using a cordless screwdriver with a back-up cutting tool or only the cutting tool for the ION. Investigators altered face-mask hardware to unexpectedly challenge participants during removal for traditional and Revolution IQ helmets. Participants completed each condition twice in random order and were blinded to hardware alteration. Removal success, removal time, helmet motion, and rating of perceived exertion (RPE). Time and 3-dimensional helmet motion were recorded. If the face mask remained attached at 3 minutes, the trial was categorized as unsuccessful. Participants rated each trial for level of difficulty (RPE). We used repeated-measures analyses of variance (α  =  .05) with follow-up comparisons to test for differences. Removal success was 100% (48 of 48) for QR, Trad, and ION; 97.9% (47 of 48) for TradAlt; and 72.9% (35 of 48) for QRAlt. Differences in time for face-mask removal were detected (F(4,20)  =  48.87, P  =  .001), with times ranging from 33.96 ± 14.14 seconds for QR to 99.22 ± 20.53 seconds for QRAlt. Differences were found in range of motion during face-mask removal (F(4,20)  =  16.25, P  =  .001), with range of motion from 10.10° ± 3.07° for QR to 16.91° ± 5.36° for TradAlt. Differences also were detected in RPE during face-mask removal (F(4,20)  =  43.20, P  =  .001), with participants reporting average

  19. Growing networks with mixed attachment mechanisms

    International Nuclear Information System (INIS)

    Shao Zhigang; Zou Xianwu; Tan Zhijie; Jin Zhunzhi

    2006-01-01

    Networks grow and evolve when new nodes and links are added in. There are two methods to add the links: uniform attachment and preferential attachment. We take account of the addition of links with mixed attachment between uniform attachment and preferential attachment in proportion. By using numerical simulations and analysis based on a continuum theory, we obtain that the degree distribution P(k) has an extended power-law form P(k) ∼ (k + k 0 ) -γ . When the number of edges k of a node is much larger than a certain value k 0 , the degree distribution reduces to the power-law form P(k) ∼ k -γ ; and when k is much smaller than k 0 , the degree distribution degenerates into the exponential form P(k)∼exp(-yk/k 0 ). It has been found that degree distribution possesses this extended power-law form for many real networks, such as the movie actor network, the citation network of scientific papers and diverse protein interaction networks

  20. Laser enhanced attachment in diffuse discharges

    International Nuclear Information System (INIS)

    Giesselmann, M.; Pashaie, B.; Kristiansen, M.; Schaefer, G.

    1987-01-01

    Measurements of the effect of laser enhanced attachment on externally sustained diffuse discharges are reported. Optical control of diffuse discharges is a promising way of upgrading the performance of e-beam controlled opening switches for repetitive operation. Ideal gases should exhibit a negligible attachment cross section for low E/N values (switch closed) in the ground state and strong attaching properties upon optical excitation in an E/N range between the conducting state and self breakdown of the switch. The ratio of resistivity change in these experiments is much higher than in previous investigations. In this investigation the attachment rate of an electronegative gas component, representing approximately 1% of the gas in the discharge volume, was increased by means of vibrational excitation with a pulsed IR-laser beam. Molecules exhibiting a strongly increased attachment rate upon IR-excitation are vinyl-chloride, vinyl flouride and trifluoroethylene, which has been verified in preliminary experiments. All experiments reported were performed with vinyl chloride and trifluoroethylene

  1. Microbiota alterations in acute and chronic gastrointestinal inflammation of cats and dogs

    Science.gov (United States)

    Honneffer, Julia B; Minamoto, Yasushi; Suchodolski, Jan S

    2014-01-01

    The intestinal microbiota is the collection of the living microorganisms (bacteria, fungi, protozoa, and viruses) inhabiting the gastrointestinal tract. Novel bacterial identification approaches have revealed that the gastrointestinal microbiota of dogs and cats is, similarly to humans, a highly complex ecosystem. Studies in dogs and cats have demonstrated that acute and chronic gastrointestinal diseases, including inflammatory bowel disease (IBD), are associated with alterations in the small intestinal and fecal microbial communities. Of interest is that these alterations are generally similar to the dysbiosis observed in humans with IBD or animal models of intestinal inflammation, suggesting that microbial responses to inflammatory conditions of the gut are conserved across mammalian host types. Studies have also revealed possible underlying susceptibilities in the innate immune system of dogs and cats with IBD, which further demonstrate the intricate relationship between gut microbiota and host health. Commonly identified microbiome changes in IBD are decreases in bacterial groups within the phyla Firmicutes and Bacteroidetes, and increases within Proteobacteia. Furthermore, a reduction in the diversity of Clostridium clusters XIVa and IV (i.e., Lachnospiraceae and Clostridium coccoides subgroups) are associated with IBD, suggesting that these bacterial groups may play an important role in maintenance of gastrointestinal health. Future studies are warranted to evaluate the functional changes associated with intestinal dysbiosis in dogs and cats. PMID:25469017

  2. Implementation and assessment of an early home-based intervention on infant attachment organisation: the CAPEDP attachment study in France.

    Science.gov (United States)

    Tereno, Susana; Guedeney, Nicole; Dugravier, Romain; Greacen, Tim; Saïas, Thomas; Tubach, Florence; Guédeney, Antoine

    2013-06-01

    Attachment is a long-term emotional link between infants and their mothers. Attachment quality influences subsequent psychosocial relationships, the ability to manage stress and, consequently, later mental health. Home intervention programmes targeting infant attachment have been implemented in several contexts with varying degrees of efficacy. Within the CAPEDP study (Parental Skills and Attachment in Early Childhood: reduction of risks linked to mental health problems and promotion of resilience), a subsample of 120 families were recruited with the objective of assessing the impact of this home-visiting programme on infant attachment organisation using the Strange Situation Procedure. The present paper describes the methodology used in this ancillary study.

  3. Attachment Theory, Foster Parents and Diversity Tolerance

    OpenAIRE

    Kenny, Michael; Fleming, Ted

    2009-01-01

    relevance to attachment within the biological and foster family. Yet every foster parent has a childhood attachment history that influences their interpersonal relationships in adulthood. The primary concern of the foster parent and their supports is with the foster child. But as a result the foster parent may distract or block reflection on their own attachment history. This presentation will focus on attachment theory and the adult, with particular reference to the foster parent. The pre...

  4. Attachment behaviour of Escherichia coli K12 and Salmonella Typhimurium P6on food contact surfaces for food transportation

    DEFF Research Database (Denmark)

    Abban, Stephen; Jakobsen, Mogens; Jespersen, Lene

    2012-01-01

    The role of cargo container lining materials aluminium, a fibre reinforced plastic (FRP) and stainless steel in bacterial cross contamination during transport was assessed. For this, attachment and detachment of Escherichia coli K12 and Salmonella Typhimurium P6 on the three surfaces in the absence....... Typhimurium P6 respectively. Correlation with roughness average was poor; r = -0.425 and -0.413 respectively for E. coli K12 and S. Typhimurium P6. Presence of residue caused significant reduction (p ... material sections of the same surfaces. We report these observations for the first time for aluminium and the FRP material and in part for stainless steel. The S. Typhimurium P6 strain also had significantly higher level of attachment than the E. coli K12 strain. Our findings show that food residue...

  5. Superego: an attachment perspective.

    Science.gov (United States)

    Holmes, Jeremy

    2011-10-01

    With the help of attachment theory and research, the paper attempts to broaden and build on classical and current views on the superego. Attachment theory's epigenetic approach and the concept of the subliminal superego are described. The superego, it is argued, is as much concerned with safety as sex. The superego is 'heir', not just to the Oedipus complex or Klein's pre-oedipal constellation, but also to the attachment relationship. Under favourable developmental conditions a 'mature superego' emerges, facilitating, in the presence of an internal secure base, maturational boundary crossings towards adult sexuality. In the light of the above, the paper reviews Lear's updating of Strachey's model of psychic change and explores the concept of transgression in relation to the 'professional superego', its development and maturation. Theoretical arguments are illustrated with clinical examples. Copyright © 2011 Institute of Psychoanalysis.

  6. Infant-parent attachment: Definition, types, antecedents, measurement and outcome.

    Science.gov (United States)

    Benoit, Diane

    2004-10-01

    Attachment theory is one of the most popular and empirically grounded theories relating to parenting. The purpose of the present article is to review some pertinent aspects of attachment theory and findings from attachment research. Attachment is one specific aspect of the relationship between a child and a parent with its purpose being to make a child safe, secure and protected. Attachment is distinguished from other aspects of parenting, such as disciplining, entertaining and teaching. Common misconceptions about what attachment is and what it is not are discussed. The distinction between attachment and bonding is provided. The recognized method to assess infant-parent attachment, the Strange Situation procedure, is described. In addition, a description is provided for the four major types of infant-parent attachment, ie, secure, insecure-avoidant, insecure-resistant and insecure-disorganized. The antecedents and consequences of each of the four types of infant-parent attachment are discussed. A special emphasis is placed on the description of disorganized attachment because of its association with significant emotional and behavioural problems, and poor social and emotional outcomes in high-risk groups and in the majority of children who have disorganized attachment with their primary caregiver. Practical applications of attachment theory and research are presented.

  7. Bacterial prostatitis.

    Science.gov (United States)

    Gill, Bradley C; Shoskes, Daniel A

    2016-02-01

    The review provides the infectious disease community with a urologic perspective on bacterial prostatitis. Specifically, the article briefly reviews the categorization of prostatitis by type and provides a distillation of new findings published on bacterial prostatitis over the past year. It also highlights key points from the established literature. Cross-sectional prostate imaging is becoming more common and may lead to more incidental diagnoses of acute bacterial prostatitis. As drug resistance remains problematic in this condition, the reemergence of older antibiotics such as fosfomycin, has proven beneficial. With regard to chronic bacterial prostatitis, no clear clinical risk factors emerged in a large epidemiological study. However, bacterial biofilm formation has been associated with more severe cases. Surgery has a limited role in bacterial prostatitis and should be reserved for draining of a prostatic abscess or the removal of infected prostatic stones. Prostatitis remains a common and bothersome clinical condition. Antibiotic therapy remains the basis of treatment for both acute and chronic bacterial prostatitis. Further research into improving prostatitis treatment is indicated.

  8. Personality and Attachment in Transsexual Adults.

    Science.gov (United States)

    Lingiardi, Vittorio; Giovanardi, Guido; Fortunato, Alexandro; Nassisi, Valentina; Speranza, Anna Maria

    2017-07-01

    The main aim of this study was to investigate the associations between personality features and attachment patterns in transsexual adults. We explored mental representations of attachment, assessed personality traits, and possible personality disorders. Forty-four individuals diagnosed with gender identity disorder (now gender dysphoria), 28 male-to-female and 16 female-to-male, were evaluated using the Shedler-Westen assessment procedure-200 (SWAP-200) to assess personality traits and disorders; the adult attachment interview was used to evaluate their attachment state-of-mind. With respect to attachment, our sample differed both from normative samples because of the high percentage of disorganized states of mind (50% of the sample), and from clinical samples for the conspicuous percentage of secure states of mind (37%). Furthermore, we found that only 16% of our sample presented a personality disorder, while 50% showed a high level of functioning according to the SWAP-200 scales. In order to find latent subgroups that shared personality characteristics, we performed a Q-factor analysis. Three personality clusters then emerged: Healthy Functioning (54% of the sample); Depressive/Introverted (32%) and Histrionic/Extroverted (14%). These data indicate that in terms of personality and attachment, GD individuals are a heterogeneous sample and show articulate and diverse types with regard to these constructs.

  9. Attachment in young children with incarcerated fathers.

    Science.gov (United States)

    Poehlmann-Tynan, Julie; Burnson, Cynthia; Runion, Hilary; Weymouth, Lindsay A

    2017-05-01

    The present study examined young children's attachment behaviors during paternal incarceration and reported on initial validity of a new measure used to rate children's attachment-related behaviors and emotions during visits in a corrections setting. Seventy-seven children, age 2 to 6 years, and their jailed fathers and current caregivers participated in the home visit portion of the study, whereas 28 of these children participated in the jail visit. The results indicated that 27% of children witnessed the father's crime and 22% of children witnessed the father's arrest, with most children who witnessed these events exhibiting extreme distress; children who witnessed these events were more likely to have insecure attachments to their caregivers. Consistent with attachment theory and research, caregivers who exhibited more sensitivity and responsivity during interactions with children and those who provided more stimulating, responsive, learning-oriented home environments had children who were more likely to have secure attachments (measured with the Attachment Q-Sort). We also found preliminary evidence for the validity of our new measure, the Jail Prison Observation Checklist, in that children's attachment-related behaviors and emotions during the jail visit correlated with their attachment security observed in the home. Our observations indicate that, in certain contexts, noncontact visits with incarcerated parents can be stressful for children and that children's caregivers may play a significant role during these visits.

  10. Attachment, caring and prosocial behavior

    NARCIS (Netherlands)

    Erez, Ayelet

    2007-01-01

    The thesis focuses on 5 studies examining the role of adult attachment in volunteering by defining volunteerism as a form of caregiving. By that we suggest an effect of one behavioral system, attachment, on another, caring or prosocial behaviors in individual or group settings. Studies 1 and 2

  11. Co-occurrence patterns in aquatic bacterial communities across changing permafrost landscapes

    Science.gov (United States)

    Comte, J.; Lovejoy, C.; Crevecoeur, S.; Vincent, W. F.

    2016-01-01

    Permafrost thaw ponds and lakes are widespread across the northern landscape and may play a central role in global biogeochemical cycles, yet knowledge about their microbial ecology is limited. We sampled a set of thaw ponds and lakes as well as shallow rock-basin lakes that are located in distinct valleys along a north-south permafrost degradation gradient. We applied high-throughput sequencing of the 16S rRNA gene to determine co-occurrence patterns among bacterial taxa (operational taxonomic units, OTUs), and then analyzed these results relative to environmental variables to identify variables controlling bacterial community structure. Network analysis was applied to identify possible ecological linkages among the bacterial taxa and with abiotic and biotic variables. The results showed an overall high level of shared taxa among bacterial communities within each valley; however, the bacterial co-occurrence patterns were non-random, with evidence of habitat preferences. There were taxonomic differences in bacterial assemblages among the different valleys that were statistically related to dissolved organic carbon concentration, conductivity and phytoplankton biomass. Co-occurrence networks revealed complex interdependencies within the bacterioplankton communities and showed contrasting linkages to environmental conditions among the main bacterial phyla. The thaw pond networks were composed of a limited number of highly connected taxa. This "small world network" property would render the communities more robust to environmental change but vulnerable to the loss of microbial "keystone species". These highly connected nodes (OTUs) in the network were not merely the numerically dominant taxa, and their loss would alter the organization of microbial consortia and ultimately the food web structure and functioning of these aquatic ecosystems.

  12. Pseudoalteromonas spp. Serve as Initial Bacterial Attractants in Mesocosms of Coastal Waters but Have Subsequent Antifouling Capacity in Mesocosms and when Embedded in Paint

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yin; Møller, Stefan

    2013-01-01

    . Pseudoalteromonas piscicida survived on a steel surface and retained antifouling activity for at least 53 days in sterile seawater, whereas P. tunicata survived and had antifouling activity for only 1 week. However, during the first week, all Pseudoalteromonas strains facilitated rather than prevented bacterial...... attachment when used to coat stainless steel surfaces and submerged in mesocosms with natural seawater. The bacterial density on surfaces coated with sterile growth medium was 105 cells/cm2 after 7 days, whereas counts on surfaces precoated with Pseudoalteromonas were significantly higher, at 106 to 108...

  13. 30 CFR 75.1438 - End attachment replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 75.1438 Section 75.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... attachment replacement. Wire rope attachments shall be replaced when cracked, deformed, or excessively worn. ...

  14. 30 CFR 77.1437 - End attachment retermination.

    Science.gov (United States)

    2010-07-01

    ... 77.1437 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL... at an attachment; (b) Improper installation of an attachment; (c) Slippage at an attachment; or (d...

  15. Shadows alter facial expressions of Noh masks.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kawai

    Full Text Available BACKGROUND: A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers' recognition of the emotional expressions. METHODOLOGY/PRINCIPAL FINDINGS: In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. CONCLUSIONS/SIGNIFICANCE: Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa's smile. They also agree with the aesthetic principle of Japanese traditional art "yugen (profound grace and subtlety", which highly appreciates subtle emotional expressions in the darkness.

  16. Place attachment and disasters: Knowns and unknowns.

    Science.gov (United States)

    Jamali, Mehdi; Nejat, Ali

    When considering the factors important for disaster recovery, one must consider the attachment individuals have toward their living area. This article reviews and synthesizes the current literature on the determinants of place attachment in the context of postdisaster recovery. Although the majority of the reviewed articles focused on disaster recovery, there were some which had a broader scope and were included due to their importance. This research categorizes the determinants of place attachment into four categories: demographic, socioeconomic, spatial, and psychosocial. Age, ethnicity, and religion were grouped under the category of demographics. Job status, education, and property ownership were categorized under the socioeconomic category. Attachment to home, neighborhood, and city, together with attachment to rural and urban areas, were grouped under the spatial category. Finally, mental health status and community attachment were classified under the psychosocial heading. Based on the outcome of the aforementioned synthesis, this article develops a conceptual framework to guide future research.

