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Sample records for bacterial detection system

  1. Bacterial concentration detection using a portable embedded sensor system for environmental monitoring

    OpenAIRE

    Grossi , Marco; Riccò , Bruno; Parolin , Carola; Vitali , Beatrice

    2017-01-01

    International audience; The detection of bacterial concentration is important in different fields since high microbial contamination or the presence of particular pathogens can seriously endanger human health. The reference technique to measure bacterial concentration is Standard Plate Count (SPC) that, however, has long response times (24 to 72 hours) and is not suitable for automatic implementation. This paper presents a portable embedded system for bacterial concentration measurement based...

  2. Nucleic Acid-based Detection of Bacterial Pathogens Using Integrated Microfluidic Platform Systems

    Directory of Open Access Journals (Sweden)

    Carl A. Batt

    2009-05-01

    Full Text Available The advent of nucleic acid-based pathogen detection methods offers increased sensitivity and specificity over traditional microbiological techniques, driving the development of portable, integrated biosensors. The miniaturization and automation of integrated detection systems presents a significant advantage for rapid, portable field-based testing. In this review, we highlight current developments and directions in nucleic acid-based micro total analysis systems for the detection of bacterial pathogens. Recent progress in the miniaturization of microfluidic processing steps for cell capture, DNA extraction and purification, polymerase chain reaction, and product detection are detailed. Discussions include strategies and challenges for implementation of an integrated portable platform.

  3. Microconductometric Detection of Bacterial Contamination

    Directory of Open Access Journals (Sweden)

    Sarra EL ICHI

    2014-05-01

    Full Text Available Several approaches can be used for the electrochemical detection of bacterial contamination. Their performance can be assessed by the ability to detect bacteria at very low concentrations within a short-time response. We have already demonstrated that a conductometric biosensor based on interdigitated thin-film electrodes is adapted to detect bacteria in clinical samples like serum and compatible with microfluidic fabrication. The type of interdigitated microelectrodes influences the performance of the biosensor. This was shown by the results obtained in this work. A magnetic-nanoparticles based immunosensor was designed using gold screen-printed electrodes. The immunosensor was able to specifically detect E. coli in the range of 1-103 CFU mL-1. The new transducer offered a larger active sensing surface with a lower cost and a robust material. Accuracy of the conductance value was enhanced by differential measurements. The immunosensor is compatible with a microfluidic system.

  4. System automation for a bacterial colony detection and identification instrument via forward scattering

    International Nuclear Information System (INIS)

    Bae, Euiwon; Hirleman, E Daniel; Aroonnual, Amornrat; Bhunia, Arun K; Robinson, J Paul

    2009-01-01

    A system design and automation of a microbiological instrument that locates bacterial colonies and captures the forward-scattering signatures are presented. The proposed instrument integrates three major components: a colony locator, a forward scatterometer and a motion controller. The colony locator utilizes an off-axis light source to illuminate a Petri dish and an IEEE1394 camera to capture the diffusively scattered light to provide the number of bacterial colonies and two-dimensional coordinate information of the bacterial colonies with the help of a segmentation algorithm with region-growing. Then the Petri dish is automatically aligned with the respective centroid coordinate with a trajectory optimization method, such as the Traveling Salesman Algorithm. The forward scatterometer automatically computes the scattered laser beam from a monochromatic image sensor via quadrant intensity balancing and quantitatively determines the centeredness of the forward-scattering pattern. The final scattering signatures are stored to be analyzed to provide rapid identification and classification of the bacterial samples

  5. gfp-based N-acyl homoserine-lactone sensor systems for detection of bacterial communication

    DEFF Research Database (Denmark)

    Andersen, Jens Bo; Heydorn, Arne; Hentzer, Morten

    2001-01-01

    In order to perform single-cell analysis and online studies of N-acyl homoserine lactone (AHL)-mediated communication among bacteria, components of the Vibrio fischeri quorum sensor encoded by luxR-P-luxI have been fused to modified versions of gfpmut3* genes encoding unstable green fluorescent...... proteins. Bacterial strains harboring this green fluorescent sensor detected a broad spectrum of AHL molecules and were capable of sensing the presence of 5 nM N-3-oxohexanoyl-L-homoserine lactone in the surroundings. In combination with epifluorescent microscopy, the sensitivity of the sensor enabled AHL...

  6. Molecular detection of human bacterial pathogens

    National Research Council Canada - National Science Library

    Liu, Dongyou

    2011-01-01

    .... Molecular Detection of Human Bacterial Pathogens addresses this issue, with international scientists in respective bacterial pathogen research and diagnosis providing expert summaries on current...

  7. Development of a Premature Stop Codon-detection method based on a bacterial two-hybrid system

    Directory of Open Access Journals (Sweden)

    Mayorga Luis S

    2006-09-01

    Full Text Available Abstract Background The detection of Premature Stop Codons (PSCs in human genes is very useful for the genetic diagnosis of different hereditary cancers, e.g. Familial Breast Cancer and Hereditary Non-Polyposis Colorectal Cancer (HNPCC. The products of these PSCs are truncated proteins, detectable in vitro by the Protein Truncation Test and in vivo by using the living translation machinery of yeast or bacteria. These living strategies are based on the construction of recombinant plasmids where the human sequence of interest is inserted upstream of a reporter gene. Although simple, these assays have their limitations. The yeast system requires extensive work to enhance its specificity, and the bacterial systems yield many false results due to translation re-initiation events occurring post PSCs. Our aim was to design a recombinant plasmid useful for detecting PSCs in human genes and resistant to bacterial translation re-initiation interferences. Results A functional recombinant plasmid (pREAL was designed based on a bacterial two-hybrid system. In our design, the in vivo translation of fused fragments of the Bordetella pertussis adenylate cyclase triggers the production of cAMP giving rise to a selectable bacterial phenotype. When a gene of interest is inserted between the two fragments, any PSC inhibits the enzymatic activity of the product, and translation re-initiation events post-PSC yield separated inactive fragments. We demonstrated that the system can accurately detect PSCs in human genes by inserting mutated fragments of the brca1 and msh2 gene. Western Blot assays revealed translation re-initiation events in all the tested colonies, implying that a simpler plasmid would not be resistant to this source of false negative results. The application of the system to a HNPCC family with a nonsense mutation in the msh2 gene correctly diagnosed wild type homozygous and heterozygous patients. Conclusion The developed pREAL is applicable to the

  8. Biosensors for Whole-Cell Bacterial Detection

    Science.gov (United States)

    Rushworth, Jo V.; Hirst, Natalie A.; Millner, Paul A.

    2014-01-01

    SUMMARY Bacterial pathogens are important targets for detection and identification in medicine, food safety, public health, and security. Bacterial infection is a common cause of morbidity and mortality worldwide. In spite of the availability of antibiotics, these infections are often misdiagnosed or there is an unacceptable delay in diagnosis. Current methods of bacterial detection rely upon laboratory-based techniques such as cell culture, microscopic analysis, and biochemical assays. These procedures are time-consuming and costly and require specialist equipment and trained users. Portable stand-alone biosensors can facilitate rapid detection and diagnosis at the point of care. Biosensors will be particularly useful where a clear diagnosis informs treatment, in critical illness (e.g., meningitis) or to prevent further disease spread (e.g., in case of food-borne pathogens or sexually transmitted diseases). Detection of bacteria is also becoming increasingly important in antibioterrorism measures (e.g., anthrax detection). In this review, we discuss recent progress in the use of biosensors for the detection of whole bacterial cells for sensitive and earlier identification of bacteria without the need for sample processing. There is a particular focus on electrochemical biosensors, especially impedance-based systems, as these present key advantages in terms of ease of miniaturization, lack of reagents, sensitivity, and low cost. PMID:24982325

  9. A system for the rapid detection of bacterial contamination in cell-based therapeutica

    Science.gov (United States)

    Bolwien, Carsten; Erhardt, Christian; Sulz, Gerd; Thielecke, Hagen; Johann, Robert; Pudlas, Marieke; Mertsching, Heike; Koch, Steffen

    2010-02-01

    Monitoring the sterility of cell or tissue cultures is of major concern, particularly in the fields of regenerative medicine and tissue engineering when implanting cells into the human body. Our sterility-control system is based on a Raman micro-spectrometer and is able to perform fast sterility testing on microliters of liquid samples. In conventional sterility control, samples are incubated for weeks to proliferate the contaminants to concentrations above the detection limit of conventional analysis. By contrast, our system filters particles from the liquid sample. The filter chip fabricated in microsystem technology comprises a silicon nitride membrane with millions of sub-micrometer holes to retain particles of critical sizes and is embedded in a microfluidic cell specially suited for concomitant microscopic observation. After filtration, identification is carried out on the single particle level: image processing detects possible contaminants and prepares them for Raman spectroscopic analysis. A custom-built Raman-spectrometer-attachment coupled to the commercial microscope uses 532nm or 785nm Raman excitation and records spectra up to 3400cm-1. In the final step, the recorded spectrum of a single particle is compared to an extensive library of GMP-relevant organisms, and classification is carried out based on a support vector machine.

  10. Optimizing a portable biosensor system for bacterial detection in milk based mix for ice cream

    Directory of Open Access Journals (Sweden)

    A. Biscotti

    2018-04-01

    Full Text Available One of the primary focuses of the food industry is providing products compliant with safety standards. The microbiological analysis helps in the identification of the presence of pathogen microorganisms in the food. The analysis with Agar Plate is the classic method. This approach guarantees a high accuracy, but it needs a long detection time (twenty-four to forty-eight hours, beyond high costs and skilled technician. In recent times have been proposed many different methods to have a faster response, and between them there is the impedance method. One of its features is that it is fast, in fact it requires between three to fourteen hours to obtain a reliable measurement. The system is accurate, and suitable to be executed automatically. To test this method has been used UHT Ice Cream Mix. A known volume of mix has been inoculated with increasing percentage of cultures of E. coli. The measurement of the impedance of the inoculated mix has been done by an electronic board designed for the application, and by applying a sinusoidal voltage to the test tube. The signal was digitally generated by the microprocessor, and supplied externally through a D.A. converter. The signal was then filtered to delete from its spectrum the high frequency components typical of the digitally generated signals. The data obtained from impedance instrument showed a reliable correspondence with those from the plate count. By working in less time compared to traditional methods, this tool is well suited for in-situ preliminary analysis in commercial and professional foodservice environment.

  11. Comparison of the EntericBio multiplex PCR system with routine culture for detection of bacterial enteric pathogens.

    LENUS (Irish Health Repository)

    O'Leary, James

    2009-11-01

    The EntericBio system uses a multiplex PCR assay for the simultaneous detection of Campylobacter spp., Salmonella enterica, Shigella spp., and Escherichia coli O157 from feces. It combines overnight broth enrichment with PCR amplification and detection by hybridization. An evaluation of this system was conducted by comparing the results obtained with the system with those obtained by routine culture, supplemented with alternative PCR detection methods. In a study of 773 samples, routine culture and the EntericBio system yielded 94.6 and 92.4% negative results, respectively. Forty-two samples had positive results by culture, and all of these were positive with the EntericBio system. This system detected an additional 17 positive samples (Campylobacter spp., n = 12; Shigella spp., n = 1; E. coli O157, n = 4), but the results for 5 samples (Campylobacter spp., n = 2; Shigella spp., n = 1; E. coli O157, n = 2) could not be confirmed. The target for Shigella spp. detected by the EntericBio system is the ipaH gene, and the molecular indication of the presence of Shigella spp. was investigated by sequence analysis, which confirmed that the ipaH gene was present in a Klebsiella pneumoniae isolate from the patient. The sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 99.3%, 91.5%, and 100%, respectively. Turnaround times were significantly reduced with the EntericBio system, and a result was available between 24 and 32 h after receipt of the sample in the laboratory. In addition, the amount of laboratory waste was significantly reduced by use of this system. In summary, the EntericBio system proved convenient to use, more sensitive than the conventional culture used in this study, and highly specific; and it generated results significantly faster than routine culture for the pathogens tested.

  12. Normalization of test and evaluation of biothreat detection systems: overcoming microbial air content fluctuations by using a standardized reagent bacterial mixture.

    Science.gov (United States)

    Berchebru, Laurent; Rameil, Pascal; Gaudin, Jean-Christophe; Gausson, Sabrina; Larigauderie, Guilhem; Pujol, Céline; Morel, Yannick; Ramisse, Vincent

    2014-10-01

    Test and evaluation of engineered biothreat agent detection systems ("biodetectors") are a challenging task for government agencies and industries involved in biosecurity and biodefense programs. In addition to user friendly features, biodetectors need to perform both highly sensitive and specific detection, and must not produce excessive false alerts. In fact, the atmosphere displays a number of variables such as airborne bacterial content that can interfere with the detection process, thus impeding comparative tests when carried out at different times or places. To overcome these bacterial air content fluctuations, a standardized reagent bacterial mixture (SRBM), consisting in a collection of selected cultivable environmental species that are prevalent in temperate climate bioaerosols, was designed to generate a stable, reproducible, and easy to use surrogate of bioaerosol sample. The rationale, design, and production process are reported. The results showed that 8.59; CI 95%: 8.46-8.72 log cfu distributed into vials underwent a 0.95; CI 95%: 0.65-1.26 log viability decay after dehydration and subsequent reconstitution, thus advantageously mimicking a natural bioaerosol sample which is typically composed of cultivable and uncultivable particles. Dehydrated SRBM was stable for more than 12months at 4°C and allowed the reconstitution of a dead/live cells aqueous suspension that is stable for 96h at +4°C, according to plate counts. Specific detection of a simulating biothreat agent (e.g. Bacillus atrophaeus) by immuno-magnetic or PCR assays did not display any significant loss of sensitivity, false negative or positive results in the presence of SRBM. This work provides guidance on testing and evaluating detection devices, and may contribute to the establishment of suitable standards and normalized procedures. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Molecular analysis of bacterial communities and detection of potential pathogens in a recirculating aquaculture system for Scophthalmus maximus and Solea senegalensis.

    Science.gov (United States)

    Martins, Patrícia; Cleary, Daniel F R; Pires, Ana C C; Rodrigues, Ana Maria; Quintino, Victor; Calado, Ricardo; Gomes, Newton C M

    2013-01-01

    The present study combined a DGGE and barcoded 16S rRNA pyrosequencing approach to assess bacterial composition in the water of a recirculating aquaculture system (RAS) with a shallow raceway system (SRS) for turbot (Scophthalmus maximus) and sole (Solea senegalensis). Barcoded pyrosequencing results were also used to determine the potential pathogen load in the RAS studied. Samples were collected from the water supply pipeline (Sup), fish production tanks (Pro), sedimentation filter (Sed), biofilter tank (Bio), and protein skimmer (Ozo; also used as an ozone reaction chamber) of twin RAS operating in parallel (one for each fish species). Our results revealed pronounced differences in bacterial community composition between turbot and sole RAS, suggesting that in the systems studied there is a strong species-specific effect on water bacterial communities. Proteobacteria was the most abundant phylum in the water supply and all RAS compartments. Other important taxonomic groups included the phylum Bacteriodetes. The saltwater supplied displayed a markedly lower richness and appeared to have very little influence on bacterial composition. The following potentially pathogenic species were detected: Photobacterium damselae in turbot (all compartments), Tenacibaculum discolor in turbot and sole (all compartments), Tenacibaculum soleae in turbot (all compartments) and sole (Pro, Sed and Bio), and Serratia marcescens in turbot (Sup, Sed, Bio and Ozo) and sole (only Sed) RAS. Despite the presence of these pathogens, no symptomatic fish were observed. Although we were able to identify potential pathogens, this approach should be employed with caution when monitoring aquaculture systems, as the required phylogenetic resolution for reliable identification of pathogens may not always be possible to achieve when employing 16S rRNA gene fragments.

  14. Molecular analysis of bacterial communities and detection of potential pathogens in a recirculating aquaculture system for Scophthalmus maximus and Solea senegalensis.

    Directory of Open Access Journals (Sweden)

    Patrícia Martins

    Full Text Available The present study combined a DGGE and barcoded 16S rRNA pyrosequencing approach to assess bacterial composition in the water of a recirculating aquaculture system (RAS with a shallow raceway system (SRS for turbot (Scophthalmus maximus and sole (Solea senegalensis. Barcoded pyrosequencing results were also used to determine the potential pathogen load in the RAS studied. Samples were collected from the water supply pipeline (Sup, fish production tanks (Pro, sedimentation filter (Sed, biofilter tank (Bio, and protein skimmer (Ozo; also used as an ozone reaction chamber of twin RAS operating in parallel (one for each fish species. Our results revealed pronounced differences in bacterial community composition between turbot and sole RAS, suggesting that in the systems studied there is a strong species-specific effect on water bacterial communities. Proteobacteria was the most abundant phylum in the water supply and all RAS compartments. Other important taxonomic groups included the phylum Bacteriodetes. The saltwater supplied displayed a markedly lower richness and appeared to have very little influence on bacterial composition. The following potentially pathogenic species were detected: Photobacterium damselae in turbot (all compartments, Tenacibaculum discolor in turbot and sole (all compartments, Tenacibaculum soleae in turbot (all compartments and sole (Pro, Sed and Bio, and Serratia marcescens in turbot (Sup, Sed, Bio and Ozo and sole (only Sed RAS. Despite the presence of these pathogens, no symptomatic fish were observed. Although we were able to identify potential pathogens, this approach should be employed with caution when monitoring aquaculture systems, as the required phylogenetic resolution for reliable identification of pathogens may not always be possible to achieve when employing 16S rRNA gene fragments.

  15. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    Directory of Open Access Journals (Sweden)

    Weir Jerry P

    2007-05-01

    Full Text Available Abstract Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2 BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome. Results Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage attL recombination sites to be efficiently inserted into the attR sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of EGFP into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction. Conclusion Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors.

  16. Bacteriophages for detection of bacterial pathogens

    International Nuclear Information System (INIS)

    Kutateladze, M.

    2009-01-01

    The G. Eliava Institute of Bacteriophages, Microbiology and Virology (Tbilisi, Georgia) is one of the most famous institutions focused on bacteriophage research for the elaboration of appropriate phage methodologies for human and animal protection. The main direction of the institute is the study and production of bacteriophages against intestinal disorders (dysentery, typhoid, intesti) and purulent-septic infections (staphylococcus, streptococcus, pyophage, etc.). These preparations were successfully introduced during the Soviet era, and for decades were used throughout the former Soviet Union and in other Socialist countries for the treatment, prophylaxis, and diagnosis of various infectious diseases, including those caused by antibiotic-resistant bacterial strains. Bacteriophages were widely used for identifying and detecting infections caused by the most dangerous pathogens and causative agents of epidemiological outbreaks. The specific topic of this presentation is the phage typing of bacterial species, which can be an important method for epidemiological diagnostics. Together with different genetic methodologies - such as PCR-based methods, PFGE, plasmid fingerprinting, and ribosomal typing - phage typing is one method for identifying bacterial pathogens. The method has a high percentage of determination of phage types, high specificity of reaction, and is easy for interpretation and use by health workers. Phage typing was applied for inter-species differentiation of different species of Salmonella, S. typhi, Brucella spp, Staphylococcus aureus, E. col,i Clostridium deficile, Vibrio cholerae, Yersinia pestis, Yersinia enterocolitica, Lysteria monocytogenes, Clostridium perfringens, Clostridium tetani, plant pathogens, and other bacterial pathogens. In addition to addressing the utility and efficacy of phage typing, the paper will discuss the isolation and selection of diagnostic typing phages for interspecies differentiation of pathogens that is necessary

  17. Detection of Ca2+-dependent acid phosphatase activity identifies neuronal integrity in damaged rat central nervous system after application of bacterial melanin

    Directory of Open Access Journals (Sweden)

    Tigran R Petrosyan

    2016-01-01

    Full Text Available The study aims to confirm the neuroregenerative effects of bacterial melanin (BM on central nervous system injury using a special staining method based on the detection of Ca2+-dependent acid phosphatase activity. Twenty-four rats were randomly assigned to undergo either unilateral destruction of sensorimotor cortex (group I; n = 12 or unilateral rubrospinal tract transection at the cervical level (C3–4 (group II; n = 12. In each group, six rats were randomly selected after surgery to undergo intramuscular injection of BM solution (BM subgroup and the remaining six rats were intramuscularly injected with saline (saline subgroup. Neurological testing confirmed that BM accelerated the recovery of motor function in rats from both BM and saline subgroups. Two months after surgery, Ca2+-dependent acid phosphatase activity detection in combination with Chilingarian's calcium adenoside triphosphate method revealed that BM stimulated the sprouting of fibers and dilated the capillaries in the brain and spinal cord. These results suggest that BM can promote the recovery of motor function of rats with central nervous system injury; and detection of Ca2+-dependent acid phosphatase activity is a fast and easy method used to study the regeneration-promoting effects of BM on the injured central nervous system.

  18. Bacterial contamination of platelet concentrates: pathogen detection and inactivation methods

    Directory of Open Access Journals (Sweden)

    Dana Védy

    2009-04-01

    Full Text Available Whereas the reduction of transfusion related viral transmission has been a priority during the last decade, bacterial infection transmitted by transfusion still remains associated to a high morbidity and mortality, and constitutes the most frequent infectious risk of transfusion. This problem especially concerns platelet concentrates because of their favorable bacterial growth conditions. This review gives an overview of platelet transfusion-related bacterial contamination as well as on the different strategies to reduce this problem by using either bacterial detection or inactivation methods.

  19. Sensitive Detection of Deliquescent Bacterial Capsules through Nanomechanical Analysis.

    Science.gov (United States)

    Nguyen, Song Ha; Webb, Hayden K

    2015-10-20

    Encapsulated bacteria usually exhibit strong resistance to a wide range of sterilization methods, and are often virulent. Early detection of encapsulation can be crucial in microbial pathology. This work demonstrates a fast and sensitive method for the detection of encapsulated bacterial cells. Nanoindentation force measurements were used to confirm the presence of deliquescent bacterial capsules surrounding bacterial cells. Force/distance approach curves contained characteristic linear-nonlinear-linear domains, indicating cocompression of the capsular layer and cell, indentation of the capsule, and compression of the cell alone. This is a sensitive method for the detection and verification of the encapsulation status of bacterial cells. Given that this method was successful in detecting the nanomechanical properties of two different layers of cell material, i.e. distinguishing between the capsule and the remainder of the cell, further development may potentially lead to the ability to analyze even thinner cellular layers, e.g. lipid bilayers.

  20. Particle surface area and bacterial activity in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo

    2017-01-01

    Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture...... but may provide significant surface area. Hence, the study substantiates that particles in RAS provide surface area supporting bacterial activity, and that particles play a key role in controlling the bacterial carrying capacity at least in less intensive RAS. Applying fast, culture-independent techniques......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation...

  1. Bacterial contamination of platelet components not detected by BacT/ALERT®.

    Science.gov (United States)

    Abela, M A; Fenning, S; Maguire, K A; Morris, K G

    2018-02-01

    To investigate the possible causes for false negative results in BacT/ALERT ® 3D Signature System despite bacterial contamination of platelet units. The Northern Ireland Blood Transfusion Service (NIBTS) routinely extends platelet component shelf life to 7 days. Components are sampled and screened for bacterial contamination using an automated microbial detection system, the BacT/ALERT ® 3D Signature System. We report on three platelet components with confirmed bacterial contamination, which represent false negative BacT/ALERT ® results and near-miss serious adverse events. NIBTS protocols for risk reduction of bacterial contamination of platelet components are described. The methodology for bacterial detection using BacT/ALERT ® is outlined. Laboratory tests, relevant patient details and relevant follow-up information are analysed. In all three cases, Staphylococcus aureus was isolated from the platelet residue and confirmed on terminal sub-culture using BacT/ALERT ® . In two cases, S. aureus with similar genetic makeup was isolated from the donors. Risk reduction measures for bacterial contamination of platelet components are not always effective. Automated bacterial culture detection does not eliminate the risk of bacterial contamination. Visual inspection of platelet components prior to release, issue and administration remains an important last line of defence. © 2017 British Blood Transfusion Society.

  2. Microfluidic immunomagnetic separation for enhanced bacterial detection

    DEFF Research Database (Denmark)

    Hoyland, James; Kunstmann-Olsen, Casper; Ahmed, Shakil

    A combined lab-on-a-chip approach combining immunomagnetic separation (IMS) and flow cytometry was developed for the enrichment and detection of salmonella contamination in food samples. Immunomagnetic beads were immobilized in chips consisting of long fractal meanders while contaminated samples...... to obtain maximum capturing efficiency. The effects of channel volume, path length and number of bends of microfluidic chip on IMS efficiency were also determined....

  3. Fluorescence immunoassay for detecting periodontal bacterial pathogens in plaque.

    OpenAIRE

    Wolff, L F; Anderson, L; Sandberg, G P; Aeppli, D M; Shelburne, C E

    1991-01-01

    A particle concentration fluorescence immunoassay has been modified into a bacterial concentration fluorescence immunoassay (BCFIA) to rapidly detect periodontopathic bacteria in human plaque samples. The BCFIA utilizes fluorescently tagged monoclonal antibodies (MAbs) directed against the lipopolysaccharide of selected gram-negative plaque bacteria. Microorganisms closely associated with periodontal disease that can be identified in plaque with the BCFIA include Porphyromonas gingivalis, Bac...

  4. Molecular analysis of cross-bacterial contamination detected in ...

    African Journals Online (AJOL)

    ... the isolate Delftia acidovorans BP(R2) and it is also coupled to protein with molecular weight 25-26 KDa. As well as, this bacterial contamination was the reason for the false positive results observed during the detection of HCV infections. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 5-10.

  5. Detection Antibiotic Resistance of Enviromental Bacterial Strains

    Directory of Open Access Journals (Sweden)

    Huda Zuheir Majeed

    2018-05-01

    Full Text Available      Antibiotics are randomly prescribed  for veterinary and human medication. Antibiotics by little number are used by human , animals are digested uncompletely  in their digestive system and ended up in communal sewage and hospitals, eventually discharge in environmental water sources directly with no processing.     Water itself consider as major factor of dispersal of bacteria between different environmental components. Besides, bacteria had  transferable genetic mobile elements to different sites of soil, water and humans.       Environmental swabs were collected locally including 50 swabs of hospital environment , 15 samples of poultry feces and chicken guts , 20 sample of heavy water and 15 sample of fish tank to identify16 isolate of Staphylococcus (4 isolate of Staphylococus aureus and 12 isolate of coagulase –ve Staphylococcus , 19 isolate of Enterococcus spp. , 7 isolates of Pseudomonas and 5 environment isolates for each Shigella spp.  and Salmonella spp. .           Teicoplanin and Vancomycin sensitivity test of isolates was done , showing that 2out of 16 isolates of Staphylococcus (12.5% were Vancomycin-resistant , and 3out of 19 isolates of Enterococcus (15.7 % were Vancomycin-resistant, while the rest of isolates were Vancomycin- sensitive. From other side , all isolates was Teicoplanin- sensitive except only 1 Enterococcus spp. Isolate which was intermediate . The range of the Vancomycin MIC were (6-64 µg/ml . Vancomycin resistant isolates , showed that some isolates have one plasmid band after Extraction of their DNA.

  6. Detection of Bacterial Endospores in Soil by Terbium Fluorescence

    Directory of Open Access Journals (Sweden)

    Andrea Brandes Ammann

    2011-01-01

    Full Text Available Spore formation is a survival mechanism of microorganisms when facing unfavorable environmental conditions resulting in “dormant” states. We investigated the occurrence of bacterial endospores in soils from various locations including grasslands (pasture, meadow, allotment gardens, and forests, as well as fluvial sediments. Bacterial spores are characterized by their high content of dipicolinic acid (DPA. In the presence of terbium, DPA forms a complex showing a distinctive photoluminescence spectrum. DPA was released from soil by microwaving or autoclaving. The addition of aluminium chloride reduced signal quenching by interfering compounds such as phosphate. The highest spore content (up to 109 spores per gram of dry soil was found in grassland soils. Spore content is related to soil type, to soil depth, and to soil carbon-to-nitrogen ratio. Our study might provide a basis for the detection of “hot spots” of bacterial spores in soil.

  7. Broad-Range Bacterial Capture from Fluid-Samples: Implications for Amplification-Free Contamination Detection

    Directory of Open Access Journals (Sweden)

    Monika WEBER

    2016-08-01

    Full Text Available Fluid-Screen, Inc. presents a bacterial concentration and filtration method based on dielectrophoresis and alternating current kinetics. Dielectrophoresis has been previously shown to induce particle motion; however, bacterial capture efficiency and reproducibility have consistently been low, reducing its potential for practical applications. In this study, we introduce a novel, patent-pending electrode system optimized to simultaneously capture a wide range of bacterial species from a variety of aqueous solutions. Specifically, we show that the method of dielectrophoresis used induces responses in both characteristic Gram- negative Escherichia coli and Gram-positive Enterococcus faecalis bacteria, as well as with Bacillus subtilis and Aestuariimicrobium kwangyangense. We have adapted the electrode design to create a bacterial sample preparatio unit, termed the sample sorter, that is able to capture multiple bacterial species and release them simultaneously for bacterial concentration and exchange from complex matrices to defined buffer media. This technology can be used on its own or in conjunction with standard bacterial detection methods such as mass spectroscopy. The Fluid-Screen product will dramatically improve testing and identification of bacterial contaminants in various industrial settings by eliminating the need for amplification of samples and by reducing the time to identification.

  8. Detection of antibiotic resistance in clinical bacterial strains from pets

    OpenAIRE

    Poeta, P.; Rodrigues, J.

    2008-01-01

    The identification of different bacterial strains and the occurrence of antibiotic resistance were investigated in several infection processes of pets as skin abscess with purulent discharge, bronco alveolar fluid, earwax, urine, mammary, and eye fluid. Streptococcus spp. and Staphylococcus spp. were the most detected in the different samples. A high frequency of antimicrobial resistance has been observed and this could reflect the wide use of antimicrobials in pets, making the effectiveness ...

  9. Study of bacterial meningitis in children below 5 years with comparative evaluation of gram staining, culture and bacterial antigen detection.

    Science.gov (United States)

    Yadhav Ml, Kala

    2014-04-01

    Bacterial meningitis is one of the most serious infections seen in infants and children, which is associated with acute complications and chronic morbidity. Infections of Central Nervous System (CNS) still dominate the scene of childhood neurological disorders in most of the developing tropical countries. To isolate, identify and determine the antibiotic susceptibility patterns of pathogens associated with bacterial meningitis. We also aimed to comparatively evaluate of Gram staining, culture and bacterial antigen detection in cerebrospinal fluid samples. Present comparative study included 100 CSF samples of children below the age of 5 years, who were clinically suspected meningitis cases. The samples were subjected to Gram staining, culture and Latex agglutination test (LAT). The organisms isolated in the study were characterized and antibiotic susceptibility test was done according to standard guidelines. It was done by using Gaussian test. Of the 100 cases, 24 were diagnosed as Acute bacterial meningitis (ABM) cases by. Gram staining, culture and latex agglutination test. 21 (87.5%) cases were culture positive, with 2 cases being positive for polymicrobial isolates. Gram staining was positive in 17 (70.53%) cases and LAT was positive in 18 (33.33%) cases. Streptococcus pneumoniae was the predominant organism which was isolated and it was sensitive to antibiotics. In the present study, male to female ratio was 1.27:1, which showed a male preponderance. With the combination of Gram staining, culture, and LAT, 100% sensitivity and specificity can be achieved (p Gram staining and LAT can detect 85% of cases of ABM. Bacterial meningitis is a medical emergency and making an early diagnosis and providing treatment early are life saving and they reduce chronic morbidity.

  10. 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

  11. SQL injection detection system

    OpenAIRE

    Vargonas, Vytautas

    2017-01-01

    SQL injection detection system Programmers do not always ensure security of developed systems. That is why it is important to look for solutions outside being reliant on developers. In this work SQL injection detection system is proposed. The system analyzes HTTP request parameters and detects intrusions. It is based on unsupervised machine learning. Trained by regular request data system detects outlier user parameters. Since training is not reliant on previous knowledge of SQL injections, t...

  12. Portable modular detection system

    Science.gov (United States)

    Brennan, James S [Rodeo, CA; Singh, Anup [Danville, CA; Throckmorton, Daniel J [Tracy, CA; Stamps, James F [Livermore, CA

    2009-10-13

    Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

  13. Smart phone based bacterial detection using bio functionalized fluorescent nanoparticles

    International Nuclear Information System (INIS)

    Rajendran, Vinoth Kumar; Bakthavathsalam, Padmavathy; Ali, Baquir Mohammed Jaffar

    2014-01-01

    We are describing immunochromatographic test strips with smart phone-based fluorescence readout. They are intended for use in the detection of the foodborne bacterial pathogens Salmonella spp. and Escherichia coli O157. Silica nanoparticles (SiNPs) were doped with FITC and Ru(bpy), conjugated to the respective antibodies, and then used in a conventional lateral flow immunoassay (LFIA). Fluorescence was recorded by inserting the nitrocellulose strip into a smart phone-based fluorimeter consisting of a light weight (40 g) optical module containing an LED light source, a fluorescence filter set and a lens attached to the integrated camera of the cell phone in order to acquire high-resolution fluorescence images. The images were analysed by exploiting the quick image processing application of the cell phone and enable the detection of pathogens within few minutes. This LFIA is capable of detecting pathogens in concentrations as low as 10 5 cfu mL −1 directly from test samples without pre-enrichment. The detection is one order of magnitude better compared to gold nanoparticle-based LFIAs under similar condition. The successful combination of fluorescent nanoparticle-based pathogen detection by LFIAs with a smart phone-based detection platform has resulted in a portable device with improved diagnosis features and having potential application in diagnostics and environmental monitoring. (author)

  14. The international experience of bacterial screen testing of platelet components with an automated microbial detection system: a need for consensus testing and reporting guidelines.