  17. Temporal succession in carbon incorporation from macromolecules by particle-attached bacteria in marine microcosms: Particle-attached bacteria incorporating organic carbon

    Energy Technology Data Exchange (ETDEWEB)

    Mayali, Xavier [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stewart, Benjamin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mabery, Shalini [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Weber, Peter K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-12-21

    Here, we investigated bacterial carbon assimilation from stable isotope-labelled macromolecular substrates (proteins; lipids; and two types of polysaccharides, starch and cellobiose) while attached to killed diatom detrital particles during laboratory microcosms incubated for 17 days. Using Chip-SIP (secondary ion mass spectrometry analysis of RNA microarrays), we identified generalist operational taxonomic units (OTUs) from the Gammaproteobacteria, belonging to the genera Colwellia, Glaciecola, Pseudoalteromonas and Rheinheimera, and from the Bacteroidetes, genera Owenweeksia and Maribacter, that incorporated the four tested substrates throughout the incubation period. Many of these OTUs exhibited the highest isotope incorporation relative to the others, indicating that they were likely the most active. Additional OTUs from the Gammaproteobacteria, Bacteroidetes and Alphaproteobacteria exhibited generally (but not always) lower activity and did not incorporate all tested substrates at all times, showing species succession in organic carbon incorporation. We also found evidence to suggest that both generalist and specialist OTUs changed their relative substrate incorporation over time, presumably in response to changing substrate availability as the particles aged. This pattern was demonstrated by temporal succession from relatively higher starch incorporation early in the incubations, eventually switching to higher cellobiose incorporation after 2 weeks.

  18. Bacterial Standing Stock, Activity, and Carbon Production during Formation and Growth of Sea Ice in the Weddell Sea, Antarctica.

    Science.gov (United States)

    Grossmann, S; Dieckmann, G S

    1994-08-01

    Bacterial response to formation and growth of sea ice was investigated during autumn in the northeastern Weddell Sea. Changes in standing stock, activity, and carbon production of bacteria were determined in successive stages of ice development. During initial ice formation, concentrations of bacterial cells, in the order of 1 x 10 to 3 x 10 liter, were not enhanced within the ice matrix. This suggests that physical enrichment of bacteria by ice crystals is not effective. Due to low concentrations of phytoplankton in the water column during freezing, incorporation of bacteria into newly formed ice via attachment to algal cells or aggregates was not recorded in this study. As soon as the ice had formed, the general metabolic activity of bacterial populations was strongly suppressed. Furthermore, the ratio of [H]leucine incorporation into proteins to [H]thymidine incorporation into DNA changed during ice growth. In thick pack ice, bacterial activity recovered and growth rates up to 0.6 day indicated actively dividing populations. However, biomass-specific utilization of organic compounds remained lower than in open water. Bacterial concentrations of up to 2.8 x 10 cells liter along with considerably enlarged cell volumes accumulated within thick pack ice, suggesting reduced mortality rates of bacteria within the small brine pores. In the course of ice development, bacterial carbon production increased from about 0.01 to 0.4 mug of C liter h. In thick ice, bacterial secondary production exceeded primary production of microalgae.

  19. Biochemical study of human periodontal ligament: preparation of cell attachment materials induced by pulsed electromagnetic fields.

    Science.gov (United States)

    Kim, K T

    1990-09-01

    The periodontium, especially the periodontal ligament and alveolar bone, are tissues constantly subjected to physical stress such as occlusion and mastication. This study was designed to explore the effect of the pulsed electromagnetic fields (PEMF) on the cell attachment and the spread of human periodontal ligament fibroblasts (HPLF) and rat osteoblasts (ROB). PEMF are categorized as one type of mechanical stress. HPLF were obtained by the explantation method described by Saito et al. They were then subcultured in Dulbecco's modified Eagle's medium (D-MEM) and supplemented with 2 mg/ml dialyzed fetal calf serum protein (FCSP), 50 micrograms/ml ascorbic acid and penicillin/streptomycin after trypsinization. ROB were isolated from a two-day-old rat calvaria by the sequential bacterial collagenase digestion method described by Dziak and Brand and were subcultured in D-MEM supplemented with FCSP, ascorbic acid and penicillin/streptomycin. After the confluent HPLF were cultured with serum-free MCDB 107 medium, the quiescent HPLF were exposed with or without PEMF for 24 hr. This was followed by the collection of the control conditioned medium (C-CM) and PEMF exposed conditioned medium (PEMF-CM). The cell attachment assay was performed so that the hydrophobic 24 multiwells were coated with the whole conditioned medium or fractionated conditioned medium by a PO-60K column. After coating, heat inactivated BSA blocked nonspecific sites for cell adhesion, and 3H-TdR labeled HPLF or ROB were cultured on the precoated wells. The activity of cell attachment and spreading was determined by the radioactivity of 3H-TdR using a scintillation counter. The characters of cell attachment factors derived from HPLF were hydrophobic, heat labile and proteolytic enzyme digestible. In addition, the fractionated PEMF-CM enhanced the spreading activity of ROB. PEMF induced the 10 KDa which can enhance the HPLF and ROB spreading. Therefore, the cell attachment and spreading factors secreted by

  20. 30 CFR 57.19028 - End attachment replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 57.19028 Section 57.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Hoisting Wire Ropes § 57.19028 End attachment replacement. Wire rope attachments shall be replaced when...

  1. 30 CFR 56.19028 - End attachment replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 56.19028 Section 56.19028 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL... Wire Ropes § 56.19028 End attachment replacement. Wire rope attachments shall be replaced when cracked...

  2. 30 CFR 77.1438 - End attachment replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false End attachment replacement. 77.1438 Section 77.1438 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND... Personnel Hoisting Wire Ropes § 77.1438 End attachment replacement. Wire rope attachments shall be replaced...

  3. Relationships between attachment and marital satisfaction in married couples

    Directory of Open Access Journals (Sweden)

    Patrícia Gallerová

    2016-01-01

    Full Text Available Theory of attachment strongly influences exploring of close relationships in childhood and in adulthood as well. According Bowlby attachment is "lasting relationship bond characterized by need of seeking and maintaining proximity with a person in stressful situations especially (Bowbly, 2010. Hazan a Shaver (1987 applied theory of early attachment in romantic relationships of adults. Behavior of adult human in relationships is more or less predictable by style of attachment in childhood (Feeney, 1999. Brennan, Clark a Shaver (1998 created four-dimensional model of attachment which was based on Ainsworth´s theory as well. The model was formed of two dimensions - anxiety and avoidance. The authors identified four types of attachment: secure, fearful, dismissive and preoccupied style of attachment (Brennan, Clark, & Shaver, 1998. Satisfaction in romantic relationship can be explained as a degree in which is relationship for a human enojyable. Attachment influences satisfaction in relationship in terms of meeting need of proximity and safety (Mikulincer, Florian, Cowan, & Cowan, 2002. Several researches show that safe attachment is associated with higher satisfaction in marriage and on the other hand people with insecure style of attachment show lower degree of satisfaction in relationship (Alexandrov, Cowan, & Cowan, 2005; Treboux, Crowell, & Waters, 2004. At the same time style of attachment of the partner also influences individual a lot, satisfaction does not depend only on his own style of attachment but also on attachment of his partner (Farinelli, & McEwan, 2009. The study examined relations between the relationship attachment and marital satisfaction. The goal was to explain the relationship between the adult attachment and marital satisfaction of the individual and her/his husband/wife. The research examined relationship between adult attachment and marital satisfaction as well. Quantitative questionnaire survey: The battery consisted of

  4. Love attitudes and attachment

    Directory of Open Access Journals (Sweden)

    María Elena Brenlla

    2016-02-01

    Full Text Available Love styles described by Lee are Eros (passionate love, Ludus (game-pla- ying love, Storge (friendship love, Mania (possessive, dependent love, Pragma (logical, “shopping list” love and Agape (all-giving, selfless love. Based on those types, Hendrick and Hendrick developed a 42-ítem rating questionnaire with 7 items measuring each love style (Love Attitudes Scale. Beside, inform about frequency in love relationships and attachment style. The purpose of this study was analyze the reliability and factor structure of the Love Attitudes Scale and to investigate the association between love attitudes and the attachment style. The results (N=280 participants indicate adequate internal consistency (alfa = 0,73. The items were intercorrelated and factored. The best solution extracted six factors using varimax rotation and all six factors accounted 41% of the total variance. Secure attachment was related positively to eros. 

  5. From secure dependency to attachment: Mary Ainsworth's integration of Blatz's security theory into Bowlby's attachment theory.

    Science.gov (United States)

    van Rosmalen, Lenny; van der Horst, Frank C P; van der Veer, René

    2016-02-01

    John Bowlby is generally regarded as the founder of attachment theory, with the help of Mary Ainsworth. Through her Uganda and Baltimore studies Ainsworth provided empirical evidence for attachment theory, and she contributed the notion of the secure base and exploratory behavior, the Strange Situation Procedure and its classification system, and the notion of maternal sensitivity. On closer scrutiny, many of these contributions appear to be heavily influenced by William Blatz and his security theory. Even though Blatz's influence on Ainsworth has been generally acknowledged, this article, partly based on understudied correspondence from several personal archives, is the first to show which specific parts of attachment theory can be traced back directly to Blatz and his security theory. When Ainsworth started working with Bowlby in the 1950s, around the time he turned to evolutionary theory for an explanation of his findings, she integrated much of Blatzian security theory into Bowlby's theory in the making and used her theoretical and practical experience to enrich attachment theory. Even though Blatz is hardly mentioned nowadays, several of his ideas live on in attachment theory. (c) 2016 APA, all rights reserved).

  6. Attachment and group psychotherapy: introduction to a special section.

    Science.gov (United States)

    Tasca, Giorgio A

    2014-03-01

    The application of attachment theory to adult psychotherapy represents a growing area of research and practice. Despite the conceptual overlap between group therapeutic factors, attachment theory, and therapeutic tasks as outlined by Bowlby (1988), there is little research on attachment functioning in group therapy. Hence, there remain substantial questions about the role of attachment theory in understanding group therapy processes and outcomes. The three studies in this special section advance the research in some of these important areas, including showing that positive changes in self-reported attachment insecurity among clients persist long after group therapy ends; attachment anxiety affects the level and rate of interpersonal learning in groups; and change in attachment to the therapy group has an impact on longer term change in individual group members' attachment. Each article also examines the impact of these attachment concepts on treatment outcomes. Numerous areas remain to be explored when it comes to the implications of attachment theory for understanding and conducting group therapy, including the conceptual and practical overlap between attachment concepts such as security and exploration with group therapeutic factors such as cohesion and interpersonal learning. The articles in this special section begin to address some of these issues related to attachment theory and its implications for group therapists. (c) 2014 APA, all rights reserved.

  7. Attachment in Middle Childhood: Progress and Prospects

    Science.gov (United States)

    Bosmans, Guy; Kerns, Kathryn A.

    2015-01-01

    Contrary to the substantial amount of research on infant, preschool, adolescent, and adult attachment, middle childhood has long been neglected by the international attachment research community. In the past two decades, however, there has been a steep increase in research focusing on middle childhood attachment. This article provides an overview…

  8. Altered States of Consciousness during an Extreme Ritual

    Science.gov (United States)

    Loewald, Tonio; Comber, Evelyn M.; Hanson, Sarah A.; Pruitt, Bria

    2016-01-01

    Extreme rituals (body-piercing, fire-walking, etc.) are anecdotally associated with altered states of consciousness—subjective alterations of ordinary mental functioning (Ward, 1984)—but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the “Dance of Souls”, a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to music provided by drummers, responded to measures of two altered states of consciousness. Participants also completed measures of positive and negative affect, salivary cortisol (a hormone associated with stress), self-reported stress, sexual arousal, and intimacy. Both pierced participants (pierced dancers) and non-pierced participants (piercers, piercing assistants, observers, drummers, and event leaders) showed evidence of altered states aligned with transient hypofrontality (Dietrich, 2003; measured with a Stroop test) and flow (Csikszentmihalyi, 1990; Csikszentmihalyi & Csikszentmihalyi, 1990; measured with the Flow State Scale). Both pierced and non-pierced participants also reported decreases in negative affect and psychological stress and increases in intimacy from before to after the ritual. Pierced and non-pierced participants showed different physiological reactions, however, with pierced participants showing increases in cortisol and non-pierced participants showing decreases from before to during the ritual. Overall, the ritual appeared to induce different physiological effects but similar psychological effects in focal ritual participants (i.e., pierced dancers) and in participants adopting other roles. PMID:27175897

  9. Altered States of Consciousness during an Extreme Ritual.

    Directory of Open Access Journals (Sweden)

    Ellen M Lee

    Full Text Available Extreme rituals (body-piercing, fire-walking, etc. are anecdotally associated with altered states of consciousness-subjective alterations of ordinary mental functioning (Ward, 1984-but empirical evidence of altered states using both direct and indirect measures during extreme rituals in naturalistic settings is limited. Participants in the "Dance of Souls", a 3.5-hour event during which participants received temporary piercings with hooks or weights attached to the piercings and danced to music provided by drummers, responded to measures of two altered states of consciousness. Participants also completed measures of positive and negative affect, salivary cortisol (a hormone associated with stress, self-reported stress, sexual arousal, and intimacy. Both pierced participants (pierced dancers and non-pierced participants (piercers, piercing assistants, observers, drummers, and event leaders showed evidence of altered states aligned with transient hypofrontality (Dietrich, 2003; measured with a Stroop test and flow (Csikszentmihalyi, 1990; Csikszentmihalyi & Csikszentmihalyi, 1990; measured with the Flow State Scale. Both pierced and non-pierced participants also reported decreases in negative affect and psychological stress and increases in intimacy from before to after the ritual. Pierced and non-pierced participants showed different physiological reactions, however, with pierced participants showing increases in cortisol and non-pierced participants showing decreases from before to during the ritual. Overall, the ritual appeared to induce different physiological effects but similar psychological effects in focal ritual participants (i.e., pierced dancers and in participants adopting other roles.

  10. Distinctive colonization of Bacillus sp. bacteria and the influence of the bacterial biofilm on electrochemical behaviors of aluminum coatings.

    Science.gov (United States)

    Abdoli, Leila; Suo, Xinkun; Li, Hua

    2016-09-01

    Formation of biofilm is usually essential for the development of biofouling and crucially impacts the corrosion of marine structures. Here we report the attachment behaviors of Bacillus sp. bacteria and subsequent formation of bacterial biofilm on stainless steel and thermal sprayed aluminum coatings in artificial seawater. The colonized bacteria accelerate the corrosion of the steel plates, and markedly enhance the anti-corrosion performances of the Al coatings in early growth stage of the bacterial biofilm. After 7days incubation, the biofilm formed on the steel is heterogeneous while exhibits homogeneous feature on the Al coating. Atomic force microscopy examination discloses inception of formation of local pitting on steel plates associated with significantly roughened surface. Electrochemical testing suggests that the impact of the bacterial biofilm on the corrosion behaviors of marine structures is not decided by the biofilm alone, it is instead attributed to synergistic influence by both the biofilm and physicochemical characteristics of the substratum materials. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. [The bacterial biofilm and the possibilities of chemical plaque control. Literature review].

    Science.gov (United States)

    Gera, István

    2008-06-01

    Most microorganisms in the oral cavity attach to surfaces and form matrix-embedded biofilms. Biofilms are structured and spatially organized, composed of consortia of interacting microorganisms. The properties of the mass of biofilm are different from that of the simple sum of the component species. The older the plaque (biofilm) is the more structurally organized and become more resistant to environmental attacks. The bacterial community favors the growth of obligatory anaerobic microorganisms. The most effective means of the elimination of matured biofilm is the mechanical disruption of the interbacterial protective matrix and removal of bacterial colonies. The antiseptic agents are primarily effective in the prevention of biofilm formation and anticipation of the maturation of the bacterial plaque. Bacteria in matured biofilms are less susceptible to antimicrobial agents because several physical and biological factors protect the bacterial consortia. To kill bacteria in a matured, well organized biofilm, significantly higher concentration and longer exposition are required. Antiseptic mouthrinses in a conventional dose and time can only reach the superficial bacteria while the bacteria in the depth of the biofilm remains intact. Therefore, the efficacy of any antiseptic mouthwash depends not just on its microbicidal properties demonstrated in vitro, but also on its ability to penetrate the organized biofilm on the teeth. Recent studies have demonstrated that both bisbiguanid compounds and essential oils are capable of penetrating the biofilm, and reduce established plaque and gingivitis. The essential oils showed high penetrability and were more effective on organized biofilm than stannous fluorides or triclosan copolymer antiplaque agents.

  12. Composing a Tumor Specific Bacterial Promoter.

    Directory of Open Access Journals (Sweden)

    Igor V Deyneko

    Full Text Available Systemically applied Salmonella enterica spp. have been shown to invade and colonize neoplastic tissues where it retards the growth of many tumors. This offers the possibility to use the bacteria as a vehicle for the tumor specific delivery of therapeutic molecules. Specificity of such delivery is solely depending on promoter sequences that control the production of a target molecule. We have established the functional structure of bacterial promoters that are transcriptionally active exclusively in tumor tissues after systemic application. We observed that the specific transcriptional activation is accomplished by a combination of a weak basal promoter and a strong FNR binding site. This represents a minimal set of control elements required for such activation. In natural promoters, additional DNA remodeling elements are found that alter the level of transcription quantitatively. Inefficiency of the basal promoter ensures the absence of transcription outside tumors. As a proof of concept, we compiled an artificial promoter sequence from individual motifs representing FNR and basal promoter and showed specific activation in a tumor microenvironment. Our results open possibilities for the generation of promoters with an adjusted level of expression of target proteins in particular for applications in bacterial tumor therapy.

  13. Attachment Figure's Regulation of Infant Brain and Behavior.

    Science.gov (United States)

    Sullivan, Regina M

    2017-01-01

    Altricial infants (i.e., requiring parental care for survival), such as humans and rats, form an attachment to their caregiver and receive the nurturing and protections needed for survival. Learning has a strong role in attachment, as is illustrated by strong attachment formed to non-biological caregivers of either sex. Here we summarize and integrate results from animal and human infant attachment research that highlights the important role of social buffering (social presence) of the stress response by the attachment figure and its effect on infant processing of threat and fear through modulation of the amygdala. Indeed, this work suggests the caregiver switches off amygdala function in rodents, although recent human research suggests a similar process in humans and nonhuman primates. This cross-species analysis helps provide insight and unique understanding of attachment and its role in the neurobiology of infant behavior within attachment.

  14. Variability of femoral muscle attachments.

    Science.gov (United States)

    Duda, G N; Brand, D; Freitag, S; Lierse, W; Schneider, E

    1996-09-01

    Analytical and experimental models of the musculoskeletal system often assume single values rather than ranges for anatomical input parameters. The hypothesis of the present study was that anatomical variability significantly influences the results of biomechanical analyses, specifically regarding the moment arms of the various thigh muscles. Insertions and origins of muscles crossing or attaching to the femur were digitized in six specimens. Muscle volumes were measured; muscle attachment area and centroid location were computed. To demonstrate the influence of inter-individual anatomic variability on a mechanical modeling parameter, the corresponding range of muscle moment arms were calculated. Standard deviations, as a percentage of the mean, were about 70% for attachment area and 80% for muscle volume and attachment centroid location. The resulting moment arms of the m. gluteus maximus and m. rectus femoris were especially sensitive to anatomical variations (SD 65%). The results indicate that sensitivity to anatomical variations should be analyzed in any investigation simulating musculoskeletal interactions. To avoid misinterpretations, investigators should consider using several anatomical configurations rather than relying on a mean data set.

  15. Best friend attachment versus peer attachment in the prediction of adolescent psychological adjustment.

    Science.gov (United States)

    Wilkinson, Ross B

    2010-10-01

    This study examined the utility of the newly developed Adolescent Friendship Attachment Scale (AFAS) for the prediction of adolescent psychological health and school attitude. High school students (266 males, 229 females) were recruited from private and public schools in the Australian Capital Territory with ages of participants ranging from 13 to 19 years. Self-report measures of depression, self-esteem, self-competence and school attitude were administered in addition to the AFAS and a short-form of the Inventory of Parental and Peer Attachment (IPPA). Regression analyses revealed that the AFAS Anxious and Avoidant scales added to the prediction of depression, self-esteem, self-competence, and school attitude beyond the contribution of the IPPA. It is concluded that the AFAS taps aspects of adolescent attachment relationships not assessed by the IPPA and provides a useful contribution to research and practice in the area of adolescent psycho-social adjustment.

  16. Spatiotemporal dynamics of the bacterial microbiota on lacustrine Cladophora glomerata (Chlorophyta).

    Science.gov (United States)

    Braus, Michael J; Graham, Linda E; Whitman, Thea L

    2017-12-01

    The branched periphytic green alga Cladophora glomerata, often abundant in nearshore waters of lakes and rivers worldwide, plays important ecosystem roles, some mediated by epibiotic microbiota that benefit from host-provided surface, organic C, and O 2 . Previous microscopy and high-throughput sequencing studies have indicated surprising epibiont taxonomic and functional diversity, but have not included adequate consideration of sample replication or the potential for spatial and temporal variation. Here, we report the results of 16S rRNA amplicon-based phylum-to-genus taxonomic analysis of Cladophora-associated bacterial epibiota sampled in replicate from three microsites and at six times during the open-water season of 2014, from the same lake locale (Picnic Point, Lake Mendota, Dane Co., WI, USA) explored by high-throughput sequencing studies in two previous years. Statistical methods were used to test null hypotheses that the bacterial community: (i) is homogeneous across microsites tested, and (ii) does not change over the course of a growth season or among successive years. Results indicated a dynamic microbial community that is more strongly influenced by sampling day during the growth season than by microsite variation. A surprising diversity of bacterial genera known to be associated with the key function of methane-oxidation (methanotrophy), including relatively high-abundance of Crenothrix, Methylomonas, Methylovulum, and Methylocaldum-showed intraseasonal and interannual variability possibly related to temperature differences, and microsite preferences possibly related to variation in methane abundance. By contrast, a core assemblage of bacterial genera seems to persist over a growth season and from year to year, possibly transmitted by a persistent attached host resting stage. © 2017 Phycological Society of America.

  17. Attachment and eating disorders: a research update.

    Science.gov (United States)

    Tasca, Giorgio A

    2018-03-16

    Prominent models of eating disorders tend to focus on cognitive and behavioral features, but tend not to consider important developmental issues related to affect regulation, interpersonal style, self concept, and mentalization-all of which are well conceptualized within attachment theory. Higher levels of attachment insecurity across diagnoses are related to greater eating disorder symptoms. Low parental care and early trauma may lead to attachment insecurity that then might lead to greater eating disorder symptoms. The association between insecure attachment and eating disorder severity is likely mediated by affect dysregulation and perfectionism. Recent research using the Adult Attachment Interview highlights the importance of reflective functioning in predicting treatment response and therapeutic processes, and on the utility of therapies that increase mentalization. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Perinatal Exposure to Environmental Tobacco Smoke (ETS Enhances Susceptibility to Viral and Secondary Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Jocelyn A. Claude

    2012-10-01

    alters the response of neonates to the timing and severity of infection as well as ETS alters the pattern of inflammation and cellular influx into the lungs due to viral and bacterial infection.

  19. Long-term salinity tolerance is accompanied by major restructuring of the coral bacterial microbiome

    KAUST Repository

    Röthig, Till

    2016-02-03

    Scleractinian corals are assumed to be stenohaline osmoconformers, although they are frequently subjected to variations in seawater salinity due to precipitation, freshwater runoff, and other processes. Observed responses to altered salinity levels include differences in photosynthetic performance, respiration, and increased bleaching and mortality of the coral host and its algal symbiont, but a study looking at bacterial community changes is lacking. Here we exposed the coral Fungia granulosa to strongly increased salinity levels in short- and long-term experiments to disentangle temporal and compartment effects of the coral holobiont (i.e. coral host, symbiotic algae, and associated bacteria). Our results show a significant reduction in calcification and photosynthesis, but a stable microbiome after short-term exposure to high salinity levels. By comparison, long-term exposure yielded unchanged photosynthesis levels and visually healthy coral colonies indicating long-term acclimation to high salinity levels that were accompanied by a major coral microbiome restructuring. Importantly, a bacterium in the family Rhodobacteraceae was succeeded by Pseudomonas veronii as the numerically most abundant taxon. Further, taxonomy-based functional profiling indicates a shift in the bacterial community towards increased osmolyte production, sulfur oxidation, and nitrogen fixation. Our study highlights that bacterial community composition in corals can change within days to weeks under altered environmental conditions, where shifts in the microbiome may enable adjustment of the coral to a more advantageous holobiont composition.

  20. Mycoplasma genitalium attaches to human spermatozoa

    DEFF Research Database (Denmark)

    Svenstrup, Helle Friis; Fedder, Jens; Abraham-Peskir, Joanna

    2003-01-01

    BACKGROUND: Mycoplasma genitalium causes urogenital diseases in men and women and is presumed to be sexually transmitted. We wanted to investigate whether spermatozoa could serve as vectors for M.genitalium in order to cause upper genital diseases in women. METHODS: By use of Nomarski light...... microscopy and transmission X-ray microscopy, the attachment of M.genitalium to spermatozoa was studied. Semen was incubated in vitro with M.genitalium. Purified, motile spermatozoa were examined for attachment of M.genitalium by immunofluorescence microscopy. RESULTS: Mycoplasma genitalium was shown...... to adhere to the head, midpiece and tail of the spermatozoa. The spermatozoa became immotile when many M.genitalium were attached. However, the motile spermatozoa were demonstrated to carry M.genitalium and in this case the mycoplasmas were seen to attach mostly to the midpiece or neck region. Occasionally...

  1. Preferential attachment in evolutionary earthquake networks

    Science.gov (United States)

    Rezaei, Soghra; Moghaddasi, Hanieh; Darooneh, Amir Hossein

    2018-04-01

    Earthquakes as spatio-temporal complex systems have been recently studied using complex network theory. Seismic networks are dynamical networks due to addition of new seismic events over time leading to establishing new nodes and links to the network. Here we have constructed Iran and Italy seismic networks based on Hybrid Model and testified the preferential attachment hypothesis for the connection of new nodes which states that it is more probable for newly added nodes to join the highly connected nodes comparing to the less connected ones. We showed that the preferential attachment is present in the case of earthquakes network and the attachment rate has a linear relationship with node degree. We have also found the seismic passive points, the most probable points to be influenced by other seismic places, using their preferential attachment values.

  2. Child-Parent Attachment Styles and Borderline Personality Disorder Relationship

    Directory of Open Access Journals (Sweden)

    Senija Tahirovic

    2016-08-01

    Full Text Available Many studies have focused on the attachment styles and their impact on human functioning and relationships (Bretherton, 1992. Some attachment styles have been associated with pathological way of human overall functioning, and it has already been observed that insecure attachment style in childhood may be associated with personality dysfunction (Brennan & Shaver, 1998. The purpose of this study is to investigate how people diagnosed with borderline personality disorder (BPD describe their attachment style to the primary caregivers from their memories from childhood. This study was conducted in Germany in an inpatient psychiatric clinic. Fifteen participants represented a convenience sample, of patients already diagnosed with BPD. For this study Adult Attachment Interview (AAI was used. The AAI is a semi-structured interview focusing on the early attachment experiences and their effects based on Attachment Theory.The results indicated that people diagnosed with BPD showed both preoccupied and dismissing child-parent attachment style,however it was the dismissing attachment style that dominated in our sample. The findings supported the hypothesis that participants who showed dismissing attachment style also used positive adjectives to describe the relationship  with their primary caregiver, and those with the preoccupied attachment style used negative adjectives to describe the relationship  with their primary caregiver. Even though, study was conducted with small number of participants, the study did provide evidence that there is a relationship between BPD and attachment styles in childhood. Threfore, the study offered contribution to the already existing knowledge and research findings regarding the influence of attachment style on BPD development. Keywords: Attachment, Personality disorder, Borderline Personality Disorder (BPD, child, childhood

  3. Combined copper/zinc attachment to prion protein

    Science.gov (United States)

    Hodak, Miroslav; Bernholc, Jerry

    2013-03-01

    Misfolding of prion protein (PrP) is responsible for diseases such as ``mad-cow disease'' in cattle and Creutzfeldt-Jacob in humans. Extensive experimental investigation has established that this protein strongly interacts with copper ions, and this ability has been linked to its still unknown function. Attachment of other metal ions (zinc, iron, manganese) have been demonstrated as well, but none of them could outcompete copper. Recent finding, however, indicates that at intermediate concentrations both copper and zinc ions can attach to the PrP at the octarepeat region, which contains high affinity metal binding sites. Based on this evidence, we have performed density functional theory simulations to investigate the combined Cu/Zn attachment. We consider all previously reported binding modes of copper at the octarepeat region and examine a possibility simultaneous Cu/Zn attachment. We find that this can indeed occur for only one of the known binding sites, when copper changes its coordination mode to allow for attachment of zinc ion. The implications of the simultaneous attachment on neural function remain to be explored.

  4. Attachment-Focused Psychotherapy and the Wounded Self.

    Science.gov (United States)

    Spiegel, Eric B

    2016-07-01

    The concept of the "wounded self" (Wolfe, 2005) offers an integrative theoretical framework for self-wounds and their developmental origins. Alladin (2013, 2014, 2016) integrated hypnotherapy into this model to comprehensively address the unconscious protective mechanisms and maladaptive conscious cognitive strategies of the wounded self. The purpose of this article is to propose how an attachment-focused psychotherapy could be utilized in working with the wounded self. With its emphasis on developmental maturation through the frame of the attachment relationship, attachment theory is well-positioned to offer conceptual and treatment insights in treating the wounded self. E. B. Spiegel's (2016) attunement, representation, and mentalization approach to attachment-focused psychotherapy described how hypnosis can be utilized across attachment processes of attunement, representation, and mentalization toward structural maturation and developmental repair of patients with histories of complex relational trauma. In this article, the attunement, representation, and mentalization attachment approach and associated interventions are further explicated in the treatment of self-wounds in the borderline and narcissistic spectrums of personality organization. These principles of conceptualization and treatment interventions are then applied in a case example.

  5. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    , which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters...

  6. Coarctation induces alterations in basement membranes in the cardiovascular system

    DEFF Research Database (Denmark)

    Lipke, D W; McCarthy, K J; Elton, T S

    1993-01-01

    ventricular hypertrophy was maximal within 5 days. In immunohistochemical studies, fibronectin and laminin were increased and the basement membrane chondroitin sulfate proteoglycan decreased in both the subendothelial space and smooth muscle cell basement membranes of the aorta above the clip compared...... membrane components in the heart and vasculature peaked before maximal cardiac hypertrophy (5 days). These studies indicate that alterations in basement membrane component deposition in the hypertrophied vasculature occur at both transcriptional and translational levels and suggest that the cell attachment...

  7. An anti-bacterial approach to nanoscale roughening of biomimetic rice-like pattern PP by thermal annealing

    Science.gov (United States)

    Jafari Nodoushan, Emad; Ebrahimi, Nadereh Golshan; Ayazi, Masoumeh

    2017-11-01

    In this paper, we introduced thermal annealing treatment as an effective way of increasing the nanoscale roughness of a semi-crystalline polymer surface. Annealing treatment applied to a biomimetic microscale pattern of rice leaf to achieve a superhydrophobic surface with a hierarchical roughness. Resulted surfaces was characterized by XRD, AFM and FE-SEM instruments and showed an increase of roughness and cristallinity within both time and temperature of treatment. These two parameters also impact on measured static contact angle up to 158°. Bacterial attachment potency has an inverse relationship with the similarity of surface pattern dimensions and bacterial size and due to that, thermal annealing could be an effective way to create anti-bacterial surface beyond its effect on water repellency. Point in case, the anti-bacterial properties of produced water-repellence surfaces of PP were measured and counted colonies of both gram-negative (E. coli) and gram-positive (S. aureus) bacteria reduced with the nature of PP and hierarchical pattern on that. Anti-bacterial characterization of the resulted surface reveals a stunning reduction in adhesion of gram-positive bacteria to the surface. S. aureus reduction rates equaled to 95% and 66% when compared to control blank plate and smooth surface of PP. Moreover, it also could affect the other type of bacteria, gram-negative (E. coli). In the latter case, adhesion reduction rates calculated 66% and 53% when against to the same controls, respectively.

  8. Bacterial adhesion to unworn and worn silicone hydrogel lenses.

    Science.gov (United States)

    Vijay, Ajay Kumar; Zhu, Hua; Ozkan, Jerome; Wu, Duojia; Masoudi, Simin; Bandara, Rani; Borazjani, Roya N; Willcox, Mark D P

    2012-08-01

    The objective of this study was to determine the bacterial adhesion to various silicone hydrogel lens materials and to determine whether lens wear modulated adhesion. Bacterial adhesion (total and viable cells) of Staphylococcus aureus (31, 38, and ATCC 6538) and Pseudomonas aeruginosa (6294, 6206, and GSU-3) to 10 commercially available different unworn and worn silicone hydrogel lenses was measured. Results of adhesion were correlated to polymer and surface properties of contact lenses. S. aureus adhesion to unworn lenses ranged from 2.8 × 10 to 4.4 × 10 colony forming units per lens. The highest adhesion was to lotrafilcon A lenses, and the lowest adhesion was to asmofilcon A lenses. P. aeruginosa adhesion to unworn lenses ranged from 8.9 × 10 to 3.2 × 10 colony forming units per lens. The highest adhesion was to comfilcon A lenses, and the lowest adhesion was to asmofilcon A and balafilcon A lenses. Lens wear altered bacterial adhesion, but the effect was specific to lens and strain type. Adhesion of bacteria, regardless of genera/species or lens wear, was generally correlated with the hydrophobicity of the lens; the less hydrophobic the lens surface, the greater the adhesion. P. aeruginosa adhered in higher numbers to lenses in comparison with S. aureus strains, regardless of the lens type or lens wear. The effect of lens wear was specific to strain and lens. Hydrophobicity of the silicone hydrogel lens surface influenced the adhesion of bacterial cells.