    Science.gov (United States)

    Benjamin, Richard J; McDonald, Carl P

    2014-04-01

    The BacT/ALERT microbial detection system (bioMerieux, Inc, Durham, NC) is in routine use in many blood centers as a prerelease test for platelet collections. Published reports document wide variation in practices and outcomes. A systematic review of the English literature was performed to describe publications assessing the use of the BacT/ALERT culture system on platelet collections as a routine screen test of more than 10000 platelet components. Sixteen publications report the use of confirmatory testing to substantiate initial positive culture results but use varying nomenclature to classify the results. Preanalytical and analytical variables that may affect the outcomes differ widely between centers. Incomplete description of protocol details complicates comparison between sites. Initial positive culture results range from 539 to 10606 per million (0.054%-1.061%) and confirmed positive from 127 to 1035 per million (0.013%-0.104%) donations. False-negative results determined by outdate culture range from 662 to 2173 per million (0.066%-0.217%) and by septic reactions from 0 to 66 per million (0%-0.007%) collections. Current culture protocols represent pragmatic compromises between optimizing analytical sensitivity and ensuring the timely availability of platelets for clinical needs. Insights into the effect of protocol variations on outcomes are generally restricted to individual sites that implement limited changes to their protocols over time. Platelet manufacturers should reassess the adequacy of their BacT/ALERT screening protocols in light of the growing international experience and provide detailed documentation of all variables that may affect culture outcomes when reporting results. We propose a framework for a standardized nomenclature for reporting of the results of BacT/ALERT screening. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Intrusion detection system elements

    International Nuclear Information System (INIS)

    Eaton, M.J.; Mangan, D.L.

    1980-09-01

    This report highlights elements required for an intrusion detection system and discusses problems which can be encountered in attempting to make the elements effective. Topics discussed include: sensors, both for exterior detection and interior detection; alarm assessment systems, with the discussion focused on video assessment; and alarm reporting systems, including alarm communication systems and dislay/console considerations. Guidance on careful planning and design of a new or to-be-improved system is presented

  16. Detection of mastitis pathogens by analysis of volatile bacterial metabolites.

    Science.gov (United States)

    Hettinga, K A; van Valenberg, H J F; Lam, T J G M; van Hooijdonk, A C M

    2008-10-01

    The ability to detect mastitis pathogens based on their volatile metabolites was studied. Milk samples from cows with clinical mastitis, caused by Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis, Streptococcus dysgalactiae, and Escherichia coli were collected. In addition, samples from cows without clinical mastitis and with low somatic cell count (SCC) were collected for comparison. All mastitis samples were examined by using classical microbiological methods, followed by headspace analysis for volatile metabolites. Milk from culture-negative samples contained a lower number and amount of volatile components compared with cows with clinical mastitis. Because of variability between samples within a group, comparisons between pathogens were not sufficient for classification of the samples by univariate statistics. Therefore, an artificial neural network was trained to classify the pathogen in the milk samples based on the bacterial metabolites. The trained network differentiated milk from uninfected and infected quarters very well. When comparing pathogens, Staph. aureus produced a very different pattern of volatile metabolites compared with the other samples. Samples with coagulase-negative staphylococci and E. coli had enough dissimilarity with the other pathogens, making it possible to separate these 2 pathogens from each other and from the other samples. The 2 streptococcus species did not show significant differences between each other but could be identified as a different group from the other pathogens. Five groups can thus be identified based on the volatile bacterial metabolites: Staph. aureus, coagulase-negative staphylococci, streptococci (Strep. uberis and Strep. dysgalactiae as one group), E. coli, and uninfected quarters.

  17. Interior intrusion detection systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.R.; Matter, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Dry, B. (BE, Inc., Barnwell, SC (United States))

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

  18. Interior intrusion detection systems

    International Nuclear Information System (INIS)

    Rodriguez, J.R.; Matter, J.C.; Dry, B.

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs

  19. Detection of Spiroplasma and Wolbachia in the bacterial gonad community of Chorthippus parallelus.

    Science.gov (United States)

    Martínez-Rodríguez, P; Hernández-Pérez, M; Bella, J L

    2013-07-01

    We have recently detected the endosymbiont Wolbachia in multiple individuals and populations of the grasshopper Chorthippus parallelus (Orthoptera: acrididae). This bacterium induces reproductive anomalies, including cytoplasmic incompatibility. Such incompatibilities may help explain the maintenance of two distinct subspecies of this grasshopper, C. parallelus parallelus and C. parallelus erythropus, which are involved in a Pyrenean hybrid zone that has been extensively studied for the past 20 years, becoming a model system for the study of genetic divergence and speciation. To evaluate whether Wolbachia is the sole bacterial infection that might induce reproductive anomalies, the gonadal bacterial community of individuals from 13 distinct populations of C. parallelus was determined by denaturing gradient gel electrophoresis analysis of bacterial 16S rRNA gene fragments and sequencing. The study revealed low bacterial diversity in the gonads: a persistent bacterial trio consistent with Spiroplasma sp. and the two previously described supergroups of Wolbachia (B and F) dominated the gonad microbiota. A further evaluation of the composition of the gonad bacterial communities was carried out by whole cell hybridization. Our results confirm previous studies of the cytological distribution of Wolbachia in C. parallelus gonads and show a homogeneous infection by Spiroplasma. Spiroplasma and Wolbachia cooccurred in some individuals, but there was no significant association of Spiroplasma with a grasshopper's sex or with Wolbachia infection, although subtle trends might be detected with a larger sample size. This information, together with previous experimental crosses of this grasshopper, suggests that Spiroplasma is unlikely to contribute to sex-specific reproductive anomalies; instead, they implicate Wolbachia as the agent of the observed anomalies in C. parallelus.

  20. An integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection

    Science.gov (United States)

    Liu, Hai-Tao; Wen, Zhi-Yu; Xu, Yi; Shang, Zheng-Guo; Peng, Jin-Lan; Tian, Peng

    2017-09-01

    In this paper, an integrated microfluidic analysis microsystems with bacterial capture enrichment and in-situ impedance detection was purposed based on microfluidic chips dielectrophoresis technique and electrochemical impedance detection principle. The microsystems include microfluidic chip, main control module, and drive and control module, and signal detection and processing modulet and result display unit. The main control module produce the work sequence of impedance detection system parts and achieve data communication functions, the drive and control circuit generate AC signal which amplitude and frequency adjustable, and it was applied on the foodborne pathogens impedance analysis microsystems to realize the capture enrichment and impedance detection. The signal detection and processing circuit translate the current signal into impendence of bacteria, and transfer to computer, the last detection result is displayed on the computer. The experiment sample was prepared by adding Escherichia coli standard sample into chicken sample solution, and the samples were tested on the dielectrophoresis chip capture enrichment and in-situ impedance detection microsystems with micro-array electrode microfluidic chips. The experiments show that the Escherichia coli detection limit of microsystems is 5 × 104 CFU/mL and the detection time is within 6 min in the optimization of voltage detection 10 V and detection frequency 500 KHz operating conditions. The integrated microfluidic analysis microsystems laid the solid foundation for rapid real-time in-situ detection of bacteria.

  1. Tape Cassette Bacteria Detection System

    Science.gov (United States)

    1973-01-01

    The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

  2. Bacterial Signaling to the Nervous System through Toxins and Metabolites.

    Science.gov (United States)

    Yang, Nicole J; Chiu, Isaac M

    2017-03-10

    Mammalian hosts interface intimately with commensal and pathogenic bacteria. It is increasingly clear that molecular interactions between the nervous system and microbes contribute to health and disease. Both commensal and pathogenic bacteria are capable of producing molecules that act on neurons and affect essential aspects of host physiology. Here we highlight several classes of physiologically important molecular interactions that occur between bacteria and the nervous system. First, clostridial neurotoxins block neurotransmission to or from neurons by targeting the SNARE complex, causing the characteristic paralyses of botulism and tetanus during bacterial infection. Second, peripheral sensory neurons-olfactory chemosensory neurons and nociceptor sensory neurons-detect bacterial toxins, formyl peptides, and lipopolysaccharides through distinct molecular mechanisms to elicit smell and pain. Bacteria also damage the central nervous system through toxins that target the brain during infection. Finally, the gut microbiota produces molecules that act on enteric neurons to influence gastrointestinal motility, and metabolites that stimulate the "gut-brain axis" to alter neural circuits, autonomic function, and higher-order brain function and behavior. Furthering the mechanistic and molecular understanding of how bacteria affect the nervous system may uncover potential strategies for modulating neural function and treating neurological diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Bacterial Gibberellins Induce Systemic Resistance of Plants

    Directory of Open Access Journals (Sweden)

    I. N. FEKLISTOVA

    2014-06-01

    Full Text Available It is generally agreed today that some rhizosphere bacteria can ensure induced systemic resistance to pathogens. In this paper we tested the ability of gibberellins produced by rhizosphere non-pathogenic bacteria Pseudomonas aurantiaca to induce systemic resistance to alternariosis agent – Alternaria brassicicola – in oilseed rape plants.Oilseed rape (Brássica nápus is one of the most promising oil-bearing croppers. It allows improving the supply of population with vegetable oil, animal and poultry industries with high quality vegetable protein. It is used for biofuel production as well.Gibberellin preparation was isolated from liquid culture of strain Pseudomonas aurantiaca grown in 250 mL of M9 medium (48 h, 28 °C under darkroom conditions. Gibberellins were extracted according procedure described by Tien et al. (1979. Gibberellins concentration in the medium was determined by fluorometric method.Elicitor activity of bacterial metabolites – gibberellins – was analyzed in model system of artificial inoculation of oilseed rape germs with phytopathogenic fungi Alternaria brassicicola. The elicitor action efficiency was evaluated on the 15th day of oilseed rape cultivation based on the percentage of leaf surface covered by necrotic lesions.Gibberellins were shown to induce systemic resistance resulted in decreasing of oil seed plants   vulnerability by 52.7%.It is known that under the unfavorable conditions plants synthesis the reactive oxygen intermediates   which activate destructive processes. One of the first organism reactions to stress action is the change of the lipid peroxidation level. It was shown that treatment of the soil with gibberellins resulted in decreasing of the lipid peroxidation level twofold.Gibberellins were shown to have a similar effect on permeability of cell membranes for free nucleotides. The permeability of cell membranes in leaves decreased 2.8-fold at room temperature. We suggest that gibberellins

  4. Bacterial Infection Potato Tuber Soft Rot Disease Detection Based on Electronic Nose

    Directory of Open Access Journals (Sweden)

    Chang Zhiyong

    2017-11-01

    Full Text Available Soft rot is a severe bacterial disease of potatoes, and soft rot infection can cause significant economic losses during the storage period of potatoes. In this study, potato soft rot was selected as the research object, and a type of potato tuber soft rot disease early detection method based on the electronic nose technology was proposed. An optimized bionic electronic nose gas chamber and a scientific and reasonable sampling device were designed to detect a change in volatile substances of the infected soft rot disease of potato tuber. The infection of soft rot disease in potato tuber samples was detected and identified by using the RBF NN algorithm and SVM algorithm. The results revealed that the proposed bionic electronic nose system can be utilized for early detection of potato tuber soft rot disease. Through comparison and analysis, the recognition rate using the SVM algorithm reached up to 89.7%, and the results were superior to the RBF NN algorithm.

  5. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  6. System Detects Vibrational Instabilities

    Science.gov (United States)

    Bozeman, Richard J., Jr.

    1990-01-01

    Sustained vibrations at two critical frequencies trigger diagnostic response or shutdown. Vibration-analyzing electronic system detects instabilities of combustion in rocket engine. Controls pulse-mode firing of engine and identifies vibrations above threshold amplitude at 5.9 and/or 12kHz. Adapted to other detection and/or control schemes involving simultaneous real-time detection of signals above or below preset amplitudes at two or more specified frequencies. Potential applications include rotating machinery and encoders and decoders in security systems.

  7. 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.

  8. π0 detection system

    International Nuclear Information System (INIS)

    Suzuki, Yoichiro

    1977-01-01

    A π-zero meson detection system used for the measurement of charge exchange reaction is described. The detection of π-zero is made by observing the coincidence events of two gamma-ray emission following the decay of π-zero meson. The angles of the emitted gamma-rays are detected with a wire spark chamber system, and the energies of the gamma-rays are measured with hodoscope type lead glass Cherenkov counters. In front of the π-zero counter system, a lead converter is set, and the incident gamma-rays convert to electron positron pairs, which can be detected with the wire spark chambers. The system is a multi-track detection system. The high voltage pulser of the wire spark chamber system is a charge line thyratron pulser, and the chamber itself is a transmission line type. Read-out can be made by a mag-line system. Wave forms and efficiencies were measured. The three-track efficiency was about 90% by the condenser method and 95% by the charge line method. (Kato, T.)

  9. Nasal chemosensory cells use bitter taste signaling to detect irritants and bacterial signals.

    Science.gov (United States)

    Tizzano, Marco; Gulbransen, Brian D; Vandenbeuch, Aurelie; Clapp, Tod R; Herman, Jake P; Sibhatu, Hiruy M; Churchill, Mair E A; Silver, Wayne L; Kinnamon, Sue C; Finger, Thomas E

    2010-02-16

    The upper respiratory tract is continually assaulted with harmful dusts and xenobiotics carried on the incoming airstream. Detection of such irritants by the trigeminal nerve evokes protective reflexes, including sneezing, apnea, and local neurogenic inflammation of the mucosa. Although free intra-epithelial nerve endings can detect certain lipophilic irritants (e.g., mints, ammonia), the epithelium also houses a population of trigeminally innervated solitary chemosensory cells (SCCs) that express T2R bitter taste receptors along with their downstream signaling components. These SCCs have been postulated to enhance the chemoresponsive capabilities of the trigeminal irritant-detection system. Here we show that transduction by the intranasal solitary chemosensory cells is necessary to evoke trigeminally mediated reflex reactions to some irritants including acyl-homoserine lactone bacterial quorum-sensing molecules, which activate the downstream signaling effectors associated with bitter taste transduction. Isolated nasal chemosensory cells respond to the classic bitter ligand denatonium as well as to the bacterial signals by increasing intracellular Ca(2+). Furthermore, these same substances evoke changes in respiration indicative of trigeminal activation. Genetic ablation of either G alpha-gustducin or TrpM5, essential elements of the T2R transduction cascade, eliminates the trigeminal response. Because acyl-homoserine lactones serve as quorum-sensing molecules for gram-negative pathogenic bacteria, detection of these substances by airway chemoreceptors offers a means by which the airway epithelium may trigger an epithelial inflammatory response before the bacteria reach population densities capable of forming destructive biofilms.

  10. Potential risk for bacterial contamination in conventional reused ventilator systems and disposable closed ventilator-suction systems.

    Science.gov (United States)

    Li, Ya-Chi; Lin, Hui-Ling; Liao, Fang-Chun; Wang, Sing-Siang; Chang, Hsiu-Chu; Hsu, Hung-Fu; Chen, Sue-Hsien; Wan, Gwo-Hwa

    2018-01-01

    Few studies have investigated the difference in bacterial contamination between conventional reused ventilator systems and disposable closed ventilator-suction systems. The aim of this study was to investigate the bacterial contamination rates of the reused and disposable ventilator systems, and the association between system disconnection and bacterial contamination of ventilator systems. The enrolled intubated and mechanically ventilated patients used a conventional reused ventilator system and a disposable closed ventilator-suction system, respectively, for a week; specimens were then collected from the ventilator circuit systems to evaluate human and environmental bacterial contamination. The sputum specimens from patients were also analyzed in this study. The detection rate of bacteria in the conventional reused ventilator system was substantially higher than that in the disposable ventilator system. The inspiratory and expiratory limbs of the disposable closed ventilator-suction system had higher bacterial concentrations than the conventional reused ventilator system. The bacterial concentration in the heated humidifier of the reused ventilator system was significantly higher than that in the disposable ventilator system. Positive associations existed among the bacterial concentrations at different locations in the reused and disposable ventilator systems, respectively. The predominant bacteria identified in the reused and disposable ventilator systems included Acinetobacter spp., Bacillus cereus, Elizabethkingia spp., Pseudomonas spp., and Stenotrophomonas (Xan) maltophilia. Both the reused and disposable ventilator systems had high bacterial contamination rates after one week of use. Disconnection of the ventilator systems should be avoided during system operation to decrease the risks of environmental pollution and human exposure, especially for the disposable ventilator system. ClinicalTrials.gov PRS / NCT03359148.

  11. Solar system fault detection

    Science.gov (United States)

    Farrington, R.B.; Pruett, J.C. Jr.

    1984-05-14

    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  12. Idaho Explosives Detection System

    International Nuclear Information System (INIS)

    Reber, Edward L.; Blackwood, Larry G.; Edwards, Andrew J.; Jewell, J. Keith; Rohde, Kenneth W.; Seabury, Edward H.; Klinger, Jeffery B.

    2005-01-01

    The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004

  13. Idaho Explosives Detection System

    Energy Technology Data Exchange (ETDEWEB)

    Reber, Edward L. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States)]. E-mail: reber@inel.gov; Blackwood, Larry G. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States); Edwards, Andrew J. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States); Jewell, J. Keith [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States); Rohde, Kenneth W. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States); Seabury, Edward H. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States); Klinger, Jeffery B. [Idaho National Laboratory, 2525 N. Freemont Ave., Idaho Falls, ID 83415-2114 (United States)

    2005-12-15

    The Idaho Explosives Detection System was developed at the Idaho National Laboratory (INL) to respond to threats imposed by delivery trucks potentially carrying explosives into military bases. A full-scale prototype system has been built and is currently undergoing testing. The system consists of two racks, one on each side of a subject vehicle. Each rack includes a neutron generator and an array of NaI detectors. The two neutron generators are pulsed and synchronized. A laptop computer controls the entire system. The control software is easily operable by minimally trained staff. The system was developed to detect explosives in a medium size truck within a 5-min measurement time. System performance was successfully demonstrated with explosives at the INL in June 2004 and at Andrews Air Force Base in July 2004.

  14. Comparison of enterovirus detection in cerebrospinal fluid with Bacterial Meningitis Score in children

    Science.gov (United States)

    Pires, Frederico Ribeiro; Franco, Andréia Christine Bonotto Farias; Gilio, Alfredo Elias; Troster, Eduardo Juan

    2017-01-01

    ABSTRACT Objective To measure the role of enterovirus detection in cerebrospinal fluid compared with the Bacterial Meningitis Score in children with meningitis. Methods A retrospective cohort based on analysis of medical records of pediatric patients diagnosed as meningitis, seen at a private and tertiary hospital in São Paulo, Brazil, between 2011 and 2014. Excluded were patients with critical illness, purpura, ventricular shunt or recent neurosurgery, immunosuppression, concomitant bacterial infection requiring parenteral antibiotic therapy, and those who received antibiotics 72 hours before lumbar puncture. Results The study included 503 patients. Sixty-four patients were excluded and 94 were not submitted to all tests for analysis. Of the remaining 345 patients, 7 were in the Bacterial Meningitis Group and 338 in the Aseptic Meningitis Group. There was no statistical difference between the groups. In the Bacterial Meningitis Score analysis, of the 338 patients with possible aseptic meningitis (negative cultures), 121 of them had one or more points in the Bacterial Meningitis Score, with sensitivity of 100%, specificity of 64.2%, and negative predictive value of 100%. Of the 121 patients with positive Bacterial Meningitis Score, 71% (86 patients) had a positive enterovirus detection in cerebrospinal fluid. Conclusion Enterovirus detection in cerebrospinal fluid was effective to differentiate bacterial from viral meningitis. When the test was analyzed together with the Bacterial Meningitis Score, specificity was higher when compared to Bacterial Meningitis Score alone. PMID:28767914

  15. Procedures involving lipid media for detection of bacterial contamination in breweries.

    Science.gov (United States)

    Van Vuuren, H J; Louw, H A; Loos, M A; Meisel, R

    1977-02-01

    The liquid equivalent of universal beer agar, designated universal beer liquid medium, and its beer-free equivalent, universal liquid medium (UL), were equally effective in demonstrating bacterial contamination in 120 of 200 samples from different stages of commercial brewing process. Growth of the contaminants after 3 days was consistently more luxuriant in the UL medium. A yeast-water substrate medium failed to reveal many contaminants detected with UL in 392 samples from three breweries and revealed only a few not detected with UL. The use of UL and a lactose-peptone medium, with microscope examination of the media for bacterial growth, permitted detection of 93% of the known contaminants compared to 87%, detected with UL alone; this combination or universal beer liquid medium plus lactose-peptone medium can therefore be recommended for the detection of bacterial contaminants in brewery samples. Bacterial contamination of pitching yeasts appeared to be a particular problem in the breweries investigated.

  16. Bacterial toxin-antitoxin systems: more than selfish entities?

    OpenAIRE

    Laurence Van Melderen; Manuel Saavedra De Bast

    2009-01-01

    Bacterial toxin?antitoxin (TA) systems are diverse and widespread in the prokaryotic kingdom. They are composed of closely linked genes encoding a stable toxin that can harm the host cell and its cognate labile antitoxin, which protects the host from the toxin's deleterious effect. TA systems are thought to invade bacterial genomes through horizontal gene transfer. Some TA systems might behave as selfish elements and favour their own maintenance at the expense of their host. As a consequence,...

  17. Proximity detection system underground

    Energy Technology Data Exchange (ETDEWEB)

    Denis Kent [Mine Site Technologies (Australia)

    2008-04-15

    Mine Site Technologies (MST) with the support ACARP and Xstrata Coal NSW, as well as assistance from Centennial Coal, has developed a Proximity Detection System to proof of concept stage as per plan. The basic aim of the project was to develop a system to reduce the risk of the people coming into contact with vehicles in an uncontrolled manner (i.e. being 'run over'). The potential to extend the developed technology into other areas, such as controls for vehicle-vehicle collisions and restricting access of vehicle or people into certain zones (e.g. non FLP vehicles into Hazardous Zones/ERZ) was also assessed. The project leveraged off MST's existing Intellectual Property and experience gained with our ImPact TRACKER tagging technology, allowing the development to be fast tracked. The basic concept developed uses active RFID Tags worn by miners underground to be detected by vehicle mounted Readers. These Readers in turn provide outputs that can be used to alert a driver (e.g. by light and/or audible alarm) that a person (Tag) approaching within their vicinity. The prototype/test kit developed proved the concept and technology, the four main components being: Active RFID Tags to send out signals for detection by vehicle mounted receivers; Receiver electronics to detect RFID Tags approaching within the vicinity of the unit to create a long range detection system (60 m to 120 m); A transmitting/exciter device to enable inner detection zone (within 5 m to 20 m); and A software/hardware device to process & log incoming Tags reads and create certain outputs. Tests undertaken in the laboratory and at a number of mine sites, confirmed the technology path taken could form the basis of a reliable Proximity Detection/Alert System.

  18. Gas detection system

    International Nuclear Information System (INIS)

    Allan, C.J.; Bayly, J.G.

    1975-01-01

    The gas detection system provides for the effective detection of gas leaks over a large area. It includes a laser which has a laser line corresponding to an absorption line of the gas to be detected. A He-Xe laser scans a number of retroreflectors which are strategically located around a D 2 O plant to detect H 2 S leaks. The reflected beam is focused by a telescope, filtered, and passed into an infrared detector. The laser may be made to emit two frequencies, one of which corresponds with an H 2 S absorption line; or it may be modulated on and off the H 2 S absorption line. The relative amplitude of the absorbed light will be a measure of the H 2 S present

  19. Hybrid Bacterial Foraging and Particle Swarm Optimization for detecting Bundle Branch Block.

    Science.gov (United States)

    Kora, Padmavathi; Kalva, Sri Ramakrishna

    2015-01-01

    Abnormal cardiac beat identification is a key process in the detection of heart diseases. Our present study describes a procedure for the detection of left and right bundle branch block (LBBB and RBBB) Electrocardiogram (ECG) patterns. The electrical impulses that control the cardiac beat face difficulty in moving inside the heart. This problem is termed as bundle branch block (BBB). BBB makes it harder for the heart to pump blood effectively through the heart circulatory system. ECG feature extraction is a key process in detecting heart ailments. Our present study comes up with a hybrid method combining two heuristic optimization methods: Bacterial Forging Optimization (BFO) and Particle Swarm Optimization (PSO) for the feature selection of ECG signals. One of the major controlling forces of BFO algorithm is the chemotactic movement of a bacterium that models a test solution. The chemotaxis process of the BFO depends on random search directions which may lead to a delay in achieving the global optimum solution. The hybrid technique: Bacterial Forging-Particle Swarm Optimization (BFPSO) incorporates the concepts from BFO and PSO and it creates individuals in a new generation. This BFPSO method performs local search through the chemotactic movement of BFO and the global search over the entire search domain is accomplished by a PSO operator. The BFPSO feature values are given as the input for the Levenberg-Marquardt Neural Network classifier.

  20. Bacterial community changes in an industrial algae production system.

    Science.gov (United States)

    Fulbright, Scott P; Robbins-Pianka, Adam; Berg-Lyons, Donna; Knight, Rob; Reardon, Kenneth F; Chisholm, Stephen T

    2018-04-01

    While microalgae are a promising feedstock for production of fuels and other chemicals, a challenge for the algal bioproducts industry is obtaining consistent, robust algae growth. Algal cultures include complex bacterial communities and can be difficult to manage because specific bacteria can promote or reduce algae growth. To overcome bacterial contamination, algae growers may use closed photobioreactors designed to reduce the number of contaminant organisms. Even with closed systems, bacteria are known to enter and cohabitate, but little is known about these communities. Therefore, the richness, structure, and composition of bacterial communities were characterized in closed photobioreactor cultivations of Nannochloropsis salina in F/2 medium at different scales, across nine months spanning late summer-early spring, and during a sequence of serially inoculated cultivations. Using 16S rRNA sequence data from 275 samples, bacterial communities in small, medium, and large cultures were shown to be significantly different. Larger systems contained richer bacterial communities compared to smaller systems. Relationships between bacterial communities and algae growth were complex. On one hand, blooms of a specific bacterial type were observed in three abnormal, poorly performing replicate cultivations, while on the other, notable changes in the bacterial community structures were observed in a series of serial large-scale batch cultivations that had similar growth rates. Bacteria common to the majority of samples were identified, including a single OTU within the class Saprospirae that was found in all samples. This study contributes important information for crop protection in algae systems, and demonstrates the complex ecosystems that need to be understood for consistent, successful industrial algae cultivation. This is the first study to profile bacterial communities during the scale-up process of industrial algae systems.

  1. Remote detection system

    International Nuclear Information System (INIS)

    Nixon, K.V.; France, S.W.; Garcia, C.; Hastings, R.D.

    1981-05-01

    A newly designed remote detection system has been developed at Los Alamos that allows the collection of high-resolution gamma-ray spectra and neutron data from a remote location. The system consists of the remote unit and a command unit. The remote unit collects data in a potentially hostile environment while the operator controls the unit by either radio or wire link from a safe position. Both units are battery powered and are housed in metal carrying cases

  2. Remote Voice Detection System

    National Research Council Canada - National Science Library

    Blackmon, Fletcher A

    2007-01-01

    A device and system to remotely detect vocalizations of speech. The skin located on the throat region of a speaking person or a reflective layer on the skin on the throat region vibrates in response to vocalizations of speech by the person...

  3. Detecting bacterial endophytes in tropical grasses of the Brachiaria ...

    African Journals Online (AJOL)

    Plant-growth-promoting (PGP) bacteria include a diverse group of soil bacteria thought to stimulate plant growth by various mechanisms. Brachiaria forage grasses, of African origin, are perennials that often grow under low-input conditions and are likely to harbour unique populations of PGP bacteria. Three bacterial strains ...

  4. Moving Sources Detection System

    International Nuclear Information System (INIS)

    Coulon, Romain; Kondrasovs, Vladimir; Boudergui, Karim; Normand, Stephane

    2013-06-01

    To monitor radioactivity passing through a pipe or in a given container such as a train or a truck, radiation detection systems are commonly employed. These detectors could be used in a network set along the source track to increase the overall detection efficiency. However detection methods are based on counting statistics analysis. The method usually implemented consists in trigging an alarm when an individual signal rises over a threshold initially estimated in regards to the natural background signal. The detection efficiency is then proportional to the number of detectors in use, due to the fact that each sensor is taken as a standalone sensor. A new approach is presented in this paper taking into account the temporal periodicity of the signals taken by all distributed sensors as a whole. This detection method is not based only on counting statistics but also on the temporal series analysis aspect. Therefore, a specific algorithm is then developed in our lab for this kind of applications and shows a significant improvement, especially in terms of detection efficiency and false alarms reduction. We also plan on extracting information from the source vector. This paper presents the theoretical approach and some preliminary results obtain in our laboratory. (authors)

  5. Determinants of bacterial communities in Canadian agroforestry systems.

    Science.gov (United States)

    Banerjee, Samiran; Baah-Acheamfour, Mark; Carlyle, Cameron N; Bissett, Andrew; Richardson, Alan E; Siddique, Tariq; Bork, Edward W; Chang, Scott X

    2016-06-01

    Land-use change is one of the most important factors influencing soil microbial communities, which play a pivotal role in most biogeochemical and ecological processes. Using agroforestry systems as a model, this study examined the effects of land uses and edaphic properties on bacterial communities in three agroforestry types covering a 270 km soil-climate gradient in Alberta, Canada. Our results demonstrate that land-use patterns exert stronger effects on soil bacterial communities than soil zones in these agroforestry systems. Plots with trees in agroforestry systems promoted greater bacterial abundance and to some extent species richness, which was associated with more nutrient-rich soil resources. While Acidobacteria, Actinobacteria and Alphaproteobacteria were the dominant bacterial phyla and subphyla across land uses, Arthrobacter, Acidobacteria_Gp16, Burkholderia, Rhodanobacter and Rhizobium were the keystone taxa in these agroforestry systems. Soil pH and carbon contents emerged as the major determinants of bacterial community characteristics. We found non-random co-occurrence and modular patterns of soil bacterial communities, and these patterns were controlled by edaphic factors and not their taxonomy. Overall, this study highlights the drivers and co-occurrence patterns of soil microbial communities in agroforestry systems. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. SIP threats detection system

    OpenAIRE

    Vozňák, Miroslav; Řezáč, Filip

    2010-01-01

    The paper deals with detection of threats in IP telephony, the authors developed a penetration testing system that is able to check up the level of protection from security threats in IP telephony. The SIP server is a key komponent of VoIP infrastructure and often becomes the aim of attacks and providers have to ensure the appropriate level of security. We have developed web-based penetration system which is able to check the SIP server if can face to the most common attacks.The d...

  7. Increased detection of mastitis pathogens by real-time PCR compared to bacterial culture.

    Science.gov (United States)

    Keane, O M; Budd, K E; Flynn, J; McCoy, F

    2013-09-21

    Rapid and accurate identification of mastitis pathogens is important for disease control. Bacterial culture and isolate identification is considered the gold standard in mastitis diagnosis but is time consuming and results in many culture-negative samples. Identification of mastitis pathogens by PCR has been proposed as a fast and sensitive alternative to bacterial culture. The results of bacterial culture and PCR for the identification of the aetiological agent of clinical mastitis were compared. The pathogen identified by traditional culture methods was also detected by PCR in 98 per cent of cases indicating good agreement between the positive results of bacterial culture and PCR. A mastitis pathogen could not be recovered from approximately 30 per cent of samples by bacterial culture, however, an aetiological agent was identified by PCR in 79 per cent of these samples. Therefore, a mastitis pathogen was detected in significantly more milk samples by PCR than by bacterial culture (92 per cent and 70 per cent, respectively) although the clinical relevance of PCR-positive culture-negative results remains controversial. A mixed infection of two or more mastitis pathogens was also detected more commonly by PCR. Culture-negative samples due to undetected Staphylococcus aureus infections were rare. The use of PCR technology may assist in rapid mastitis diagnosis, however, accurate interpretation of PCR results in the absence of bacterial culture remains problematic.

  8. Bacterial toxin-antitoxin systems: more than selfish entities?

    Science.gov (United States)

    Van Melderen, Laurence; Saavedra De Bast, Manuel

    2009-03-01

    Bacterial toxin-antitoxin (TA) systems are diverse and widespread in the prokaryotic kingdom. They are composed of closely linked genes encoding a stable toxin that can harm the host cell and its cognate labile antitoxin, which protects the host from the toxin's deleterious effect. TA systems are thought to invade bacterial genomes through horizontal gene transfer. Some TA systems might behave as selfish elements and favour their own maintenance at the expense of their host. As a consequence, they may contribute to the maintenance of plasmids or genomic islands, such as super-integrons, by post-segregational killing of the cell that loses these genes and so suffers the stable toxin's destructive effect. The function of the chromosomally encoded TA systems is less clear and still open to debate. This Review discusses current hypotheses regarding the biological roles of these evolutionarily successful small operons. We consider the various selective forces that could drive the maintenance of TA systems in bacterial genomes.