  9. Bacterial Actins.

    Science.gov (United States)

    Izoré, Thierry; van den Ent, Fusinita

    2017-01-01

    A diverse set of protein polymers, structurally related to actin filaments contributes to the organization of bacterial cells as cytomotive or cytoskeletal filaments. This chapter describes actin homologs encoded by bacterial chromosomes. MamK filaments, unique to magnetotactic bacteria, help establishing magnetic biological compasses by interacting with magnetosomes. Magnetosomes are intracellular membrane invaginations containing biomineralized crystals of iron oxide that are positioned by MamK along the long-axis of the cell. FtsA is widespread across bacteria and it is one of the earliest components of the divisome to arrive at midcell, where it anchors the cell division machinery to the membrane. FtsA binds directly to FtsZ filaments and to the membrane through its C-terminus. FtsA shows altered domain architecture when compared to the canonical actin fold. FtsA's subdomain 1C replaces subdomain 1B of other members of the actin family and is located on the opposite side of the molecule. Nevertheless, when FtsA assembles into protofilaments, the protofilament structure is preserved, as subdomain 1C replaces subdomain IB of the following subunit in a canonical actin filament. MreB has an essential role in shape-maintenance of most rod-shaped bacteria. Unusually, MreB filaments assemble from two protofilaments in a flat and antiparallel arrangement. This non-polar architecture implies that both MreB filament ends are structurally identical. MreB filaments bind directly to membranes where they interact with both cytosolic and membrane proteins, thereby forming a key component of the elongasome. MreB filaments in cells are short and dynamic, moving around the long axis of rod-shaped cells, sensing curvature of the membrane and being implicated in peptidoglycan synthesis.

  10. Quantitative characterization of the influence of the nanoscale morphology of nanostructured surfaces on bacterial adhesion and biofilm formation.

    Directory of Open Access Journals (Sweden)

    Ajay Vikram Singh

    Full Text Available Bacterial infection of implants and prosthetic devices is one of the most common causes of implant failure. The nanostructured surface of biocompatible materials strongly influences the adhesion and proliferation of mammalian cells on solid substrates. The observation of this phenomenon has led to an increased effort to develop new strategies to prevent bacterial adhesion and biofilm formation, primarily through nanoengineering the topology of the materials used in implantable devices. While several studies have demonstrated the influence of nanoscale surface morphology on prokaryotic cell attachment, none have provided a quantitative understanding of this phenomenon. Using supersonic cluster beam deposition, we produced nanostructured titania thin films with controlled and reproducible nanoscale morphology respectively. We characterized the surface morphology; composition and wettability by means of atomic force microscopy, X-ray photoemission spectroscopy and contact angle measurements. We studied how protein adsorption is influenced by the physico-chemical surface parameters. Lastly, we characterized Escherichia coli and Staphylococcus aureus adhesion on nanostructured titania surfaces. Our results show that the increase in surface pore aspect ratio and volume, related to the increase of surface roughness, improves protein adsorption, which in turn downplays bacterial adhesion and biofilm formation. As roughness increases up to about 20 nm, bacterial adhesion and biofilm formation are enhanced; the further increase of roughness causes a significant decrease of bacterial adhesion and inhibits biofilm formation. We interpret the observed trend in bacterial adhesion as the combined effect of passivation and flattening effects induced by morphology-dependent protein adsorption. Our findings demonstrate that bacterial adhesion and biofilm formation on nanostructured titanium oxide surfaces are significantly influenced by nanoscale morphological

  11. Effect of Attachment Type on Implant Strain in Maxillary Implant Overdentures: Comparison of Ball, Locator, and Magnet Attachments. Part 1. Overdenture with Palate.

    Science.gov (United States)

    Takahashi, Toshihito; Gonda, Tomoya; Maeda, Yoshinobu

    Implant overdentures with attachments have been used in clinical practice and the effect of attachments on implant strain has been frequently reported. However, most studies have focused on mandibular overdentures; there are few reports on maxillary overdentures. The purpose of this study was to examine the influence of attachment type on implant strain in maxillary overdentures under various implant configurations. A maxillary edentulous model with implants and experimental overdentures were fabricated. Four strain gauges were attached to each implant, positioned in anterior, premolar, and molar areas. Three types of unsplinted attachments-ball, locator, and magnet-were set on the implants under various implant configurations. A vertical occlusal load of 98 N was applied through the mandibular complete denture, and implant strain was compared using the Kruskal-Wallis test. Ball attachments caused the greatest amount of strain, while magnet attachments caused the least amount under all conditions. For all attachments, two anterior implants caused significantly more strain than four implants (P magnet attachments are recommended to reduce implant stress. Using only two implants, especially two anterior implants, is not recommended regardless of attachment type.

  12. Effect of antibiotics on bacterial populations: a multi-hierachical selection process.

    Science.gov (United States)

    Martínez, José Luis

    2017-01-01

    Antibiotics have been widely used for a number of decades for human therapy and farming production. Since a high percentage of antibiotics are discharged from the human or animal body without degradation, this means that different habitats, from the human body to river water or soils, are polluted with antibiotics. In this situation, it is expected that the variable concentration of this type of microbial inhibitor present in different ecosystems may affect the structure and the productivity of the microbiota colonizing such habitats. This effect can occur at different levels, including changes in the overall structure of the population, selection of resistant organisms, or alterations in bacterial physiology. In this review, I discuss the available information on how the presence of antibiotics may alter the microbiota and the consequences of such alterations for human health and for the activity of microbiota from different habitats.

  13. Microplastic-associated Bacterial Assemblages in the Intertidal Zone

    Science.gov (United States)

    Jiang, P.; Zhao, S.; Zhu, L.; Li, D.

    2017-12-01

    Plastic debris is posing a planetary-scale threat. As a zone where terrestrial and marine ecosystems interactions occur, the accumulation of plastic marine debris (PMD) in intertidal environments has been well documented. But the information of plastic-associated microbial community (the "Plastisphere") in the intertidal zone is scanty. Utilizing the high-throughput sequencing, we profiled the bacterial communities attached to microplastic samples from the intertidal locations around Yangtze estuary. The structure and composition of Plastisphere communities in current study varied significantly with geographical stations. The taxonomic composition on microplastic samples implied their sedimental and aquatic origins. Some members of hydrocarbon degrading microorganisms and potential pathogens were detected on microplastic. Overall, our findings fuel the evidence for the occurrence of diverse microbial assemblages on PMD and improving our understanding of Plastisphere ecology, which could support the management action and policy change related to PMD.

  14. Relationship between attachment styles and happiness in medical students.

    Science.gov (United States)

    Moghadam, Marzyeh; Rezaei, Farzin; Ghaderi, Ebrahim; Rostamian, Negar

    2016-01-01

    Attachment theory is one of the most important achievements of contemporary psychology. Role of medical students in the community health is important, so we need to know about the situation of happiness and attachment style in these students. This study was aimed to assess the relationship between medical students' attachment styles and demographic characteristics. This cross-sectional study was conducted on randomly selected students of Medical Sciences in Kurdistan University, in 2012. To collect data, Hazan and Shaver's attachment style measure and the Oxford Happiness Questionnaire were used. The results were analyzed using the SPSS software version 16 (IBM, Chicago IL, USA) and statistical analysis was performed via t-test, Chi-square test, and multiple regression tests. Secure attachment style was the most common attachment style and the least common was ambivalent attachment style. Avoidant attachment style was more common among single persons than married people ( P = 0.03). No significant relationship was observed between attachment style and gender and grade point average of the studied people. The mean happiness score of students was 62.71. In multivariate analysis, the variables of secure attachment style ( P = 0.001), male gender ( P = 0.005), and scholar achievement ( P = 0.047) were associated with higher happiness score. The most common attachment style was secure attachment style, which can be a positive prognostic factor in medical students, helping them to manage stress. Higher frequency of avoidant attachment style among single persons, compared with married people, is mainly due to their negative attitude toward others and failure to establish and maintain relationships with others.

  15. Evaluation of alteration in mucogingival line location following use of subepithelial connective tissue graft

    Directory of Open Access Journals (Sweden)

    Saber Fariba

    2010-01-01

    Full Text Available Aim and Objective : The aim of this study is to evaluate the positional changes that occur in mucogingival line following the use of subepithelial connective tissue graft (SCTG. Materials and Methods : In 19 Miller class I or II gingival recession defects, distance between mucogingival line (MGL and cemento-enamel junction, also width of keratinized and attached gingiva, and clinical attachment level were measured. SCTG were used for covering the exposed roots. A fore mentioned parameters were repeated at 3, 6 and 12 months after surgery and alterations were measured. Paired t test was used to analyze the results. Results : MGL had been moved in coronal direction (4.39 ± 0.77 mm on average during surgical approach. After 1 year, MGL shifted 2.11 ± 0.7 mm apically. In accordance with this apical shift, a significant increase in the width of keratinized and attached gingival width (2.89 ± 0.63 mm and 2.82 ± 0.5 mm, respectively was seen (P < 0.05. Conclusion : MGL tended to revert back to its original position following the use of SCTG, and this reversion is accompanied with an increase in the keratinized and attached gingival width.

  16. Attachment and Aggressive Manifestations in Younger Adulthood - "Preliminary Findings"

    Directory of Open Access Journals (Sweden)

    Tatiana Lorincová

    2014-07-01

    Full Text Available The main topic of the contribution was comparison between retrospective attachment (emocional warmth and rejection and aggressive manifestations (physical aggressivness, verbal aggressivness, anger and hostility among younger adulthood. Bowlby's theory of attachment was that once a core attachment style develops in an infant, it will influence and shape the nature of all intimate relations for the individual moving forward throughout the infant's life cycle. Authors Mikulincer and Shaver (2011 explain how these primary attachment experiences would affect future emotional, cognitive and behavioral processes. Secure adolescents, in comparison to insecure ones are perceived as being less aggressive. Research has pointed out that secure parental attachment promotes adaptive psychological functioning. The direct relationship between attachment security and aggressive/delinquent behaviour is in line with prior evidence that secure adolescents rate higher in terms of emotional and social adjustment, enjoy more positive relationships with their family and peers, and are less likely to engage in externalizing problems, such as antisocial and aggressive behaviours. On the other hand, insecure attachment is connected with aggressive and externalizing behaviour. Hypotheses were formulated on the base of theoretical background and our assumption was, that younger adults with emocional warmth attachment will have lower level of aggressive manifestations (physical aggression, verbal aggression, anger and hostility than younger adults with rejectional attachment. We used two standardized questionnaires for data collection, s.E.M.B.U. Questionnaire, which measured retrospective attachment (emocional warmth and rejection and Questionnaire of Aggressivness, which measured aggressive manifestations. We used statistical analysis and we found statistically significant differencies, which are preliminary findings from broader research, between emocional warmth

  17. Vaginal flora alterations and clinical symptoms in low-risk pregnant women.

    Science.gov (United States)

    Gondo, Fausto; da Silva, Márcia G; Polettini, Jossimara; Tristao, Andréa da R; Peracoli, José C; Witkin, Steven S; Rudge, Marilza V C

    2011-01-01

    To evaluate associations between alterations in vaginal flora and clinical symptoms in low-risk pregnant women. Vaginal specimens from 245 pregnant women were analyzed by microscopy for vaginal flora. Signs and symptoms of vaginal infection were determined by patient interviews and gynecologic examinations. Abnormal vaginal flora was identified in 45.7% of the subjects. The final clinical diagnoses were bacterial vaginosis (21.6%), vaginal candidosis (10.2%), intermediate vaginal flora (5.2%), aerobic vaginitis (2.9%), mixed flora (2.9%) and other abnormal findings (2.9%). The percentage of women with or without clinical signs or symptoms was not significantly different between these categories. The presence of vaginal odor or vaginal discharge characteristics was not diagnostic of any specific flora alteration; pruritus was highly associated with candidosis (p vaginal odor was associated with bacterial vaginosis (p = 0.0026). The prevalence of atypical vaginal flora is common in our low-risk pregnant population and is not always associated with pathology. The occurrence of specific signs or symptoms does not always discriminate between women with different types of atypical vaginal flora or between those with abnormal and normal vaginal flora. Copyright © 2010 S. Karger AG, Basel.

  18. Development of molecularly imprinted polymers to block quorum sensing and inhibit bacterial biofilm formation.

    Science.gov (United States)

    Ma, Luyao; Feng, Shaolong; de la Fuente-Nunez, Cesar; Hancock, Robert E W; Lu, Xiaonan

    2018-05-16

    Bacterial biofilms are responsible for most clinical infections and show increased antimicrobial resistance. In this study, molecularly imprinted polymers (MIPs) were developed to specifically capture prototypical quorum sensing autoinducers [i.e., N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12AHL)], interrupt quorum sensing, and subsequently inhibit biofilm formation of Pseudomonas aeruginosa, an important human nosocomial pathogen. The synthesis of MIPs was optimized by considering the amount and type of the functional monomers itaconic acid (IA) and 2-hydroxyethyl methacrylate (HEMA). IA-based MIPs showed high adsorption affinity towards 3-oxo-C12AHL with an imprinting factor of 1.68. Compared to IA-based MIPs, the adsorption capacity of HEMA-based MIPs was improved 5-fold. HEMA-based MIPs significantly reduced biofilm formation (by ~65%), while biofilm suppression by IA-based MIPs was neutralized due to increased bacterial attachment. The developed MIPs represent promising alternative biofilm intervention agents that can be applied to surfaces relevant to clinical settings and food processing equipment.

  19. Attachment patterns and Reflective Functioning in Traumatized Refugees

    DEFF Research Database (Denmark)

    Riber, Karin

    , attachment systems, emotion-regulation, and personality. Attachment research on the consequences of organized violence and forced migration is sparse and research in PTSD-treatment for refugees is lacking behind. Cumulative pre-migration traumatic experiences and ongoing post-migration stressors might lead...... Psychiatry, Denmark. June 2011-March 2012 patients fulfilling inclusion criteria entered the trial. The present sample consisted of those of the 135 patients who were Arabic-speaking (N=67). Measures involved the Adult Attachment Interview, The Reflective Functioning Scale, Revised Adult Attachment Scale...... and reflective functioning will be described and implications for psychotherapy discussed. Keywords: Adult attachment, reflective functioning, refugee traumatisation....

  20. Attachment and prejudice: The mediating role of empathy.

    Science.gov (United States)

    Boag, Elle M; Carnelley, Katherine B

    2016-06-01

    In two studies, we examined the novel hypothesis that empathy is a mechanism through which the relationship between attachment patterns and prejudice can be explained. Study 1 examined primed attachment security (vs. neutral prime), empathy, and prejudice towards immigrants. Study 2 examined primed attachment patterns (secure, avoidant, anxious), empathy subscales (perspective taking, empathic concern, personal distress), and prejudice towards Muslims. Across both studies, empathy mediated the relationship between primed attachment security and low prejudice levels. The findings suggest that enhancing felt security and empathic skills in individuals high in attachment-avoidance may lead to reduced prejudice. © 2015 The British Psychological Society.

  1. Parental material and cultivation determine soil bacterial community structure and fertility.

    Science.gov (United States)

    Sun, Li; Gao, Jusheng; Huang, Ting; Kendall, Joshua R A; Shen, Qirong; Zhang, Ruifu

    2015-01-01

    Microbes are the key components of the soil environment, playing important roles during soil development. Soil parent material provides the foundation elements that comprise the basic nutritional environment for the development of microbial community. After 30 years artificial maturation of cultivation, the soil developments of three different parental materials were evaluated and bacterial community compositions were investigated using the high-throughput sequencing approach. Thirty years of cultivation increased the soil fertility and soil microbial biomass, richness and diversity, greatly changed the soil bacterial communities, the proportion of phylum Actinobacteria decreased significantly, while the relative abundances of the phyla Acidobacteria, Chloroflexi, Gemmatimonadetes, Armatimonadetes and Nitrospira were significantly increased. Soil bacterial communities of parental materials were separated with the cultivated ones, and comparisons of different soil types, granite soil and quaternary red clay soil were similar and different with purple sandy shale soil in both parental materials and cultivated treatments. Bacterial community variations in the three soil types were affected by different factors, and their alteration patterns in the soil development also varied with soil type. Soil properties (except total potassium) had a significant effect on the soil bacterial communities in all three soil types and a close relationship with abundant bacterial phyla. The amounts of nitrogen-fixing bacteria as well as the abundances of the nifH gene in all cultivated soils were higher than those in the parental materials; Burkholderia and Rhizobacte were enriched significantly with long-term cultivation. The results suggested that crop system would not deplete the nutrients of soil parental materials in early stage of soil maturation, instead it increased soil fertility and changed bacterial community, specially enriched the nitrogen-fixing bacteria to accumulate

  2. Engineered CRISPR-Cas9 nucleases with altered PAM specificities.

    Science.gov (United States)

    Kleinstiver, Benjamin P; Prew, Michelle S; Tsai, Shengdar Q; Topkar, Ved V; Nguyen, Nhu T; Zheng, Zongli; Gonzales, Andrew P W; Li, Zhuyun; Peterson, Randall T; Yeh, Jing-Ruey Joanna; Aryee, Martin J; Joung, J Keith

    2015-07-23

    Although CRISPR-Cas9 nucleases are widely used for genome editing, the range of sequences that Cas9 can recognize is constrained by the need for a specific protospacer adjacent motif (PAM). As a result, it can often be difficult to target double-stranded breaks (DSBs) with the precision that is necessary for various genome-editing applications. The ability to engineer Cas9 derivatives with purposefully altered PAM specificities would address this limitation. Here we show that the commonly used Streptococcus pyogenes Cas9 (SpCas9) can be modified to recognize alternative PAM sequences using structural information, bacterial selection-based directed evolution, and combinatorial design. These altered PAM specificity variants enable robust editing of endogenous gene sites in zebrafish and human cells not currently targetable by wild-type SpCas9, and their genome-wide specificities are comparable to wild-type SpCas9 as judged by GUIDE-seq analysis. In addition, we identify and characterize another SpCas9 variant that exhibits improved specificity in human cells, possessing better discrimination against off-target sites with non-canonical NAG and NGA PAMs and/or mismatched spacers. We also find that two smaller-size Cas9 orthologues, Streptococcus thermophilus Cas9 (St1Cas9) and Staphylococcus aureus Cas9 (SaCas9), function efficiently in the bacterial selection systems and in human cells, suggesting that our engineering strategies could be extended to Cas9s from other species. Our findings provide broadly useful SpCas9 variants and, more importantly, establish the feasibility of engineering a wide range of Cas9s with altered and improved PAM specificities.