  9. Gas Flow Detection System

    Science.gov (United States)

    Moss, Thomas; Ihlefeld, Curtis; Slack, Barry

    2010-01-01

    This system provides a portable means to detect gas flow through a thin-walled tube without breaking into the tubing system. The flow detection system was specifically designed to detect flow through two parallel branches of a manifold with only one inlet and outlet, and is a means for verifying a space shuttle program requirement that saves time and reduces the risk of flight hardware damage compared to the current means of requirement verification. The prototype Purge Vent and Drain Window Cavity Conditioning System (PVD WCCS) Flow Detection System consists of a heater and a temperature-sensing thermistor attached to a piece of Velcro to be attached to each branch of a WCCS manifold for the duration of the requirement verification test. The heaters and thermistors are connected to a shielded cable and then to an electronics enclosure, which contains the power supplies, relays, and circuit board to provide power, signal conditioning, and control. The electronics enclosure is then connected to a commercial data acquisition box to provide analog to digital conversion as well as digital control. This data acquisition box is then connected to a commercial laptop running a custom application created using National Instruments LabVIEW. The operation of the PVD WCCS Flow Detection System consists of first attaching a heater/thermistor assembly to each of the two branches of one manifold while there is no flow through the manifold. Next, the software application running on the laptop is used to turn on the heaters and to monitor the manifold branch temperatures. When the system has reached thermal equilibrium, the software application s graphical user interface (GUI) will indicate that the branch temperatures are stable. The operator can then physically open the flow control valve to initiate the test flow of gaseous nitrogen (GN2) through the manifold. Next, the software user interface will be monitored for stable temperature indications when the system is again at

  10. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  11. Gallium-67 myocardial imaging for the detection of bacterial endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Wiseman, J.; Rouleau, J.; Rigo, P.; Strauss, H.W.; Pitt, B.

    1976-07-01

    Eleven patients with a clinical diagnosis of bacterial endocarditis underwent scintillation scanning of the precordial region 2--7 days after the intravenous administration of 3 mCi of gallium-67 citrate. Seven had positive scans, 3 of which were confirmed by postmortem imaging at autopsy. Serial images revealed the scans to be frequently negative at 48 hours and positive from 3 to 8 days following injection. Uptake was not seen in the region of the myocardium 48 hours or longer after the injection of 15 patients without endocarditis used as controls.

  12. Gallium-67 myocardial imaging for the detection of bacterial endocarditis

    International Nuclear Information System (INIS)

    Wiseman, J.; Rouleau, J.; Rigo, P.; Strauss, H.W.; Pitt, B.

    1976-01-01

    Eleven patients with a clinical diagnosis of bacterial endocarditis underwent scintillation scanning of the precordial region 2--7 days after the intravenous administration of 3 mCi of gallium-67 citrate. Seven had positive scans, 3 of which were confirmed by postmortem imaging at autopsy. Serial images revealed the scans to be frequently negative at 48 hours and positive from 3 to 8 days following injection. Uptake was not seen in the region of the myocardium 48 hours or longer after the injection of 15 patients without endocarditis used as controls

  13. Arc fault detection system

    Science.gov (United States)

    Jha, K.N.

    1999-05-18

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

  14. Arc fault detection system

    Science.gov (United States)

    Jha, Kamal N.

    1999-01-01

    An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

  15. DETECTION OF BACTERIAL SMALL TRANSCRIPTS FROM RNA-SEQ DATA: A COMPARATIVE ASSESSMENT.

    Science.gov (United States)

    Peña-Castillo, Lourdes; Grüell, Marc; Mulligan, Martin E; Lang, Andrew S

    2016-01-01

    Small non-coding RNAs (sRNAs) are regulatory RNA molecules that have been identified in a multitude of bacterial species and shown to control numerous cellular processes through various regulatory mechanisms. In the last decade, next generation RNA sequencing (RNA-seq) has been used for the genome-wide detection of bacterial sRNAs. Here we describe sRNA-Detect, a novel approach to identify expressed small transcripts from prokaryotic RNA-seq data. Using RNA-seq data from three bacterial species and two sequencing platforms, we performed a comparative assessment of five computational approaches for the detection of small transcripts. We demonstrate that sRNA-Detect improves upon current standalone computational approaches for identifying novel small transcripts in bacteria.

  16. 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

  17. Counterbalanced radiation detection system

    International Nuclear Information System (INIS)

    Platz, W.

    1987-01-01

    A counterbalanced radiation detection system is described comprising: (a) a stand; (b) a first radiation detector; (c) a first radiation detector arm means for tiltably connecting the first radiation detector with the stand; (d) a second radiation detector; (e) a second radiation detector arm means for tiltably connecting the second radiation detector with the stand, whereby the tilting angles of the radiation detector arm means define a distance between the radiation detectors; and (f) a torque transforming means connected between the first and second radiation detector arm means for transforming the torque created by one of the radiation detectors in a sense opposed to the torque created by the other radiation detector

  18. Detection of Pathogenic Biofilms with Bacterial Amyloid Targeting Fluorescent Probe, CDy11

    DEFF Research Database (Denmark)

    Kim, Jun Young; Sahu, Srikanta; Yau, Yin Hoe

    2016-01-01

    Bacterial biofilms are responsible for a wide range of persistent infections. In the clinic, diagnosis of biofilm-associated infections relies heavily on culturing methods, which fail to detect nonculturable bacteria. Identification of novel fluorescent probes for biofilm imaging will greatly...... facilitate diagnosis of pathogenic bacterial infection. Herein, we report a novel fluorescent probe, CDy11 (compound of designation yellow 11), which targets amyloid in the Pseudomonas aeruginosa biofilm matrix through a diversity oriented fluorescent library approach (DOFLA). CDy11 was further demonstrated...

  19. Radiation detection system

    International Nuclear Information System (INIS)

    Haeuszer, F.A.

    1976-01-01

    A circuit is disclosed that detects radiation transients and provides a clamping signal in response to each transient. The clamping signal is present from the time the transient rises above a given threshold level and for a known duration thereafter. The system includes radiation sensors, a blocking oscillator that generates a pulse in response to each sensor signal, and an output pulse duration control circuit. The oscillator pulses are fed simultaneously to the output pulse duration control circuit and to an OR gate, the output of which comprises the system output. The output pulse duration is controlled by the time required to magnetize a magnetic core to saturation in first one direction and then the other

  20. Detection of mastitis pathogens by analysis of volatile bacterial metabolites

    NARCIS (Netherlands)

    Hettinga, K.A.; Valenberg, van H.J.F.; Lam, T.J.G.M.; Hooijdonk, van A.C.M.

    2008-01-01

    The ability to detect mastitis pathogens based on their volatile metabolites was studied. Milk samples from cows with clinical mastitis, caused by Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis, Streptococcus dysgalactiae, and Escherichia coli were collected. In

  1. A Feasibility Study for Microwave Breast Cancer Detection Using Contrast-Agent-Loaded Bacterial Microbots

    Directory of Open Access Journals (Sweden)

    Yifan Chen

    2013-01-01

    Full Text Available We propose a new approach to microwave breast tumor sensing and diagnosis based on the use of biocompatible flagellated magnetotactic bacteria (MTB adapted to operate in human microvasculature. It has been verified experimentally by Martel et al. that externally generated magnetic gradients could be applied to guide the MTB along preplanned routes inside the human body, and a nanoload could be attached to these bacterial microbots. Motivated by these useful properties, we suggest loading a nanoscale microwave contrast agent such as carbon nanotubes (CNTs or ferroelectric nanoparticles (FNPs onto the MTB in order to modify the dielectric properties of tissues near the agent-loaded bacteria. Subsequently, we propose a novel differential microwave imaging (DMI technique to track simultaneously multiple swarms of MTB microbots injected into the breast. We also present innovative strategies to detect and localize a breast tissue malignancy and estimate its size via this DMI-trackable bacterial microrobotic system. Finally, we use an anatomically realistic numerical breast phantom as a platform to demonstrate the feasibility of this tumor diagnostic method.

  2. Ferret Workflow Anomaly Detection System

    National Research Council Canada - National Science Library

    Smith, Timothy J; Bryant, Stephany

    2005-01-01

    The Ferret workflow anomaly detection system project 2003-2004 has provided validation and anomaly detection in accredited workflows in secure knowledge management systems through the use of continuous, automated audits...

  3. Thin-layer chromatographic technique for rapid detection of bacterial phospholipases.

    Science.gov (United States)

    Legakis, N J; Papavassiliou, J

    1975-11-01

    Silica gel thin-layer chromatography was employed to detect lecithinase activity induced from bacterial resting cell preparations induced from bacterial resting cell preparations incubated at 37 C for 4 h in the presence of purified egg yolk lecithin. Bacillus subtilis, Bacillus cereus, Serratia marcescens, and Pseudomonas aeruginosa hydrolyzed lecithin with the formation of free fatty acids as the sole lipid-soluble product. In none of the Escherichia coli and Citrobacter freundii strains tested could lecithinase activity be detected. Four among eight strains of Enterobacter aerogenes and one among 12 strains of Proteus tested produced negligible amounts of free fatty acid.

  4. Comparison of Two Suspension Arrays for Simultaneous Detection of Five Biothreat Bacterial in Powder Samples

    Directory of Open Access Journals (Sweden)

    Yu Yang

    2012-01-01

    Full Text Available We have developed novel Bio-Plex assays for simultaneous detection of Bacillus anthracis, Yersinia pestis, Brucella spp., Francisella tularensis, and Burkholderia pseudomallei. Universal primers were used to amplify highly conserved region located within the 16S rRNA amplicon, followed by hybridized to pathogen-specific probes for identification of these five organisms. The other assay is based on multiplex PCR to simultaneously amplify five species-specific pathogen identification-targeted regions unique to individual pathogen. Both of the two arrays are validated to be flexible and sensitive for simultaneous detection of bioterrorism bacteria. However, universal primer PCR-based array could not identify Bacillus anthracis, Yersinia pestis, and Brucella spp. at the species level because of the high conservation of 16S rDNA of the same genus. The two suspension arrays can be utilized to detect Bacillus anthracis sterne spore and Yersinia pestis EV76 from mimic “write powder” samples, they also proved that the suspension array system will be valuable tools for diagnosis of bacterial biothreat agents in environmental samples.

  5. Bacterial levels in the Nyl River system, Limpopo province, South ...

    African Journals Online (AJOL)

    Heterotrophic plate counts, faecal coliform counts and total coliform counts indicated that the system was stressed. The Modimolle sewage treatment works and local agricultural activities were found to be the point and diffuse sources of bacterial contamination, respectively. African Journal of Aquatic Science 2010, 35(1): ...

  6. A functional gene array for detection of bacterial virulence elements

    Energy Technology Data Exchange (ETDEWEB)

    Jaing, C

    2007-11-01

    We report our development of the first of a series of microarrays designed to detect pathogens with known mechanisms of virulence and antibiotic resistance. By targeting virulence gene families as well as genes unique to specific biothreat agents, these arrays will provide important data about the pathogenic potential and drug resistance profiles of unknown organisms in environmental samples. To validate our approach, we developed a first generation array targeting genes from Escherichia coli strains K12 and CFT073, Enterococcus faecalis and Staphylococcus aureus. We determined optimal probe design parameters for microorganism detection and discrimination, measured the required target concentration, and assessed tolerance for mismatches between probe and target sequences. Mismatch tolerance is a priority for this application, due to DNA sequence variability among members of gene families. Arrays were created using the NimbleGen Maskless Array Synthesizer at Lawrence Livermore National Laboratory. Purified genomic DNA from combinations of one or more of the four target organisms, pure cultures of four related organisms, and environmental aerosol samples with spiked-in genomic DNA were hybridized to the arrays. Based on the success of this prototype, we plan to design further arrays in this series, with the goal of detecting all known virulence and antibiotic resistance gene families in a greatly expanded set of organisms.

  7. Multiplex PCR assay for simultaneous detection of six major bacterial pathogens of rice.

    Science.gov (United States)

    Cui, Z; Ojaghian, M R; Tao, Z; Kakar, K U; Zeng, J; Zhao, W; Duan, Y; Vera Cruz, C M; Li, B; Zhu, B; Xie, G

    2016-05-01

    The aim of this study was to develop a multiplex PCR (mPCR) assay for rapid, sensitive and simultaneous detection of six important rice pathogens: Xanthomonas oryzae pv. oryzae, X. oryzae pv. oryzicola, Pseudomonas fuscovaginae, Burkholderia glumae, Burkholderia gladioli and Acidovorax avenae subsp. avenae. Specific primers were designed through a bioinformatics pipeline. Sensitivity of detection was established using both traditional PCR and quantitative real-time PCR on isolated DNA and on bacterial cells both in vitro and in simulated diseased seeds and the parameters were optimized for an mPCR assay. A total of 150 bacterial strains were tested for specificity. The mPCR assay accurately predicted the presence of pathogens among 44 symptomatic and asymptomatic rice seed, sheath and leaf samples. This study confirmed that this mPCR assay is a rapid, reliable and simple tool for the simultaneous detection of six important rice bacterial pathogens. This study is the first report of a method allowing simultaneous detection of six major rice pathogens. The ability to use crude extracts from plants without bacterial isolation or DNA extraction enhances the value of this mPCR technology for rapid detection and aetiological/epidemiological studies. © 2016 The Society for Applied Microbiology.

  8. Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    In Jeong Kang

    2016-12-01

    Full Text Available Burkholderia glumae (bacterial grain rot, Xanthomonas oryzae pv. oryzae (bacterial leaf blight, and Acidovorax avenae subsp. avenae (bacterial brown stripe are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants.

  9. Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction.

    Science.gov (United States)

    Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

    2016-12-01

    Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae , and transposase A gene sequence for X. oryzae pv. oryzae , three sets of primers had been designed to produce 402 bp for B. glumae , 490 bp for X. oryzae , and 290 bp for A. avenae subsp. avenae with the 63°C as an optimum annealing temperature. Samples collected from naturally infected fields were detected with two bacteria, B. glumae and A. avenae subsp. avenae but X. oryzae pv. oryzae was not detected. This assay can be used to identify pathogens directly from infected seeds, and will be an effective tool for the identification of the three pathogens in rice plants.

  10. Introduction to detection systems

    DEFF Research Database (Denmark)

    Larsen, Jan

    Presentation of the information processing pipleline for detection including discussing of various issues and the use of mathematical modeling. A simple example of detection a signal in noise illustrated that simple modeling outperforms human visual and auditory perception. Particiants are going...... to discuss issues in detection which is followed by an auditory object recognition exercise. The results of the exercise and its relation to issues in the information processing pipleline is also discussed....

  11. Evaluation of a PCR for detection of Actinobacillus pleuropneumoniae in mixed bacterial cultures from tonsils

    DEFF Research Database (Denmark)

    Gram, T.; Ahrens, Peter; Nielsen, J.P.

    1996-01-01

    strains of A. lignieresii. The lower detection limit of the PCR test was 10(3) A. pleuropneumoniae CFU/PCR test tube and was not affected by addition of 10(6) E. coli CFU/PCR test tube. Mixed bacterial cultures from tonsils of 101 pigs from 9 different herds were tested by culture and by PCR using four...

  12. Comparison of PCR with Standard Method (MPN for detection of bacterial contamination in drinking water

    Directory of Open Access Journals (Sweden)

    Fatemeh Dehghan

    2014-11-01

    Full Text Available Background: Detection of bacterial contamination in drinking water by culture method is a time and cost consuming method and spends a few days depending on contamination degree. However, the people use the tap water during that time. Molecular methods are rapid and sensitive. In this study a rapid Multiplex PCR method was used for rapid analysis both coliform bacteria and E.coli, and probable detection of VBNC bacteria in drinking water, the experiments were performed in bacteriological lab of water and Wastewater Corporation in Markazi province. Material and Methods:Amplification of a fragment from each of lacZ and uidA genes in a Multiplex PCR was used for detection of coliforms. Eight samples was taken from Arak drinking water system including 36 samples of wells, 41 samples of water distribution network and 3 samples from water storages were examined by amplification of lacZ and uidA genes in a Multiplex PCR. Equivalently, the MPN test was applied as a standard method for all samples for comparison of results. Standard bacteria, pure bacteria isolated from positive MPN and CRM were examined by PCR and MPN method. Results: The result of most samples water network, water storages, and water well were same in both MPN and PCR method .The results of standard bacteria and pure cultures of bacteria isolated from positive MPN and CRM confirmed the PCR method. Five samples were positive in PCR but negative in MPN method. Duration time of PCR was decreased about 105 min by changing the PCR program and electrophoreses factors. Conclusion: The Multiplex PCR can detect coliform bacteria and E.coli synchronous in drinking water.

  13. Bacterial Toxin–Antitoxin Systems: More Than Selfish Entities?

    Science.gov (United States)

    Van Melderen, Laurence; Saavedra De Bast, Manuel

    2009-01-01

    Bacterial toxin–antitoxin (TA) systems are diverse and widespread in the prokaryotic kingdom. They are composed of closely linked genes encoding a stable toxin that can harm the host cell and its cognate labile antitoxin, which protects the host from the toxin's deleterious effect. TA systems are thought to invade bacterial genomes through horizontal gene transfer. Some TA systems might behave as selfish elements and favour their own maintenance at the expense of their host. As a consequence, they may contribute to the maintenance of plasmids or genomic islands, such as super-integrons, by post-segregational killing of the cell that loses these genes and so suffers the stable toxin's destructive effect. The function of the chromosomally encoded TA systems is less clear and still open to debate. This Review discusses current hypotheses regarding the biological roles of these evolutionarily successful small operons. We consider the various selective forces that could drive the maintenance of TA systems in bacterial genomes. PMID:19325885

  14. Bacterial toxin-antitoxin systems: more than selfish entities?

    Directory of Open Access Journals (Sweden)

    Laurence Van Melderen

    2009-03-01

    Full Text Available Bacterial toxin-antitoxin (TA systems are diverse and widespread in the prokaryotic kingdom. They are composed of closely linked genes encoding a stable toxin that can harm the host cell and its cognate labile antitoxin, which protects the host from the toxin's deleterious effect. TA systems are thought to invade bacterial genomes through horizontal gene transfer. Some TA systems might behave as selfish elements and favour their own maintenance at the expense of their host. As a consequence, they may contribute to the maintenance of plasmids or genomic islands, such as super-integrons, by post-segregational killing of the cell that loses these genes and so suffers the stable toxin's destructive effect. The function of the chromosomally encoded TA systems is less clear and still open to debate. This Review discusses current hypotheses regarding the biological roles of these evolutionarily successful small operons. We consider the various selective forces that could drive the maintenance of TA systems in bacterial genomes.

  15. CRISPR technologies for bacterial systems: Current achievements and future directions.

    Science.gov (United States)

    Choi, Kyeong Rok; Lee, Sang Yup

    2016-11-15

    Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now revolutionizing biotechnology as well as biology. Diverse technologies have been derived from CRISPR/Cas systems in bacteria, yet the applications unfortunately have not been actively employed in bacteria as extensively as in eukaryotic organisms. A recent trend of engineering less explored strains in industrial microbiology-metabolic engineering, synthetic biology, and other related disciplines-is demanding facile yet robust tools, and various CRISPR technologies have potential to cater to the demands. Here, we briefly review the science in CRISPR/Cas systems and the milestone inventions that enabled numerous CRISPR technologies. Next, we describe CRISPR/Cas-derived technologies for bacterial strain development, including genome editing and gene expression regulation applications. Then, other CRISPR technologies possessing great potential for industrial applications are described, including typing and tracking of bacterial strains, virome identification, vaccination of bacteria, and advanced antimicrobial approaches. For each application, we note our suggestions for additional improvements as well. In the same context, replication of CRISPR/Cas-based chromosome imaging technologies developed originally in eukaryotic systems is introduced with its potential impact on studying bacterial chromosomal dynamics. Also, the current patent status of CRISPR technologies is reviewed. Finally, we provide some insights to the future of CRISPR technologies for bacterial systems by proposing complementary techniques to be developed for the use of CRISPR technologies in even wider range of applications. Copyright © 2016. Published by Elsevier Inc.

  16. Harnessing CRISPR-Cas systems for bacterial genome editing.

    Science.gov (United States)

    Selle, Kurt; Barrangou, Rodolphe

    2015-04-01

    Manipulation of genomic sequences facilitates the identification and characterization of key genetic determinants in the investigation of biological processes. Genome editing via clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) constitutes a next-generation method for programmable and high-throughput functional genomics. CRISPR-Cas systems are readily reprogrammed to induce sequence-specific DNA breaks at target loci, resulting in fixed mutations via host-dependent DNA repair mechanisms. Although bacterial genome editing is a relatively unexplored and underrepresented application of CRISPR-Cas systems, recent studies provide valuable insights for the widespread future implementation of this technology. This review summarizes recent progress in bacterial genome editing and identifies fundamental genetic and phenotypic outcomes of CRISPR targeting in bacteria, in the context of tool development, genome homeostasis, and DNA repair. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Small intestinal bacterial overgrowth in patients with systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Saara Rawn

    2017-01-01

    Full Text Available Small intestinal bacterial overgrowth (SIBO is common in patients with systemic sclerosis (SSc yet often goes underrecognized in clinical practice. In patients with SSc, untreated SIBO may result in marked morbidity and possible mortality. The pathogenesis of SIBO is multifactorial and relates to immune dysregulation, vasculopathy, and dysmotility. This article reviews various diagnostic approaches and therapeutic options for SIBO. Treatment modalities mainly include prokinetics, probiotics, and antibiotics.

  18. Antigen detection systems

    Science.gov (United States)

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...

  19. Detection and counting systems

    International Nuclear Information System (INIS)

    Abreu, M.A.N. de

    1976-01-01

    Detection devices based on gaseous ionization are analysed, such as: electroscopes ionization chambers, proportional counters and Geiger-Mueller counters. Scintillation methods are also commented. A revision of the basic concepts in electronics is done and the main equipment for counting is detailed. In the study of gama spectrometry, scintillation and semiconductor detectors are analysed [pt

  20. Duplex recombinase polymerase amplification assays incorporating competitive internal controls for bacterial meningitis detection.

    Science.gov (United States)

    Higgins, Owen; Clancy, Eoin; Forrest, Matthew S; Piepenburg, Olaf; Cormican, Martin; Boo, Teck Wee; O'Sullivan, Nicola; McGuinness, Claire; Cafferty, Deirdre; Cunney, Robert; Smith, Terry J

    2018-04-01

    Recombinase polymerase amplification (RPA) is an isothermal nucleic acid amplification technology that provides rapid and robust infectious disease pathogen detection, ideal for point-of-care (POC) diagnostics in disease-prevalent low-resource countries. We have developed and evaluated three duplex RPA assays incorporating competitive internal controls for the detection of leading bacterial meningitis pathogens. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae singleplex RPA assays were initially developed and evaluated, demonstrating 100% specificity with limits of detection of 4.1, 8.5 and 3.9 genome copies per reaction, respectively. Each assay was further developed into internally controlled duplex RPA assays via the incorporation of internal amplification control templates. Clinical performance of each internally controlled duplex RPA assay was evaluated by testing 64 archived PCR-positive clinical samples. Compared to real-time PCR, all duplex RPA assays demonstrated 100% diagnostic specificity, with diagnostic sensitivities of 100%, 86.3% and 100% for the S. pneumoniae, N. meningitidis and H. influenzae assays, respectively. This study details the first report of internally controlled duplex RPA assays for the detection of bacterial meningitis pathogens: S. pneumoniae, N. meningitidis and H. influenzae. We have successfully demonstrated the clinical diagnostic utility of each duplex RPA assay, introducing effective diagnostic technology for POC bacterial meningitis identification in disease-prevalent developing countries. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Rapid deployment intrusion detection system

    International Nuclear Information System (INIS)

    Graham, R.H.

    1997-01-01

    A rapidly deployable security system is one that provides intrusion detection, assessment, communications, and annunciation capabilities; is easy to install and configure; can be rapidly deployed, and is reusable. A rapidly deployable intrusion detection system (RADIDS) has many potential applications within the DOE Complex: back-up protection for failed zones in a perimeter intrusion detection and assessment system, intrusion detection and assessment capabilities in temporary locations, protection of assets during Complex reconfiguration, and protection in hazardous locations, protection of assets during Complex reconfiguration, and protection in hazardous locations. Many DOE user-need documents have indicated an interest in a rapidly deployable intrusion detection system. The purpose of the RADIDS project is to design, develop, and implement such a system. 2 figs

  2. Real-time detection of antibiotic activity by measuring nanometer-scale bacterial deformation

    Science.gov (United States)

    Iriya, Rafael; Syal, Karan; Jing, Wenwen; Mo, Manni; Yu, Hui; Haydel, Shelley E.; Wang, Shaopeng; Tao, Nongjian

    2017-12-01

    Diagnosing antibiotic-resistant bacteria currently requires sensitive detection of phenotypic changes associated with antibiotic action on bacteria. Here, we present an optical imaging-based approach to quantify bacterial membrane deformation as a phenotypic feature in real-time with a nanometer scale (˜9 nm) detection limit. Using this approach, we found two types of antibiotic-induced membrane deformations in different bacterial strains: polymyxin B induced relatively uniform spatial deformation of Escherichia coli O157:H7 cells leading to change in cellular volume and ampicillin-induced localized spatial deformation leading to the formation of bulges or protrusions on uropathogenic E. coli CFT073 cells. We anticipate that the approach will contribute to understanding of antibiotic phenotypic effects on bacteria with a potential for applications in rapid antibiotic susceptibility testing.

  3. The SOS chromotest: bacterial cells to detect and characterize genotoxic products and radiations

    International Nuclear Information System (INIS)

    Quillardet, P.; Hofnung, M.

    1994-01-01

    The advanced knowledge we have on the bacterium Escherichia coli has facilitated the development of the colorimetric and fast assay, the SOS chromotest, which involves a single tester strain and gives a qualitative and a quantitative assay of the action of a genotoxic agent. We discuss a number of possibilities opened by this test in order to make a genetic diagnosis of the chemical nature of the damages caused in the genetic material by means of a battery of strains which have been genetically modified for that purpose. In order to give an idea of the accuracy of the bacterial responses and of the way they can be used to characterize the DNA damage by a genetic approach, the case of alkylating agents is described in a relatively detailed fashion, and the case of oxidative agents is rapidly mentioned. The sensitivity to ionizing radiation is such that the test is able to detect doses of the order of 1 Gy. We discuss briefly how it could be possible to increase this sensitivity by genetically inactivating repair systems which process the injuries caused by these agents, and how the use of a battery of tester strains could also give information on the nature of injuries caused by various types of ionizing radiation. (authors). 39 refs. 4 figs. 1 tab

  4. Detection of respiratory bacterial pathogens causing atypical pneumonia by multiplex Lightmix® RT-PCR.

    Science.gov (United States)

    Wagner, Karoline; Springer, Burkard; Imkamp, Frank; Opota, Onya; Greub, Gilbert; Keller, Peter M

    2018-04-01

    Pneumonia is a severe infectious disease. In addition to common viruses and bacterial pathogens (e.g. Streptococcus pneumoniae), fastidious respiratory pathogens like Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella spp. can cause severe atypical pneumonia. They do not respond to penicillin derivatives, which may cause failure of antibiotic empirical therapy. The same applies for infections with B. pertussis and B. parapertussis, the cause of pertussis disease, that may present atypically and need to be treated with macrolides. Moreover, these fastidious bacteria are difficult to identify by culture or serology, and therefore often remain undetected. Thus, rapid and accurate identification of bacterial pathogens causing atypical pneumonia is crucial. We performed a retrospective method evaluation study to evaluate the diagnostic performance of the new, commercially available Lightmix ® multiplex RT-PCR assay that detects these fastidious bacterial pathogens causing atypical pneumonia. In this retrospective study, 368 clinical respiratory specimens, obtained from patients suffering from atypical pneumonia that have been tested negative for the presence of common agents of pneumonia by culture and viral PCR, were investigated. These clinical specimens have been previously characterized by singleplex RT-PCR assays in our diagnostic laboratory and were used to evaluate the diagnostic performance of the respiratory multiplex Lightmix ® RT-PCR. The multiplex RT-PCR displayed a limit of detection between 5 and 10 DNA copies for different in-panel organisms and showed identical performance characteristics with respect to specificity and sensitivity as in-house singleplex RT-PCRs for pathogen detection. The Lightmix ® multiplex RT-PCR assay represents a low-cost, time-saving and accurate diagnostic tool with high throughput potential. The time-to-result using an automated DNA extraction device for respiratory specimens followed by multiplex RT-PCR detection was

  5. Practical application of immunofluorescence for the detection of bacterial contaminants during vinification

    Directory of Open Access Journals (Sweden)

    Marielle Bouix

    1997-03-01

    Full Text Available This study presents a rapid and specific microscopie technique for detecting and identifying populations of lactic acid bacteria in musts, wines, and inoculum starter cultures. Through the use of fluorescent antibodies, this procedure can be performed in less than two hours, and it is effective with Leuconostoc, Pediococcus and Lactobacillus concentrations as small as 102 cells/ml. Implementation of this technique will assist winemakers in controlling malolactic fermentations and in preventing lactic acid bacterial spoilage.

  6. The bacterial sealing capacity of morse taper implant-abutment systems in vitro.

    Science.gov (United States)

    Ranieri, Rogerio; Ferreira, Andreia; Souza, Emmanuel; Arcoverde, Joao; Dametto, Fabio; Gade-Neto, Cicero; Seabra, Flavio; Sarmento, Carlos

    2015-05-01

    The use of Morse taper systems in dental implantology has been associated widely with a more precise adaptation between implants and their respective abutments. This may lead to an increase in the stability of the implant system and may also prevent microbial invasion through the implant-abutment interface. The aim of this study was to investigate in vitro the ability of four commercially available Morse taper system units to impede bacterial penetration through their implant-abutment interfaces. Abutments were screwed onto the implants, and the units were subsequently immersed in Streptococcus sanguinis bacterial broth (1 × 10(8) colony forming units/mL) for 48 hours. The units were examined by scanning electron microscopy (SEM) under three conditions: 1) with the implant-abutment components assembled as units to investigate for both the existence of microgaps and the presence of bacteria; 2) with the implants and abutments separated for examination of internal surfaces; and 3) with the implant-abutment components again assembled as units to measure any microgaps detected. The mean size of the microgaps in each unit was determined by measuring, under SEM, their width in four equidistant points. Microgaps were detected in all units with no significant differences in dimension (Kruskal-Wallis test, P >0.05). Within all units, the presence of bacteria was also observed. The seals provided by the interfaces of the commercially available Morse taper implant-abutment units tested were not sufficiently small to shield the implant from bacterial penetration.

  7. Particle detection systems and methods

    Science.gov (United States)

    Morris, Christopher L.; Makela, Mark F.

    2010-05-11

    Techniques, apparatus and systems for detecting particles such as muons and neutrons. In one implementation, a particle detection system employs a plurality of drift cells, which can be for example sealed gas-filled drift tubes, arranged on sides of a volume to be scanned to track incoming and outgoing charged particles, such as cosmic ray-produced muons. The drift cells can include a neutron sensitive medium to enable concurrent counting of neutrons. The system can selectively detect devices or materials, such as iron, lead, gold, uranium, plutonium, and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can concurrently detect any unshielded neutron sources occupying the volume from neutrons emitted therefrom. If necessary, the drift cells can be used to also detect gamma rays. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

  8. Histo-FISH protocol to detect bacterial compositions and biofilms formation in vivo.

    Science.gov (United States)

    Madar, M; Slizova, M; Czerwinski, J; Hrckova, G; Mudronova, D; Gancarcikova, S; Popper, M; Pistl, J; Soltys, J; Nemcova, R

    2015-01-01

    The study of biofilm function in vivo in various niches of the gastrointestinal tract (GIT) is rather limited. It is more frequently used in in vitro approaches, as an alternative to the studies focused on formation mechanisms and function of biofilms, which do not represent the actual in vivo complexity of microbial structures. Additionally, in vitro tests can sometimes lead to unreliable results. The goal of this study was to develop a simple approach to detect bacterial populations, particularly Lactobacillus and Bifidobacterium in biofilms, in vivo by the fluorescent in situ hybridisation (FISH) method. We standardised a new Histo-FISH method based on specific fluorochrome labelling probes which are able to detect Lactobacillus spp. and Bifidobacterium spp. within biofilms on the mucosal surface of the GIT embedded in paraffin in histological slices. This method is also suitable for visualisation of bacterial populations in the GIT internal content. Depending on the labelling probes, the Histo-FISH method has the potential to detect other probiotic strains or pathogenic bacteria. This original approach permits us to analyse bacterial colonisation processes as well as biofilm formation in stomach and caecum of BALB/c and germ-free mice.

  9. Applications of CRISPR/Cas System to Bacterial Metabolic Engineering

    Directory of Open Access Journals (Sweden)

    Suhyung Cho

    2018-04-01

    Full Text Available The clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas adaptive immune system has been extensively used for gene editing, including gene deletion, insertion, and replacement in bacterial and eukaryotic cells owing to its simple, rapid, and efficient activities in unprecedented resolution. Furthermore, the CRISPR interference (CRISPRi system including deactivated Cas9 (dCas9 with inactivated endonuclease activity has been further investigated for regulation of the target gene transiently or constitutively, avoiding cell death by disruption of genome. This review discusses the applications of CRISPR/Cas for genome editing in various bacterial systems and their applications. In particular, CRISPR technology has been used for the production of metabolites of high industrial significance, including biochemical, biofuel, and pharmaceutical products/precursors in bacteria. Here, we focus on methods to increase the productivity and yield/titer scan by controlling metabolic flux through individual or combinatorial use of CRISPR/Cas and CRISPRi systems with introduction of synthetic pathway in industrially common bacteria including Escherichia coli. Further, we discuss additional useful applications of the CRISPR/Cas system, including its use in functional genomics.

  10. 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.

  11. Dynamic laser speckle to detect motile bacterial response of Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Sendra, H; Murialdo, S; Passoni, L

    2007-01-01

    This proposal deals with the technique for detection of motile response of Pseudomonas aeruginosa using dynamic laser speckle or biospeckle as an alternative method. The study of bacterial displacement plays an essential role in biocatalysts processes and biodegradation. Hence, some biodegrading enzymes are benign catalytic that could be used for the production of industrially useful compounds as well as in wastewater treatments. This work presents an experimental set up and a computational process using frame sequences of dynamic laser speckle as a novel application. The objective was the detection of different levels of motility in bacteria. The encouraging results were achieved through a direct and non invasive observation method of the phenomenon

  12. Visual Estimation of Bacterial Growth Level in Microfluidic Culture Systems

    Directory of Open Access Journals (Sweden)

    Kyukwang Kim

    2018-02-01

    Full Text Available Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.

  13. Visual Estimation of Bacterial Growth Level in Microfluidic Culture Systems.

    Science.gov (United States)

    Kim, Kyukwang; Kim, Seunggyu; Jeon, Jessie S

    2018-02-03

    Microfluidic devices are an emerging platform for a variety of experiments involving bacterial cell culture, and has advantages including cost and convenience. One inevitable step during bacterial cell culture is the measurement of cell concentration in the channel. The optical density measurement technique is generally used for bacterial growth estimation, but it is not applicable to microfluidic devices due to the small sample volumes in microfluidics. Alternately, cell counting or colony-forming unit methods may be applied, but these do not work in situ; nor do these methods show measurement results immediately. To this end, we present a new vision-based method to estimate the growth level of the bacteria in microfluidic channels. We use Fast Fourier transform (FFT) to detect the frequency level change of the microscopic image, focusing on the fact that the microscopic image becomes rough as the number of cells in the field of view increases, adding high frequencies to the spectrum of the image. Two types of microfluidic devices are used to culture bacteria in liquid and agar gel medium, and time-lapsed images are captured. The images obtained are analyzed using FFT, resulting in an increase in high-frequency noise proportional to the time passed. Furthermore, we apply the developed method in the microfluidic antibiotics susceptibility test by recognizing the regional concentration change of the bacteria that are cultured in the antibiotics gradient. Finally, a deep learning-based data regression is performed on the data obtained by the proposed vision-based method for robust reporting of data.

  14. Radiation detecting system

    International Nuclear Information System (INIS)

    1975-01-01

    In spectrophotometry systems, a usual arrangement for modulating the radiation is a rotating disc having one or more sectors removed. A beam of radiation may be blocked by the disc except when a cut-away sector is in the path of the beam. With a double-beam system, a cut-away sector of 180 0 may be used so that when the first path is blocked, the second is allowed through, and vice versa. One or both sides of the disc may be formed as mirrors to facilitate beam switching and to allow use of more than two beams for background compensation purposes or for analysis of more than one substance within a sample. (G.T.H.)

  15. Radiation detection system

    Science.gov (United States)

    Whited, R.C.

    A system for obtaining improved resolution in relatively thick semiconductor radiation detectors, such as HgI/sub 2/, which exhibit significant hole trapping. Two amplifiers are used: the first measures the charge collected and the second the contribution of the electrons to the charge collected. The outputs of the two amplifiers are utilized to unfold the total charge generated within the detector in response to a radiation event.

  16. Distribution and diversity of bacterial secretion systems across metagenomic datasets.

    Science.gov (United States)

    Barret, Matthieu; Egan, Frank; O'Gara, Fergal

    2013-02-01

    Bacteria can manipulate their surrounding environment through the secretion of proteins into other living organisms and into the extracellular milieu. In Gram stain negative bacteria this process is mediated by different types of secretion systems from type I through type VI secretion system (T1SS-T6SS). In this study the prevalence of these secretion systems in 312 publicly available microbiomes derived from a wide range of ecosystems was investigated by a gene-centric approach. Our analysis demonstrates that some secretion systems are over-represented in some specific samples. In addition, some T3SS and T6SS phylogenetic clusters were specifically enriched in particular ecological niches, which could indicate specific bacterial adaptation to these environments. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  17. An environmental monitoring detection system

    International Nuclear Information System (INIS)

    Leli Yuniarsari; Istofa; Sukandar

    2015-01-01

    Is part of radiation detection of the nuclear facilities engineering activities within nuclear facilities. The system comprised of gamma-ray radiation detector and weather detection which includes anemometer to detect the wind direction and speed, as well as rain gauge to measure the rainfall in a period of time. Data acquisition of the output is processed by Arduino Uno system which transformed the data into a particular standard and then displayed online in the website. The radiation detection system uses gamma-ray detector of NaI(Tl) and GM which convert the radiation detected into electric pulse to be fed into a pre-amp and amplifier and modified into square pulse. The weather detection system on the other hand works based on switch principle. For example, the wind with a certain speed could turn on a switch in the system and produce a voltage or pulse which can be measured. This value will then be interpreted as the wind direction and speed. Likewise for the rainfall gauge, the volume of water entering the bucket will turn the switch on, at the same time producing 1 pulse. The result of the experiment shows that for radiation detection system the output is a square pulse 4 volts by using detector NaI(Tl) and 4.4 volts by using detector GM. For weather detection system, basically was able to detect the wind direction, wind speed and rainfall just to find out further research is needed accuracy and the results compared with the standard tools available in BMKG. (author)

  18. Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus).

    Science.gov (United States)

    Leydet, Brian F; Liang, Fang-Ting

    2013-04-01

    There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.

  19. Non-Enzymatic Detection of Bacterial Genomic DNA Using the Bio-Barcode Assay

    Science.gov (United States)

    Hill, Haley D.; Vega, Rafael A.; Mirkin, Chad A.

    2011-01-01

    The detection of bacterial genomic DNA through a non-enzymatic nanomaterials based amplification method, the bio-barcode assay, is reported. The assay utilizes oligonucleotide functionalized magnetic microparticles to capture the target of interest from the sample. A critical step in the new assay involves the use of blocking oligonucleotides during heat denaturation of the double stranded DNA. These blockers bind to specific regions of the target DNA upon cooling, and prevent the duplex DNA from re-hybridizing, which allows the particle probes to bind. Following target isolation using the magnetic particles, oligonucleotide functionalized gold nanoparticles act as target recognition agents. The oligonucleotides on the nanoparticle (barcodes) act as amplification surrogates. The barcodes are then detected using the Scanometric method. The limit of detection for this assay was determined to be 2.5 femtomolar, and this is the first demonstration of a barcode type assay for the detection of double stranded, genomic DNA. PMID:17927207

  20. Ferromagnetic Objects Magnetovision Detection System.

    Science.gov (United States)

    Nowicki, Michał; Szewczyk, Roman

    2013-12-02

    This paper presents the application of a weak magnetic fields magnetovision scanning system for detection of dangerous ferromagnetic objects. A measurement system was developed and built to study the magnetic field vector distributions. The measurements of the Earth's field distortions caused by various ferromagnetic objects were carried out. The ability for passive detection of hidden or buried dangerous objects and the determination of their location was demonstrated.

  1. Ferromagnetic Objects Magnetovision Detection System

    Directory of Open Access Journals (Sweden)

    Michał Nowicki

    2013-12-01

    Full Text Available This paper presents the application of a weak magnetic fields magnetovision scanning system for detection of dangerous ferromagnetic objects. A measurement system was developed and built to study the magnetic field vector distributions. The measurements of the Earth’s field distortions caused by various ferromagnetic objects were carried out. The ability for passive detection of hidden or buried dangerous objects and the determination of their location was demonstrated.

  2. Current advances in aptamer-assisted technologies for detecting bacterial and fungal toxins.

    Science.gov (United States)

    Alizadeh, N; Memar, M Y; Mehramuz, B; Abibiglou, S S; Hemmati, F; Samadi Kafil, H

    2018-03-01

    Infectious diseases are among the common leading causes of morbidity and mortality worldwide. Associated with the emergence of new infectious diseases, the increasing number of antimicrobial-resistant isolates presents a serious threat to public health and hospitalized patients. A microbial pathogen may elicit several host responses and use a variety of mechanisms to evade host defences. These methods and mechanisms include capsule, lipopolysaccharides or cell wall components, adhesions and toxins. Toxins inhibit phagocytosis, cause septic shock and host cell damages by binding to host surface receptors and invasion. Bacterial and fungal pathogens are able to apply many different toxin-dependent mechanisms to disturb signalling pathways and the structural integrity of host cells for establishing and maintaining infections Initial techniques for analysis of bacterial toxins were based on in vivo or in vitro assessments. There is a permanent demand for appropriate detection methods which are affordable, practical, careful, rapid, sensitive, efficient and economical. Aptamers are DNA or RNA oligonucleotides that are selected by systematic evolution of ligands using exponential enrichment (SELEX) methods and can be applied in diagnostic applications. This review provides an overview of aptamer-based methods as a novel approach for detecting toxins in bacterial and fungal pathogens. © 2017 The Society for Applied Microbiology.

  3. Comparison of enterovirus detection in cerebrospinal fluid with Bacterial Meningitis Score in children.

    Science.gov (United States)

    Pires, Frederico Ribeiro; Franco, Andréia Christine Bonotto Farias; Gilio, Alfredo Elias; Troster, Eduardo Juan

    2017-01-01

    To measure the role of enterovirus detection in cerebrospinal fluid compared with the Bacterial Meningitis Score in children with meningitis. A retrospective cohort based on analysis of medical records of pediatric patients diagnosed as meningitis, seen at a private and tertiary hospital in São Paulo, Brazil, between 2011 and 2014. Excluded were patients with critical illness, purpura, ventricular shunt or recent neurosurgery, immunosuppression, concomitant bacterial infection requiring parenteral antibiotic therapy, and those who received antibiotics 72 hours before lumbar puncture. The study included 503 patients. Sixty-four patients were excluded and 94 were not submitted to all tests for analysis. Of the remaining 345 patients, 7 were in the Bacterial Meningitis Group and 338 in the Aseptic Meningitis Group. There was no statistical difference between the groups. In the Bacterial Meningitis Score analysis, of the 338 patients with possible aseptic meningitis (negative cultures), 121 of them had one or more points in the Bacterial Meningitis Score, with sensitivity of 100%, specificity of 64.2%, and negative predictive value of 100%. Of the 121 patients with positive Bacterial Meningitis Score, 71% (86 patients) had a positive enterovirus detection in cerebrospinal fluid. Enterovirus detection in cerebrospinal fluid was effective to differentiate bacterial from viral meningitis. When the test was analyzed together with the Bacterial Meningitis Score, specificity was higher when compared to Bacterial Meningitis Score alone. Avaliar o papel da pesquisa de enterovírus no líquido cefalorraquidiano em comparação com o Escore de Meningite Bacteriana em crianças com meningite. Coorte retrospectiva, realizada pela análise de prontuários, incluindo pacientes pediátricos, com diagnóstico de meningite e atendidos em um hospital privado e terciário, localizado em São Paulo, entre 2011 e 2014. Foram excluídos os pacientes com doença crítica, púrpura, deriva

  4. Newer systems for bacterial resistances to toxic heavy metals.

    Science.gov (United States)

    Silver, S; Ji, G

    1994-01-01

    Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+. Recent progress with plasmid copper-resistance systems in Escherichia coli and Pseudomonas syringae show a system of four gene products, an inner membrane protein (PcoD), an outer membrane protein (PcoB), and two periplasmic Cu(2+)-binding proteins (PcoA and PcoC). Synthesis of this system is governed by two regulatory proteins (the membrane sensor PcoS and the soluble responder PcoR, probably a DNA-binding protein), homologous to other bacterial two-component regulatory systems. Chromosomally encoded Cu2+ P-type ATPases have recently been recognized in Enterococcus hirae and these are closely homologous to the bacterial cadmium efflux ATPase and the human copper-deficiency disease Menkes gene product. The Cd(2+)-efflux ATPase of gram-positive bacteria is a large P-type ATPase, homologous to the muscle Ca2+ ATPase and the Na+/K+ ATPases of animals. The arsenic-resistance system of gram-negative bacteria functions as an oxyanion efflux ATPase for arsenite and presumably antimonite. However, the structure of the arsenic ATPase is fundamentally different from that of P-type ATPases. The absence of the arsA gene (for the ATPase subunit) in gram-positive bacteria raises questions of energy-coupling for arsenite efflux. The ArsC protein product of the arsenic-resistance operons of both gram-positive and gram-negative bacteria is an intracellular enzyme that reduces arsenate [As(V)] to arsenite [As(III)], the substrate for the transport pump. Newly studied cation efflux systems for Cd2+, Zn2+, and Co2+ (Czc) or Co2+ and Ni2+ resistance (Cnr) lack ATPase motifs in their predicted polypeptide sequences. Therefore, not all plasmid-resistance systems that function through toxic ion efflux are ATPases. The first well-defined bacterial metallothionein was found in the cyanobacterium Synechococcus

  5. Bacterial DNA in water and dialysate: detection and significance for patient outcomes.

    Science.gov (United States)

    Handelman, Garry J; Megdal, Peter A; Handelman, Samuel K

    2009-01-01

    The fluid used for hemodialysis may contain DNA fragments from bacteria, which could be harmful for patient outcomes. DNA fragments from bacteria, containing the nonmethylated CpG motif, can trigger inflammation through the monocyte and lymphocyte Toll-like receptor 9, and these DNA fragments have been observed in dialysate. The fragments may transfer across the dialyzer into the patient's bloodstream during hemodialysis treatment. During hemodiafiltration, the fragments would be introduced directly into the bloodstream. The DNA fragments may arise from biofilm in the pipes of the water system, from growth of bacteria in the water, or as contaminants in the bicarbonate and salt mixture used for preparation of dialysate. Current filtration methods, such as Diasafe filters, are not able to remove these fragments. It would be prudent to seek to reduce or eliminate these contaminants. However, the cost and effort of decreasing bacterial DNA content may ultimately require substantial facility improvements; we therefore need to fund research studies to determine if modifications to reduce bacterial DNA content are clinically warranted. This research will require methods to accurately determine the species of bacteria that contribute the DNA, since this information will allow the source to be established as biofilm, bicarbonate mixtures, or other problems in the dialysis system such as bacterial growth or leakage during water preparation. In this review, the evidence for bacterial DNA fragments will be examined and suggestions for further studies will be described.

  6. Rapid Methods for the Detection of Foodborne Bacterial Pathogens: Principles, Applications, Advantages and Limitations

    Directory of Open Access Journals (Sweden)

    Law eJodi Woan-Fei

    2015-01-01

    Full Text Available The incidence of foodborne diseases has increased over the years and resulted in major public health problem globally. Foodborne pathogens can be found in various foods and it is important to detect foodborne pathogens to provide safe food supply and to prevent foodborne diseases. The conventional methods used to detect foodborne pathogen are time consuming and laborious. Hence, a variety of methods have been developed for rapid detection of foodborne pathogens as it is required in many food analyses. Rapid detection methods can be categorized into nucleic acid-based, biosensor-based and immunological-based methods. This review emphasizes on the principles and application of recent rapid methods for the detection of foodborne bacterial pathogens. Detection methods included are simple polymerase chain reaction (PCR, multiplex PCR, real-time PCR, nucleic acid sequence-based amplification (NASBA, loop-mediated isothermal amplification (LAMP and oligonucleotide DNA microarray which classified as nucleic acid-based methods; optical, electrochemical and mass-based biosensors which classified as biosensor-based methods; enzyme-linked immunosorbent assay (ELISA and lateral flow immunoassay which classified as immunological-based methods. In general, rapid detection methods are generally time-efficient, sensitive, specific and labor-saving. The developments of rapid detection methods are vital in prevention and treatment of foodborne diseases.

  7. 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

  8. Novel aptamer-linked nanoconjugate approach for detection of waterborne bacterial pathogens: an update

    International Nuclear Information System (INIS)

    Singh, Gulshan; Manohar, Murli; Adegoke, Anthony Ayodeji; Stenström, Thor Axel; Shanker, Rishi

    2017-01-01

    The lack of microbiologically safe water in underdeveloped nations is the prime cause of infectious disease outbreaks. The need for the specific identification and detection of microorganisms encourages the development of advanced, rapid, sensitive and highly specific methods for the monitoring of pathogens and management of potential risk to human health. The rapid molecular assays based on detection of specific molecular signatures offer advantages over conventional methods in terms of specificity and sensitivity but require complex instrumentation and skilled personnel. Nanotechnology is an emerging area and provides a robust approach for the identification of pathogenic microorganism utilizing the peculiar properties of nanomaterials, i.e. small size (1–100 nm) and large surface area. This emerging technology promises to fulfill the urgent need of a novel strategy to enhance the bacterial identification and quantitation in the environment. In this context, the peculiar properties of gold nanoparticles, their plasmonic shifts, and changes in magnetic properties have been utilized for the simple and cost-effective detection of bacterial nucleic acids, antigens and toxins with quite improved sensitivity. One of the promising leads to develop an advance detection method might be the coupling of nucleic acid aptamers (capable of interacting specifically with bacteria, protozoa, and viruses) with nanomaterials. Such aptamer-nano conjugate can be used for the specific recognition of infectious agents in different environmental matrices. This review summarizes the application of nanotechnology in the area of pathogen detection and discusses the prospects of coupling nucleic acid aptamers with nanoparticles for the specific detection of targeted pathogens.

  9. Novel aptamer-linked nanoconjugate approach for detection of waterborne bacterial pathogens: an update

    Science.gov (United States)

    Singh, Gulshan; Manohar, Murli; Adegoke, Anthony Ayodeji; Stenström, Thor Axel; Shanker, Rishi

    2017-01-01

    The lack of microbiologically safe water in underdeveloped nations is the prime cause of infectious disease outbreaks. The need for the specific identification and detection of microorganisms encourages the development of advanced, rapid, sensitive and highly specific methods for the monitoring of pathogens and management of potential risk to human health. The rapid molecular assays based on detection of specific molecular signatures offer advantages over conventional methods in terms of specificity and sensitivity but require complex instrumentation and skilled personnel. Nanotechnology is an emerging area and provides a robust approach for the identification of pathogenic microorganism utilizing the peculiar properties of nanomaterials, i.e. small size (1-100 nm) and large surface area. This emerging technology promises to fulfill the urgent need of a novel strategy to enhance the bacterial identification and quantitation in the environment. In this context, the peculiar properties of gold nanoparticles, their plasmonic shifts, and changes in magnetic properties have been utilized for the simple and cost-effective detection of bacterial nucleic acids, antigens and toxins with quite improved sensitivity. One of the promising leads to develop an advance detection method might be the coupling of nucleic acid aptamers (capable of interacting specifically with bacteria, protozoa, and viruses) with nanomaterials. Such aptamer-nano conjugate can be used for the specific recognition of infectious agents in different environmental matrices. This review summarizes the application of nanotechnology in the area of pathogen detection and discusses the prospects of coupling nucleic acid aptamers with nanoparticles for the specific detection of targeted pathogens.

  10. Simultaneous Detection of 13 Key Bacterial Respiratory Pathogens by Combination of Multiplex PCR and Capillary Electrophoresis.

    Science.gov (United States)

    Jiang, Lu Xi; Ren, Hong Yu; Zhou, Hai Jian; Zhao, Si Hong; Hou, Bo Yan; Yan, Jian Ping; Qin, Tian; Chen, Yu

    2017-08-01

    Lower respiratory tract infections continue to pose a significant threat to human health. It is important to accurately and rapidly detect respiratory bacteria. To compensate for the limits of current respiratory bacteria detection methods, we developed a combination of multiplex polymerase chain reaction (PCR) and capillary electrophoresis (MPCE) assay to detect thirteen bacterial pathogens responsible for lower respiratory tract infections, including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Mycoplasma pneumoniae, Legionella spp., Bordetella pertussis, Mycobacterium tuberculosis complex, Corynebacterium diphtheriae, and Streptococcus pyogenes. Three multiplex PCR reactions were built, and the products were analyzed by capillary electrophoresis using the high-throughput DNA analyzer. The specificity of the MPCE assay was examined and the detection limit was evaluated using DNA samples from each bacterial strain and the simulative samples of each strain. This assay was further evaluated using 152 clinical specimens and compared with real-time PCR reactions. For this assay, three nested-multiplex-PCRs were used to detect these clinical specimens. The detection limits of the MPCE assay for the 13 pathogens were very low and ranged from 10-7 to 10-2 ng/μL. Furthermore, analysis of the 152 clinical specimens yielded a specificity ranging from 96.5%-100.0%, and a sensitivity of 100.0% for the 13 pathogens. This study revealed that the MPCE assay is a rapid, reliable, and high-throughput method with high specificity and sensitivity. This assay has great potential in the molecular epidemiological survey of respiratory pathogens. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  11. Novel aptamer-linked nanoconjugate approach for detection of waterborne bacterial pathogens: an update

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Gulshan, E-mail: gsingh.gulshan@gmail.com [Durban University of Technology, Institute for Water and Wastewater Technology (IWWT) (South Africa); Manohar, Murli [Jamia Hamdard (Hamdard University), Department of Biochemistry (India); Adegoke, Anthony Ayodeji; Stenström, Thor Axel [Durban University of Technology, Institute for Water and Wastewater Technology (IWWT) (South Africa); Shanker, Rishi [Ahmedabad University, Division of Biological & Life Sciences, School of Arts & Sciences (India)

    2017-01-15

    The lack of microbiologically safe water in underdeveloped nations is the prime cause of infectious disease outbreaks. The need for the specific identification and detection of microorganisms encourages the development of advanced, rapid, sensitive and highly specific methods for the monitoring of pathogens and management of potential risk to human health. The rapid molecular assays based on detection of specific molecular signatures offer advantages over conventional methods in terms of specificity and sensitivity but require complex instrumentation and skilled personnel. Nanotechnology is an emerging area and provides a robust approach for the identification of pathogenic microorganism utilizing the peculiar properties of nanomaterials, i.e. small size (1–100 nm) and large surface area. This emerging technology promises to fulfill the urgent need of a novel strategy to enhance the bacterial identification and quantitation in the environment. In this context, the peculiar properties of gold nanoparticles, their plasmonic shifts, and changes in magnetic properties have been utilized for the simple and cost-effective detection of bacterial nucleic acids, antigens and toxins with quite improved sensitivity. One of the promising leads to develop an advance detection method might be the coupling of nucleic acid aptamers (capable of interacting specifically with bacteria, protozoa, and viruses) with nanomaterials. Such aptamer-nano conjugate can be used for the specific recognition of infectious agents in different environmental matrices. This review summarizes the application of nanotechnology in the area of pathogen detection and discusses the prospects of coupling nucleic acid aptamers with nanoparticles for the specific detection of targeted pathogens.

  12. Integrated multisensor perimeter detection systems

    Science.gov (United States)

    Kent, P. J.; Fretwell, P.; Barrett, D. J.; Faulkner, D. A.

    2007-10-01

    The report describes the results of a multi-year programme of research aimed at the development of an integrated multi-sensor perimeter detection system capable of being deployed at an operational site. The research was driven by end user requirements in protective security, particularly in threat detection and assessment, where effective capability was either not available or prohibitively expensive. Novel video analytics have been designed to provide robust detection of pedestrians in clutter while new radar detection and tracking algorithms provide wide area day/night surveillance. A modular integrated architecture based on commercially available components has been developed. A graphical user interface allows intuitive interaction and visualisation with the sensors. The fusion of video, radar and other sensor data provides the basis of a threat detection capability for real life conditions. The system was designed to be modular and extendable in order to accommodate future and legacy surveillance sensors. The current sensor mix includes stereoscopic video cameras, mmWave ground movement radar, CCTV and a commercially available perimeter detection cable. The paper outlines the development of the system and describes the lessons learnt after deployment in a pilot trial.

  13. Disposable bioluminescence-based biosensor for detection of bacterial count in food.

    Science.gov (United States)

    Luo, Jinping; Liu, Xiaohong; Tian, Qing; Yue, Weiwei; Zeng, Jing; Chen, Guangquan; Cai, Xinxia

    2009-11-01

    A biosensor for rapid detection of bacterial count based on adenosine 5'-triphosphate (ATP) bioluminescence has been developed. The biosensor is composed of a key sensitive element and a photomultiplier tube used as a detector element. The disposable sensitive element consists of a sampler, a cartridge where intracellular ATP is chemically extracted from bacteria, and a microtube where the extracted ATP reacts with the luciferin-luciferase reagent to produce bioluminescence. The bioluminescence signal is transformed into relevant electrical signal by the detector and further measured with a homemade luminometer. Parameters affecting the amount of the extracted ATP, including the types of ATP extractants, the concentrations of ATP extractant, and the relevant neutralizing reagent, were optimized. Under the optimal experimental conditions, the biosensor showed a linear response to standard bacteria in a concentration range from 10(3) to 10(8) colony-forming units (CFU) per milliliter with a correlation coefficient of 0.925 (n=22) within 5min. Moreover, the bacterial count of real food samples obtained by the biosensor correlated well with those by the conventional plate count method. The proposed biosensor, with characteristics of low cost, easy operation, and fast response, provides potential application to rapid evaluation of bacterial contamination in the food industry, environment monitoring, and other fields.

  14. A simple bacterial turbidimetric method for detection of some radurized foods

    International Nuclear Information System (INIS)

    Gautam, S.; Sharma, Arun; Thomas, Paul

    1998-01-01

    A simple and quick method for detection of irradiated food is proposed. The method is based on the principle of microbial contribution to the development of turbidity in a clear medium. It employs measurement of absorbance at 600 nm of the medium after the test commodity has been suspended and shaken in it for a fixed interval. The differences in the bacterial turbidity from irradiated and nonirradiated samples are quite marked so as to allow identification of the irradiated foods like fish, lamb meat, chicken and mushroom. (author)

  15. Development of a bacterial bioassay for atrazine and cyanuric acid detection

    Directory of Open Access Journals (Sweden)

    Anna eHUA

    2015-03-01

    Full Text Available The s-triazine herbicides are compounds which can disseminate into soils and water. Due to their toxic effects on living organisms, their concentrations in drinking water are legislated by WHO recommendations. Here we have developed for the first time, to the best of our knowledge, an alternative method for physicochemical quantification using two bioluminescent bacterial biosensors: E. coli SM003 for cyanuric acid detection and E. coli SM004 for both atrazine and cyanuric acid detection. The concentration of cyanuric acid detection for E. coli SM003 ranges from 7.83 µM to 2.89 mM, and for E. coli SM004 ranges from 0.22 µM to 15 µM. Moreover, atrazine detection by E. coli SM004 ranges from 1.08 µM to 15 µM. According to WHO recommendations, the cyanuric acid detection range is sensitive enough to discriminate between polluted and drinking water. Nevertheless, the detection of atrazine by E. coli SM004 is only applicable for high concentrations of contaminants.

  16. Pattern Transitions in Bacterial Oscillating System under Nanofluidic Confinement

    Science.gov (United States)

    Shen, Jie-Pan; Chou, Chia-Fu

    2011-03-01

    Successful binary fission in E. coli relies on remarkable oscillatory behavior of the MinCDE protein system to determine the exact division site. The most favorable models to explain this fascinating spatiotemporal regulation on dynamic MinDE pattern formation in cells are based on reaction-diffusion scenario. Although not fully understood, geometric factors caused by bacterial morphology play a crucial role in MinDE dynamics. In the present study, bacteria were cultured, confined and reshaped in various micro/nanofluidic devices, to mimic either curvature changes of cell peripherals. Fluorescence imaging was utilized to detail the mode transitions in multiple MinDE patterns. The understanding of the physics in multiple pattern formations is further complemented via in silico modeling. The study synergizes the join merits of in vivo, in vitro and in silico approaches, to grasp the insight of stochastic dynamics inherited from the noisy mesoscopic biophysics. We acknowledge support from the Foresight Project, Academia Sinica.

  17. Detecting Release of Bacterial dsDNA into the Host Cytosol Using Fluorescence Microscopy.

    Science.gov (United States)

    Dreier, Roland Felix; Santos, José Carlos; Broz, Petr

    2018-01-01

    Recognition of pathogens by the innate immune system relies on germline-encoded pattern recognition receptors (PRRs) that recognize unique microbial molecules, so-called pathogen-associated molecular patterns (PAMPs). Nucleic acids and their derivatives are one of the most important groups of PAMPs, and are recognized by a number of surface-associated as well as cytosolic PRRs. Cyclic GMP-AMP synthase (cGAS) recognizes the presence of pathogen- or host-derived dsDNA in the cytosol and initiates type-I-IFN production. Here, we describe a methodology that allows for evaluating the association of cGAS with released bacterial dsDNA during Francisella novicida infection of macrophages, by fluorescence confocal microscopy. This method can be adapted to the study of cGAS-dependent responses elicited by other intracellular bacterial pathogens and in other cell types.

  18. Basis UST leak detection systems

    International Nuclear Information System (INIS)

    Silveria, V.

    1992-01-01

    This paper reports that gasoline and other petroleum products are leaking from underground storage tanks (USTs) at an alarming rate, seeping into soil and groundwater. Buried pipes are an even greater culprit, accounting for most suspected and detected leaks according to Environmental Protection Agency (EPA) estimates. In response to this problem, the EPA issued regulations setting standards for preventing, detecting, reporting, and cleaning up leaks, as well as fiscal responsibility. However, federal regulations are only a minimum; some states have cracked down even harder Plant managers and engineers have a big job ahead of them. The EPA estimates that there are more than 75,000 fuel USTs at US industrial facilities. When considering leak detection systems, the person responsible for making the decision has five primary choices: inventory reconciliation combined with regular precision tightness tests; automatic tank gauging; groundwater monitoring; interstitial monitoring of double containment systems; and vapor monitoring

  19. Sensitive Detection of Thirteen Bacterial Vaginosis-Associated Agents Using Multiplex Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Natália Malaguti

    2015-01-01

    Full Text Available Bacterial vaginosis (BV is characterized by a polymicrobial proliferation of anaerobic bacteria and depletion of lactobacilli, which are components of natural vaginal microbiota. Currently, there are limited conventional methods for BV diagnosis, and these methods are time-consuming, expensive, and rarely allow for the detection of more than one agent simultaneously. Therefore, we conceived and validated a multiplex polymerase chain reaction (M-PCR assay for the simultaneous screening of thirteen bacterial vaginosis-associated agents (BV-AAs related to symptomatic BV: Gardnerella vaginalis, Mobiluncus curtisii, Mobiluncus mulieris, Bacteroides fragilis, Mycoplasma hominis, Atopobium vaginae, Ureaplasma urealyticum, Megasphaera type I, Clostridia-like bacteria vaginosis-associated bacteria (BVABs 1, 2, and 3, Sneathia sanguinegens, and Mycoplasma genitalium. The overall validation parameters of M-PCR compared to single PCR (sPCR were extremely high, including agreement of 99.1% and sensitivity, specificity, and positive predictive values of 100.0%, negative predictive value of 97.0%, accuracy of 99.3%, and agreement with Nugent results of 100.0%. The prevalence of BV-AAs was very high (72.6%, and simultaneous agents were detected in 53.0%, which demonstrates the effectiveness of the M-PCR assay. Therefore, the M-PCR assay has great potential to impact BV diagnostic methods in vaginal samples and diminish associated complications in the near future.

  20. Analysis of bacterial metagenomes from the Southwestern Gulf of Mexico for pathogens detection.

    Science.gov (United States)

    Escobedo-Hinojosa, Wendy; Pardo-López, Liliana

    2017-07-31

    Little is known about the diversity of bacteria in the Southwestern Gulf of Mexico. The aim of the study illustrated in this perspective was to search for the presence of bacterial pathogens in this ecosystem, using metagenomic data recently generated by the Mexican research group known as the Gulf of Mexico Research Consortium. Several genera of bacteria annotated as pathogens were detected in water and sediment marine samples. As expected, native and ubiquitous pathogenic bacteria genera such as Burkolderia, Halomonas, Pseudomonas, Shewanella and Vibrio were highly represented. Surprisingly, non-native genera of public health concern were also detected, including Borrelia, Ehrlichia, Leptospira, Mycobacterium, Mycoplasma, Salmonella, Staphylococcus, Streptococcus and Treponema. While there are no previous metagenomics studies of this environment, the potential influences of natural, anthropogenic and ecological factors on the diversity of putative pathogenic bacteria found in it are reviewed. The taxonomic annotation herein reported provides a starting point for an improved understanding of bacterial biodiversity in the Southwestern Gulf of Mexico. It also represents a useful tool in public health as it may help identify infectious diseases associated with exposure to marine water and ingestion of fish or shellfish, and thus may be useful in predicting and preventing waterborne disease outbreaks. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. An improved haemolytic plaque assay for the detection of cells secreting antibody to bacterial antigens

    DEFF Research Database (Denmark)

    Barington, T; Heilmann, C

    1992-01-01

    Recent advances in the development of conjugate polysaccharide vaccines for human use have stimulated interest in the use of assays detecting antibody-secreting cells (AbSC) with specificity for bacterial antigens. Here we present improved haemolytic plaque-forming cell (PFC) assays detecting Ab......SC with specificity for tetanus and diphtheria toxoid as well as for Haemophilus influenzae type b and pneumococcal capsular polysaccharides. These assays were found to be less time consuming, more economical and yielded 1.9-3.4-fold higher plaque numbers than traditional Jerne-type PFC assays. In the case of anti......-polysaccharide antibodies aggregation of secreted monomeric antibody (IgG) is critical for plaque formation and increases the avidity of binding to target cells....