  3. Attachment security and obesity in US preschool-aged children.

    Science.gov (United States)

    Anderson, Sarah E; Whitaker, Robert C

    2011-03-01

    To estimate the association between attachment security in children aged 24 months and their risk for obesity at 4½ years of age. Insecure attachment is associated with unhealthy physiologic and behavioral responses to stress, which could lead to development of obesity. Cohort study. National sample of US children born in 2001. Children and mothers participating in the 2003 and 2005-2006 waves of the Early Childhood Longitudinal Study, Birth Cohort, conducted by the National Center for Education Statistics. Our analytic sample included 6650 children (76.0% of children assessed in both waves). Attachment security at 24 months was assessed by trained interviewers during observation in the child's home. Insecure attachment was defined as lowest quartile of attachment security, based on the security score from the Toddler Attachment Sort-45 Item. Obesity at 4½ years of age (sex-specific body mass index ≥95th percentile for age). The prevalence of obesity was 23.1% in children with insecure attachment and 16.6% in those with secure attachment. For children with insecure attachment, the odds of obesity were 1.30 (95% confidence interval, 1.05-1.62) times higher than for children with secure attachment after controlling for the quality of mother-child interaction during play, parenting practices related to obesity, maternal body mass index, and sociodemographic characteristics. Insecure attachment in early childhood may be a risk factor for obesity. Interventions to increase children's attachment security should examine the effects on children's weight.

  4. High bacterial diversity of biological soil crusts in water tracks over permafrost in the high arctic polar desert.

    Science.gov (United States)

    Steven, Blaire; Lionard, Marie; Kuske, Cheryl R; Vincent, Warwick F

    2013-01-01

    In this study we report the bacterial diversity of biological soil crusts (biocrusts) inhabiting polar desert soils at the northern land limit of the Arctic polar region (83° 05 N). Employing pyrosequencing of bacterial 16S rRNA genes this study demonstrated that these biocrusts harbor diverse bacterial communities, often as diverse as temperate latitude communities. The effect of wetting pulses on the composition of communities was also determined by collecting samples from soils outside and inside of permafrost water tracks, hill slope flow paths that drain permafrost-affected soils. The intermittent flow regime in the water tracks was correlated with altered relative abundance of phylum level taxonomic bins in the bacterial communities, but the alterations varied between individual sampling sites. Bacteria related to the Cyanobacteria and Acidobacteria demonstrated shifts in relative abundance based on their location either inside or outside of the water tracks. Among cyanobacterial sequences, the proportion of sequences belonging to the family Oscillatoriales consistently increased in relative abundance in the samples from inside the water tracks compared to those outside. Acidobacteria showed responses to wetting pulses in the water tracks, increasing in abundance at one site and decreasing at the other two sites. Subdivision 4 acidobacterial sequences tended to follow the trends in the total Acidobacteria relative abundance, suggesting these organisms were largely responsible for the changes observed in the Acidobacteria. Taken together, these data suggest that the bacterial communities of these high latitude polar biocrusts are diverse but do not show a consensus response to intermittent flow in water tracks over high Arctic permafrost.

  5. CRISPR/Cas systems: new players in gene regulation and bacterial physiology

    Directory of Open Access Journals (Sweden)

    David eWeiss

    2014-04-01

    Full Text Available CRISPR-Cas systems are bacterial defenses against foreign nucleic acids derived from bacteriophages, plasmids or other sources. These systems are targeted in an RNA-dependent, sequence-specific manner, and are also adaptive, providing protection against previously encountered foreign elements. In addition to their canonical function in defense against foreign nucleic acid, their roles in various aspects of bacterial physiology are now being uncovered. We recently revealed a role for a Cas9-based Type II CRISPR-Cas system in the control of endogenous gene expression, a novel form of prokaryotic gene regulation. Cas9 functions in association with two small RNAs to target and alter the stability of an endogenous transcript encoding a bacterial lipoprotein (BLP. Since BLPs are recognized by the host innate immune protein Toll-like Receptor 2 (TLR2, CRISPR-Cas-mediated repression of BLP expression facilitates evasion of TLR2 by the intracellular bacterial pathogen Francisella novicida, and is essential for its virulence. Here we describe the Cas9 regulatory system in detail, as well as data on its role in controlling virulence traits of Neisseria meningitidis and Campylobacter jejuni. We also discuss potential roles of CRISPR-Cas systems in the response to envelope stress and other aspects of bacterial physiology. Since ~45% of bacteria and ~83% of Archaea encode these machineries, the newly appreciated regulatory functions of CRISPR-Cas systems are likely to play broad roles in controlling the pathogenesis and physiology of diverse prokaryotes.

  6. Relationship between attachment styles and happiness in medical students

    Directory of Open Access Journals (Sweden)

    Marzyeh Moghadam

    2016-01-01

    Full Text Available Background: Attachment theory is one of the most important achievements of contemporary psychology. Role of medical students in the community health is important, so we need to know about the situation of happiness and attachment style in these students. Objectives: This study was aimed to assess the relationship between medical students′ attachment styles and demographic characteristics. Materials and Methods: This cross-sectional study was conducted on randomly selected students of Medical Sciences in Kurdistan University, in 2012. To collect data, Hazan and Shaver′s attachment style measure and the Oxford Happiness Questionnaire were used. The results were analyzed using the  SPSS software version 16 (IBM, Chicago IL, USA and statistical analysis was performed via t-test, Chi-square test, and multiple regression tests. Results: Secure attachment style was the most common attachment style and the least common was ambivalent attachment style. Avoidant attachment style was more common among single persons than married people (P = 0.03. No significant relationship was observed between attachment style and gender and grade point average of the studied people. The mean happiness score of students was 62.71. In multivariate analysis, the variables of secure attachment style (P = 0.001, male gender (P = 0.005, and scholar achievement (P = 0.047 were associated with higher happiness score. Conclusion: The most common attachment style was secure attachment style, which can be a positive prognostic factor in medical students, helping them to manage stress. Higher frequency of avoidant attachment style among single persons, compared with married people, is mainly due to their negative attitude toward others and failure to establish and maintain relationships with others.

  7. Pyrosequencing reveals changes in soil bacterial communities after conversion of Yungas forests to agriculture.

    Directory of Open Access Journals (Sweden)

    Marcela S Montecchia

    Full Text Available The Southern Andean Yungas in Northwest Argentina constitute one of the main biodiversity hotspots in the world. Considerable changes in land use have taken place in this ecoregion, predominantly related to forest conversion to croplands, inducing losses in above-ground biodiversity and with potential impact on soil microbial communities. In this study, we used high-throughput pyrosequencing of the 16S ribosomal RNA gene to assess whether land-use change and time under agriculture affect the composition and diversity of soil bacterial communities. We selected two areas dedicated to sugarcane and soybean production, comprising both short- and long-term agricultural sites, and used the adjacent native forest soils as a reference. Land-use change altered the composition of bacterial communities, with differences between productive areas despite the similarities between both forests. At the phylum level, only Verrucomicrobia and Firmicutes changed in abundance after deforestation for sugarcane and soybean cropping, respectively. In cultivated soils, Verrucomicrobia decreased sharply (~80%, while Firmicutes were more abundant. Despite the fact that local diversity was increased in sugarcane systems and was not altered by soybean cropping, phylogenetic beta diversity declined along both chronosequences, evidencing a homogenization of soil bacterial communities over time. In spite of the detected alteration in composition and diversity, we found a core microbiome resistant to the disturbances caused by the conversion of forests to cultivated lands and few or none exclusive OTUs for each land-use type. The overall changes in the relative abundance of copiotrophic and oligotrophic taxa may have an impact in soil ecosystem functionality. However, communities with many taxa in common may also share many functional attributes, allowing to maintain at least some soil ecosystem services after forest conversion to croplands.

  8. Impact of Monochorionicity and Twin to Twin Transfusion Syndrome on Prenatal Attachment, Post Traumatic Stress Disorder, Anxiety and Depressive Symptoms.

    Science.gov (United States)

    Beauquier-Maccotta, Berengere; Chalouhi, Gihad E; Picquet, Anne-Laure; Carrier, Aude; Bussières, Laurence; Golse, Bernard; Ville, Yves

    2016-01-01

    Monochronioric (MC) twin pregnancies are considered as high-risk pregnancies with potential complications requiring in-utero interventions. We aimed to assess prenatal attachment, anxiety, post-traumatic stress disorder (PTSD) and depressive symptoms in MC pregnancies complicated with Twin-To-Twin-transfusion syndrome (TTTS) in comparison to uncomplicated monochorionic (UMC) and dichorionic pregnancies (DC). Auto-questionnaires were filled out at diagnosis of TTTS and at successive milestones. Prenatal attachment, PTSD, anxiety and perinatal depression were evaluated respectively by the Prenatal Attachment Inventory (PAI) completed for each twin, the Post-traumatic Checklist Scale (PCLS), the State-Trait Anxiety Inventory (STAI) and the Edinburgh Perinatal Depression Scale (EPDS). There was no significant difference in the PAI scores between the two twins. In the DC and UMC groups, PAI scores increased throughout pregnancy, whilst it didn't for TTTS group. TTTS and DC had a similar prenatal attachment while MC mothers expressed a significantly higher attachment to their fetuses and expressed it earlier. At the announcement of TTTS, 72% of the patients present a score over the threshold at the EPDS Scale, with a higher score for TTTS than for DC (p = 0.005), and UMC (p = 0.007) at the same GA. 30% of mothers in TTTS group have PTSD during pregnancy. 50% of TTTS- patients present an anxiety score over the threshold (STAI-Scale), with a score significantly higher in TTTS than in UMC (panxiety and an alteration of the prenatal attachment. These results should guide the psychological support provided to these patients.

  9. Respiration and carbon dynamics of free-living and particle-attached bacteria in coastal waters of NE Pacific

    Science.gov (United States)

    Guo, C.; Ke, Y.; Liu, H.

    2016-02-01

    Bacterial respiration (BR) rates are fundamental to understand the role of bacteria in carbon flow in aquatic ecosystem, and therefore it is critical to obtain reliable measurements. Prefiltration- (mostly 1-3μm) and dark-incubation- (mostly 24 h) based direct measurements of oxygen consumption have been the most commonly used method for BR. However, the prefiltration procedure and long incubation time may cause change of the bacterial abundance and structure, leading to inaccurate measurements. In this study, by measuring bacterial abundance, production and respiration of both particle-attached (PA) and free-living (FL) bacteria at two contrasting site in coastal NE Pacific from Nov 2014 to Mar 2015, we found that the 24 h growth rate of FL bacteria in the traditional BR incubations were significantly higher for 30% and 54% than those obtained for FL and total (FL+PA) bacteria in unfiltered incubations respectively, suggesting removal of protist grazers could cause a significant biomass accumulation during 24 h incubation than the in situ condition. This biomass overestimation resulted in 40% (±12%) overestimation of measured FL BR rates compared with the corrected in situ FL BR. Nevertheless, for the corrected in situ total BR, the rates were overestimated by traditional method in three measurements over nine for 6-46%, and were underestimated in the rest six measurements for 7-67%. Interestingly, those underestimations were attributed to the ignorance of PA bacteria due to prefiltration, which had larger cell size than the FL bacteria, accounted for 19% (±16%) in total bacterial abundance, and contributed to 50% (±19%) of total bacterial production. The average bacterial growth efficiency calculated by comparable 24 h integrated bacterial production and respiration was 0.42 (±0.24). Our results confirmed two major flaws in the current BR methodology, i.e., 1) it only measures the respiration of FL bacteria, and 2) the removal of grazers causing dramatic

  10. Regulation of the Contribution of Integrin to Cell Attachment on Poly(2-Methoxyethyl Acrylate (PMEA Analogous Polymers for Attachment-Based Cell Enrichment.

    Directory of Open Access Journals (Sweden)

    Takashi Hoshiba

    Full Text Available Cell enrichment is currently in high demand in medical engineering. We have reported that non-blood cells can attach to a blood-compatible poly(2-methoxyethyl acrylate (PMEA substrate through integrin-dependent and integrin-independent mechanisms because the PMEA substrate suppresses protein adsorption. Therefore, we assumed that PMEA analogous polymers can change the contribution of integrin to cell attachment through the regulation of protein adsorption. In the present study, we investigated protein adsorption, cell attachment profiles, and attachment mechanisms on PMEA analogous polymer substrates. Additionally, we demonstrated the possibility of attachment-based cell enrichment on PMEA analogous polymer substrates. HT-1080 and MDA-MB-231 cells started to attach to poly(butyl acrylate (PBA and poly(tetrahydrofurfuryl acrylate (PTHFA, on which proteins could adsorb well, within 1 h. HepG2 cells started to attach after 1 h. HT-1080, MDA-MB-231, and HepG2 cells started to attach within 30 min to PMEA, poly(2-(2-methoxyethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe2A and poly(2-(2-methoxyethoxy ethoxy ethyl acrylate-co-butyl acrylate (30:70 mol%, PMe3A, which suppress protein adsorption. Moreover, the ratio of attached cells from a cell mixture can be changed on PMEA analogous polymers. These findings suggested that PMEA analogous polymers can be used for attachment-based cell enrichment.

  11. CRISPR Perturbation of Gene Expression Alters Bacterial Fitness under Stress and Reveals Underlying Epistatic Constraints.

    Science.gov (United States)

    Otoupal, Peter B; Erickson, Keesha E; Escalas-Bordoy, Antoni; Chatterjee, Anushree

    2017-01-20

    The evolution of antibiotic resistance has engendered an impending global health crisis that necessitates a greater understanding of how resistance emerges. The impact of nongenetic factors and how they influence the evolution of resistance is a largely unexplored area of research. Here we present a novel application of CRISPR-Cas9 technology for investigating how gene expression governs the adaptive pathways available to bacteria during the evolution of resistance. We examine the impact of gene expression changes on bacterial adaptation by constructing a library of deactivated CRISPR-Cas9 synthetic devices to tune the expression of a set of stress-response genes in Escherichia coli. We show that artificially inducing perturbations in gene expression imparts significant synthetic control over fitness and growth during stress exposure. We present evidence that these impacts are reversible; strains with synthetically perturbed gene expression regained wild-type growth phenotypes upon stress removal, while maintaining divergent growth characteristics under stress. Furthermore, we demonstrate a prevailing trend toward negative epistatic interactions when multiple gene perturbations are combined simultaneously, thereby posing an intrinsic constraint on gene expression underlying adaptive trajectories. Together, these results emphasize how CRISPR-Cas9 can be employed to engineer gene expression changes that shape bacterial adaptation, and present a novel approach to synthetically control the evolution of antimicrobial resistance.

  12. Attachment Style and Internet Addiction: An Online Survey

    Science.gov (United States)

    Schott, Markus; Decker, Oliver; Sindelar, Brigitte

    2017-01-01

    Background One of the clinically relevant problems of Internet use is the phenomenon of Internet addiction. Considering the fact that there is ample evidence for the relationship between attachment style and substance abuse, it stands to reason that attachment theory can also make an important contribution to the understanding of the pathogenesis of Internet addiction. Objective The aim of this study was to examine people’s tendency toward pathological Internet usage in relation to their attachment style. Methods An online survey was conducted. Sociodemographic data, attachment style (Bielefeld questionnaire partnership expectations), symptoms of Internet addiction (scale for online addiction for adults), used Web-based services, and online relationship motives (Cyber Relationship Motive Scale, CRMS-D) were assessed. In order to confirm the findings, a study using the Rorschach test was also conducted. Results In total, 245 subjects were recruited. Participants with insecure attachment style showed a higher tendency to pathological Internet usage compared with securely attached participants. An ambivalent attachment style was particularly associated with pathological Internet usage. Escapist and social-compensatory motives played an important role for insecurely attached subjects. However, there were no significant effects with respect to Web-based services and apps used. Results of the analysis of the Rorschach protocol with 16 subjects corroborated these results. Users with pathological Internet use frequently showed signs of infantile relationship structures in the context of social groups. This refers to the results of the Web-based survey, in which interpersonal relationships were the result of an insecure attachment style. Conclusions Pathological Internet use was a function of insecure attachment and limited interpersonal relationships. PMID:28526662

  13. Magnetic comparison of abiogenic and biogenic alteration products of lepidocrocite

    Science.gov (United States)

    Till, J. L.; Guyodo, Y.; Lagroix, F.; Ona-Nguema, G.; Brest, J.