  2. Bacterial and viral pathogens detected in sea turtles stranded along the coast of Tuscany, Italy.

    Science.gov (United States)

    Fichi, G; Cardeti, G; Cersini, A; Mancusi, C; Guarducci, M; Di Guardo, G; Terracciano, G

    2016-03-15

    During 2014, six loggerhead turtles, Caretta caretta and one green turtle, Chelonia mydas, found stranded on the Tuscany coast of Italy, were examined for the presence of specific bacterial and viral agents, along with their role as carriers of fish and human pathogens. Thirteen different species of bacteria, 10 Gram negative and 3 Gram positive, were identified. Among them, two strains of Vibrio parahaemolyticus and one strain of Lactococcus garviae were recovered and confirmed by specific PCR protocols. No trh and tdh genes were detected in V. parahaemolyticus. The first isolation of L. garviae and the first detection of Betanodavirus in sea turtles indicate the possibility for sea turtles to act as carriers of fish pathogens. Furthermore, the isolation of two strains of V. parahaemolyticus highlights the possible role of these animals in human pathogens' diffusion. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  4. Wide range neutron detection system

    International Nuclear Information System (INIS)

    Todt, W.H. Sr.

    1978-01-01

    A neutron detection system for reactor control is described which is operable over a wide range of neutron flux levels. The system includes a fission type ionization chamber neutron detector, means for gamma and alpha signal compensation, and means for operating the neutron detector in the pulse counting mode for low neutron flux levels, and in the direct current mode for high neutron flux levels

  5. Bacterial burden in the operating room: impact of airflow systems.

    Science.gov (United States)

    Hirsch, Tobias; Hubert, Helmine; Fischer, Sebastian; Lahmer, Armin; Lehnhardt, Marcus; Steinau, Hans-Ulrich; Steinstraesser, Lars; Seipp, Hans-Martin

    2012-09-01

    Wound infections present one of the most prevalent and frequent complications associated with surgical procedures. This study analyzes the impact of currently used ventilation systems in the operating room to reduce bacterial contamination during surgical procedures. Four ventilation systems (window-based ventilation, supported air nozzle canopy, low-turbulence displacement airflow, and low-turbulence displacement airflow with flow stabilizer) were analyzed. Two hundred seventy-seven surgical procedures in 6 operating rooms of 5 different hospitals were analyzed for this study. Window-based ventilation showed the highest intraoperative contamination (13.3 colony-forming units [CFU]/h) followed by supported air nozzle canopy (6.4 CFU/h; P = .001 vs window-based ventilation) and low-turbulence displacement airflow (3.4 and 0.8 CFU/h; P system showed no increase of contamination in prolonged durations of surgical procedures. This study shows that intraoperative contamination can be significantly reduced by the use of adequate ventilation systems. Copyright © 2012 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  6. Real-time Bacterial Detection by Single Cell Based Sensors UsingSynchrotron FTIR Spectromicroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Veiseh, Mandana; Veiseh, Omid; Martin, Michael C.; Bertozzi,Carolyn; Zhang, Miqin

    2005-08-10

    Microarrays of single macrophage cell based sensors weredeveloped and demonstrated for real time bacterium detection bysynchrotron FTIR microscopy. The cells were patterned on gold-SiO2substrates via a surface engineering technique by which the goldelectrodes were immobilized with fibronectin to mediate cell adhesion andthe silicon oxide background were passivated with PEG to resist proteinadsorption and cell adhesion. Cellular morphology and IR spectra ofsingle, double, and triple cells on gold electrodes exposed tolipopolysaccharide (LPS) of different concentrations were compared toreveal the detection capabilities of these biosensors. The single-cellbased sensors were found to generate the most significant IR wave numbervariation and thus provide the highest detection sensitivity. Changes inmorphology and IR spectrum for single cells exposed to LPS were found tobe time- and concentration-dependent and correlated with each other verywell. FTIR spectra from single cell arrays of gold electrodes withsurface area of 25 mu-m2, 100 mu-m2, and 400 mu-m2 were acquired usingboth synchrotron and conventional FTIR spectromicroscopes to study thesensitivity of detection. The results indicated that the developedsingle-cell platform can be used with conventional FTIRspectromicroscopy. This technique provides real-time, label-free, andrapid bacterial detection, and may allow for statistic and highthroughput analyses, and portability.

  7. Mass Cytometry for Detection of Silver at the Bacterial Single Cell Level

    Directory of Open Access Journals (Sweden)

    Yuting Guo

    2017-07-01

    Full Text Available Background: Mass cytometry (Cytometry by Time of Flight, CyTOF allows single-cell characterization on the basis of specific metal-based cell markers. In addition, other metals in the mass range such as silver can be detected per cell. Bacteria are known to be sensible to silver and a protocol was developed to measure both the number of affected cells per population and the quantities of silver per cell.Methods: For mass cytometry ruthenium red was used as a marker for all cells of a population while parallel application of cisplatin discriminated live from dead cells. Silver quantities per cell and frequencies of silver containing cells in a population were measured by mass cytometry. In addition, live/dead subpopulations were analyzed by flow cytometry and distinguished by cell sorting based on ruthenium red and propidium iodide double staining. Verification of the cells’ silver load was performed on the bulk level by using ICP-MS in combination with cell sorting. The protocol was developed by conveying both, fast and non-growing Pseudomonas putida cells as test organisms.Results: A workflow for labeling bacteria in order to be analyzed by mass cytometry was developed. Three different parameters were tested: ruthenium red provided counts for all bacterial cells in a population while consecutively applied cisplatin marked the frequency of dead cells. Apparent population heterogeneity was detected by different frequencies of silver containing cells. Silver quantities per cell were also well measurable. Generally, AgNP-10 treatment caused higher frequencies of dead cells, higher frequencies of silver containing cells and higher per-cell silver quantities. Due to an assumed chemical equilibrium of free and bound silver ions live and dead cells were associated with silver in equal quantities and this preferably during exponential growth. With ICP-MS up to 1.5 fg silver per bacterial cell were detected.Conclusion: An effective mass cytometry

  8. Road Anomalies Detection System Evaluation.

    Science.gov (United States)

    Silva, Nuno; Shah, Vaibhav; Soares, João; Rodrigues, Helena

    2018-06-21

    Anomalies on road pavement cause discomfort to drivers and passengers, and may cause mechanical failure or even accidents. Governments spend millions of Euros every year on road maintenance, often causing traffic jams and congestion on urban roads on a daily basis. This paper analyses the difference between the deployment of a road anomalies detection and identification system in a “conditioned” and a real world setup, where the system performed worse compared to the “conditioned” setup. It also presents a system performance analysis based on the analysis of the training data sets; on the analysis of the attributes complexity, through the application of PCA techniques; and on the analysis of the attributes in the context of each anomaly type, using acceleration standard deviation attributes to observe how different anomalies classes are distributed in the Cartesian coordinates system. Overall, in this paper, we describe the main insights on road anomalies detection challenges to support the design and deployment of a new iteration of our system towards the deployment of a road anomaly detection service to provide information about roads condition to drivers and government entities.

  9. Regulation of bacterial virulence by Csr (Rsm) systems.

    Science.gov (United States)

    Vakulskas, Christopher A; Potts, Anastasia H; Babitzke, Paul; Ahmer, Brian M M; Romeo, Tony

    2015-06-01

    Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5' untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Evaluation of vaginal pH for detection of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    R Hemalatha

    2013-01-01

    Full Text Available Background & objectives : Bacterial vaginosis (BV is highly prevalent among women in reproductive age group. Little information exists on routine vaginal p H measurement in women with BV. We undertook this study to assess the utility of vaginal p H determination for initial evaluation of bacterial vaginosis. Methods : In this cross-sectional study vaginal swabs were collected from women with complaints of white discharge, back ache and pain abdomen attending a government hospital and a community health clinic, and subjected to vaginal p H determination, Gram stain, wet mount and whiff test. Nugent score and Amsel criteria were used for BV confirmation. Results : Of the 270 women included in the analysis, 154 had BV based on Nugents′ score. The mean vaginal p H in women with BV measured by p H strips and p H glove was 5 and 4.9, respectively. The vaginal p H was significantly higher in women with BV. Vaginal discharge was prevalent in 84.8 per cent women, however, only 56.8 per cent of these actually had BV by Nugent score (NS. Presence of clue cells and positive whiff test were significant for BV. Vaginal p H >4.5 by p H strips and p H Glove had a sensitivity of 72 and 79 per cent and specificity of 60 and 53 per cent, respectively to detect BV. Among the combination criteria, clue cells and glove p H >4.5 had highest sensitivity and specificity to detect BV. Interpretation & conclusions : Vaginal p H determination is relatively sensitive, but less specific in detecting women with BV. Inclusion of whiff test along with p H test reduced the sensitivity, but improved specificity. Both, the p H strip and p H glove are equally suitable for screening women with BV on outpatient basis.

  11. Effect of semi-permeable cover system on the bacterial diversity during sewage sludge composting.

    Science.gov (United States)

    Robledo-Mahón, Tatiana; Aranda, Elisabet; Pesciaroli, Chiara; Rodríguez-Calvo, Alfonso; Silva-Castro, Gloria Andrea; González-López, Jesús; Calvo, Concepción

    2018-06-01

    Sewage sludge composting is a profitable process economically viable and environmentally friendly. In despite of there are several kind of composting types, the use of combined system of semipermeable cover film and aeration air-floor is widely developed at industrial scale. However, the knowledge of the linkages between microbial communities structure, enzyme activities and physico-chemical factors under these conditions it has been poorly explored. Thus, the aim of this study was to investigate the bacterial dynamic and community structure using next generation sequencing coupled to analyses of microbial enzymatic activity and culturable dependent techniques in a full-scale real composting plant. Sewage sludge composting process was conducted using a semi-permeable Gore-tex cover, in combination with an air-insufflation system. The highest values of enzymatic activities such as dehydrogenase, protease and arylsulphatase were detected in the first 5 days of composting; suggesting that during this period of time a greater degrading activity of organic matter took place. Culturable bacteria identified were in agreement with the bacteria found by massive sequencing technologies. The greatest bacterial diversity was detected between days 15 and 30, with Actinomycetales and Bacillales being the predominant orders at the beginning and end of the process. Bacillus was the most representative genus during all the process. A strong correlation between abiotic factors as total organic content and organic matter and enzymatic activities such as dehydrogenase, alkaline phosphatase, and ß-glucosidase activity was found. Bacterial diversity was strongly influenced by the stage of the process, community-structure change was concomitant with a temperature rise, rendering favorable conditions to stimulate microbial activity and facilitate the change in the microbial community linked to the degradation process. Moreover, results obtained confirmed that the use of semipermeable

  12. Bacterial communities in full-scale wastewater treatment systems.

    Science.gov (United States)

    Cydzik-Kwiatkowska, Agnieszka; Zielińska, Magdalena

    2016-04-01

    Bacterial metabolism determines the effectiveness of biological treatment of wastewater. Therefore, it is important to define the relations between the species structure and the performance of full-scale installations. Although there is much laboratory data on microbial consortia, our understanding of dependencies between the microbial structure and operational parameters of full-scale wastewater treatment plants (WWTP) is limited. This mini-review presents the types of microbial consortia in WWTP. Information is given on extracellular polymeric substances production as factor that is key for formation of spatial structures of microorganisms. Additionally, we discuss data on microbial groups including nitrifiers, denitrifiers, Anammox bacteria, and phosphate- and glycogen-accumulating bacteria in full-scale aerobic systems that was obtained with the use of molecular techniques, including high-throughput sequencing, to shed light on dependencies between the microbial ecology of biomass and the overall efficiency and functional stability of wastewater treatment systems. Sludge bulking in WWTPs is addressed, as well as the microbial composition of consortia involved in antibiotic and micropollutant removal.

  13. Lightning Protection and Detection System

    Science.gov (United States)

    Dudley, Kenneth L. (Inventor); Szatkowski, George N. (Inventor); Woodard, Marie (Inventor); Nguyen, Truong X. (Inventor); Ely, Jay J. (Inventor); Wang, Chuantong (Inventor); Mielnik, John J. (Inventor); Koppen, Sandra V. (Inventor); Smith, Laura J. (Inventor)

    2017-01-01

    A lightning protection and detection system includes a non-conductive substrate material of an apparatus; a sensor formed of a conductive material and deposited on the non-conductive substrate material of the apparatus. The sensor includes a conductive trace formed in a continuous spiral winding starting at a first end at a center region of the sensor and ending at a second end at an outer corner region of the sensor, the first and second ends being open and unconnected. An electrical measurement system is in communication with the sensor and receives a resonant response from the sensor, to perform detection, in real-time, of lightning strike occurrences and damage therefrom to the sensor and the non-conductive substrate material.

  14. Optical detection in microfluidic systems

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Kutter, Jörg Peter

    2009-01-01

    Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent...... to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest....

  15. Beetroot-pigment-derived colorimetric sensor for detection of calcium dipicolinate in bacterial spores.

    Directory of Open Access Journals (Sweden)

    Letícia Christina Pires Gonçalves

    Full Text Available In this proof-of-concept study, we describe the use of the main red beet pigment betanin for the quantification of calcium dipicolinate in bacterial spores, including Bacillus anthracis. In the presence of europium(III ions, betanin is converted to a water-soluble, non-luminescent orange 1∶1 complex with a stability constant of 1.4 × 10(5 L mol(-1. The addition of calcium dipicolinate, largely found in bacterial spores, changes the color of the aqueous solution of [Eu(Bn(+] from orange to magenta. The limit of detection (LOD of calcium dipicolinate is around 2.0 × 10(-6 mol L(-1 and the LOD determined for both spores, B. cereus and B. anthracis, is (1.1 ± 0.3× 10(6 spores mL(-1. This simple, green, fast and low cost colorimetric assay was selective for calcium dipicolinate when compared to several analogous compounds. The importance of this work relies on the potential use of betalains, raw natural pigments, as colorimetric sensors for biological applications.

  16. [Investigation of bacterial and viral etiology in community acquired central nervous system infections with molecular methods].

    Science.gov (United States)

    Kahraman, Hasip; Tünger, Alper; Şenol, Şebnem; Gazi, Hörü; Avcı, Meltem; Örmen, Bahar; Türker, Nesrin; Atalay, Sabri; Köse, Şükran; Ulusoy, Sercan; Işıkgöz Taşbakan, Meltem; Sipahi, Oğuz Reşat; Yamazhan, Tansu; Gülay, Zeynep; Alp Çavuş, Sema; Pullukçu, Hüsnü

    2017-07-01

    In this multicenter prospective cohort study, it was aimed to evaluate the bacterial and viral etiology in community-acquired central nervous system infections by standart bacteriological culture and multiplex polymerase chain reaction (PCR) methods. Patients hospitalized with central nervous system infections between April 2012 and February 2014 were enrolled in the study. Demographic and clinical information of the patients were collected prospectively. Cerebrospinal fluid (CSF) samples of the patients were examined by standart bacteriological culture methods, bacterial multiplex PCR (Seeplex meningitis-B ACE Detection (Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Listeria monocytogenes, Group B streptococci) and viral multiplex PCR (Seeplex meningitis-V1 ACE Detection kits herpes simplex virus-1 (HSV1), herpes simplex virus-2 (HSV2), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein Barr virus (EBV) and human herpes virus 6 (HHV6)) (Seeplex meningitis-V2 ACE Detection kit (enteroviruses)). Patients were classified as purulent meningitis, aseptic meningitis and encephalitis according to their clinical, CSF (leukocyte level, predominant cell type, protein and glucose (blood/CSF) levels) and cranial imaging results. Patients who were infected with a pathogen other than the detection of the kit or diagnosed as chronic meningitis and other diseases during the follow up, were excluded from the study. A total of 79 patients (28 female, 51 male, aged 42.1 ± 18.5) fulfilled the study inclusion criteria. A total of 46 patients were classified in purulent meningitis group whereas 33 were in aseptic meningitis/encephalitis group. Pathogens were detected by multiplex PCR in 41 patients. CSF cultures were positive in 10 (21.7%) patients (nine S.pneumoniae, one H.influenzae) and PCR were positive for 27 (58.6%) patients in purulent meningitis group. In this group one type of bacteria were detected in 18 patients (14 S.pneumoniae, two N

  17. Nucleic acid detection system and method for detecting influenza

    Science.gov (United States)

    Cai, Hong; Song, Jian

    2015-03-17

    The invention provides a rapid, sensitive and specific nucleic acid detection system which utilizes isothermal nucleic acid amplification in combination with a lateral flow chromatographic device, or DNA dipstick, for DNA-hybridization detection. The system of the invention requires no complex instrumentation or electronic hardware, and provides a low cost nucleic acid detection system suitable for highly sensitive pathogen detection. Hybridization to single-stranded DNA amplification products using the system of the invention provides a sensitive and specific means by which assays can be multiplexed for the detection of multiple target sequences.

  18. Preparation of Pd/Bacterial Cellulose Hybrid Nanofibers for Dopamine Detection

    Directory of Open Access Journals (Sweden)

    Dawei Li

    2016-05-01

    Full Text Available Palladium nanoparticle-bacterial cellulose (PdBC hybrid nanofibers were synthesized by in-situ chemical reduction method. The obtained PdBC nanofibers were characterized by a series of analytical techniques. The results revealed that Pd nanoparticles were evenly dispersed on the surfaces of BC nanofibers. Then, the as-prepared PdBC nanofibers were mixed with laccase (Lac and Nafion to obtain mixture suspension, which was further modified on electrode surface to construct novel biosensing platform. Finally, the prepared electrochemical biosensor was employed to detect dopamine. The analysis result was satisfactory, the sensor showed excellent electrocatalysis towards dopamine with high sensitivity (38.4 µA·mM−1, low detection limit (1.26 µM, and wide linear range (5–167 µM. Moreover, the biosensor also showed good repeatability, reproducibility, selectivity and stability and was successfully used in the detection of dopamine in human urine, thus providing a promising method for dopamine analysis in clinical application.

  19. Portable bacterial identification system based on elastic light scatter patterns

    Directory of Open Access Journals (Sweden)

    Bae Euiwon

    2012-08-01

    Full Text Available Abstract Background Conventional diagnosis and identification of bacteria requires shipment of samples to a laboratory for genetic and biochemical analysis. This process can take days and imposes significant delay to action in situations where timely intervention can save lives and reduce associated costs. To enable faster response to an outbreak, a low-cost, small-footprint, portable microbial-identification instrument using forward scatterometry has been developed. Results This device, weighing 9 lb and measuring 12 × 6 × 10.5 in., utilizes elastic light scatter (ELS patterns to accurately capture bacterial colony characteristics and delivers the classification results via wireless access. The overall system consists of two CCD cameras, one rotational and one translational stage, and a 635-nm laser diode. Various software algorithms such as Hough transform, 2-D geometric moments, and the traveling salesman problem (TSP have been implemented to provide colony count and circularity, centering process, and minimized travel time among colonies. Conclusions Experiments were conducted with four bacteria genera using pure and mixed plate and as proof of principle a field test was conducted in four different locations where the average classification rate ranged between 95 and 100%.

  20. Compensated intruder-detection systems

    Science.gov (United States)

    McNeilly, David R.; Miller, William R.

    1984-01-01

    Intruder-detection systems in which intruder-induced signals are transmitted through a medium also receive spurious signals induced by changes in a climatic condition affecting the medium. To combat this, signals received from the detection medium are converted to a first signal. The system also provides a reference signal proportional to climate-induced changes in the medium. The first signal and the reference signal are combined for generating therefrom an output signal which is insensitive to the climatic changes in the medium. An alarm is energized if the output signal exceeds a preselected value. In one embodiment, an acoustic cable is coupled to a fence to generate a first electrical signal proportional to movements thereof. False alarms resulting from wind-induced movements of the fence (detection medium) are eliminated by providing an anemometer-driven voltage generator to provide a reference voltage proportional to the velocity of wind incident on the fence. An analog divider receives the first electrical signal and the reference signal as its numerator and denominator inputs, respectively, and generates therefrom an output signal which is insensitive to the wind-induced movements in the fence.

  1. 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...

  2. Concurrent Detection of Human Norovirus and Bacterial Pathogens in Water Samples from an Agricultural Region in Central California Coast

    Directory of Open Access Journals (Sweden)

    Peng Tian

    2017-08-01

    Full Text Available Bacterial pathogens and human norovirus (HuNoV are major cause for acute gastroenteritis caused by contaminated food and water. Public waterways can become contaminated from a variety of sources and flood after heavy rain events, leading to pathogen contamination of produce fields. We initiated a survey of several public watersheds in a major leafy green produce production region of the Central California Coast to determine the prevalence of HuNoV as well as bacterial pathogens. Moore swabs were used to collect environmental samples bi-monthly at over 30 sampling sites in the region. High prevalence of HuNoV and bacterial pathogens were detected in environmental water samples in the region. The overall detection rates of HuNoV, O157 Shiga toxin-producing Escherichia coli (STEC, non-O157 STEC, Salmonella, and Listeria were 25.58, 7.91, 9.42, 59.65, and 44.30%, respectively. The detection rates of Salmonella and L. monocytogenes were significantly higher in the spring. Fall and spring had elevated detection rates of O157 STEC. The overall detection rates of non-O157 STEC in the fall were lower than the other seasons but not significant. The overall detection rates of HuNoV were highest in fall, followed by spring and winter, with summer being lowest and significantly lower than other seasons. This study presented the first study of evaluating the correlation between the detection rate of HuNoV and the detection rates of four bacterial pathogens from environmental water. Overall, there was no significant difference in HuNoV detection rates between samples testing positive or negative for the four bacterial pathogens tested. Pathogens in animal-impacted and human-impacted areas were investigated. There were significant higher detection rates in animal-impacted areas than that of human-impacted areas for bacterial pathogens. However, there was no difference in HuNoV detection rates between these two areas. The overall detection levels of generic E

  3. Rapid detection of Mannheimia haemolytica in lung tissues of sheep and from bacterial culture

    Directory of Open Access Journals (Sweden)

    Jyoti Kumar

    2015-09-01

    Full Text Available Aim: This study was aimed to detect Mannheimia haemolytica in lung tissues of sheep and from a bacterial culture. Introduction: M. haemolytica is one of the most important and well-established etiological agents of pneumonia in sheep and other ruminants throughout the world. Accurate diagnosis of M. haemolytica primarily relies on bacteriological examination, biochemical characteristics and, biotyping and serotyping of the isolates. In an effort to facilitate rapid M. haemolytica detection, polymerase chain reaction assay targeting Pasteurella haemolytica serotype-1 specific antigens (PHSSA, Rpt2 and 12S ribosomal RNA (rRNA genes were used to detect M. haemolytica directly from lung tissues and from bacterial culture. Materials and Methods: A total of 12 archived lung tissues from sheep that died of pneumonia on an organized farm were used. A multiplex polymerase chain reaction (mPCR based on two-amplicons targeted PHSSA and Rpt2 genes of M. haemolytica were used for identification of M. haemolytica isolates in culture from the lung samples. All the 12 lung tissue samples were tested for the presence M. haemolytica by PHSSA and Rpt2 genes based PCR and its confirmation by sequencing of the amplicons. Results: All the 12 lung tissue samples tested for the presence of PHSSA and Rpt2 genes of M. haemolytica by mPCR were found to be positive. Amplification of 12S rRNA gene fragment as internal amplification control was obtained with each mPCR reaction performed from DNA extracted directly from lung tissue samples. All the M. haemolytica were also positive for mPCR. No amplified DNA bands were observed for negative control reactions. All the three nucleotide sequences were deposited in NCBI GenBank (Accession No. KJ534629, KJ534630 and KJ534631. Sequencing of the amplified products revealed the identity of 99-100%, with published sequence of PHSSA and Rpt2 genes of M. haemolytica available in the NCBI database. Sheep specific mitochondrial 12S r

  4. Ionization detection system for aerosols

    International Nuclear Information System (INIS)

    Jacobs, M.E.

    1977-01-01

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber. 8 claims, 7 figures

  5. Microcontroller based driver alertness detection systems to detect drowsiness

    Science.gov (United States)

    Adenin, Hasibah; Zahari, Rahimi; Lim, Tiong Hoo

    2018-04-01

    The advancement of embedded system for detecting and preventing drowsiness in a vehicle is a major challenge for road traffic accident systems. To prevent drowsiness while driving, it is necessary to have an alert system that can detect a decline in driver concentration and send a signal to the driver. Studies have shown that traffc accidents usually occur when the driver is distracted while driving. In this paper, we have reviewed a number of detection systems to monitor the concentration of a car driver and propose a portable Driver Alertness Detection System (DADS) to determine the level of concentration of the driver based on pixelated coloration detection technique using facial recognition. A portable camera will be placed at the front visor to capture facial expression and the eye activities. We evaluate DADS using 26 participants and have achieved 100% detection rate with good lighting condition and a low detection rate at night.

  6. Long-Term Bacterial Dynamics in a Full-Scale Drinking Water Distribution System.

    Directory of Open Access Journals (Sweden)

    E I Prest

    Full Text Available Large seasonal variations in microbial drinking water quality can occur in distribution networks, but are often not taken into account when evaluating results from short-term water sampling campaigns. Temporal dynamics in bacterial community characteristics were investigated during a two-year drinking water monitoring campaign in a full-scale distribution system operating without detectable disinfectant residual. A total of 368 water samples were collected on a biweekly basis at the water treatment plant (WTP effluent and at one fixed location in the drinking water distribution network (NET. The samples were analysed for heterotrophic plate counts (HPC, Aeromonas plate counts, adenosine-tri-phosphate (ATP concentrations, and flow cytometric (FCM total and intact cell counts (TCC, ICC, water temperature, pH, conductivity, total organic carbon (TOC and assimilable organic carbon (AOC. Multivariate analysis of the large dataset was performed to explore correlative trends between microbial and environmental parameters. The WTP effluent displayed considerable seasonal variations in TCC (from 90 × 103 cells mL-1 in winter time up to 455 × 103 cells mL-1 in summer time and in bacterial ATP concentrations (<1-3.6 ng L-1, which were congruent with water temperature variations. These fluctuations were not detected with HPC and Aeromonas counts. The water in the network was predominantly influenced by the characteristics of the WTP effluent. The increase in ICC between the WTP effluent and the network sampling location was small (34 × 103 cells mL-1 on average compared to seasonal fluctuations in ICC in the WTP effluent. Interestingly, the extent of bacterial growth in the NET was inversely correlated to AOC concentrations in the WTP effluent (Pearson's correlation factor r = -0.35, and positively correlated with water temperature (r = 0.49. Collecting a large dataset at high frequency over a two year period enabled the characterization of previously

  7. Long-Term Bacterial Dynamics in a Full-Scale Drinking Water Distribution System

    KAUST Repository

    Prest, E. I.; Weissbrodt, D. G.; Hammes, F.; Van Loosdrecht, M. C M; Vrouwenvelder, Johannes S.

    2016-01-01

    Large seasonal variations in microbial drinking water quality can occur in distribution networks, but are often not taken into account when evaluating results from short-term water sampling campaigns. Temporal dynamics in bacterial community characteristics were investigated during a two-year drinking water monitoring campaign in a full-scale distribution system operating without detectable disinfectant residual. A total of 368 water samples were collected on a biweekly basis at the water treatment plant (WTP) effluent and at one fixed location in the drinking water distribution network (NET). The samples were analysed for heterotrophic plate counts (HPC), Aeromonas plate counts, adenosine-tri-phosphate (ATP) concentrations, and flow cytometric (FCM) total and intact cell counts (TCC, ICC), water temperature, pH, conductivity, total organic carbon (TOC) and assimilable organic carbon (AOC). Multivariate analysis of the large dataset was performed to explore correlative trends between microbial and environmental parameters. The WTP effluent displayed considerable seasonal variations in TCC (from 90 × 103 cells mL-1 in winter time up to 455 × 103 cells mL-1 in summer time) and in bacterial ATP concentrations (<1–3.6 ng L-1), which were congruent with water temperature variations. These fluctuations were not detected with HPC and Aeromonas counts. The water in the network was predominantly influenced by the characteristics of the WTP effluent. The increase in ICC between the WTP effluent and the network sampling location was small (34 × 103 cells mL-1 on average) compared to seasonal fluctuations in ICC in the WTP effluent. Interestingly, the extent of bacterial growth in the NET was inversely correlated to AOC concentrations in the WTP effluent (Pearson’s correlation factor r = -0.35), and positively correlated with water temperature (r = 0.49). Collecting a large dataset at high frequency over a two year period enabled the characterization of previously

  8. Long-Term Bacterial Dynamics in a Full-Scale Drinking Water Distribution System.

    Science.gov (United States)

    Prest, E I; Weissbrodt, D G; Hammes, F; van Loosdrecht, M C M; Vrouwenvelder, J S

    2016-01-01

    Large seasonal variations in microbial drinking water quality can occur in distribution networks, but are often not taken into account when evaluating results from short-term water sampling campaigns. Temporal dynamics in bacterial community characteristics were investigated during a two-year drinking water monitoring campaign in a full-scale distribution system operating without detectable disinfectant residual. A total of 368 water samples were collected on a biweekly basis at the water treatment plant (WTP) effluent and at one fixed location in the drinking water distribution network (NET). The samples were analysed for heterotrophic plate counts (HPC), Aeromonas plate counts, adenosine-tri-phosphate (ATP) concentrations, and flow cytometric (FCM) total and intact cell counts (TCC, ICC), water temperature, pH, conductivity, total organic carbon (TOC) and assimilable organic carbon (AOC). Multivariate analysis of the large dataset was performed to explore correlative trends between microbial and environmental parameters. The WTP effluent displayed considerable seasonal variations in TCC (from 90 × 103 cells mL-1 in winter time up to 455 × 103 cells mL-1 in summer time) and in bacterial ATP concentrations (water temperature variations. These fluctuations were not detected with HPC and Aeromonas counts. The water in the network was predominantly influenced by the characteristics of the WTP effluent. The increase in ICC between the WTP effluent and the network sampling location was small (34 × 103 cells mL-1 on average) compared to seasonal fluctuations in ICC in the WTP effluent. Interestingly, the extent of bacterial growth in the NET was inversely correlated to AOC concentrations in the WTP effluent (Pearson's correlation factor r = -0.35), and positively correlated with water temperature (r = 0.49). Collecting a large dataset at high frequency over a two year period enabled the characterization of previously undocumented seasonal dynamics in the distribution

  9. Long-Term Bacterial Dynamics in a Full-Scale Drinking Water Distribution System

    KAUST Repository

    Prest, E. I.

    2016-10-28

    Large seasonal variations in microbial drinking water quality can occur in distribution networks, but are often not taken into account when evaluating results from short-term water sampling campaigns. Temporal dynamics in bacterial community characteristics were investigated during a two-year drinking water monitoring campaign in a full-scale distribution system operating without detectable disinfectant residual. A total of 368 water samples were collected on a biweekly basis at the water treatment plant (WTP) effluent and at one fixed location in the drinking water distribution network (NET). The samples were analysed for heterotrophic plate counts (HPC), Aeromonas plate counts, adenosine-tri-phosphate (ATP) concentrations, and flow cytometric (FCM) total and intact cell counts (TCC, ICC), water temperature, pH, conductivity, total organic carbon (TOC) and assimilable organic carbon (AOC). Multivariate analysis of the large dataset was performed to explore correlative trends between microbial and environmental parameters. The WTP effluent displayed considerable seasonal variations in TCC (from 90 × 103 cells mL-1 in winter time up to 455 × 103 cells mL-1 in summer time) and in bacterial ATP concentrations (<1–3.6 ng L-1), which were congruent with water temperature variations. These fluctuations were not detected with HPC and Aeromonas counts. The water in the network was predominantly influenced by the characteristics of the WTP effluent. The increase in ICC between the WTP effluent and the network sampling location was small (34 × 103 cells mL-1 on average) compared to seasonal fluctuations in ICC in the WTP effluent. Interestingly, the extent of bacterial growth in the NET was inversely correlated to AOC concentrations in the WTP effluent (Pearson’s correlation factor r = -0.35), and positively correlated with water temperature (r = 0.49). Collecting a large dataset at high frequency over a two year period enabled the characterization of previously

  10. An empirical strategy to detect bacterial transcript structure from directional RNA-seq transcriptome data.

    Science.gov (United States)

    Wang, Yejun; MacKenzie, Keith D; White, Aaron P

    2015-05-07

    As sequencing costs are being lowered continuously, RNA-seq has gradually been adopted as the first choice for comparative transcriptome studies with bacteria. Unlike microarrays, RNA-seq can directly detect cDNA derived from mRNA transcripts at a single nucleotide resolution. Not only does this allow researchers to determine the absolute expression level of genes, but it also conveys information about transcript structure. Few automatic software tools have yet been established to investigate large-scale RNA-seq data for bacterial transcript structure analysis. In this study, 54 directional RNA-seq libraries from Salmonella serovar Typhimurium (S. Typhimurium) 14028s were examined for potential relationships between read mapping patterns and transcript structure. We developed an empirical method, combined with statistical tests, to automatically detect key transcript features, including transcriptional start sites (TSSs), transcriptional termination sites (TTSs) and operon organization. Using our method, we obtained 2,764 TSSs and 1,467 TTSs for 1331 and 844 different genes, respectively. Identification of TSSs facilitated further discrimination of 215 putative sigma 38 regulons and 863 potential sigma 70 regulons. Combining the TSSs and TTSs with intergenic distance and co-expression information, we comprehensively annotated the operon organization in S. Typhimurium 14028s. Our results show that directional RNA-seq can be used to detect transcriptional borders at an acceptable resolution of ±10-20 nucleotides. Technical limitations of the RNA-seq procedure may prevent single nucleotide resolution. The automatic transcript border detection methods, statistical models and operon organization pipeline that we have described could be widely applied to RNA-seq studies in other bacteria. Furthermore, the TSSs, TTSs, operons, promoters and unstranslated regions that we have defined for S. Typhimurium 14028s may constitute valuable resources that can be used for

  11. Diagnostic Accuracy of Ascites Fluid Gross Appearance in Detection of Spontaneous Bacterial Peritonitis.

    Science.gov (United States)

    Aminiahidashti, Hamed; Hosseininejad, Seyed Mohammad; Montazer, Hosein; Bozorgi, Farzad; Goli Khatir, Iraj; Jahanian, Fateme; Raee, Behnaz

    2014-01-01

    Spontaneous bacterial peritonitis (SBP) as a monomicrobial infection of ascites fluid is one of the most important causes of morbidity and mortality in cirrhotic patients. This study was aimed to determine the diagnostic accuracy of ascites fluid color in detection of SBP in cirrhotic cases referred to the emergency department. Cirrhotic patients referred to the ED for the paracentesis of ascites fluid were enrolled. For all studied patients, the results of laboratory analysis and gross appearance of ascites fluid registered and reviewed by two emergency medicine specialists. The sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ration of the ascites fluid gross appearance in detection of SBP were measured with 95% confidence interval. The present project was performed in 80 cirrhotic patients with ascites (52.5 female). The mean of the subjects' age was 56.25±12.21 years (35-81). Laboratory findings revealed SBP in 23 (29%) cases. Fifty nine (73%) cases had transparent ascites fluid appearance of whom 17 (29%) ones suffered from SBP. From 21 (26%) cases with opaque ascites appearance, 15 (71%) had SBP. The sensitivity and specificity of the ascites fluid appearance in detection of SBP were 46.88% (Cl: 30.87-63.55) and 87.50% (95% Cl: 75.3-94.14), respectively. It seems that the gross appearance of ascites fluid had poor diagnostic accuracy in detection of SBP and considering its low sensitivity, it could not be used as a good screening tool for this propose.

  12. Diagnostic Accuracy of Ascites Fluid Gross Appearance in Detection of Spontaneous Bacterial Peritonitis

    Directory of Open Access Journals (Sweden)

    Hamed Aminiahidashti

    2014-08-01

    Full Text Available Introduction: Spontaneous bacterial peritonitis (SBP as a monomicrobial infection of ascites fluid is one of the most important causes of morbidity and mortality in cirrhotic patients. This study was aimed to determine the diagnostic accuracy of ascites fluid color in detection of SBP in cirrhotic cases referred to the emergency department. Methods: Cirrhotic patients referred to the ED for the paracentesis of ascites fluid were enrolled. For all studied patients, the results of laboratory analysis and gross appearance of ascites fluid registered and reviewed by two emergency medicine specialists. The sensitivity, specificity, positive and negative predictive value, and positive and negative likelihood ration of the ascites fluid gross appearance in detection of SBP were measured with 95% confidence interval. Results: The present project was performed in 80 cirrhotic patients with ascites (52.5 female. The mean of the subjects’ age was 56.25±12.21 years (35-81. Laboratory findings revealed SBP in 23 (29% cases. Fifty nine (73% cases had transparent ascites fluid appearance of whom 17 (29% ones suffered from SBP. From 21 (26% cases with opaque ascites appearance, 15 (71% had SBP. The sensitivity and specificity of the ascites fluid appearance in detection of SBP were 46.88% (Cl: 30.87-63.55 and 87.50% (95% Cl: 75.3-94.14, respectively. Conclusion: It seems that the gross appearance of ascites fluid had poor diagnostic accuracy in detection of SBP and considering its low sensitivity, it could not be used as a good screening tool for this propose.

  13. Evaluation of two real time PCR assays for the detection of bacterial DNA in amniotic fluid.

    Science.gov (United States)

    Girón de Velasco-Sada, Patricia; Falces-Romero, Iker; Quiles-Melero, Inmaculada; García-Perea, Adela; Mingorance, Jesús

    2018-01-01

    The aim of this study was to evaluate two non-commercial Real-Time PCR assays for the detection of microorganisms in amniotic fluid followed by identification by pyrosequencing. We collected 126 amniotic fluids from 2010 to 2015 for the evaluation of two Real-Time PCR assays for detection of bacterial DNA in amniotic fluid (16S Universal PCR and Ureaplasma spp. specific PCR). The method was developed in the Department of Microbiology of the University Hospital La Paz. Thirty-seven samples (29.3%) were positive by PCR/pyrosequencing and/or culture, 4 of them were mixed cultures with Ureaplasma urealyticum. The Universal 16S Real-Time PCR was compared with the standard culture (81.8% sensitivity, 97.4% specificity, 75% positive predictive value, 98% negative predictive value). The Ureaplasma spp. specific Real-Time PCR was compared with the Ureaplasma/Mycoplasma specific culture (92.3% sensitivity, 89.4% specificity, 50% positive predictive value, 99% negative predictive value) with statistically significant difference (p=0.005). Ureaplasma spp. PCR shows a rapid response time (5h from DNA extraction until pyrosequencing) when comparing with culture (48h). So, the response time of bacteriological diagnosis in suspected chorioamnionitis is reduced. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Engineering Rugged Field Assays to Detect Hazardous Chemicals Using Spore-Based Bacterial Biosensors.

    Science.gov (United States)

    Wynn, Daniel; Deo, Sapna; Daunert, Sylvia

    2017-01-01

    Bacterial whole cell-based biosensors have been genetically engineered to achieve selective and reliable detection of a wide range of hazardous chemicals. Although whole-cell biosensors demonstrate many advantages for field-based detection of target analytes, there are still some challenges that need to be addressed. Most notably, their often modest shelf life and need for special handling and storage make them challenging to use in situations where access to reagents, instrumentation, and expertise are limited. These problems can be circumvented by developing biosensors in Bacillus spores, which can be engineered to address all of these concerns. In its sporulated state, a whole cell-based biosensor has a remarkably long life span and is exceptionally resistant to environmental insult. When these spores are germinated for use in analytical techniques, they show no loss in performance, even after long periods of storage under harsh conditions. In this chapter, we will discuss the development and use of whole cell-based sensors, their adaptation to spore-based biosensors, their current applications, and future directions in the field. © 2017 Elsevier Inc. All rights reserved.

  15. Detection of NASBA amplified bacterial tmRNA molecules on SLICSel designed microarray probes

    Directory of Open Access Journals (Sweden)

    Toome Kadri

    2011-02-01

    Full Text Available Abstract Background We present a comprehensive technological solution for bacterial diagnostics using tmRNA as a marker molecule. A robust probe design algorithm for microbial detection microarray is implemented. The probes were evaluated for specificity and, combined with NASBA (Nucleic Acid Sequence Based Amplification amplification, for sensitivity. Results We developed a new web-based program SLICSel for the design of hybridization probes, based on nearest-neighbor thermodynamic modeling. A SLICSel minimum binding energy difference criterion of 4 kcal/mol was sufficient to design of Streptococcus pneumoniae tmRNA specific microarray probes. With lower binding energy difference criteria, additional hybridization specificity tests on the microarray were needed to eliminate non-specific probes. Using SLICSel designed microarray probes and NASBA we were able to detect S. pneumoniae tmRNA from a series of total RNA dilutions equivalent to the RNA content of 0.1-10 CFU. Conclusions The described technological solution and both its separate components SLICSel and NASBA-microarray technology independently are applicative for many different areas of microbial diagnostics.

  16. Detection of NASBA amplified bacterial tmRNA molecules on SLICSel designed microarray probes

    LENUS (Irish Health Repository)

    Scheler, Ott

    2011-02-28

    Abstract Background We present a comprehensive technological solution for bacterial diagnostics using tmRNA as a marker molecule. A robust probe design algorithm for microbial detection microarray is implemented. The probes were evaluated for specificity and, combined with NASBA (Nucleic Acid Sequence Based Amplification) amplification, for sensitivity. Results We developed a new web-based program SLICSel for the design of hybridization probes, based on nearest-neighbor thermodynamic modeling. A SLICSel minimum binding energy difference criterion of 4 kcal\\/mol was sufficient to design of Streptococcus pneumoniae tmRNA specific microarray probes. With lower binding energy difference criteria, additional hybridization specificity tests on the microarray were needed to eliminate non-specific probes. Using SLICSel designed microarray probes and NASBA we were able to detect S. pneumoniae tmRNA from a series of total RNA dilutions equivalent to the RNA content of 0.1-10 CFU. Conclusions The described technological solution and both its separate components SLICSel and NASBA-microarray technology independently are applicative for many different areas of microbial diagnostics.

  17. Implementation of immunomagnetic separation (IMS) for the enrichment and automated detection of bacterial contaminants in flow through lab on the chip technology

    DEFF Research Database (Denmark)

    Ahmed, Shakil

    Due to an increased public concern for food safety and quality, food processing industries have an urgent need for fast and reliable contaminant detection technologies. Conventional pathogen detection methods are time consuming, cost intensive, require skilled laboratory workers and are inappropr...... and detect pathogens in food, feed or beverage industries in real-time and has the potential to offer significant advantages compared to conventional systems.......Due to an increased public concern for food safety and quality, food processing industries have an urgent need for fast and reliable contaminant detection technologies. Conventional pathogen detection methods are time consuming, cost intensive, require skilled laboratory workers...... diacetate (CFDA) was used to evaluate the viability of the cell. Under final optimized condition, the developed method showed 98 % capture efficiency towards the specific antigen Salmonella Typhimurium and very low (target bacterial strains. Subsequently, IMS was implemented...

  18. Detection of Pneumocystis DNA in samples from patients suspected of bacterial pneumonia--a case-control study

    DEFF Research Database (Denmark)

    Helweg-Larsen, Jannik; Jensen, Jørgen Skov; Dohn, Birthe

    2002-01-01

    Pneumocystis jiroveci (formerly known as P. carinii f.sp. hominis) is an opportunistic fungus that causes Pneumocystis pneumonia (PCP) in immunocompromised individuals. Pneumocystis jiroveci can be detected by polymerase chain reaction (PCR). To investigate the clinical importance of a positive P...... Pneumocystis-PCR among HIV-uninfected patients suspected of bacterial pneumonia, a retrospective matched case-control study was conducted....

  19. Nuclear detection systems in traffic

    International Nuclear Information System (INIS)

    Farkas, T.; Pernicka, L.; Svec, A.

    2005-01-01

    Illicit trafficking in nuclear materials (nuclear criminality) has become a problem, due to the circulation of a high number of radioactive sources caused by the changes of the organisational infrastructures to supervise these material within the successor states of the former Soviet Union. Aim of this paper is to point out the technical requirements and the practicability of an useful monitoring system at preselected traffic check points (railway and highway border crossings, industrial sites entry gates, international airports). The ITRAP lab test was designed to work as strict benchmark to qualify border monitoring systems 67 with very low false alarm rates, in addition the minimum sensitivity to give an alarm has been defined for fix-installed systems, pocket type and hand held instruments. For the neutron tests a special prepared Californium source ( 252 Cf) was used to simulate the weapons plutonium. The source is shielded against gamma radiation, use a moderator and provides the required neutron rate of 20000 n/s at 2 rn distance. To test the false alarm rate (rate of false positive ) the same test facility , under the same background conditions, was used but without a radioactive test source. The ITRAP lab tests for the fix-installed systems started at May 1998 and first results were given in September 1998. Only 2 of 14 fix-installed monitoring systems could fulfil the minimum requirement for neutron detection. 7 of 14 fix-installed monitoring systems (50%) passed the ITRAP lab test. The analytical method developed and used for certification of installed radiation monitors in the Slovak Institute of Metrology consists in measurement of radiation activity of selected radionuclide in defined conditions. (authors)

  20. Bacterial communities in the collection and chlorinated distribution sections of a drinking water system in Budapest, Hungary.

    Science.gov (United States)

    Homonnay, Zalán G; Török, György; Makk, Judit; Brumbauer, Anikó; Major, Eva; Márialigeti, Károly; Tóth, Erika

    2014-07-01

    Bacterial communities of a bank-filtered drinking water system were investigated by aerobic cultivation and clone library analysis. Moreover, bacterial communities were compared using sequence-aided terminal restriction fragment length polymorphism (T-RFLP) fingerprinting at ten characteristic points located at both the collecting and the distributing part of the water supply system. Chemical characteristics of the samples were similar, except for the presence of chlorine residuals in the distribution system and increased total iron concentration in two of the samples. Assimilable organic carbon (AOC) concentration increased within the collection system, it was reduced by chlorination and it increased again in the distribution system. Neither fecal indicators nor pathogens were detected by standard cultivation techniques. Chlorination reduced bacterial diversity and heterotrophic plate counts. Community structures were found to be significantly different before and after chlorination: the diverse communities in wells and the collection system were dominated by chemolithotrophic (e.g., Gallionella and Nitrospira) and oligocarbophilic-heterotrophic bacteria (e.g., Sphingomonas, Sphingopyxis, and Bradyrhizobium). After chlorination in the distribution system, the most characteristic bacterium was related to the facultative methylotrophic Methylocella spp. Communities changed within the distribution system too, Mycobacterium spp. or Sphingopyxis spp. became predominant in certain samples. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Live bacterial delivery systems for development of mucosal vaccines

    NARCIS (Netherlands)

    Thole, J.E.R.; Dalen, P.J. van; Havenith, C.E.G.; Pouwels, P.H.; Seegers, J.F.M.L.; Tielen, F.D.; Zee, M.D. van der; Zegers, N.D.; Shaw, M.

    2000-01-01

    By expression of foreign antigens in attenuated strains derived from bacterial pathogens and in non-pathogenic commensal bacteria, recombinant vaccines are being developed that aim to stimulate mucosal immunity. Recent advances in the pathogenesis and molecular biology of these bacteria have allowed

  2. Parallel reaction monitoring on a Q Exactive mass spectrometer increases reproducibility of phosphopeptide detection in bacterial phosphoproteomics measurements.

    Science.gov (United States)

    Taumer, Christoph; Griesbaum, Lena; Kovacevic, Alen; Soufi, Boumediene; Nalpas, Nicolas C; Macek, Boris

    2018-03-29

    Increasing number of studies report the relevance of protein Ser/Thr/Tyr phosphorylation in bacterial physiology, yet the analysis of this type of modification in bacteria still presents a considerable challenge. Unlike in eukaryotes, where tens of thousands of phosphorylation events likely occupy more than two thirds of the proteome, the abundance of protein phosphorylation is much lower in bacteria. Even the state-of-the-art phosphopeptide enrichment protocols fail to remove the high background of abundant unmodified peptides, leading to low signal intensity and undersampling of phosphopeptide precursor ions in consecutive data-dependent MS runs. Consequently, large-scale bacterial phosphoproteomic datasets often suffer from poor reproducibility and a high number of missing values. Here we explore the application of parallel reaction monitoring (PRM) on a Q Exactive mass spectrometer in bacterial phosphoproteome analysis, focusing especially on run-to-run sampling reproducibility. In multiple measurements of identical phosphopeptide-enriched samples, we show that PRM outperforms data-dependent acquisition (DDA) in terms of detection frequency, reaching almost complete sampling efficiency, compared to 20% in DDA. We observe a similar trend over multiple heterogeneous phosphopeptide-enriched samples and conclude that PRM shows a great promise in bacterial phosphoproteomics analyses where reproducible detection and quantification of a relatively small set of phosphopeptides is desired. Bacterial phosphorylated peptides occur in low abundance compared to their unmodified counterparts, and are therefore rarely reproducibly detected in shotgun (DDA) proteomics measurements. Here we show that parallel reaction monitoring complements DDA analyses and makes detection of known, targeted phosphopeptides more reproducible. This will be of significance in replicated MS measurements that have a goal to reproducibly detect and quantify phosphopeptides of interest. Copyright

  3. Thermal animal detection system (TADS)

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M.

    2003-03-01

    This report presents data from equipment tests and software development for the Thermal Animal Detection System (TADS) development project: 'Development of a method for estimating collision frequency between migrating birds and offshore wind turbines'. The technical tests were performed to investigate the performance of remote controlling, video file compression tool and physical stress of the thermal camera when operating outdoors and under the real time vibration conditions at a 2 MW turbine. Furthermore, experimental tests on birds were performed to describe the decreasing detectability with distance on free flying birds, the performance of the thermal camera during poor visibility, and finally, the performance of the thermal sensor software developed for securing high -quality data. In general, it can be concluded that the thermal camera and its related hardware and software, the TADS, are capable of recording migrating birds approaching the rotating blades of a turbine, even under conditions with poor visibility. If the TADS is used in a vertical viewing scenario it would comply with the requirements for a setup used for estimating the avian collision frequency at offshore wind turbines. (au)

  4. Thermal animal detection system (TADS)

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M

    2003-03-01

    This report presents data from equipment tests and software development for the Thermal Animal Detection System (TADS) development project: 'Development of a method for estimating collision frequency between migrating birds and offshore wind turbines'. The technical tests were performed to investigate the performance of remote controlling, video file compression tool and physical stress of the thermal camera when operating outdoors and under the real time vibration conditions at a 2 MW turbine. Furthermore, experimental tests on birds were performed to describe the decreasing detectability with distance on free flying birds, the performance of the thermal camera during poor visibility, and finally, the performance of the thermal sensor software developed for securing high -quality data. In general, it can be concluded that the thermal camera and its related hardware and software, the TADS, are capable of recording migrating birds approaching the rotating blades of a turbine, even under conditions with poor visibility. If the TADS is used in a vertical viewing scenario it would comply with the requirements for a setup used for estimating the avian collision frequency at offshore wind turbines. (au)

  5. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit, E-mail: amgross@exchange.bgu.ac.il

    2016-08-15

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) – a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0–9.7 × 10{sup 4} CFU m{sup −2} h{sup −1}) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1 m away from the GW systems. At the 5 m distance amounts of these bacteria were not statistically different (p > 0.05) from background concentrations tested over 50 m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques

  6. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems

    International Nuclear Information System (INIS)

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit

    2016-01-01

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) – a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0–9.7 × 10"4 CFU m"−"2 h"−"1) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1 m away from the GW systems. At the 5 m distance amounts of these bacteria were not statistically different (p > 0.05) from background concentrations tested over 50 m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide

  7. Membrane Lipids as Indicators for Viable Bacterial Communities Inhabiting Petroleum Systems.

    Science.gov (United States)

    Gruner, Andrea; Mangelsdorf, Kai; Vieth-Hillebrand, Andrea; Horsfield, Brian; van der Kraan, Geert M; Köhler, Thomas; Janka, Christoph; Morris, Brandon E L; Wilkes, Heinz

    2017-08-01

    Microbial activity in petroleum reservoirs has been implicated in a suite of detrimental effects including deterioration of petroleum quality, increases in oil sulfur content, biofouling of steel pipelines and other infrastructures, and well plugging. Here, we present a biogeochemical approach, using phospholipid fatty acids (PLFAs), for detecting viable bacteria in petroleum systems. Variations within the bacterial community along water flow paths (producing well, topside facilities, and injection well) can be elucidated in the field using the same technique, as shown here within oil production plants in the Molasse Basin of Upper Austria. The abundance of PLFAs is compared to total cellular numbers, as detected by qPCR of the 16S rDNA gene, to give an overall comparison between the resolutions of both methods in a true field setting. Additionally, the influence of biocide applications on lipid- and DNA-based quantification was investigated. The first oil field, Trattnach, showed significant PLFA abundances and cell numbers within the reservoir and topside facilities. In contrast, the second field (Engenfeld) showed very low PLFA levels overall, likely due to continuous treatment of the topside facilities with a glutaraldehyde-based antimicrobial. In comparison, Trattnach is dosed once per week in a batch fashion. Changes within PLFA compositions across the flow path, throughout the petroleum production plants, point to cellular adaptation within the system and may be linked to shifts in the dominance of certain bacterial types in oil reservoirs versus topside facilities. Overall, PLFA-based monitoring provides a useful tool to assess the abundance and high-level taxonomic diversity of viable microbial populations in oil production wells, topside infrastructure, pipelines, and other related facilities.

  8. Utility of the serum C-reactive protein for detection of occult bacterial infection in children.

    Science.gov (United States)

    Isaacman, Daniel J; Burke, Bonnie L

    2002-09-01

    To assess the utility of serum C-reactive protein (CRP) as a screen for occult bacterial infection in children. Febrile children ages 3 to 36 months who visited an urban children's hospital emergency department and received a complete blood cell count and blood culture as part of their evaluation were prospectively enrolled from February 2, 2000, through May 30, 2001. Informed consent was obtained for the withdrawal of an additional 1-mL aliquot of blood for use in CRP evaluation. Logistic regression and receiver operator characteristic (ROC) curves were modeled for each predictor to identify optimal test values, and were compared using likelihood ratio tests. Two hundred fifty-six patients were included in the analysis, with a median age of 15.3 months (range, 3.1-35.2 months) and median temperature at triage 40.0 degrees C (range, 39.0 degrees C-41.3 degrees C). Twenty-nine (11.3%) cases of occult bacterial infection (OBI) were identified, including 17 cases of pneumonia, 9 cases of urinary tract infection, and 3 cases of bacteremia. The median white blood cell count in this data set was 12.9 x 10(3)/ micro L [corrected] (range, 3.6-39.1 x10(3)/ micro L) [corrected], the median absolute neutrophil count (ANC) was 7.12 x 10(3)/L [corrected] (range, 0.56-28.16 x10(3)/L) [corrected], and the median CRP level was 1.7 mg/dL (range, 0.2-43.3 mg/dL). The optimal cut-off point for CRP in this data set (4.4 mg/dL) achieved a sensitivity of 63% and a specificity of 81% for detection of OBI in this population. Comparing models using cut-off values from individual laboratory predictors (ANC, white blood cell count, and CRP) that maximized sensitivity and specificity revealed that a model using an ANC of 10.6 x10(3)/L [corrected] (sensitivity, 69%; specificity, 79%) was the best predictive model. Adding CRP to the model insignificantly increased sensitivity to 79%, while significantly decreasing specificity to 50%. Active monitoring of emergency department blood cultures

  9. Simultaneous amplification of two bacterial genes: more reliable method of Helicobacter pylori detection in microbial rich dental plaque samples.

    Science.gov (United States)

    Chaudhry, Saima; Idrees, Muhammad; Izhar, Mateen; Butt, Arshad Kamal; Khan, Ayyaz Ali

    2011-01-01

    Polymerase Chain reaction (PCR) assay is considered superior to other methods for detection of Helicobacter pylori (H. pylori) in oral cavity; however, it also has limitations when sample under study is microbial rich dental plaque. The type of gene targeted and number of primers used for bacterial detection in dental plaque samples can have a significant effect on the results obtained as there are a number of closely related bacterial species residing in plaque biofilm. Also due to high recombination rate of H. pylori some of the genes might be down regulated or absent. The present study was conducted to determine the frequency of H. pylori colonization of dental plaque by simultaneously amplifying two genes of the bacterium. One hundred dental plaque specimens were collected from dyspeptic patients before their upper gastrointestinal endoscopy and presence of H. pylori was determined through PCR assay using primers targeting two different genes of the bacterium. Eighty-nine of the 100 samples were included in final analysis. With simultaneous amplification of two bacterial genes 51.6% of the dental plaque samples were positive for H. pylori while this prevalence increased to 73% when only one gene amplification was used for bacterial identification. Detection of H. pylori in dental plaque samples is more reliable when two genes of the bacterium are simultaneously amplified as compared to one gene amplification only.

  10. Detection of hepatitis A virus and bacterial contamination in raw oysters in Thailand.

    Science.gov (United States)

    Kittigul, Leera; Pombubpa, Kannika; Sukonthalux, Suntharee; Rattanatham, Tippawan; Utrarachkij, Fuangfa; Diraphat, Pornphan

    2010-01-01

    This study was conducted to determine the presence of hepatitis A virus (HAV) in raw oysters (Crassostrea belcheri) using a virus concentration method and reverse transcription-nested polymerase chain reaction (RT-nested PCR). A total of 220 oyster samples were collected from oyster farms and local markets in Thailand. HAV was found in three oyster samples. Nested PCR products of HAV detected in oysters were characterized further by DNA sequencing of the VP1/2A region and subjected to phylogenetic analysis. All HAV sequences (168 basepairs) were associated with human HAV subgenotype IB (GIB). Fecal coliforms and Escherichia coli were determined using the multiple tube fermentation method, to assess the microbiological quality of collected oysters. Among oyster samples tested, 65% had fecal coliforms higher than the standard level for raw shellfish [oyster samples (85%) were contaminated with E. coli in the range of 3.0-4.6 x 10(4) MPN/g. One oyster sample with an acceptable level of fecal coliforms contained HAV GIB. E. coli was found in all HAV-positive oyster samples. The results suggest a significant presence of HAV and bacterial indicators of fecal contamination in raw oysters, which are a health risk for consumers and a source of gastrointestinal illness. Enteric viruses should also be tested to assess the microbiological quality of oysters.

  11. Phytoplankton production systems in a shellfish hatchery: variations of the bacterial load and diversity of vibrios.

    Science.gov (United States)

    Dubert, J; Fernández-Pardo, A; Nóvoa, S; Barja, J L; Prado, S

    2015-06-01

    Outbreaks of disease caused by some Vibrio species represent the main production bottleneck in shellfish hatcheries. Although the phytoplankton used as food is one of the main sources of bacteria, studies of the associated bacterial populations, specifically vibrios, are scarce. The aim of the study was the microbiological monitoring of the microalgae as the first step in assessing the risk disease for bivalve cultures. Two phytoplankton production systems were sampled weekly throughout 1-year period in a bivalve hatchery. Quantitative analysis revealed high levels of marine heterotrophic bacteria in both systems throughout the study. Presumptive vibrios were detected occasionally and at low concentrations. In most of the cases, they belonged to the Splendidus and Harveyi clades. The early detection of vibrios in the microalgae may be the key for a successful bivalve culture. Their abundance and diversity were affected by factors related to the hatchery environment. This work represents the first long study where the presence of vibrios was evaluated rigorously in phytoplankton production systems and provides a suitable microbiological protocol to control and guarantee the quality of the algal cultures to avoid the risk of transferring potential pathogens to shellfish larvae and/or broodstock. © 2015 The Society for Applied Microbiology.

  12. Nanobiocomposite platform based on polyaniline-iron oxide-carbon nanotubes for bacterial detection.

    Science.gov (United States)

    Singh, Renu; Verma, Rachna; Sumana, G; Srivastava, Avanish Kumar; Sood, Seema; Gupta, Rajinder K; Malhotra, B D

    2012-08-01

    The nanocomposite based on polyaniline (PANI)-iron oxide nanoparticles (nFe(3)O(4)) and multi walled carbon-nanotubes (CNT) has been fabricated onto indium tin oxide (ITO) coated glass plate via facile electrochemical synthesis of polyaniline in presence of nFe(3)O(4) (~20 nm) and CNT (20-80 nm in diameter). The results of transmission electron microscopic studies show evidence of coating of PANI and nFe(3)O(4) onto the CNT. The PANI-nFe(3)O(4)-CNT/ITO nanoelectrode has been characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy studies. The biotinylated nucleic acid probe sequence consisting of 20 bases has been immobilized onto PANI-nFe(3)O(4)-CNT/ITO nanoelectrode using biotin-avidin coupling. It is shown that the PANI-nFe(3)O(4)-CNT platform based biosensor can be used to specifically detect bacteria (N. gonorrhoeae) at minute concentration as low as (1×10(-19) M) indicating high sensitivity within 45 s of hybridization time at 298 K by differential pulse voltammetry using methylene blue as electroactive indicator. This bacterial sensor has also been tested with 4 positive and 4 negative PCR amplicons of gonorrhoea affected patient samples. The results of these studies have implications towards the fabrication of a handheld device for Neisseria gonorrhoeae detection that may perhaps result in a decrease in the human immunodeficiency virus infections. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. A novel multiplex PCR assay for simultaneous detection of nine clinically significant bacterial pathogens associated with bovine mastitis.

    Science.gov (United States)

    Ashraf, Aqeela; Imran, Muhammad; Yaqub, Tahir; Tayyab, Muhammad; Shehzad, Wasim; Thomson, Peter C

    2017-06-01

    For rapid and simultaneous detection of nine bovine mastitic pathogens, a sensitive and specific multiplex PCR assay was developed. The assay was standardized using reference strains and validated on mastitic milk cultures which were identified to species level based on 16S rRNA sequencing. Multiplex PCR assay also efficiently detected the target bacterial strains directly from milk. The detection limit of the assay was up to 50 pg for DNA isolated from pure cultures and 10 4  CFU/ml for spiked milk samples. As estimated by latent class analysis, the assay was sensitive up to 88% and specific up to 98% for targeted mastitic pathogens, compared with the bacterial culture method and the 16S rRNA sequence analysis. This novel molecular assay could be useful for monitoring and maintaining the bovine udder health, ensuring the bacteriological safety of milk, and conducting epidemiological studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Bacterial communities in full-scale wastewater treatment systems

    OpenAIRE

    Cydzik-Kwiatkowska, Agnieszka; Zieli?ska, Magdalena

    2016-01-01

    Bacterial metabolism determines the effectiveness of biological treatment of wastewater. Therefore, it is important to define the relations between the species structure and the performance of full-scale installations. Although there is much laboratory data on microbial consortia, our understanding of dependencies between the microbial structure and operational parameters of full-scale wastewater treatment plants (WWTP) is limited. This mini-review presents the types of microbial consortia in...

  15. 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...

  16. Generalized Detectability for Discrete Event Systems

    Science.gov (United States)

    Shu, Shaolong; Lin, Feng

    2011-01-01

    In our previous work, we investigated detectability of discrete event systems, which is defined as the ability to determine the current and subsequent states of a system based on observation. For different applications, we defined four types of detectabilities: (weak) detectability, strong detectability, (weak) periodic detectability, and strong periodic detectability. In this paper, we extend our results in three aspects. (1) We extend detectability from deterministic systems to nondeterministic systems. Such a generalization is necessary because there are many systems that need to be modeled as nondeterministic discrete event systems. (2) We develop polynomial algorithms to check strong detectability. The previous algorithms are based on observer whose construction is of exponential complexity, while the new algorithms are based on a new automaton called detector. (3) We extend detectability to D-detectability. While detectability requires determining the exact state of a system, D-detectability relaxes this requirement by asking only to distinguish certain pairs of states. With these extensions, the theory on detectability of discrete event systems becomes more applicable in solving many practical problems. PMID:21691432

  17. Convergent bacterial microbiotas in the fungal agricultural systems of insects.

    Science.gov (United States)

    Aylward, Frank O; Suen, Garret; Biedermann, Peter H W; Adams, Aaron S; Scott, Jarrod J; Malfatti, Stephanie A; Glavina del Rio, Tijana; Tringe, Susannah G; Poulsen, Michael; Raffa, Kenneth F; Klepzig, Kier D; Currie, Cameron R

    2014-11-18

    The ability to cultivate food is an innovation that has produced some of the most successful ecological strategies on the planet. Although most well recognized in humans, where agriculture represents a defining feature of civilization, species of ants, beetles, and termites have also independently evolved symbioses with fungi that they cultivate for food. Despite occurring across divergent insect and fungal lineages, the fungivorous niches of these insects are remarkably similar, indicating convergent evolution toward this successful ecological strategy. Here, we characterize the microbiota of ants, beetles, and termites engaged in nutritional symbioses with fungi to define the bacterial groups associated with these prominent herbivores and forest pests. Using culture-independent techniques and the in silico reconstruction of 37 composite genomes of dominant community members, we demonstrate that different insect-fungal symbioses that collectively shape ecosystems worldwide have highly similar bacterial microbiotas comprised primarily of the genera Enterobacter, Rahnella, and Pseudomonas. Although these symbioses span three orders of insects and two phyla of fungi, we show that they are associated with bacteria sharing high whole-genome nucleotide identity. Due to the fine-scale correspondence of the bacterial microbiotas of insects engaged in fungal symbioses, our findings indicate that this represents an example of convergence of entire host-microbe complexes. The cultivation of fungi for food is a behavior that has evolved independently in ants, beetles, and termites and has enabled many species of these insects to become ecologically important and widely distributed herbivores and forest pests. Although the primary fungal cultivars of these insects have been studied for decades, comparatively little is known of their bacterial microbiota. In this study, we show that diverse fungus-growing insects are associated with a common bacterial community composed of the

  18. Fluorescence detection system for microfluidic droplets

    Science.gov (United States)

    Chen, Binyu; Han, Xiaoming; Su, Zhen; Liu, Quanjun

    2018-05-01

    In microfluidic detection technology, because of the universality of optical methods in laboratory, optical detection is an attractive solution for microfluidic chip laboratory equipment. In addition, the equipment with high stability and low cost can be realized by integrating appropriate optical detection technology on the chip. This paper reports a detection system for microfluidic droplets. Photomultiplier tubes (PMT) is used as a detection device to improve the sensitivity of detection. This system improves the signal to noise ratio by software filtering and spatial filter. The fluorescence intensity is proportional to the concentration of the fluorescence and intensity of the laser. The fluorescence micro droplets of different concentrations can be distinguished by this system.