    2014-06-01

    Lepidocrocite is a potentially important Fe-bearing precursor phase for the production of nanoscale Fe-oxide particles in the environment. We present a detailed magnetic characterization of various alteration products of lepidocrocite resulting from thermal dehydroxylation reactions and bacterially induced bioreduction and remineralization, accompanied by characterization with x-ray diffraction (XRD) and transmission electron microscopy. Dehydroxylation during annealing at moderate temperatures produces a topotactic transformation from lepidocrocite to maghemite when heated in an oxidizing atmosphere, or to magnetite when heated in a reducing atmosphere. The abiotic Fe-oxide products form an oriented framework of strongly interacting superparamagnetic crystallites and are characterized by a distinctive porous nanostructure observed by electron microscopy. Lepidocrocite bioreduction by the iron-reducing bacterium Shewanella putrefaciens ATCC 8071 produces nanoscale particles of a strongly magnetic phase. This Fe(II)-bearing mineral produced by bioreduction is highly crystalline and euhedral in shape, with a broad grain size distribution and is indicated by magnetic and XRD measurements to be a cation-excess magnetite. We highlight the distinguishing microscopic characteristics of magnetite from both abiotic and bacterially induced mineralization that should allow them to be identified in natural settings. Moreover, both mechanisms of alteration represent potential pathways for the direct formation of strongly magnetic fine-grained Fe-oxide particles in sedimentary environments.

  14. Adult attachment security and college student substance use.

    Science.gov (United States)

    Kassel, Jon D; Wardle, Margaret; Roberts, John E

    2007-06-01

    Previous research has demonstrated strong links between quality of adult attachment styles and various forms of psychological distress. A burgeoning literature further points to a relationship between insecure attachment and drug use, particularly alcohol consumption. In the present study, we expanded upon the existing literature by examining the relationship between adult attachment style and use of cigarettes, alcohol, and marijuana in a sample of 212 college students. Moreover, based on our previous work [Hankin, B.L., Kassel, J.D., and Abela, J.R.Z. (2005). Adult attachment dimensions and specificity of emotional distress symptoms: prospective investigations of cognitive risk and interpersonal stress generation as mediating mechanisms. Personality and Social Psychology Bulletin, 31, 136-151.], we proposed a conceptual model positing that adult attachment style influences both frequency of drug use and stress-motivated drug use through its impact on dysfunctional attitudes and self-esteem. Initial correlational analyses indicated significant (positive) associations between anxious attachment (tapping neediness and fear of abandonment) and both drug use frequency and stress-motivated drug use. Simultaneous regression analyses revealed that, for drug use frequency, the influence of anxious attachment operated primarily through its effect on dysfunctional attitudes and self-esteem. Regarding drug use attributable to negative affect reduction, anxious attachment demonstrated direct, independent effects on both cigarette smoking and alcohol use. These findings highlight the potential importance of adult attachment styles as a risk factor for drug use among college students.

  15. Of the Phrensy: an update on the epidemiology and pathogenesis of bacterial meningitis in the pediatric population [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Andrew Janowski

    2017-01-01

    Full Text Available In the past century, advances in antibiotics and vaccination have dramatically altered the incidence and clinical outcomes of bacterial meningitis. We review the shifting epidemiology of meningitis in children, including after the implementation of vaccines that target common meningitic pathogens and the introduction of intrapartum antibiotic prophylaxis offered to mothers colonized with Streptococcus agalactiae. We also discuss what is currently known about the pathogenesis of meningitis. Recent studies of the human microbiome have illustrated dynamic relationships of bacterial and viral populations with the host, which may potentiate the risk of bacterial meningitis.

  16. Infant-mother and infant-sibling attachment in Zambia.

    Science.gov (United States)

    Mooya, Haatembo; Sichimba, Francis; Bakermans-Kranenburg, Marian

    2016-12-01

    This study, the first in Zambia using the Strange Situation Procedure (SSP) to observe attachment relationships and the "very first" observational study of infant-sibling attachment, examined patterns of infant-mother and infant-sibling attachment, and tested their association. We included siblings who were substantially involved in caregiving activities with their younger siblings. We hypothesized that infants would develop attachment relationships to both mothers and siblings; the majority of infants would be classified as securely attached to both caregivers, and infant-mother and infant-sibling attachment would be unrelated. The sample included 88 low-income families in Lusaka, Zambia (average of 3.5 children; SD = 1.5). The SSP distributions (infant-mother) were 59% secure, 24% avoidant and 17% resistant, and 46% secure, 20% avoidant, 5% resistant and 29% disorganized for three- and four-way classifications, respectively. The infant-sibling classifications were 42% secure, 23% avoidant and 35% resistant, and 35% secure, 23% avoidant, 9% resistant and 33% disorganized for three- and four-way classifications, respectively. Infant-mother and infant-sibling attachment relationships were not associated.

  17. PMA-Linked Fluorescence for Rapid Detection of Viable Bacterial Endospores

    Science.gov (United States)

    LaDuc, Myron T.; Venkateswaran, Kasthuri; Mohapatra, Bidyut

    2012-01-01

    The most common approach for assessing the abundance of viable bacterial endospores is the culture-based plating method. However, culture-based approaches are heavily biased and oftentimes incompatible with upstream sample processing strategies, which make viable cells/spores uncultivable. This shortcoming highlights the need for rapid molecular diagnostic tools to assess more accurately the abundance of viable spacecraft-associated microbiota, perhaps most importantly bacterial endospores. Propidium monoazide (PMA) has received a great deal of attention due to its ability to differentiate live, viable bacterial cells from dead ones. PMA gains access to the DNA of dead cells through compromised membranes. Once inside the cell, it intercalates and eventually covalently bonds with the double-helix structures upon photoactivation with visible light. The covalently bound DNA is significantly altered, and unavailable to downstream molecular-based manipulations and analyses. Microbiological samples can be treated with appropriate concentrations of PMA and exposed to visible light prior to undergoing total genomic DNA extraction, resulting in an extract comprised solely of DNA arising from viable cells. This ability to extract DNA selectively from living cells is extremely powerful, and bears great relevance to many microbiological arenas.

  18. Attachment systems for mandibular implant overdentures: a systematic review

    Science.gov (United States)

    Kim, Ha-Young; Lee, Jeong-Yol; Bryant, S. Ross

    2012-01-01

    PURPOSE The aim of this systematic review was to address treatment outcome according to attachment systems for mandibular implant overdentures in terms of implant survival rate, prosthetic maintenance and complications, and patient satisfaction. MATERIALS AND METHODS A systematic literature search was conducted using PubMed and hand searching of relevant journals considering inclusion and exclusion criteria. Clinical trial studies on mandibular implant overdentures until August, 2010 were selected if more than one type of overdenture attachment was reported. Twenty four studies from 1098 studies were finally included and the data on implant survival rate, prosthetic maintenance and complications, patient satisfaction were analyzed relative to attachment systems. RESULTS Four studies presented implant survival rates (95.8 - 97.5% for bar, 96.2 - 100% for ball, 91.7% for magnet) according to attachment system. Ten other studies presented an implant survival rate ranging from 93.3% to 100% without respect to the attachment groups. Common prosthetic maintenance and complications were replacement of an assay for magnet attachments, and activation of a matrix or clip for ball or bar attachments. Prosthetic maintenance and complications most commonly occurred in the magnet groups. Conflicting findings were found on the rate of prosthetic maintenance and complications comparing ball and bar attachments. Most studies showed no significant differences in patient satisfaction depending upon attachment systems. CONCLUSION The implant survival rate of mandibular overdentures seemed to be high regardless attachment systems. The prosthetic maintenance and complications may be influenced by attachment systems. However patient satisfaction may be independent of the attachment system. PMID:23236571

  19. Lightning attachment process to common buildings

    Science.gov (United States)

    Saba, M. M. F.; Paiva, A. R.; Schumann, C.; Ferro, M. A. S.; Naccarato, K. P.; Silva, J. C. O.; Siqueira, F. V. C.; Custódio, D. M.

    2017-05-01

    The physical mechanism of lightning attachment to grounded structures is one of the most important issues in lightning physics research, and it is the basis for the design of the lightning protection systems. Most of what is known about the attachment process comes from leader propagation models that are mostly based on laboratory observations of long electrical discharges or from observations of lightning attachment to tall structures. In this paper we use high-speed videos to analyze the attachment process of downward lightning flashes to an ordinary residential building. For the first time, we present characteristics of the attachment process to common structures that are present in almost every city (in this case, two buildings under 60 m in São Paulo City, Brazil). Parameters like striking distance and connecting leaders speed, largely used in lightning attachment models and in lightning protection standards, are revealed in this work.Plain Language SummarySince the time of Benjamin Franklin, no one has ever recorded high-speed video images of a lightning connection to a common building. It is very difficult to do it. Cameras need to be very close to the structure chosen to be observed, and long observation time is required to register one lightning strike to that particular structure. Models and theories used to determine the zone of protection of a lightning rod have been developed, but they all suffer from the lack of field data. The submitted manuscript provides results from high-speed video observations of lightning attachment to low buildings that are commonly found in almost every populated area around the world. The proximity of the camera and the high frame rate allowed us to see interesting details that will improve the understanding of the attachment process and, consequently, the models and theories used by lightning protection standards. This paper also presents spectacular images and videos of lightning flashes connecting lightning rods that

  20. In vitro assessment of attachment pattern and replication efficiency of H5N1 influenza A viruses with altered receptor specificity.

    Science.gov (United States)

    Chutinimitkul, Salin; van Riel, Debby; Munster, Vincent J; van den Brand, Judith M A; Rimmelzwaan, Guus F; Kuiken, Thijs; Osterhaus, Albert D M E; Fouchier, Ron A M; de Wit, Emmie

    2010-07-01

    The continuous circulation of the highly pathogenic avian influenza (HPAI) H5N1 virus has been a cause of great concern. The possibility of this virus acquiring specificity for the human influenza A virus receptor, alpha2,6-linked sialic acids (SA), and being able to transmit efficiently among humans is a constant threat to human health. Different studies have described amino acid substitutions in hemagglutinin (HA) of clinical HPAI H5N1 isolates or that were introduced experimentally that resulted in an increased, but not exclusive, binding of these virus strains to alpha2,6-linked SA. We introduced all previously described amino acid substitutions and combinations thereof into a single genetic background, influenza virus A/Indonesia/5/05 HA, and tested the receptor specificity of these 27 mutant viruses. The attachment pattern to ferret and human tissues of the upper and lower respiratory tract of viruses with alpha2,6-linked SA receptor preference was then determined and compared to the attachment pattern of a human influenza A virus (H3N2). At least three mutant viruses showed an attachment pattern to the human respiratory tract similar to that of the human H3N2 virus. Next, the replication efficiencies of these mutant viruses and the effects of three different neuraminidases on virus replication were determined. These data show that influenza virus A/Indonesia/5/05 potentially requires only a single amino acid substitution to acquire human receptor specificity, while at the same time remaining replication competent, thus suggesting that the pandemic threat posed by HPAI H5N1 is far from diminished.

  1. In Vitro Assessment of Attachment Pattern and Replication Efficiency of H5N1 Influenza A Viruses with Altered Receptor Specificity▿

    Science.gov (United States)

    Chutinimitkul, Salin; van Riel, Debby; Munster, Vincent J.; van den Brand, Judith M. A.; Rimmelzwaan, Guus F.; Kuiken, Thijs; Osterhaus, Albert D. M. E.; Fouchier, Ron A. M.; de Wit, Emmie

    2010-01-01

    The continuous circulation of the highly pathogenic avian influenza (HPAI) H5N1 virus has been a cause of great concern. The possibility of this virus acquiring specificity for the human influenza A virus receptor, α2,6-linked sialic acids (SA), and being able to transmit efficiently among humans is a constant threat to human health. Different studies have described amino acid substitutions in hemagglutinin (HA) of clinical HPAI H5N1 isolates or that were introduced experimentally that resulted in an increased, but not exclusive, binding of these virus strains to α2,6-linked SA. We introduced all previously described amino acid substitutions and combinations thereof into a single genetic background, influenza virus A/Indonesia/5/05 HA, and tested the receptor specificity of these 27 mutant viruses. The attachment pattern to ferret and human tissues of the upper and lower respiratory tract of viruses with α2,6-linked SA receptor preference was then determined and compared to the attachment pattern of a human influenza A virus (H3N2). At least three mutant viruses showed an attachment pattern to the human respiratory tract similar to that of the human H3N2 virus. Next, the replication efficiencies of these mutant viruses and the effects of three different neuraminidases on virus replication were determined. These data show that influenza virus A/Indonesia/5/05 potentially requires only a single amino acid substitution to acquire human receptor specificity, while at the same time remaining replication competent, thus suggesting that the pandemic threat posed by HPAI H5N1 is far from diminished. PMID:20392847

  2. Strategies for managing rival bacterial communities: Lessons from burying beetles.

    Science.gov (United States)

    Duarte, Ana; Welch, Martin; Swannack, Chris; Wagner, Josef; Kilner, Rebecca M

    2018-03-01

    the production of antimicrobials themselves. Whether these alterations to the bacterial community are adaptive from the beetle's perspective, or are simply a by-product of the way in which the beetles prepare the carcass for reproduction, remains to be determined in future work. In general, our work suggests that animals might use more sophisticated techniques for attacking and disrupting rival microbial communities than is currently appreciated. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  3. Shadows Alter Facial Expressions of Noh Masks

    Science.gov (United States)

    Kawai, Nobuyuki; Miyata, Hiromitsu; Nishimura, Ritsuko; Okanoya, Kazuo

    2013-01-01

    Background A Noh mask, worn by expert actors during performance on the Japanese traditional Noh drama, conveys various emotional expressions despite its fixed physical properties. How does the mask change its expressions? Shadows change subtly during the actual Noh drama, which plays a key role in creating elusive artistic enchantment. We here describe evidence from two experiments regarding how attached shadows of the Noh masks influence the observers’ recognition of the emotional expressions. Methodology/Principal Findings In Experiment 1, neutral-faced Noh masks having the attached shadows of the happy/sad masks were recognized as bearing happy/sad expressions, respectively. This was true for all four types of masks each of which represented a character differing in sex and age, even though the original characteristics of the masks also greatly influenced the evaluation of emotions. Experiment 2 further revealed that frontal Noh mask images having shadows of upward/downward tilted masks were evaluated as sad/happy, respectively. This was consistent with outcomes from preceding studies using actually tilted Noh mask images. Conclusions/Significance Results from the two experiments concur that purely manipulating attached shadows of the different types of Noh masks significantly alters the emotion recognition. These findings go in line with the mysterious facial expressions observed in Western paintings, such as the elusive qualities of Mona Lisa’s smile. They also agree with the aesthetic principle of Japanese traditional art “yugen (profound grace and subtlety)”, which highly appreciates subtle emotional expressions in the darkness. PMID:23940748

  4. Attachment Narratives in Refugee Children

    DEFF Research Database (Denmark)

    De Haene, L.; Dalgård, Nina Thorup; Montgomery, E.

    2013-01-01

    J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study.......J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study....

  5. Attachment theory and group processes: the association between attachment style and group-related representations, goals, memories, and functioning.

    Science.gov (United States)

    Rom, Eldad; Mikulincer, Mario

    2003-06-01

    Four studies examined attachment-style differences in group-related cognitions and behaviors. In Studies 1-2, participants completed scales on group-related cognitions and emotions. In Studies 3-4, participants were divided into small groups, and their performance in group tasks as well as the cohesion of their group were assessed. Both attachment anxiety and avoidance in close relationships were associated with negative group-related cognitions and emotions. Anxiety was also related to the pursuit of closeness goals and impaired instrumental performance in group tasks. Avoidance was related to the pursuit of distance goals and deficits in socioemotional and instrumental performance. Group cohesion significantly moderated the effects of attachment anxiety. The discussion emphasizes the relevance of attachment theory within group contexts.

  6. 14 CFR 33.23 - Engine mounting attachments and structure.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine mounting attachments and structure... mounting attachments and structure. (a) The maximum allowable limit and ultimate loads for engine mounting attachments and related engine structure must be specified. (b) The engine mounting attachments and related...

  7. Japanese children's family drawings and their link to attachment.

    Science.gov (United States)

    Behrens, Kazuko Y; Kaplan, Nancy

    2011-09-01

    This study explored the applicability of family drawings as a tool to estimate attachment security in a sample of Japanese six-year-olds (N = 47), applying Kaplan and Main's ( 1986 ) Family Drawing system. Maternal secure/insecure attachment status judged by the Adult Attachment Interview predicted family drawings' secure/insecure distinction produced by Japanese six-year-olds. However, insecure Japanese drawings took forms not seen in the original Berkeley drawings, such as a lineup of faces alone. Further examination of the Japanese children's drawings using global rating scales (Fury, Carlson, & Sroufe, 1997 ) yielded significant gender differences, rarely reported in the attachment literature, with girls scoring higher in scales that predict attachment security and boys scoring higher in scales that predict attachment insecurity. However, attachment security, as captured in the drawings, was not related to attachment security, observed behaviorally using Main and Cassidy's ( 1988 ) sixth-year reunion system. Implications of the findings are discussed in light of measurements, gender, and culture.

  8. Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: impacts on immunity and metabolism.