  19. Inhibition of bacterial oxidation of ferrous iron by lead nitrate in sulfate-rich systems.

    Science.gov (United States)

    Wang, Hongmei; Gong, Linfeng; Cravotta, Charles A; Yang, Xiaofen; Tuovinen, Olli H; Dong, Hailiang; Fu, Xiang

    2013-01-15

    Inhibition of bacterial oxidation of ferrous iron (Fe(II)) by Pb(NO(3))(2) was investigated with a mixed culture of Acidithiobacillus ferrooxidans. The culture was incubated at 30 °C in ferrous-sulfate medium amended with 0-24.2 mM Pb(II) added as Pb(NO(3))(2). Anglesite (PbSO(4)) precipitated immediately upon Pb addition and was the only solid phase detected in the abiotic controls. Both anglesite and jarosite (KFe(3)(SO(4))(2)(OH)(6)) were detected in inoculated cultures. Precipitation of anglesite maintained dissolved Pb concentrations at 16.9-17.6 μM regardless of the concentrations of Pb(NO(3))(2) added. Fe(II) oxidation was suppressed by 24.2 mM Pb(NO(3))(2) addition even when anglesite was removed before inoculation. Experiments with 0-48 mM KNO(3) demonstrated that bacterial Fe(II) oxidation decreased as nitrate concentration increased. Therefore, inhibition of Fe(II) oxidation at 24.2 mM Pb(NO(3))(2) addition resulted from nitrate toxicity instead of Pb addition. Geochemical modeling that considered the initial precipitation of anglesite to equilibrium followed by progressive oxidation of Fe(II) and the precipitation of jarosite and an amorphous iron hydroxide phase, without allowing plumbojarosite to precipitate were consistent with the experimental time-series data on Fe(II) oxidation under biotic conditions. Anglesite precipitation in mine tailings and other sulfate-rich systems maintains dissolved Pb concentrations below the toxicity threshold of A. ferrooxidans. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Bacterial diversity of bacteriomes and organs of reproductive, digestive and excretory systems in two cicada species (Hemiptera: Cicadidae).

    Science.gov (United States)

    Zheng, Zhou; Wang, Dandan; He, Hong; Wei, Cong

    2017-01-01

    Cicadas form intimate symbioses with bacteria to obtain nutrients that are scarce in the xylem fluid they feed on. The obligate symbionts in cicadas are purportedly confined to specialized bacteriomes, but knowledge of bacterial communities associated with cicadas is limited. Bacterial communities in the bacteriomes and organs of reproductive, digestive and excretory systems of two cicada species (Platypleura kaempferi and Meimuna mongolica) were investigated using different methods, and the bacterial diversity and distribution patterns of dominant bacteria in different tissues were compared. Within each species, the bacterial communities of testes are significantly different from those of bacteriomes and ovaries. The dominant endosymbiont Candidatus Sulcia muelleri is found not only in the bacteriomes and reproductive organs, but also in the "filter chamber + conical segment" of both species. The transmission mode of this endosymbiont in the alimentary canal and its effect on physiological processes merits further study. A novel bacterium of Rhizobiales, showing ~80% similarity to Candidatus Hodgkinia cicadicola, is dominant in the bacteriomes and ovaries of P. kaempferi. Given that the genome of H. cicadicola exhibits rapid sequence evolution, it is possible that this novel bacterium is a related endosymbiont with beneficial trophic functions similar to that of H. cicadicola in some other cicadas. Failure to detect H. cicadicola in M. mongolica suggests that it has been subsequently replaced by another bacterium, a yeast or gut microbiota which compensates for the loss of H. cicadicola. The distribution of this novel Rhizobiales species in other cicadas and its identification require further investigation to help establish the definition of the bacterial genus Candidatus Hodgkinia and to provide more information on sequence divergence of related endosymbionts of cicadas. Our results highlight the complex bacterial communities of cicadas, and are informative for

  1. Bacterial diversity of bacteriomes and organs of reproductive, digestive and excretory systems in two cicada species (Hemiptera: Cicadidae.

    Directory of Open Access Journals (Sweden)

    Zhou Zheng

    Full Text Available Cicadas form intimate symbioses with bacteria to obtain nutrients that are scarce in the xylem fluid they feed on. The obligate symbionts in cicadas are purportedly confined to specialized bacteriomes, but knowledge of bacterial communities associated with cicadas is limited. Bacterial communities in the bacteriomes and organs of reproductive, digestive and excretory systems of two cicada species (Platypleura kaempferi and Meimuna mongolica were investigated using different methods, and the bacterial diversity and distribution patterns of dominant bacteria in different tissues were compared. Within each species, the bacterial communities of testes are significantly different from those of bacteriomes and ovaries. The dominant endosymbiont Candidatus Sulcia muelleri is found not only in the bacteriomes and reproductive organs, but also in the "filter chamber + conical segment" of both species. The transmission mode of this endosymbiont in the alimentary canal and its effect on physiological processes merits further study. A novel bacterium of Rhizobiales, showing ~80% similarity to Candidatus Hodgkinia cicadicola, is dominant in the bacteriomes and ovaries of P. kaempferi. Given that the genome of H. cicadicola exhibits rapid sequence evolution, it is possible that this novel bacterium is a related endosymbiont with beneficial trophic functions similar to that of H. cicadicola in some other cicadas. Failure to detect H. cicadicola in M. mongolica suggests that it has been subsequently replaced by another bacterium, a yeast or gut microbiota which compensates for the loss of H. cicadicola. The distribution of this novel Rhizobiales species in other cicadas and its identification require further investigation to help establish the definition of the bacterial genus Candidatus Hodgkinia and to provide more information on sequence divergence of related endosymbionts of cicadas. Our results highlight the complex bacterial communities of cicadas, and

  2. Nuclear fuel element leak detection system

    International Nuclear Information System (INIS)

    John, C.D. Jr.

    1978-01-01

    Disclosed is a leak detection system integral with a wall of a building used to fabricate nuclear fuel elements for detecting radiation leakage from the nuclear fuel elements as the fuel elements exit the building. The leak detecting system comprises a shielded compartment constructed to withstand environmental hazards extending into a similarly constructed building and having sealed doors on both ends along with leak detecting apparatus connected to the compartment. The leak detecting system provides a system for removing a nuclear fuel element from its fabrication building while testing for radiation leaks in the fuel element

  3. Simultaneous Detection of Three Bacterial Seed-Borne Diseases in Rice Using Multiplex Polymerase Chain Reaction

    OpenAIRE

    Kang, In Jeong; Kang, Mi-Hyung; Noh, Tae-Hwan; Shim, Hyeong Kwon; Shin, Dong Bum; Heu, Suggi

    2016-01-01

    Burkholderia glumae (bacterial grain rot), Xanthomonas oryzae pv. oryzae (bacterial leaf blight), and Acidovorax avenae subsp. avenae (bacterial brown stripe) are major seedborne pathogens of rice. Based on the 16S and 23S rDNA sequences for A. avenae subsp. avenae and B. glumae, and transposase A gene sequence for X. oryzae pv. oryzae, three sets of primers had been designed to produce 402 bp for B. glumae, 490 bp for X. oryzae, and 290 bp for A. avenae subsp. avenae with the 63°C as an opti...

  4. Shear horizontal surface acoustic wave microsensor for Class A viral and bacterial detection.

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Darren W.; Huber, Dale L.; Brozik, Susan Marie; Edwards, Thayne L.

    2008-10-01

    The rapid autonomous detection of pathogenic microorganisms and bioagents by field deployable platforms is critical to human health and safety. To achieve a high level of sensitivity for fluidic detection applications, we have developed a 330 MHz Love wave acoustic biosensor on 36{sup o} YX Lithium Tantalate (LTO). Each die has four delay-line detection channels, permitting simultaneous measurement of multiple analytes or for parallel detection of single analyte containing samples. Crucial to our biosensor was the development of a transducer that excites the shear horizontal (SH) mode, through optimization of the transducer, minimizing propagation losses and reducing undesirable modes. Detection was achieved by comparing the reference phase of an input signal to the phase shift from the biosensor using an integrated electronic multi-readout system connected to a laptop computer or PDA. The Love wave acoustic arrays were centered at 330 MHz, shifting to 325-328 MHz after application of the silicon dioxide waveguides. The insertion loss was -6 dB with an out-of-band rejection of 35 dB. The amplitude and phase ripple were 2.5 dB p-p and 2-3{sup o} p-p, respectively. Time-domain gating confirmed propagation of the SH mode while showing suppression of the triple transit. Antigen capture and mass detection experiments demonstrate a sensitivity of 7.19 {+-} 0.74{sup o} mm{sup 2}/ng with a detection limit of 6.7 {+-} 0.40 pg/mm{sup 2} for each channel.

  5. Impact of well intake systems on bacterial, algae, and organic carbon reduction in SWRO desalination systems, SAWACO, Jeddah, Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2014-07-18

    The intake system can play a significant role in improving the feed water quality and ultimately influence the performance of downstream components of the seawater reverse osmosis desalination processes. In most cases, open-ocean intakes produce poor feed water quality in terms of the abundance of naturally occurring organic matter, which increases the risk of membrane fouling. An alternative intake is the subsurface system, which is based on the riverbank filtration concept that provides natural filtration and biological treatment of the feed water prior to the entry of the water into the desalination plant. The use of subsurface intakes normally improves the raw water quality by reducing suspended solids, algae, bacterial, and dissolved organic carbon concentrations. Therefore, the risk of biofouling caused by these substances can be reduced by implementing the appropriate type of intake system. The use of well intake systems was investigated along the Red Sea shoreline of Saudi Arabia in the Jeddah region. Data were collected from a seawater reverse osmosis (SWRO) plant with a capacity of 10,000 m3/d. The well system produces feed water from an artificial-fill peninsula that was constructed atop of the seabed. Ten wells have been constructed on the peninsula for extracting raw seawater. Water samples were collected from nearby surface seawater as a reference and from selected individual wells. The percentage of algae and bacterial removal by induced filtration process was evaluated by comparison of the seawater concentrations with the well discharges. Transparent exopolymer particles and organic carbon fractions reduction was also measured. The quality of raw water extracted from the well systems was highly improved compared with the raw seawater source. It was observed that algae were virtually 100% removed and the bacterial concentration was significantly removed by the aquifer matrix. The detailed analysis of organic carbon fraction using liquid

  6. Nucleic Acid-Based Detection and Identification of Bacterial and Fungal Plant Pathogens - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Kingsley, Mark T.

    2001-03-13

    The threat to American interests from terrorists is not limited to attacks against humans. Terrorists might seek to inflict damage to the U.S. economy by attacking our agricultural sector. Infection of commodity crops by bacterial or fungal crop pathogens could adversely impact U.S. agriculture, either directly from damage to crops or indirectly from damage to our ability to export crops suspected of contamination. Recognizing a terrorist attack against U.S. agriculture, to be able to prosecute the terrorists, is among the responsibilities of the members of Hazardous Material Response Unit (HMRU) of the Federal Bureau of Investigation (FBI). Nucleic acid analysis of plant pathogen strains by the use of polymerase chain reaction (PCR) amplification techniques is a powerful method for determining the exact identity of pathogens, as well as their possible region of origin. This type of analysis, however, requires that PCR assays be developed specific to each particular pathogen strain, and analysis protocols developed that are specific to the particular instrument used for detection. The objectives of the work described here were threefold: 1) to assess the potential terrorist threat to U.S. agricultural crops, 2) to determine whether suitable assays exist to monitor that threat, and 3) where assays are needed for priority plant pathogen threats, to modify or develop those assays for use by specialists at the HMRU. The assessment of potential threat to U.S. commodity crops and the availability of assays for those threats were described in detail in the Technical Requirements Document (9) and will be summarized in this report. This report addresses development of specific assays identified in the Technical Requirements Document, and offers recommendations for future development to ensure that HMRU specialists will be prepared with the PCR assays they need to protect against the threat of economic terrorism.

  7. Molecularly specific detection of bacterial lipoteichoic acid for diagnosis of prosthetic joint infection of the bone.

    Science.gov (United States)

    Pickett, Julie E; Thompson, John M; Sadowska, Agnieszka; Tkaczyk, Christine; Sellman, Bret R; Minola, Andrea; Corti, Davide; Lanzavecchia, Antonio; Miller, Lloyd S; Thorek, Daniel Lj

    2018-01-01

    Discriminating sterile inflammation from infection, especially in cases of aseptic loosening versus an actual prosthetic joint infection, is challenging and has significant treatment implications. Our goal was to evaluate a novel human monoclonal antibody (mAb) probe directed against the Gram-positive bacterial surface molecule lipoteichoic acid (LTA). Specificity and affinity were assessed in vitro. We then radiolabeled the anti-LTA mAb and evaluated its effectiveness as a diagnostic imaging tool for detecting infection via immunoPET imaging in an in vivo mouse model of prosthetic joint infection (PJI). In vitro and ex vivo binding of the anti-LTA mAb to pathogenic bacteria was measured with Octet, ELISA, and flow cytometry. The in vivo PJI mouse model was assessed using traditional imaging modalities, including positron emission tomography (PET) with [ 18 F]FDG and [ 18 F]NaF as well as X-ray computed tomography (CT), before being evaluated with the zirconium-89-labeled antibody specific for LTA ([ 89 Zr]SAC55). The anti-LTA mAb exhibited specific binding in vitro to LTA-expressing bacteria. Results from imaging showed that our model could reliably simulate infection at the surgical site by bioluminescent imaging, conventional PET tracer imaging, and bone morphological changes by CT. One day following injection of both the radiolabeled anti-LTA and isotype control antibodies, the anti-LTA antibody demonstrated significantly greater ( P  infected prosthesis sites over either the same antibody at sterile prosthesis sites or of control non-specific antibody at infected prosthesis sites. Taken together, the radiolabeled anti-LTA mAb, [ 89 Zr]SAC55, may serve as a valuable diagnostic molecular imaging probe to help distinguish between sterile inflammation and infection in the setting of PJI. Future studies are needed to determine whether these findings will translate to human PJI.

  8. NIST Special Publication on Intrusion Detection Systems

    National Research Council Canada - National Science Library

    Bace, Rebecca Gurley

    2001-01-01

    Intrusion detection systems (IDSs) are software or hardware systems that automate the process of monitoring the events occurring in a computer system or network, analyzing them for signs of security problems...

  9. Detection of bacterial contaminants and hybrid sequences in the genome of the kelp Saccharina japonica using Taxoblast

    Directory of Open Access Journals (Sweden)

    Simon M. Dittami

    2017-11-01

    Full Text Available Modern genome sequencing strategies are highly sensitive to contamination making the detection of foreign DNA sequences an important part of analysis pipelines. Here we use Taxoblast, a simple pipeline with a graphical user interface, for the post-assembly detection of contaminating sequences in the published genome of the kelp Saccharina japonica. Analyses were based on multiple blastn searches with short sequence fragments. They revealed a number of probable bacterial contaminations as well as hybrid scaffolds that contain both bacterial and algal sequences. This or similar types of analysis, in combination with manual curation, may thus constitute a useful complement to standard bioinformatics analyses prior to submission of genomic data to public repositories. Our analysis pipeline is open-source and freely available at http://sdittami.altervista.org/taxoblast and via SourceForge (https://sourceforge.net/projects/taxoblast.

  10. Fusion of Heterogeneous Intrusion Detection Systems for Network Attack Detection

    Directory of Open Access Journals (Sweden)

    Jayakumar Kaliappan

    2015-01-01

    Full Text Available An intrusion detection system (IDS helps to identify different types of attacks in general, and the detection rate will be higher for some specific category of attacks. This paper is designed on the idea that each IDS is efficient in detecting a specific type of attack. In proposed Multiple IDS Unit (MIU, there are five IDS units, and each IDS follows a unique algorithm to detect attacks. The feature selection is done with the help of genetic algorithm. The selected features of the input traffic are passed on to the MIU for processing. The decision from each IDS is termed as local decision. The fusion unit inside the MIU processes all the local decisions with the help of majority voting rule and makes the final decision. The proposed system shows a very good improvement in detection rate and reduces the false alarm rate.

  11. Detection of irradiated chicken and fish meats by the determination of Gram negative bacterial count and bacterial endotoxins

    International Nuclear Information System (INIS)

    Badr, H.M.

    2010-01-01

    The aim of this investigation was to study the possibility of detecting irradiated chicken and fish meats by the determination of Gram negative bacteria combined with the determination of endotoxin concentrations. Samples of chicken breast with skin, skinless chicken breast and eviscerated Bolti fish (Tilabia nilotica) were irradiated at room temperature at doses of 0, 1.5 and 3 kGy followed by storage at refrigeration temperature (4 ± 1 degree C) for 12 days or frozen storage at -18 degree C for 60 days. Furthermore, other samples of chicken and Bolti fish were irradiated in the frozen sate at doses of 0, 3, and 7 kGy followed by frozen storage at - 18 degree C for 60 days. Then the enumeration of Gram negative bacteria in conjunction with the determination of endotoxin concentrations were carried out for both irradiated and non-irradiated samples post treatments and during storage in addition to the discovery of Pseudomonas spp. The obtained results showed that chicken and fish samples irradiated at dose of 1.5 kGy could be identified during refrigerated storage for 6 and 9 days, respectively, while all samples irradiated at dose of 3 kGy were identifiable during 12 days of refrigerated storage. Moreover, all irradiated and frozen stored samples were identifiable during their frozen storage (- 18 degree C). The absence of Pseudomonads in all irradiated samples may aid in the differentiation of irradiated and non-irradiated samples especially during refrigerated storage. This method can be applied as a general screening method to predict the possible treatment of chicken and fish meats by ionizing radiation

  12. Computational modeling and experimental characterization of bacterial microcolonies for rapid detection using light scattering

    Science.gov (United States)

    Bai, Nan

    A label-free and nondestructive optical elastic forward light scattering method has been extended for the analysis of microcolonies for food-borne bacteria detection and identification. To understand the forward light scattering phenomenon, a model based on the scalar diffraction theory has been employed: a bacterial colony is considered as a biological spatial light modulator with amplitude and phase modulation to the incoming light, which continues to propagate to the far-field to form a distinct scattering 'fingerprint'. Numerical implementation via angular spectrum method (ASM) and Fresnel approximation have been carried out through Fast Fourier Transform (FFT) to simulate this optical model. Sampling criteria to achieve unbiased and un-aliased simulation results have been derived and the effects of violating these conditions have been studied. Diffraction patterns predicted by these two methods (ASM and Fresnel) have been compared to show their applicability to different simulation settings. Through the simulation work, the correlation between the colony morphology and its forward scattering pattern has been established to link the number of diffraction rings and the half cone angle with the diameter and the central height of the Gaussian-shaped colonies. In order to experimentally prove the correlation, a colony morphology analyzer has been built and used to characterize the morphology of different bacteria genera and investigate their growth dynamics. The experimental measurements have demonstrated the possibility of differentiating bacteria Salmonella, Listeria, Escherichia in their early growth stage (100˜500 µm) based on their phenotypic characteristics. This conclusion has important implications in microcolony detection, as most bacteria of our interest need much less incubation time (8˜12 hours) to grow into this size range. The original forward light scatterometer has been updated to capture scattering patterns from microcolonies. Experiments have

  13. 8.3 Microbiology and Biodegradation: A New Bacterial Communication System

    Science.gov (United States)

    2014-04-09

    Approved for Public Release; Distribution Unlimited 8.3 Microbiology and Biodegradation: A new bacterial communication system The views, opinions and...JB.01479-10 Federico E. Rey, Caroline S. Harwood. FixK, a global regulator of microaerobic growth, controls photosynthesis in Rhodopseudomonas...Quorum sensing is a term used to describe bacterial cell-to-cell communication that allows cell-density-dependent gene expression. There are many

  14. Reduction of Airborne Bacterial Burden in the OR by Installation of Unidirectional Displacement Airflow (UDF) Systems.

    Science.gov (United States)

    Fischer, Sebastian; Thieves, Martin; Hirsch, Tobias; Fischer, Klaus-Dieter; Hubert, Helmine; Beppler, Steffen; Seipp, Hans-Martin

    2015-08-13

    Intraoperative bacterial contamination is a major risk factor for postoperative wound infections. This study investigated the influence of type of ventilation system on intraoperative airborne bacterial burden before and after installation of unidirectional displacement air flow systems. We microbiologically monitored 1286 surgeries performed by a single surgical team that moved from operating rooms (ORs) equipped with turbulent mixing ventilation (TMV, according to standard DIN-1946-4 [1999], ORs 1, 2, and 3) to ORs with unidirectional displacement airflow (UDF, according to standard DIN-1946-4, annex D [2008], ORs 7 and 8). The airborne bacteria were collected intraoperatively with sedimentation plates. After incubation for 48 h, we analyzed the average number of bacteria per h, peak values, and correlation to surgery duration. In addition, we compared the last 138 surgeries in ORs 1-3 with the first 138 surgeries in ORs 7 and 8. Intraoperative airborne bacterial burden was 5.4 CFU/h, 5.5 CFU/h, and 6.1 CFU/h in ORs 1, 2, and 3, respectively. Peak values of burden were 10.7 CFU/h, 11.1 CFU/h, and 11.0 CFU/h in ORs 1, 2, and 3, respectively). With the UDF system, the intraoperative airborne bacterial burden was reduced to 0.21 CFU/h (OR 7) and 0.35 CFU/h (OR 8) on average (pAirborne bacterial burden increased linearly with surgery duration in ORs 1-3, but the UDF system in ORs 7 and 8 kept bacterial levels constantly low (airborne bacterial burden (5 CFU/h vs. 0.29 CFU/h, pairborne bacterial burden under real clinical conditions by more than 90%. Although decreased postoperative wound infection incidence was not specifically assessed, it is clear that airborne microbiological burden contributes to surgical infections.

  15. Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Letícia Eichstaedt Mayer

    2012-04-01

    Full Text Available INTRODUCTION: Metallo-β-lactamase (MBL has been reported all over the world. METHODS: The inhibitory effect of mercaptopropionic acid (MPA on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC for multidrug-resistant Acinetobacter baumanni strains. RESULTS: MPA significantly inhibited growth of the strains. CONCLUSIONS: The use of MPA can affect the results in phenotypic methods of MBL detection.

  16. Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Mayer, Letícia Eichstaedt; Hörner, Rosmari; Tizotti, Maisa Kräulich; Martini, Rosiéli; Roehrs, Magda Cristina Souza Marques; Kempfer, Cláudia Barbisan

    2012-01-01

    Metallo-β-lactamase (MBL) has been reported all over the world. The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. MPA significantly inhibited growth of the strains. The use of MPA can affect the results in phenotypic methods of MBL detection.

  17. System for detecting nuclear explosions

    International Nuclear Information System (INIS)

    Rawls, L.E.

    1978-01-01

    Apparatus for detecting underground nuclear explosions is described that is comprised of an antenna located in the dielectric substance of a deep waveguide in the earth and adapted to detect low frequency electromagnetic waves generated by a nuclear explosion, the deep waveguide comprising the high conductivity upper sedimentary layers of the earth, the dielectric basement rock, and a high conductivity layer of basement rock due to the increased temperature thereof at great depths, and means for receiving the electromagnetic waves detected by said antenna means

  18. Microbial Genomics: The Expanding Universe of Bacterial Defense Systems.

    Science.gov (United States)

    Forsberg, Kevin J; Malik, Harmit S

    2018-04-23

    Bacteria protect themselves against infection using multiple defensive systems that move by horizontal gene transfer and accumulate in genomic 'defense islands'. A recent study exploited these features to uncover ten novel defense systems, substantially expanding the catalog of bacterial defense systems and predicting the discovery of many more. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Homodyne detection of holographic memory systems

    Science.gov (United States)

    Urness, Adam C.; Wilson, William L.; Ayres, Mark R.

    2014-09-01

    We present a homodyne detection system implemented for a page-wise holographic memory architecture. Homodyne detection by holographic memory systems enables phase quadrature multiplexing (doubling address space), and lower exposure times (increasing read transfer rates). It also enables phase modulation, which improves signal-to-noise ratio (SNR) to further increase data capacity. We believe this is the first experimental demonstration of homodyne detection for a page-wise holographic memory system suitable for a commercial design.

  20. 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.

  1. Cone-morse implant connection system significantly reduces bacterial leakage between implant and abutment: an in vitro study.

    Science.gov (United States)

    Baj, A; Bolzoni, A; Russillo, A; Lauritano, D; Palmieri, A; Cura, F; Silvestre, F J; Giannì, A B

    2017-01-01

    Osseointegrated implants are very popular dental treatments today in the world. In osseointegrated implants, the occlusal forces are transmitted from prosthesis through an abutment to a dental implant. The abutment is connected to the implant by mean of a screw. A screw is the most used mean for connecting an implant to an abutment. Frequently the screws break and are lost. There is an alternative to screw retained abutment systems: the cone-morse connection (CMC). The CMC, thanks to the absence of the abutment screw, guarantees no micro-gaps, no micro-movements, and a reduction of bacterial leakage between implant and abutment. As P. gingivalis and T. forsythia penetration might have clinical relevance, it was the purpose of this investigation to evaluate molecular leakage of these two bacteria in a new CMC implants systems (Leone Spa®, Florence, Italy). To identify the capability of the implant to protect the internal space from the external environment, the passage of genetically modified Escherichia coli across implant-abutment interface was evaluated. Four cone-morse Leone implants (Leone® Spa, Florence, Italy) were immerged in a bacterial culture for 24 h and bacteria amount was then measured inside implant-abutment interface with Real-time PCR. Bacteria were detected inside all studied implants, with a median percentage of 3% for P. gingivalis and 4% for T. forsythia. Cone-morse connection implant system has very low bacterial leakage percentage and is similar to one-piece implants.

  2. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.

    2016-01-06

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach combines (i) quantification of changes in autochthonous bacterial cell concentrations in full-scale distribution systems with (ii) laboratoryscale batch bacterial growth potential tests of drinking water samples under defined conditions. The growth potential tests were done by direct incubation of water samples, without modification of the original bacterial flora, and with flow cytometric quantification of bacterial growth. This method was shown to be reproducible (ca. 4% relative standard deviation) and sensitive (detection of bacterial growth down to 5 μg L-1 of added assimilable organic carbon). The principle of step-wise assessment of bacterial growth-controlling factors was demonstrated on bottled water, shown to be primarily carbon limited at 133 (±18) × 103 cells mL-1 and secondarily limited by inorganic nutrients at 5,500 (±1,700) × 103 cells mL-1. Analysis of the effluent of a Dutch full-scale drinking water treatment plant showed (1) bacterial growth inhibition as a result of end-point chlorination, (2) organic carbon limitation at 192 (±72) × 103 cells mL-1 and (3) inorganic nutrient limitation at 375 (±31) × 103 cells mL-1. Significantly lower net bacterial growth was measured in the corresponding full-scale distribution system (176 (±25) × 103 cells mL-1) than in the laboratory-scale growth potential test of the same water (294 (±35) × 103 cells mL-1), highlighting the influence of distribution on bacterial growth. The systematic approach described herein provides quantitative information on the effect of drinking water properties and distribution system conditions on biological stability, which can assist water utilities in decision-making on treatment or distribution system improvements to

  3. Bacterial decolorization and detoxification of black liquor from rayon grade pulp manufacturing paper industry and detection of their metabolic products.

    Science.gov (United States)

    Chandra, Ram; Abhishek, Amar; Sankhwar, Monica

    2011-06-01

    This study deals with the decolorization of black liquor (BL) by isolated potential bacterial consortium comprising Serratia marcescens (GU193982), Citrobacter sp. (HQ873619) and Klebsiella pneumoniae (GU193983). The decolorization of BL was studied by using the different nutritional as well as environmental parameters. In this study, result revealed that the ligninolytic activities were found to be growth associated and the developed bacterial consortium was efficient for the reduction of COD, BOD and color up to 83%, 74% and 85%, respectively. The HPLC analysis of degraded samples of BL has shown the reduction in peak area compared to control. Further, the GC-MS analysis showed that, most of the compounds detected in control were diminished after bacterial treatment while, formic acid hydrazide, 4-cyclohexane-1,2-dicarboxylic acid, carbamic acid, 1,2-benzenedicarboxylic acid and erythropentanoic acid were found as new metabolites. Further, the seed germination test using Phaseolus aureus has supported the detoxification of bacterial decolorized BL. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Bacterial community composition of a wastewater treatment system reliant on N{sub 2} fixation

    Energy Technology Data Exchange (ETDEWEB)

    Reid, N.M.; Bowers, T.H.; Lloyd-Jones, G. [Scion, Rotorua (New Zealand)

    2008-05-15

    The temporal stability and change of the dominant phylogenetic groups of the domain bacteria were studied in a model plant-based industrial wastewater treatment system showing high levels of organic carbon removal supported by high levels of N{sub 2} fixation. Community profiles were obtained through terminal restriction fragment length polymorphism analysis and cloning of 16S rRNA amplicons followed by sequencing. Bacterial community profiles showed that ten common terminal restriction fragments made up approximately 50% of the measured bacterial community. As much as 42% of the measured bacterial community could be monitored by using quantitative PCR and primers that targeted three dominant operational taxonomic units. Despite changes in wastewater composition and dissolved oxygen levels, the bacterial community composition appeared stable and was dominated by {alpha}-Proteobacteria and {beta}-Proteobacteria, with a lesser amount of the highly diverse bacterial phylum Bacteroidetes. A short period of considerable change in the bacterial community composition did not appear to affect treatment performance indicating functional redundancy in this treatment system. (orig.)

  5. Damage Detection and Deteriorating Structural Systems

    DEFF Research Database (Denmark)

    Long, Lijia; Thöns, Sebastian; Döhler, Michael

    2017-01-01

    This paper addresses the quantification of the value of damage detection system and algorithm information on the basis of Value of Information (VoI) analysis to enhance the benefit of damage detection information by providing the basis for its optimization before it is performed and implemented....... The approach of the quantification the value of damage detection information builds upon the Bayesian decision theory facilitating the utilization of damage detection performance models, which describe the information and its precision on structural system level, facilitating actions to ensure the structural...... detection information is determined utilizing Bayesian updating. The damage detection performance is described with the probability of indication for different component and system damage states taking into account type 1 and type 2 errors. The value of damage detection information is then calculated...

  6. Using optical coherence tomography to detect bacterial biofilms on foley catheters (Conference Presentation)

    Science.gov (United States)

    Heidari, Andrew E.; Oh, Kyungjin; Chen, Zhongping

    2017-02-01

    Urinary tract infections(UTI) pose a serious problem for hospital patients accounting for 33% of all hospital acquired(nosocomial) infections with indwelling foley catheters. The presence of an indwelling foley catheter provides a scaffolding for circulating planktonic bacteria to adhere to and to form microbial biofilm communities that would typically be hindered by the body's innate immune system response. It is these biofilm communities that form on the inner lumen of foley catheters that provide a reservoir of pathogenic bacteria that could dislodge or disperse from the biofilm and infect urethra or bladder mucosal tissue in the urinary tract. Current diagnostic techniques of urine microbiological cultures are lacking in differentiating asymptomatic bacteriuria and symptomatic catheter-associated urinary tract infection(CAUTI) since almost all patients with chronic indwelling catheters are almost universally bacteriuruic. There is an unmet need of a diagnostic tool to assess the difference between the pathogenesis of asymptomatic bacteriuria and CAUTI, specifically at the site of the native biofilm formation. Optical Coherence Tomography(OCT) is an emerging high resolution, minimally invasive tomographic imaging technique that has shown promise in imaging biofilm structures previously in an endoscopic setting of the airway in-vivo and in microfluidic chambers. OCT can be adapted to image various sized biological surfaces and orifices such as airway branches and blood vessels by using a variety of minature endoscopic probes. In this work OCT will be used to image biofilm structure in-vitro on the inner lumen of extravasated critical care patient's foley catheters. Scanning electron microscopy will be conducted post OCT to confirm the presence of bacterial biofilm in OCT images.

  7. Influence of hydraulic regimes on bacterial community structure and composition in an experimental drinking water distribution system.