    Science.gov (United States)

    Dong, Guozhong; Liu, Shimin; Wu, Yongxia; Lei, Chunlong; Zhou, Jun; Zhang, Sen

    2011-08-09

    Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA), occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS) is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA), haptoglobin (Hp), LPS binding protein (LBP), and C-reactive protein (CRP) in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydroxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn) are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP) are associated with declines in milk fat content

  9. Diet-induced bacterial immunogens in the gastrointestinal tract of dairy cows: Impacts on immunity and metabolism

    Directory of Open Access Journals (Sweden)

    Zhou Jun

    2011-08-01

    Full Text Available Abstract Dairy cows are often fed high grain diets to meet the energy demand for high milk production or simply due to a lack of forages at times. As a result, ruminal acidosis, especially subacute ruminal acidosis (SARA, occurs frequently in practical dairy production. When SARA occurs, bacterial endotoxin (or lipopolysaccharide, LPS is released in the rumen and the large intestine in a large amount. Many other bacterial immunogens may also be released in the digestive tract following feeding dairy cows diets containing high proportions of grain. LPS can be translocated into the bloodstream across the epithelium of the digestive tract, especially the lower tract, due to possible alterations of permeability and injuries of the epithelial tissue. As a result, the concentration of blood LPS increases. Immune responses are subsequently caused by circulating LPS, and the systemic effects include increases in concentrations of neutrophils and the acute phase proteins such as serum amyloid-A (SAA, haptoglobin (Hp, LPS binding protein (LBP, and C-reactive protein (CRP in blood. Entry of LPS into blood can also result in metabolic alterations. Blood glucose and nonesterified fatty acid concentrations are enhanced accompanying an increase of blood LPS after increasing the amount of grain in the diet, which adversely affects feed intake of dairy cows. As the proportions of grain in the diet increase, patterns of plasma β-hydoxybutyric acid, cholesterol, and minerals (Ca, Fe, and Zn are also perturbed. The bacterial immunogens can also lead to reduced supply of nutrients for synthesis of milk components and depressed functions of the epithelial cells in the mammary gland. The immune responses and metabolic alterations caused by circulating bacterial immunogens will exert an effect on milk production. It has been demonstrated that increases in concentrations of ruminal LPS and plasma acute phase proteins (CRP, SAA, and LBP are associated with declines in

  10. Dissociation of Tissue Destruction and Bacterial Expansion during Bubonic Plague.

    Directory of Open Access Journals (Sweden)

    Françoise Guinet

    2015-10-01

    Full Text Available Activation and/or recruitment of the host plasmin, a fibrinolytic enzyme also active on extracellular matrix components, is a common invasive strategy of bacterial pathogens. Yersinia pestis, the bubonic plague agent, expresses the multifunctional surface protease Pla, which activates plasmin and inactivates fibrinolysis inhibitors. Pla is encoded by the pPla plasmid. Following intradermal inoculation, Y. pestis has the capacity to multiply in and cause destruction of the lymph node (LN draining the entry site. The closely related, pPla-negative, Y. pseudotuberculosis species lacks this capacity. We hypothesized that tissue damage and bacterial multiplication occurring in the LN during bubonic plague were linked and both driven by pPla. Using a set of pPla-positive and pPla-negative Y. pestis and Y. pseudotuberculosis strains in a mouse model of intradermal injection, we found that pPla is not required for bacterial translocation to the LN. We also observed that a pPla-cured Y. pestis caused the same extensive histological lesions as the wild type strain. Furthermore, the Y. pseudotuberculosis histological pattern, characterized by infectious foci limited by inflammatory cell infiltrates with normal tissue density and follicular organization, was unchanged after introduction of pPla. However, the presence of pPla enabled Y. pseudotuberculosis to increase its bacterial load up to that of Y. pestis. Similarly, lack of pPla strongly reduced Y. pestis titers in LNs of infected mice. This pPla-mediated enhancing effect on bacterial load was directly dependent on the proteolytic activity of Pla. Immunohistochemistry of Pla-negative Y. pestis-infected LNs revealed extensive bacterial lysis, unlike the numerous, apparently intact, microorganisms seen in wild type Y. pestis-infected preparations. Therefore, our study demonstrates that tissue destruction and bacterial survival/multiplication are dissociated in the bubo and that the primary action of Pla

  11. Phytoplankton-bacterial interactions mediate micronutrient colimitation at the coastal Antarctic sea ice edge.

    Science.gov (United States)

    Bertrand, Erin M; McCrow, John P; Moustafa, Ahmed; Zheng, Hong; McQuaid, Jeffrey B; Delmont, Tom O; Post, Anton F; Sipler, Rachel E; Spackeen, Jenna L; Xu, Kai; Bronk, Deborah A; Hutchins, David A; Allen, Andrew E

    2015-08-11

    Southern Ocean primary productivity plays a key role in global ocean biogeochemistry and climate. At the Southern Ocean sea ice edge in coastal McMurdo Sound, we observed simultaneous cobalamin and iron limitation of surface water phytoplankton communities in late Austral summer. Cobalamin is produced only by bacteria and archaea, suggesting phytoplankton-bacterial interactions must play a role in this limitation. To characterize these interactions and investigate the molecular basis of multiple nutrient limitation, we examined transitions in global gene expression over short time scales, induced by shifts in micronutrient availability. Diatoms, the dominant primary producers, exhibited transcriptional patterns indicative of co-occurring iron and cobalamin deprivation. The major contributor to cobalamin biosynthesis gene expression was a gammaproteobacterial population, Oceanospirillaceae ASP10-02a. This group also contributed significantly to metagenomic cobalamin biosynthesis gene abundance throughout Southern Ocean surface waters. Oceanospirillaceae ASP10-02a displayed elevated expression of organic matter acquisition and cell surface attachment-related genes, consistent with a mutualistic relationship in which they are dependent on phytoplankton growth to fuel cobalamin production. Separate bacterial groups, including Methylophaga, appeared to rely on phytoplankton for carbon and energy sources, but displayed gene expression patterns consistent with iron and cobalamin deprivation. This suggests they also compete with phytoplankton and are important cobalamin consumers. Expression patterns of siderophore- related genes offer evidence for bacterial influences on iron availability as well. The nature and degree of this episodic colimitation appear to be mediated by a series of phytoplankton-bacterial interactions in both positive and negative feedback loops.

  12. Macrolide antibiotic interaction and resistance on the bacterial ribosome.

    Science.gov (United States)

    Poehlsgaard, Jacob; Douthwaite, Stephen

    2003-02-01

    Our understanding of the fine structure of many antibiotic target sites has reached a new level of enlightenment in the last couple of years due to the advent, by X-ray crystallography, of high-resolution structures of the bacterial ribosome. Many classes of clinically useful antibiotics bind to the ribosome to inhibit bacterial protein synthesis. Macrolide, lincosamide and streptogramin B (MLSB) antibiotics form one of the largest groups, and bind to the same site on the 50S ribosomal subunit. Here, we review the molecular details of the ribosomal MLSB site to put into perspective the main points from a wealth of biochemical and genetic data that have been collected over several decades. The information is now available to understand, at atomic resolution, how macrolide antibiotics interact with their ribosomal target, how the target is altered to confer resistance, and in which directions we need to look if we are to rationally design better drugs to overcome the extant resistance mechanisms.

  13. Epistemological Development and Attachment in European College Students

    Science.gov (United States)

    Faria, Carla; Soares, Isabel; Silva, Carolina; Bastos, Alice

    2015-01-01

    Epistemological development and attachment theory have been independent frameworks for understanding psychological development. This study examined the association between epistemological development (using the Measure of Epistemological Reflection) and attachment (using the Adult Attachment Interview) in a sample of 60 pre- and postgraduated…

  14. The association between state attachment security and state Mindfulness.

    Directory of Open Access Journals (Sweden)

    Christopher A Pepping

    Full Text Available Recent research suggests that attachment and mindfulness are related, though the nature of this association is unclear. Here we present two studies examining whether there is a causal relationship between state attachment and state mindfulness. Study 1 investigated the effects of experimentally increasing state mindfulness on state attachment security. State mindfulness was successfully enhanced, but this led to no change in state attachment security. Study 2 investigated the effects of experimentally enhancing state attachment security on state mindfulness. State attachment security was successfully enhanced, but this did not lead to any change in state mindfulness. These findings suggest that there is not a direct, immediate causal relationship between state attachment and state mindfulness as a result of brief experimental manipulations. Future research should examine these associations in longer term interventions.

  15. Attachment Style and Internet Addiction: An Online Survey.

    Science.gov (United States)

    Eichenberg, Christiane; Schott, Markus; Decker, Oliver; Sindelar, Brigitte

    2017-05-17

    One of the clinically relevant problems of Internet use is the phenomenon of Internet addiction. Considering the fact that there is ample evidence for the relationship between attachment style and substance abuse, it stands to reason that attachment theory can also make an important contribution to the understanding of the pathogenesis of Internet addiction. The aim of this study was to examine people's tendency toward pathological Internet usage in relation to their attachment style. An online survey was conducted. Sociodemographic data, attachment style (Bielefeld questionnaire partnership expectations), symptoms of Internet addiction (scale for online addiction for adults), used Web-based services, and online relationship motives (Cyber Relationship Motive Scale, CRMS-D) were assessed. In order to confirm the findings, a study using the Rorschach test was also conducted. In total, 245 subjects were recruited. Participants with insecure attachment style showed a higher tendency to pathological Internet usage compared with securely attached participants. An ambivalent attachment style was particularly associated with pathological Internet usage. Escapist and social-compensatory motives played an important role for insecurely attached subjects. However, there were no significant effects with respect to Web-based services and apps used. Results of the analysis of the Rorschach protocol with 16 subjects corroborated these results. Users with pathological Internet use frequently showed signs of infantile relationship structures in the context of social groups. This refers to the results of the Web-based survey, in which interpersonal relationships were the result of an insecure attachment style. Pathological Internet use was a function of insecure attachment and limited interpersonal relationships. ©Christiane Eichenberg, Markus Schott, Oliver Decker, Brigitte Sindelar. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 17.05.2017.

  16. An Adapted Measure of Sibling Attachment: Factor Structure and Internal Consistency of the Sibling Attachment Inventory in Youth.

    Science.gov (United States)

    Noel, Valerie A; Francis, Sarah E; Tilley, Micah A

    2018-04-01

    Parent-youth and peer relationship inventories based on attachment theory measure communication, trust, and alienation, yet sibling relationships have been overlooked. We developed the Sibling Attachment Inventory and evaluated its psychometric properties in a sample of 172 youth ages 10-14 years. We adapted the 25-item Sibling Attachment Inventory from the Inventory of Parent and Peer Attachment-Revised peer measure. Items loaded onto three factors, identified as communication, trust, and alienation, α = 0.93, 0.90, and 0.76, respectively. Sibling trust and alienation correlated with depression (r s  = -0.33, r s  = 0.48) and self-worth (r s  = 0.23; r s  = -0.32); sibling trust and alienation correlated with depression after controlling for parent trust and parent alienation (r s  = -0.23, r s  = 0.22). Preliminary analyses showed good internal consistency, construct validity, and incremental predictive validity. Following replication of these properties, this measure can facilitate large cohort assessments of sibling attachment.

  17. Internal Representational Models of Attachment Relationships.

    Science.gov (United States)

    Crittenden, Patricia M.

    This paper outlines several properties of internal representational models (IRMs) and offers terminology that may help to differentiate the models. Properties of IRMs include focus, memory systems, content, cognitive function, "metastructure," quality of attachment, behavioral strategies, and attitude toward attachment. An IRM focuses on…

  18. Interspecific Plant Interactions Reflected in Soil Bacterial Community Structure and Nitrogen Cycling in Primary Succession.

    Science.gov (United States)

    Knelman, Joseph E; Graham, Emily B; Prevéy, Janet S; Robeson, Michael S; Kelly, Patrick; Hood, Eran; Schmidt, Steve K

    2018-01-01

    Past research demonstrating the importance plant-microbe interactions as drivers of ecosystem succession has focused on how plants condition soil microbial communities, impacting subsequent plant performance and plant community assembly. These studies, however, largely treat microbial communities as a black box. In this study, we sought to examine how emblematic shifts from early successional Alnus viridus ssp. sinuata (Sitka alder) to late successional Picea sitchensis (Sitka spruce) in primary succession may be reflected in specific belowground changes in bacterial community structure and nitrogen cycling related to the interaction of these two plants. We examined early successional alder-conditioned soils in a glacial forefield to delineate how alders alter the soil microbial community with increasing dominance. Further, we assessed the impact of late-successional spruce plants on these early successional alder-conditioned microbiomes and related nitrogen cycling through a leachate addition microcosm experiment. We show how increasingly abundant alder select for particular bacterial taxa. Additionally, we found that spruce leachate significantly alters the composition of these microbial communities in large part by driving declines in taxa that are enriched by alder, including bacterial symbionts. We found these effects to be spruce specific, beyond a general leachate effect. Our work also demonstrates a unique influence of spruce on ammonium availability. Such insights bolster theory relating the importance of plant-microbe interactions with late-successional plants and interspecific plant interactions more generally.

  19. Preferential Attachment in Online Networks: Measurement and Explanations

    NARCIS (Netherlands)

    Kunegis, J; Blattner, M; Moser, C.

    2013-01-01

    We perform an empirical study of the preferential attachment phenomenon in temporal networks and show that on the Web, networks follow a nonlinear preferential attachment model in which the exponent depends on the type of network considered. The classical preferential attachment model for networks

  20. Precursors and sequelae of attachment in foster children

    NARCIS (Netherlands)

    Oosterman, M.; Schuengel, C.

    2008-01-01

    This study focused on attachment of foster children by examining factors associated with attachment relationships of children raised from birth by the same parents. The sample included 61 children between 26 to 88 months of age and their foster caregivers. Attachment security and caregiver

  1. Discrete and structurally unique proteins (tāpirins) mediate attachment of extremely thermophilic Caldicellulosiruptor species to cellulose.

    Science.gov (United States)

    Blumer-Schuette, Sara E; Alahuhta, Markus; Conway, Jonathan M; Lee, Laura L; Zurawski, Jeffrey V; Giannone, Richard J; Hettich, Robert L; Lunin, Vladimir V; Himmel, Michael E; Kelly, Robert M

    2015-04-24

    A variety of catalytic and noncatalytic protein domains are deployed by select microorganisms to deconstruct lignocellulose. These extracellular proteins are used to attach to, modify, and hydrolyze the complex polysaccharides present in plant cell walls. Cellulolytic enzymes, often containing carbohydrate-binding modules, are key to this process; however, these enzymes are not solely responsible for attachment. Few mechanisms of attachment have been discovered among bacteria that do not form large polypeptide structures, called cellulosomes, to deconstruct biomass. In this study, bioinformatics and proteomics analyses identified unique, discrete, hypothetical proteins ("tāpirins," origin from Māori: to join), not directly associated with cellulases, that mediate attachment to cellulose by species in the noncellulosomal, extremely thermophilic bacterial genus Caldicellulosiruptor. Two tāpirin genes are located directly downstream of a type IV pilus operon in strongly cellulolytic members of the genus, whereas homologs are absent from the weakly cellulolytic Caldicellulosiruptor species. Based on their amino acid sequence, tāpirins are specific to these extreme thermophiles. Tāpirins are also unusual in that they share no detectable protein domain signatures with known polysaccharide-binding proteins. Adsorption isotherm and trans vivo analyses demonstrated the carbohydrate-binding module-like affinity of the tāpirins for cellulose. Crystallization of a cellulose-binding truncation from one tāpirin indicated that these proteins form a long β-helix core with a shielded hydrophobic face. Furthermore, they are structurally unique and define a new class of polysaccharide adhesins. Strongly cellulolytic Caldicellulosiruptor species employ tāpirins to complement substrate-binding proteins from the ATP-binding cassette transporters and multidomain extracellular and S-layer-associated glycoside hydrolases to process the carbohydrate content of lignocellulose.

  2. Addressing Parent-Child Conflict: Attachment-Based Interventions with Parents

    Science.gov (United States)

    Kindsvatter, Aaron; Desmond, Kimberly J.

    2013-01-01

    This article describes the use of attachment theory to address parent-child conflict. The authors propose that parent-child conflict is attributable to the unmet attachment needs of both children and parents and that attachment insecurity results in problematic patterns of attachment in parent-child relationships. Three conversational frames are…

  3. Moxifloxacin superior to cefuroxime in reducing bacterial adhesion of Staphylococcus epidermidis on hydrophobic intraocular lenses.

    Science.gov (United States)

    Benbouzid, Fathalah; Kodjikian, Laurent; Hartmann, Daniel; Renaud, François; Baillif, Stéphanie

    2016-02-01

    To compare the anti-adhesive effect of cefuroxime and moxifloxacin on the primary attachment phase of Staphylococcus epidermidis on hydrophobic acrylic intraocular lenses (IOLs). Forty hydrophobic acrylic IOLs were used. Two groups of IOLs were soaked in a moxifloxacin (Mox-T1: 0.5 mg/0.1 ml) or a cefuroxime (Cef-T1: cefuroxime 1 mg/0.1 ml) solution before incubation in a S. epidermidis bacterial suspension. Two other groups were incubated in the bacterial suspension before antibiotics (Cef-T2 and Mox-T2) were added. The control group (Ctrl) consisted of IOLs incubated in the bacterial suspension. After incubation, IOLs were sonicated and vortexed. The resultant suspension was spread over a nutritive agar plate. Bacterial colonies were counted after 24 hr of incubation. Mean number of colony-forming units per IOL was Cef-T1: 184 × 10(3) (SE: 5.24; SD: 28.21), Cef-T2: 117 × 10(3) (SE: 5.74; SD: 30.37), Mox-T1: 1.27 × 10(3) (SE: 0.12; SD: 0.61), Mox-T2: 25 × 10(3) (SE:1.98; SD: 9.72) and Ctrl: 361 × 10(3) (SE: 26.9; SD: 107.6). The number of adhering bacteria did not vary whether cefuroxime was added before or after IOL incubation in the bacterial suspension (p = 0.132). Moxifloxacin was more effective in reducing the number of adhering bacteria when used before IOL incubation (p < 0.001). Overall for T1 and T2, moxifloxacin was more effective than cefuroxime in reducing bacterial adhesion on IOLs (p < 0.001). Moxifloxacin and cefuroxime significantly reduced S. epidermidis adhesion on hydrophobic acrylic IOLs. The anti-adhesive effect was superior with moxifloxacin. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  4. Parent-Child Attachment and Emotion Regulation

    Science.gov (United States)

    Brumariu, Laura E.

    2015-01-01

    Given the centrality of both parent-child attachment and emotion regulation in children's development and adjustment, it is important to evaluate the relations between these constructs. This article discusses conceptual and empirical links between attachment and emotion regulation in middle childhood, highlights progress and challenges in the…

  5. Attachment of Adolescents to Parents: Turkey Profile

    Directory of Open Access Journals (Sweden)

    Turkan Dogan

    2016-12-01

    Full Text Available The present study aims to determine the attachment of adolescents to their parents according to geographical regions in Turkey and gender. The research group consisted of 6061 adolescents. With an age average of 15.53 years. The Inventory of Attachment to Parents and Friends- Brief Form (EABE was used as data acquisition tool. The results of the study indicated significant difference between the scores of students regarding the inventory of attachment to parents according to regions. Evaluating the findings regarding attachment to father and mother together, the findings were similar, and the attachment levels of adolescents in Middle Anatolia, Eastern Anatolia and Black Sea Region were found to be higher than the ones in other regions. This result may be related with socioeconomic, geographical and cultural structures of the regions. Examining the finding according to gender variable, the scores of male students are significantly lower than the scores of female students. As a result according to the data gained from a wide sample group; the main factors for the attachment of adolescents to their parents in Turkey are the geographical regions in Turkey and the gender. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(4.000: 406-419

  6. In situ synthesis of silver-nanoparticles/bacterial cellulose composites for slow-released antimicrobial wound dressing.

    Science.gov (United States)

    Wu, Jian; Zheng, Yudong; Song, Wenhui; Luan, Jiabin; Wen, Xiaoxiao; Wu, Zhigu; Chen, Xiaohua; Wang, Qi; Guo, Shaolin

    2014-02-15

    Bacterial cellulose has attracted increasing attention as a novel wound dressing material, but it has no antimicrobial activity, which is one of critical skin-barrier functions in wound healing. To overcome such deficiency, we developed a novel method to synthesize and impregnate silver nanoparticles on to bacterial cellulose nanofibres (AgNP-BC). Uniform spherical silver nano-particles (10-30 nm) were generated and self-assembled on the surface of BC nano-fibers, forming a stable and evenly distributed Ag nanoparticles coated BC nanofiber. Such hybrid nanostructure prevented Ag nanoparticles from dropping off BC network and thus minimized the toxicity of nanoparticles. Regardless the slow Ag(+) release, AgNP-BC still exhibited significant antibacterial activities with more than 99% reductions in Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Moreover, AgNP-BC allowed attachment and growth of epidermal cells with no cytotoxicity emerged. The results demonstrated that AgNP-BC could reduce inflammation and promote wound healing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Effect of flow on bacterial transport and biofilm formation in saturated porous media

    Science.gov (United States)

    Rusconi, R.

    2016-12-01

    Understanding the transport of bacteria in saturated porous media is crucial for many applications ranging from the management of pumping wells subject to bio-clogging to the design of new bioremediation schemes for subsurface contamination. However, little is known about the spatial distribution of bacteria at the pore scale, particularly when small-scale heterogeneities - always present even in seemingly homogeneous aquifers - lead to preferential pathways for groundwater flow. In particular, the coupling of flow and motility has recently been shown to strongly affect bacterial transport1, and this leads us to predict that subsurface flow may strongly affect the dispersal of bacteria and the formation of biofilms in saturated aquifers. I present here microfluidic experiments combined with numerical simulations to show how the topological features of the flow correlate with bacterial concentration and promote the attachment of bacteria to specific regions of the pore network, which will ultimately influence the formations of biofilms. These results highlight the intimate link between small-scale biological processes and transport in porous media.

  8. UV radiation and organic matter composition shape bacterial functional diversity in sediments

    Directory of Open Access Journals (Sweden)

    Ellard Roy Hunting

    2013-10-01

    Full Text Available AbstractUV radiation and organic matter (OM composition are known to influence the speciescomposition of bacterioplankton communities. Potential effects of UV radiation onbacterial communities residing in sediments remain completely unexplored to date.However, it has been demonstrated that UV radiation can reach the bottom of shallowwaters and wetlands and alter the OM composition of the sediment, suggesting thatUV radiation may be more important for sediment bacteria than previously anticipated.It is hypothesized here that exposure of shallow OMcontaining sediments to UVradiation induces OMsource dependant shifts in the functional composition ofsediment bacterial communities. This study therefore investigated the combinedinfluence of both UV radiation and OM composition on bacterial functional diversity inlaboratory sediments. Two different organic matter sources, labile and recalcitrantorganic matter (OM, were used and metabolic diversity was measured with BiologGN. Radiation exerted strong negative effects on the metabolic diversity in thetreatments containing recalcitrant OM, more than in treatments containing labile OM.The functional composition of the bacterial community also differed significantlybetween the treatments. Our findings demonstrate that a combined effect of UVradiation and OM composition shapes the functional composition of microbialcommunities developing in sediments, hinting that UV radiation may act as animportant sorting mechanism for bacterial communities and driver for bacterialfunctioning in shallow lakes and wetlands.

  9. A typology of place attachment and activity involvement

    Science.gov (United States)

    Andrew J. Mowen; Alan R. Graefe; Randy J. Virden

    1998-01-01

    While previous research suggests that place attachment and activity involvement impact visitor perceptions, it has not examined the simultaneous effects of these affective constructs. This study develops a typology of both place attachment and activity involvement. It examines variations between attachment-involvement levels and visitor evaluations of quality. Results...

  10. Long-term salinity tolerance is accompanied by major restructuring of the coral bacterial microbiome.

    Science.gov (United States)

    Röthig, Till; Ochsenkühn, Michael A; Roik, Anna; van der Merwe, Riaan; Voolstra, Christian R

    2016-03-01

    Scleractinian corals are assumed to be stenohaline osmoconformers, although they are frequently subjected to variations in seawater salinity due to precipitation, freshwater run-off and other processes. Observed responses to altered salinity levels include differences in photosynthetic performance, respiration and increased bleaching and mortality of the coral host and its algal symbiont, but a study looking at bacterial community changes is lacking. Here, we exposed the coral Fungia granulosa to strongly increased salinity levels in short- and long-term experiments to disentangle temporal and compartment effects of the coral holobiont (i.e. coral host, symbiotic algae and associated bacteria). Our results show a significant reduction in calcification and photosynthesis, but a stable microbiome after short-term exposure to high-salinity levels. By comparison, long-term exposure yielded unchanged photosynthesis levels and visually healthy coral colonies indicating long-term acclimation to high-salinity levels that were accompanied by a major coral microbiome restructuring. Importantly, a bacterium in the family Rhodobacteraceae was succeeded by Pseudomonas veronii as the numerically most abundant taxon. Further, taxonomy-based functional profiling indicates a shift in the bacterial community towards increased osmolyte production, sulphur oxidation and nitrogen fixation. Our study highlights that bacterial community composition in corals can change within days to weeks under altered environmental conditions, where shifts in the microbiome may enable adjustment of the coral to a more advantageous holobiont composition. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  11. Attachment style and readiness for psychotherapy among psychiatric outpatients.

    Science.gov (United States)

    Kealy, David; Tsai, Michelle; Ogrodniczuk, John S

    2017-06-01

    Ninety-two adults attending outpatient mental health services completed measures of attachment style and readiness to engage in psychotherapy. Correlation and linear regression analyses found anxious attachment to be positively associated with treatment-seeking distress and found avoidant attachment to be negatively associated with openness to personal disclosure in the therapy relationship. Insecure attachment may influence prospective patients' readiness for psychotherapy. Patients with an avoidant attachment style may need assistance in preparing for the relational aspects of psychotherapy. © 2016 The British Psychological Society.

  12. The Development of Father-Child Attachment: Associations between Adult Attachment Representations, Recollections of Childhood Experiences and Caregiving

    Science.gov (United States)

    McFarland-Piazza, Laura; Hazen, Nancy; Jacobvitz, Deborah; Boyd-Soisson, Erin

    2012-01-01

    The association between fathers' adult attachment representations and their recollections of childhood experiences with their caregiving quality with their eight-month-old infants and with father-infant attachment classification was examined in a longitudinal study of 117 fathers and their infants. Sensitive caregiving was related to…

  13. Endometrial stromal cell attachment and matrix homeostasis in abdominal wall endometriomas.

    Science.gov (United States)

    Itoh, Hiroko; Mogami, Haruta; Bou Nemer, Laurice; Word, Larry; Rogers, David; Miller, Rodney; Word, R Ann

    2018-02-01

    How does progesterone alter matrix remodeling in abdominal wall endometriomas compared with normal endometrium? Progesterone may prevent attachment of endometrial cells to the abdominal wall, but does not ameliorate abnormal stromal cell responses of abdominal wall endometriomas. Menstruation is a tightly orchestrated physiologic event in which steroid hormones and inflammatory cells cooperatively initiate shedding of the endometrium. Abdominal wall endometriomas represent a unique form of endometriosis in which endometrial cells inoculate fascia or dermis at the time of obstetrical or gynecologic surgery. Invasion of endometrium into ectopic sites requires matrix metalloproteinases (MMPs) for tissue remodeling but endometrium is not shed externally. Observational study in 14 cases and 19 controls. Tissues and stromal cells isolated from 14 abdominal wall endometriomas were compared with 19 normal cycling endometrium using immunohistochemistry, quantitative PCR, gelatin zymography and cell attachment assays. P values cell preps to provide scientific rigor to the conclusions. The results indicate that MMP2 and MMP9 are not increased by TGFβ1 in endometrioma stromal cells. Although progesterone prevents attachment of endometrioma cells to matrix components of the abdominal wall, it does not ameliorate these abnormal stromal cell responses to TGFβ1. N/A. Endometriomas were collected from women identified pre-operatively. Not all endometriomas were collected. Stromal cells from normal endometrium were from different patients, not women undergoing endometrioma resection. This work provides insight into the mechanisms by which progesterone may prevent abdominal wall endometriomas but, once established, are refractory to progesterone treatment. Tissue acquisition was supported by NIH P01HD087150. Authors have no competing interests. © The Author(s) 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All

  14. Investigation of multimodal forward scatter phenotyping from bacterial colonies

    Science.gov (United States)

    Kim, Huisung

    the 2-D spatial density map from the ICMA. The MS-BARDOT can measure multispectral elastic-light-scatter patterns of the bacterial colony and its spectral OD to overcome the inherent limits of the single-wavelength BARDOT. A theoretical model for spectral forward scatter patterns from a bacterial colony based on elastic light scatter is presented. The spectral forward scatter patterns are computed by scalar diffraction theory, and compared with experimental results of three discrete wavelengths (405 nm, 635 nm, and 904 nm). Both model and experiment results show an excellent agreement; a longer wavelength induces a wider ring width, a wider ring gap, a smaller pattern size, and smaller numbers of rings. Further analysis using spatial fast Fourier transform (SFFT) shows a good agreement; the spatial frequencies are increasing towards the inward direction, and the slope is inversely proportional to the incoming wavelength. Four major pathogenic bacterial genera (Escherichia coli O157:H7 EDL933, Listeria monocytogenes F4244, Salmonella enterica serovar Enteritidis PT21, and Staphylococcus aureus ATCC 25923) and the seven major Escherichia coli serovar (O26, O45, O103, O111, O121, O145, and O157) with 3-4 strains each are measured and analyzed with the proposed instrument and algorithm. The MM-BARDOT can measure six different modalities: 1) light microscopy, 2) 3D morphology map from confocal microscopy, 3) 3D optical density map, 4) spectral forward scattering pattern, 5) spectral OD, 6) surface backward reflection pattern, and 7) fluorescence of a bacterial colony without moving the specimen. A custom-built confocal microscope with a controller which can be easily attached to an infinity-corrected commercial microscope is designed and built. Since the current BARDOT needs additional information from a bacterial colony to enhance the identification/classification ratio for a lower hierarchy of bacterial taxonomy such as serovar or strain level, the approach can offer a

  15. Activating attachment representations during memory retrieval modulates intrusive traumatic memories.

    Science.gov (United States)

    Bryant, Richard A; Chan, Iris

    2017-10-01

    Although priming mental representations of attachment security reduces arousal, research has not examined the effect of attachment on the retrieval of emotionally arousing memories. This study investigated the effect of priming attachment security on the retrieval of emotional memories. Seventy-five participants viewed negative and neutral images, and two days later received either an attachment prime or a control prime immediately prior to free recall of the images. Two days later, participants reported how frequently they experienced intrusions of the negative images. The attachment group had less distress, and reported fewer subsequent intrusions than the control group. Attachment style moderated these effects such that individuals with an avoidant attachment style were not impacted by the attachment prime. These findings suggest that priming attachment security decreases distress during memory reactivation, and this may reduce subsequent intrusive memories. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Quorum-sensing and cheating in bacterial biofilms

    Science.gov (United States)

    Popat, Roman; Crusz, Shanika A.; Messina, Marco; Williams, Paul; West, Stuart A.; Diggle, Stephen P.

    2012-01-01

    The idea from human societies that self-interest can lead to a breakdown of cooperation at the group level is sometimes termed the public goods dilemma. We tested this idea in the opportunistic bacterial pathogen, Pseudomonas aeruginosa, by examining the influence of putative cheats that do not cooperate via cell-to-cell signalling (quorum-sensing, QS). We found that: (i) QS cheating occurs in biofilm populations owing to exploitation of QS-regulated public goods; (ii) the thickness and density of biofilms was reduced by the presence of non-cooperative cheats; (iii) population growth was reduced by the presence of cheats, and this reduction was greater in biofilms than in planktonic populations; (iv) the susceptibility of biofilms to antibiotics was increased by the presence of cheats; and (v) coercing cooperator cells to increase their level of cooperation decreases the extent to which the presence of cheats reduces population productivity. Our results provide clear support that conflict over public goods reduces population fitness in bacterial biofilms, and that this effect is greater than in planktonic populations. Finally, we discuss the clinical implications that arise from altering the susceptibility to antibiotics. PMID:23034707

  17. Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

    Directory of Open Access Journals (Sweden)

    Geisla Mary Silva Soares

    2012-06-01

    Full Text Available Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

  18. Attachment Styles among Bullies, Victims and Uninvolved Adolescents

    Science.gov (United States)

    Koiv, Kristi

    2012-01-01

    Attachment theory provides a frame for understanding the role of attachment styles in the development of bullying behaviour in adolescence. The present study examined attachment styles (secure, avoidant and anxious/ambivalent) that differentiated bullies, victims, bully/victims and uninvolved adolescents. A total of 1,921 students (1,006 girls and…

  19. Nuclear reactor fuel rod attachment system

    International Nuclear Information System (INIS)

    Christiansen, D.W.

    1983-01-01

    The invention involves a technique to quickly, inexpensively and rigidly attach a nuclear reactor fuel rod to a support member. The invention also allows for the repeated non-destructive removal and replacement of the fuel rod. The proposed fuel rod and support member attachment and removal system consists of a locking cap fastened to the fuel rod and a locking strip fastened to the support member or vice versa. The locking cap has two or more opposing fingers shaped to form a socket. The fingers spring back when moved apart and released. The locking strip has an extension shaped to rigidly attach to the socket's body portion

  20. Romantic Attachment and Subtypes/Dimensions of Jealousy

    Science.gov (United States)

    Marazziti, Donatella; Consoli, Giorgio; Albanese, Francesco; Laquidara, Emanuela; Baroni, Stefano; Catena Dell’Osso, Mario

    2010-01-01

    The present study explored the possible relationship between romantic attachment and jealousy in 100 healthy subjects. The romantic attachment and jealousy were evaluated by means of, respectively, the “Experiences in Close Relationships” questionnaire (ECR), and the “Questionario della Gelosia” (QUEGE). The ECR anxiety scale was related to all QUEGE dimensions, while the ECR avoidance scale to three. Individuals with the preoccupied attachment style showed higher scores than secure subjects on the obsessionality, interpersonal sensitivity and fear of loss dimensions. Fearful-avoidant individuals had higher score than secure subjects on the fear of loss dimension only, while dismissing individuals had lower scores on the self-esteem dimension. These findings suggest that romantic attachment and jealousy are intertwined. PMID:20835357