    Science.gov (United States)

    Douterelo, I; Sharpe, R L; Boxall, J B

    2013-02-01

    Microbial biofilms formed on the inner-pipe surfaces of drinking water distribution systems (DWDS) can alter drinking water quality, particularly if they are mechanically detached from the pipe wall to the bulk water, such as due to changes in hydraulic conditions. Results are presented here from applying 454 pyrosequencing of the 16S ribosomal RNA (rRNA) gene to investigate the influence of different hydrological regimes on bacterial community structure and to study the potential mobilisation of material from the pipe walls to the network using a full scale, temperature-controlled experimental pipeline facility accurately representative of live DWDS. Analysis of pyrosequencing and water physico-chemical data showed that habitat type (water vs. biofilm) and hydraulic conditions influenced bacterial community structure and composition in our experimental DWDS. Bacterial community composition clearly differed between biofilms and bulk water samples. Gammaproteobacteria and Betaproteobacteria were the most abundant phyla in biofilms while Alphaproteobacteria was predominant in bulk water samples. This suggests that bacteria inhabiting biofilms, predominantly species belonging to genera Pseudomonas, Zooglea and Janthinobacterium, have an enhanced ability to express extracellular polymeric substances to adhere to surfaces and to favour co-aggregation between cells than those found in the bulk water. Highest species richness and diversity were detected in 28 days old biofilms with this being accentuated at highly varied flow conditions. Flushing altered the pipe-wall bacterial community structure but did not completely remove bacteria from the pipe walls, particularly under highly varied flow conditions, suggesting that under these conditions more compact biofilms were generated. This research brings new knowledge regarding the influence of different hydraulic regimes on the composition and structure of bacterial communities within DWDS and the implication that this

  8. T3SEdb: data warehousing of virulence effectors secreted by the bacterial Type III Secretion System.

    Science.gov (United States)

    Tay, Daniel Ming Ming; Govindarajan, Kunde Ramamoorthy; Khan, Asif M; Ong, Terenze Yao Rui; Samad, Hanif M; Soh, Wei Wei; Tong, Minyan; Zhang, Fan; Tan, Tin Wee

    2010-10-15

    Effectors of Type III Secretion System (T3SS) play a pivotal role in establishing and maintaining pathogenicity in the host and therefore the identification of these effectors is important in understanding virulence. However, the effectors display high level of sequence diversity, therefore making the identification a difficult process. There is a need to collate and annotate existing effector sequences in public databases to enable systematic analyses of these sequences for development of models for screening and selection of putative novel effectors from bacterial genomes that can be validated by a smaller number of key experiments. Herein, we present T3SEdb http://effectors.bic.nus.edu.sg/T3SEdb, a specialized database of annotated T3SS effector (T3SE) sequences containing 1089 records from 46 bacterial species compiled from the literature and public protein databases. Procedures have been defined for i) comprehensive annotation of experimental status of effectors, ii) submission and curation review of records by users of the database, and iii) the regular update of T3SEdb existing and new records. Keyword fielded and sequence searches (BLAST, regular expression) are supported for both experimentally verified and hypothetical T3SEs. More than 171 clusters of T3SEs were detected based on sequence identity comparisons (intra-cluster difference up to ~60%). Owing to this high level of sequence diversity of T3SEs, the T3SEdb provides a large number of experimentally known effector sequences with wide species representation for creation of effector predictors. We created a reliable effector prediction tool, integrated into the database, to demonstrate the application of the database for such endeavours. T3SEdb is the first specialised database reported for T3SS effectors, enriched with manual annotations that facilitated systematic construction of a reliable prediction model for identification of novel effectors. The T3SEdb represents a platform for inclusion of

  9. T3SEdb: data warehousing of virulence effectors secreted by the bacterial Type III Secretion System

    Directory of Open Access Journals (Sweden)

    Tong Minyan

    2010-10-01

    Full Text Available Abstract Background Effectors of Type III Secretion System (T3SS play a pivotal role in establishing and maintaining pathogenicity in the host and therefore the identification of these effectors is important in understanding virulence. However, the effectors display high level of sequence diversity, therefore making the identification a difficult process. There is a need to collate and annotate existing effector sequences in public databases to enable systematic analyses of these sequences for development of models for screening and selection of putative novel effectors from bacterial genomes that can be validated by a smaller number of key experiments. Results Herein, we present T3SEdb http://effectors.bic.nus.edu.sg/T3SEdb, a specialized database of annotated T3SS effector (T3SE sequences containing 1089 records from 46 bacterial species compiled from the literature and public protein databases. Procedures have been defined for i comprehensive annotation of experimental status of effectors, ii submission and curation review of records by users of the database, and iii the regular update of T3SEdb existing and new records. Keyword fielded and sequence searches (BLAST, regular expression are supported for both experimentally verified and hypothetical T3SEs. More than 171 clusters of T3SEs were detected based on sequence identity comparisons (intra-cluster difference up to ~60%. Owing to this high level of sequence diversity of T3SEs, the T3SEdb provides a large number of experimentally known effector sequences with wide species representation for creation of effector predictors. We created a reliable effector prediction tool, integrated into the database, to demonstrate the application of the database for such endeavours. Conclusions T3SEdb is the first specialised database reported for T3SS effectors, enriched with manual annotations that facilitated systematic construction of a reliable prediction model for identification of novel effectors

  10. US Army Nuclear Burst Detection System (NBDS)

    International Nuclear Information System (INIS)

    Glaser, R.F.

    1980-07-01

    The Nuclear Burst Detection System (NBDS) was developed to meet the Army requirements of an unattended, automatic nuclear burst reporting system. It provides pertinent data for battlefield commanders on a timely basis with high reliability

  11. Apriori-based network intrusion detection system

    International Nuclear Information System (INIS)

    Wang Wenjin; Liu Junrong; Liu Baoxu

    2012-01-01

    With the development of network communication technology, more and more social activities run by Internet. In the meantime, the network information security is getting increasingly serious. Intrusion Detection System (IDS) has greatly improved the general security level of whole network. But there are still many problem exists in current IDS, e.g. high leak rate detection/false alarm rates and feature library need frequently upgrade. This paper presents an association-rule based IDS. This system can detect unknown attack by generate rules from training data. Experiment in last chapter proved the system has great accuracy on unknown attack detection. (authors)

  12. Development of Nested-PCR Assay to Detect Acidovorax citrulli, a Causal Agent of Bacterial Fruit Blotch at Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Young-Tak Kim

    2015-06-01

    Full Text Available The specific and sensitive nested-PCR method to detect Acidovorax citrulli, a causal agent of bacterial fruit blotch on cucurbitaceae, was developed. PCR primers were designed from the draft genome sequence which was obtained with the Next Generation Sequencing of A. citrulli KACC10651, and the nested-PCR primer set (Ac-ORF 21F/Ac-ORF 21R were selected by checking of specificity to A. citrulli with PCR assays. The selected nested-PCR primer amplified the 140 bp DNA only from A. citrulli strains, and detection sensitivity of the nested PCR increased 10,000 times of 1st PCR detection limit (10 ng genomic DNA/PCR. The nested PCR detected A. citrulli from the all samples of seed surface wash (external seed detection of the artificially inoculated watermelon seeds with 101 cfu/ml and above population of A. citrulli while the nested PCR could not detected A. citrulli from the mashed seed suspension (internal seed detection of the all artificially inoculated watermelon seeds. When the naturally infested watermelon seeds (10% seed infested rate with grow-out test used, the nested PCR detected A. citrulli from 2 seed samples out of 10 replication samples externally and 5 seed samples out of 10 replication samples internally. We believe that the nested-PCR developed in this study will be useful method to detect A. citrulli from the Cucurbitaceae seeds.

  13. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff.

    Science.gov (United States)

    Miller, Melissa A; Byrne, Barbara A; Jang, Spencer S; Dodd, Erin M; Dorfmeier, Elene; Harris, Michael D; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A; Miller, Woutrina A

    2010-01-01

    Although protected for nearly a century, California's sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health.

  14. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff

    Science.gov (United States)

    Miller, Melissa A.; Byrne, Barbara A.; Jang, Spencer S.; Dodd, Erin M.; Dorfmeier, Elene; Harris, Michael D.; Ames, Jack; Paradies, David; Worcester, Karen; Jessup, David A.; Miller, Woutrina A.

    2009-01-01

    Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. PMID:19720009

  15. Detection of bacterial species involved in perimplantitis concerned with cultural and RT-PCR

    Directory of Open Access Journals (Sweden)

    Marcello Gatti

    2010-06-01

    .6% of the samples, as well as Capnocytophaga spp. in 54.1%, F.nucleatum spp. in 50% and Campylobacter spp. 25%. Conclusions.The data show that RT-PCR has greater sensitivity than culture examination as well as response times are in favor of RT-PCR, but the kits Trade identify a limited number of species present no bacterial resistance if it were taking antibiotics.There are several factors (genetic, environmental and systemic diseases of the subject that may affect the results of microbiological contamination. It is perhaps for this reason that many dentists often consider the microbiological examination of “unsafe” because there are not always matching the survey clinical microbiological examination then the same situation microbiological not always the same clinical situation. Being able to pinpoint those responsible for periodontal infection and inflammation, however, offers the opportunity to vary quite rightly, on the basis of virulence factors and evaluation of bacteria, the timing of recalls for the TPS (periodontal therapy support, leaving as a last choice antibiotic therapy targeted.

  16. A Gateway((R)) -compatible bacterial adenylate cyclase-based two-hybrid system

    Czech Academy of Sciences Publication Activity Database

    Ouellette, S. P.; Gauliard, E.; Antošová, Zuzana; Ladant, D.

    2014-01-01

    Roč. 6, č. 3 (2014), s. 259-267 ISSN 1758-2229 Institutional support: RVO:67985823 Keywords : bacterial two-hybrid system * protein–protein interactions * cell division * Gateway((R))(GW) cloning system Subject RIV: EE - Microbiology, Virology Impact factor: 3.293, year: 2014

  17. CHANGES IN BACTERIAL COMPOSITION OF BIOFILM IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM

    Science.gov (United States)

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e., groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The b...

  18. A Fuzzy Expert System for Distinguishing between Bacterial and Aseptic Meningitis

    Directory of Open Access Journals (Sweden)

    Mostafa Langarizadeh

    2015-05-01

    Data were extracted from 106 records of patients with meningitis (42 cases with bacterial meningitis in order to evaluate the proposed system. The system accuracy, specificity, and sensitivity were 89%, 92 %, and 97%, respectively. The area under the ROC curve was 0.93, and Kappa test revealed a good level of agreement (k=0.84, P

  19. Simultaneous Detection of Brown Rot- and Soft Rot-Causing Bacterial Pathogens from Potato Tubers Through Multiplex PCR.

    Science.gov (United States)

    Ranjan, R K; Singh, Dinesh; Baranwal, V K

    2016-11-01

    Ralstonia solanacearum (Smith) Yabuuchi et al. and Erwinia carotovora subsp. carotovora (Jones) Bergey et al. (Pectobacterium carotovorum subsp. carotovorum) are the two major bacterial pathogens of potato causing brown rot (wilt) and soft rot diseases, respectively, in the field and during storage. Reliable and early detection of these pathogens are keys to avoid occurrence of these diseases in potato crops and reduce yield loss. In the present study, multiplex polymerase chain reaction (PCR) protocol was developed for simultaneous detection of R. solanacearum and E. carotovora subsp. carotovora from potato tubers. A set of oligos targeting the pectatelyase (pel) gene of E. carotovora subsp. carotovora and the universal primers based on 16S r RNA gene of R. solanacearum were used. The standardized multiplex PCR protocol could detect R. solanacearum and E. carotovora subsp. carotovora up to 0.01 and 1.0 ng of genomic DNA, respectively. The protocol was further validated on 96 stored potato tuber samples, collected from different potato-growing states of India, viz. Uttarakhand, Odisha, Meghalaya and Delhi. 53.1 % tuber samples were positive for R. solanacearum, and 15.1 % of samples were positive for E. carotovora subsp. carotovora, and both the pathogens were positive in 26.0 % samples when BIO-PCR was used. This method offers sensitive, specific, reliable and fast detection of two major bacterial pathogens from potato tubers simultaneously, particularly pathogen-free seed certification in large scale.

  20. Fluorescent detection of dipicolinic acid as a biomarker of bacterial spores using lanthanide-chelated gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Donmez, Mert [Department of Chemistry, Faculty of Art and Sciences, Duzce University, Duzce 81620 (Turkey); Yilmaz, M. Deniz, E-mail: deniz.yilmaz@gidatarim.edu.tr [Department of Bioengineering, Faculty of Engineering and Architecture, Konya Food and Agriculture University, Konya 42080 (Turkey); Kilbas, Benan, E-mail: benankilbas@duzce.edu.tr [Department of Chemistry, Faculty of Art and Sciences, Duzce University, Duzce 81620 (Turkey)

    2017-02-15

    Highlights: • The nanosensors based on gold nanoparticles functionalized with lanthanide complexes were synthesized. • The nanosensors selectively and sensitively detected DPA, a biomarker of bacterial spores. • Ratiometric sensing of DPA by a ternary complex was achieved by ligand displacement strategy. - Abstract: Gold nanoparticles (GNPs) functionalized with ethylenediamine-lanthanide complexes (Eu-GNPs and Tb-GNPs) were used for the selective fluorescent detection of dipicolinic acid (DPA), a unique biomarker of bacterial spores, in water. Particles were characterized by transmission electron microscopy and zeta potential measurements. The coordination of DPA to the lanthanides resulted in the enhancement of the fluorescence. A selective response to DPA was observed over the nonselective binding of aromatic ligands. The ligand displacement strategy were also employed for the ratiometric fluorescent detection of DPA. 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedion (TFNB) was chosen as an antenna to synthesize ternary complexes. The addition of DPA on EuGNP:TFNB ternary complex quenched the initial emission of the complex at 615 nm and increased the TFNB emission at 450 nm when excited at 350 nm. The results demonstrated that the ratiometric fluorescent detection of DPA was achieved by ligand displacement strategy.

  1. Bacterial detection using bacteriophages and gold nanorods by following time-dependent changes in Raman spectral signals.

    Science.gov (United States)

    Moghtader, Farzaneh; Tomak, Aysel; Zareie, Hadi M; Piskin, Erhan

    2018-03-27

    This study attemps to develop bacterial detection strategies using bacteriophages and gold nanorods (GNRs) by Raman spectral analysis. Escherichia coli was selected as the target and its specific phage was used as the bioprobe. Target bacteria and phages were propagated/purified by traditional techniques. GNRs were synthesized by using hexadecyltrimethyl ammonium bromide (CTAB) as stabilizer. A two-step detection strategy was applied: Firstly, the target bacteria were interacted with GNRs in suspensions, and then they were dropped onto silica substrates for detection. It was possible to obtain clear surface-enchanced Raman spectroscopy (SERS) peaks of the target bacteria, even without using phages. In the second step, the phage nanoemulsions were droped onto the bacterial-GNRs complexes on those surfaces and time-dependent changes in the Raman spectra were monitored at different time intervals upto 40 min. These results demonstrated that how one can apply phages with plasmonic nanoparticles for detection of pathogenic bacteria very effectively in a quite simple test.

  2. Comparison of direct-plating and broth-enrichment culture methods for detection of potential bacterial pathogens in respiratory secretions.

    Science.gov (United States)

    Kaur, Ravinder; Wischmeyer, Jareth; Morris, Matthew; Pichichero, Michael E

    2017-11-01

    We compared the recovery of potential respiratory bacterial pathogens and normal flora from nasopharyngeal specimens collected from children during health and at the onset of acute otitis media (AOM) by selective direct-plating and overnight broth-enrichment. Overall, 3442 nasal wash (NW) samples collected from young children were analysed from a 10-year prospective study. NWs were cultured by (1) direct-plating to TSAII/5 % sheep blood agar and chocolate agar plates and (2) overnight broth-enrichment in BacT/ALERT SA-broth followed by plating. Standard microbiology techniques were applied to identify three dominant respiratory bacterial pathogens: Streptococcus pneumoniae (Spn), Haemophilus influenzae (Hflu) and Moraxella catarrhalis (Mcat) as well as two common nasal flora, Staphylococcus aureus (SA) and alpha-haemolytic Streptococci (AHS).Results/Key findings. Direct-plating of NW resulted in isolation of Spn from 37.8 %, Hflu from 13.6 % and Mcat from 33.2 % of samples. In comparison, overnight broth-enrichment isolated fewer Spn (30.1 %), Hflu (6.2 %) and Mcat (16.2 %) (Penrichment resulted in significant increased isolation of SA (6.0 %) and AHS (30.1 %) (Penrichment when samples were collected from healthy children but not during AOM. In middle ear fluids (MEF) at the onset of AOM, broth-enrichment resulted in higher recovery of Spn (+10.4 %, Penrichment significantly reduces the accurate detection of bacterial respiratory pathogens and increases identification of SA and AHS in NW. Broth-enrichment improves detection of bacterial respiratory pathogens in MEF samples.

  3. Detection of Bacterial Pathogens from Broncho-Alveolar Lavage by Next-Generation Sequencing.

    Science.gov (United States)

    Leo, Stefano; Gaïa, Nadia; Ruppé, Etienne; Emonet, Stephane; Girard, Myriam; Lazarevic, Vladimir; Schrenzel, Jacques

    2017-09-20

    The applications of whole-metagenome shotgun sequencing (WMGS) in routine clinical analysis are still limited. A combination of a DNA extraction procedure, sequencing, and bioinformatics tools is essential for the removal of human DNA and for improving bacterial species identification in a timely manner. We tackled these issues with a broncho-alveolar lavage (BAL) sample from an immunocompromised patient who had developed severe chronic pneumonia. We extracted DNA from the BAL sample with protocols based either on sequential lysis of human and bacterial cells or on the mechanical disruption of all cells. Metagenomic libraries were sequenced on Illumina HiSeq platforms. Microbial community composition was determined by k-mer analysis or by mapping to taxonomic markers. Results were compared to those obtained by conventional clinical culture and molecular methods. Compared to mechanical cell disruption, a sequential lysis protocol resulted in a significantly increased proportion of bacterial DNA over human DNA and higher sequence coverage of Mycobacterium abscessus , Corynebacterium jeikeium and Rothia dentocariosa , the bacteria reported by clinical microbiology tests. In addition, we identified anaerobic bacteria not searched for by the clinical laboratory. Our results further support the implementation of WMGS in clinical routine diagnosis for bacterial identification.

  4. Development of the environmental neutron detection system

    International Nuclear Information System (INIS)

    Kume, Kyo

    2002-03-01

    Environmental neutron detection system was proposed and developed. The main goal of this system was set to detect fast and thermal neutrons with the identical detectors setup without degraders. This system consists of a 10 B doped liquid scintillator for n detection and CsI scintillators for simultaneous γ emission from 10 B doped in the liquid scintillator after the n capture reaction. The first setup was optimized for the thermal n detection, while the second setup was for the fast n detection. It was shown that the thermal n flux was obtained in the first setup by using the method of the γ coincidence method with the help of the Monte Carlo calculation. The second setup was designed to improve the detection efficiency for the fast n, and was shown qualitatively that both the pulse shape discrimination and the coincidence methods are efficient. There will be more improvements, particularly for the quantitative discussion. (author)

  5. Real-time petroleum spill detection system

    International Nuclear Information System (INIS)

    Dakin, D.T.

    2001-01-01

    A real-time autonomous oil and fuel spill detection system has been developed to rapidly detect of a wide range of petroleum products floating on, or suspended in water. The system consists of an array of spill detection buoys distributed within the area to be monitored. The buoys are composed of a float and a multispectral fluorometer, which looks up through the top 5 cm of water to detect floating and suspended petroleum products. The buoys communicate to a base station computer that controls the sampling of the buoys and analyses the data from each buoy to determine if a spill has occurred. If statistically significant background petroleum levels are detected, the system raises an oil spill alarm. The system is useful because early detection of a marine oil spill allows for faster containment, thereby minimizing the contaminated area and reducing cleanup costs. This paper also provided test results for biofouling, various petroleum product detection, water turbidity and wave tolerance. The technology has been successfully demonstrated. The UV light source keeps the optic window free from biofouling, and the electronics are fully submerged so there is no risk that the unit could ignite the vapours of a potential oil spill. The system can also tolerate moderately turbid waters and can therefore be used in many rivers, harbours, water intakes and sumps. The system can detect petroleum products with an average thickness of less than 3 micrometers floating on the water surface. 3 refs., 15 figs

  6. A multi-channel bioluminescent bacterial biosensor for the on-line detection of metals and toxicity. Part I: design and optimization of bioluminescent bacterial strains

    Energy Technology Data Exchange (ETDEWEB)

    Charrier, Thomas; Durand, Marie-Jose; Jouanneau, Sulivan; Thouand, Gerald [UMR CNRS 6144 GEPEA, CBAC, Nantes University, PRES UNAM, Campus de la Courtaisiere-IUT, La Roche-sur-Yon cedex (France); Dion, Michel [UMR CNRS 6204, Nantes University, PRES UNAM, Biotechnologie, Biocatalyse, Bioregulation, 2, Rue de la Houssiniere, BP 92208, Nantes cedex 3 (France); Pernetti, Mimma; Poncelet, Denis [ONIRIS-ENITIAA, UMR CNRS GEPEA, Rue de la Geraudiere, BP 82225, Nantes cedex 3 (France)

    2011-05-15

    This study describes the construction of inducible bioluminescent strains via genetic engineering along with their characterization and optimization in the detection of heavy metals. Firstly, a preliminary comparative study enabled us to select a suitable carbon substrate from pyruvate, glucose, citrate, diluted Luria-Bertani, and acetate. The latter carbon source provided the best induction ratios for comparison. Results showed that the three constructed inducible strains, Escherichia coli DH1 pBzntlux, pBarslux, and pBcoplux, were usable when conducting a bioassay after a 14-h overnight culture at 30 C. Utilizing these sensors gave a range of 12 detected heavy metals including several cross-detections. Detection limits for each metal were often close to and sometimes lower than the European standards for water pollution. Finally, in order to maintain sensitive bacteria within the future biosensor-measuring cell, the agarose immobilization matrix was compared to polyvinyl alcohol (PVA). Agarose was selected because the detection limits of the bioluminescent strains were not affected, in contrast to PVA. Specific detection and cross-detection ranges determined in this study will form the basis of a multiple metals detection system by the new multi-channel Lumisens3 biosensor. (orig.)

  7. Anomaly Detection for Complex Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — In performance maintenance in large, complex systems, sensor information from sub-components tends to be readily available, and can be used to make predictions about...

  8. System tuning and measurement error detection testing

    International Nuclear Information System (INIS)

    Krejci, Petr; Machek, Jindrich

    2008-09-01

    The project includes the use of the PEANO (Process Evaluation and Analysis by Neural Operators) system to verify the monitoring of the status of dependent measurements with a view to early measurement fault detection and estimation of selected signal levels. At the present stage, the system's capabilities of detecting measurement errors was assessed and the quality of the estimates was evaluated for various system configurations and the formation of empiric models, and rules were sought for system training at chosen process data recording parameters and operating modes. The aim was to find a suitable system configuration and to document the quality of the tuned system on artificial failures

  9. PCR-Independent Detection of Bacterial Species-Specific 16S rRNA at 10 fM by a Pore-Blockage Sensor

    Directory of Open Access Journals (Sweden)

    Leyla Esfandiari

    2016-07-01

    Full Text Available A PCR-free, optics-free device is used for the detection of Escherichia coli (E. coli 16S rRNA at 10 fM, which corresponds to ~100–1000 colony forming units/mL (CFU/mL depending on cellular rRNA levels. The development of a rapid, sensitive, and cost-effective nucleic acid detection platform is sought for the detection of pathogenic microbes in food, water and body fluids. Since 16S rRNA sequences are species specific and are present at high copy number in viable cells, these nucleic acids offer an attractive target for microbial pathogen detection schemes. Here, target 16S rRNA of E. coli at 10 fM concentration was detected against a total RNA background using a conceptually simple approach based on electromechanical signal transduction, whereby a step change reduction in ionic current through a pore indicates blockage by an electrophoretically mobilized bead-peptide nucleic acid probe conjugate hybridized to target nucleic acid. We investigated the concentration detection limit for bacterial species-specific 16S rRNA at 1 pM to 1 fM and found a limit of detection of 10 fM for our device, which is consistent with our previous finding with single-stranded DNA of similar length. In addition, no false positive responses were obtained with control RNA and no false negatives with target 16S rRNA present down to the limit of detection (LOD of 10 fM. Thus, this detection scheme shows promise for integration into portable, low-cost systems for rapid detection of pathogenic microbes in food, water and body fluids.

  10. Bacterial diversity in water injection systems of Brazilian offshore oil platforms.

    Science.gov (United States)

    Korenblum, Elisa; Valoni, Erika; Penna, Mônica; Seldin, Lucy

    2010-01-01

    Biogenic souring and microbial-influenced corrosion is a common scenario in water-flooded petroleum reservoirs. Water injection systems are continuously treated to control bacterial contamination, but some bacteria that cause souring and corrosion can persist even after different treatments have been applied. Our aim was to increase our knowledge of the bacterial communities that persist in the water injection systems of three offshore oil platforms in Brazil. To achieve this goal, we used a culture-independent molecular approach (16S ribosomal RNA gene clone libraries) to analyze seawater samples that had been subjected to different treatments. Phylogenetic analyses revealed that the bacterial communities from the different platforms were taxonomically different. A predominance of bacterial clones affiliated with Gammaproteobacteria, mostly belonging to the genus Marinobacter (60.7%), were observed in the platform A samples. Clones from platform B were mainly related to the genera Colwellia (37.9%) and Achromobacter (24.6%), whereas clones obtained from platform C were all related to unclassified bacteria. Canonical correspondence analyses showed that different treatments such as chlorination, deoxygenation, and biocide addition did not significantly influence the bacterial diversity in the platforms studied. Our results demonstrated that the injection water used in secondary oil recovery procedures contained potentially hazardous bacteria, which may ultimately cause souring and corrosion.

  11. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems.

    Science.gov (United States)

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit

    2016-08-15

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0-9.7×10(4)CFUm(-2)h(-1)) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate

  12. Changes in bacterial composition of biofilm in a metropolitan drinking water distribution system.

    Science.gov (United States)

    Revetta, R P; Gomez-Alvarez, V; Gerke, T L; Santo Domingo, J W; Ashbolt, N J

    2016-07-01

    This study examined the development of bacterial biofilms within a metropolitan distribution system. The distribution system is fed with different source water (i.e. groundwater, GW and surface water, SW) and undergoes different treatment processes in separate facilities. The biofilm community was characterized using 16S rRNA gene clone libraries and functional potential analysis, generated from total DNA extracted from coupons in biofilm annular reactors fed with onsite drinking water for up to 18 months. Differences in the bacterial community structure were observed between GW and SW. Representatives that explained the dissimilarity were associated with the classes Betaproteobacteria, Alphaproteobacteria, Actinobacteria, Gammaproteobacteria and Firmicutes. After 9 months the biofilm bacterial community from both GW and SW were dominated by Mycobacterium species. The distribution of the dominant operational taxonomic unit (OTU) (Mycobacterium) positively correlated with the drinking water distribution system (DWDS) temperature. In this study, the biofilm community structure observed between GW and SW were dissimilar, while communities from different locations receiving SW did not show significant differences. The results suggest that source water and/or the water quality shaped by their respective treatment processes may play an important role in shaping the bacterial communities in the distribution system. In addition, several bacterial groups were present in all samples, suggesting that they are an integral part of the core microbiota of this DWDS. These results provide an ecological insight into biofilm bacterial structure in chlorine-treated drinking water influenced by different water sources and their respective treatment processes. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  13. Breakdown of the innate immune system by bacterial proteases

    NARCIS (Netherlands)

    Laarman, A.J.

    2011-01-01

    Bacteria have developed many strategies to circumvent our immune system to survive and colonize human tissues. One of these strategies is by secreting proteases that specifically target the innate immune system. Aureolysin is a metalloprotease from Staphylococcus aureus which target the main

  14. Intrusion Detection Systems with Live Knowledge System

    Science.gov (United States)

    2016-05-31

    people try to reveal sensitive information of Internet users, also called as phishing. Phishing detection has received great attention but there has...node. Figure 3 describes the result of modified nodes from the original RDR rule tree. Red- coloured ‘X’ sign represents the stopping rule, and the...green- coloured boxes describe the refined rule. However, when human knowledge is applied to those incorrectly classified data, not all of the

  15. Characterization of CRISPR-Cas system in clinical Staphylococcus epidermidis strains revealed its potential association with bacterial infection sites

    DEFF Research Database (Denmark)

    Li, Qiuchun; Xie, Xiaolei; Yin, Kequan

    2016-01-01

    Staphylococcus epidermidis is considered as a major cause of nosocomial infections, bringing an immense burden to healthcare systems. Virulent phages have been confirmed to be efficient in combating the pathogen, but the prensence of CRISPR-Cas system, which is a bacterial immune system eliminating...... phages was reported in few S. epidermidis strains. In this study, the CRISPR-Cas system was detected in 12 from almost 300 published genomes in GenBank and by PCR of cas6 gene in 18 strains out of 130 clinical isolates obtained in Copenhagen. Four strains isolated in 1965-1966 harboured CRISPR elements...... spacers located in the CRISPR1 locus with homolgy to virulent phage 6ec DNA sequences, and 19 strains each carrying 2 or 3 different spacers recognizing this phage, implied that the CRISPR-Cas immunity could be abrogated by nucleotide mismatch between the spacer and its target phage sequence, while new...

  16. M13 virus based detection of bacterial infections in living hosts.

    Science.gov (United States)

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

    2014-08-01

    We report a first method for using M13 bacteriophage as a multifunctional scaffold for optically imaging bacterial infections in vivo. We demonstrate that M13 virus conjugated with hundreds of dye molecules (M13-Dye) can target and distinguish pathogenic infections of F-pili expressing and F-negative strains of E. coli. Further, in order to tune this M13-Dye complex suitable for targeting other strains of bacteria, we have used a 1-step reaction for creating an anti-bacterial antibody-M13-Dye probe. As an example, we show anti-S. aureus-M13-Dye able to target and image infections of S. aureus in living hosts, with a 3.7× increase in fluorescence over background. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Bacterial discrimination by means of a universal array approach mediated by LDR (ligase detection reaction

    Directory of Open Access Journals (Sweden)

    Consolandi Clarissa

    2002-09-01

    Full Text Available Abstract Background PCR amplification of bacterial 16S rRNA genes provides the most comprehensive and flexible means of sampling bacterial communities. Sequence analysis of these cloned fragments can provide a qualitative and quantitative insight of the microbial population under scrutiny although this approach is not suited to large-scale screenings. Other methods, such as denaturing gradient gel electrophoresis, heteroduplex or terminal restriction fragment analysis are rapid and therefore amenable to field-scale experiments. A very recent addition to these analytical tools is represented by microarray technology. Results Here we present our results using a Universal DNA Microarray approach as an analytical tool for bacterial discrimination. The proposed procedure is based on the properties of the DNA ligation reaction and requires the design of two probes specific for each target sequence. One oligo carries a fluorescent label and the other a unique sequence (cZipCode or complementary ZipCode which identifies a ligation product. Ligated fragments, obtained in presence of a proper template (a PCR amplified fragment of the 16s rRNA gene contain either the fluorescent label or the unique sequence and therefore are addressed to the location on the microarray where the ZipCode sequence has been spotted. Such an array is therefore "Universal" being unrelated to a specific molecular analysis. Here we present the design of probes specific for some groups of bacteria and their application to bacterial diagnostics. Conclusions The combined use of selective probes, ligation reaction and the Universal Array approach yielded an analytical procedure with a good power of discrimination among bacteria.

  18. Bacterial Biofilm Infection Detected in Breast Implant-Associated Anaplastic Large-Cell Lymphoma.

    Science.gov (United States)

    Hu, Honghua; Johani, Khalid; Almatroudi, Ahmad; Vickery, Karen; Van Natta, Bruce; Kadin, Marshall E; Brody, Garry; Clemens, Mark; Cheah, Chan Yoon; Lade, Stephen; Joshi, Preeti Avinash; Prince, H Miles; Deva, Anand K

    2016-06-01

    A recent association between breast implants and the development of anaplastic large-cell lymphoma (ALCL) has been observed. The purpose of this study was to identify whether bacterial biofilm is present in breast implant-associated ALCL and, if so, to compare the bacterial microbiome to nontumor capsule samples from breast implants with contracture. Twenty-six breast implant-associated ALCL samples were analyzed for the presence of biofilm by real-time quantitative polymerase chain reaction, next-generation sequencing, fluorescent in situ hybridization, and scanning electron microscopy, and compared to 62 nontumor capsule specimens. Both the breast implant-associated ALCL and nontumor capsule samples yielded high mean numbers of bacteria (breast implant-associated ALCL, 4.7 × 10 cells/mg of tissue; capsule, 4.9 × 10 cells/mg of tissue). Analysis of the microbiome in breast implant-associated ALCL specimens showed significant differences with species identified in nontumor capsule specimens. There was a significantly greater proportion of Ralstonia spp. present in ALCL specimens compared with nontumor capsule specimens (p capsule specimens compared with breast implant-associated ALCL specimens (p < 0.001). Bacterial biofilm was visualized both on scanning electron microscopy and fluorescent in situ hybridization. This novel finding of bacterial biofilm and a distinct microbiome in breast implant-associated ALCL samples points to a possible infectious contributing cause. Breast implants are widely used in both reconstructive and aesthetic surgery, and strategies to reduce their contamination should be more widely studied and practiced. Risk, V.

  19. Detection of bacterial soft-rot of crown imperial caused by Pectobacterium carotovorum subsp. carotovorum using specific PCR primers

    Directory of Open Access Journals (Sweden)

    E. Mahmoudi

    2007-08-01

    Full Text Available Pectobacterium is one of the major destructive causal agent in most crop plants throughout the world. During a survey in spring of 2005 in the rangeland of Kermanshah and Isfahan, provinces of Iran, samples of bulbs and stems of crown imperial with brown spot and soft rot were collected. Eight strains of pectolytic Erwinia were isolated and purified from these samples. Phenotypic tests indicated that the strains were gram-negative, facultative anaerobic, rod shaped, motile with peritrichous flagella. They were oxidase negative, catalase positive and also able to macerate potato slices. Pathogenicity of all the strains were confirmed on corn, philodendron and crown imperial by inoculation of these crops with a bacterial suspension and reisolation of the strain from symptomatic tissues. A pair of specific PCR primers was used to detect these bacterial strains. The primer set (EXPCCF/EXPCCR amplified a single fragment of the expected size (0.55 kb from genomic DNA of all strains used in this study. In nested PCR, the primer set (INPCCR/INPCCF amplified the expected single fragment (0.4 kb from the PCR product of first PCR amplification. On the basis of the biochemical and phenotypic characteristics and PCR amplification by the specific PCR primers, these strains were identified as Pectobacterium carotovorum subsp. carotovorum. This is the first report of occurrence of crown imperial bacterial soft-rot in Iran.

  20. 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.

  1. Embedded Systems - Missile Detection/Interception

    Directory of Open Access Journals (Sweden)

    Luis Cintron

    2010-01-01

    Full Text Available Missile defense systems are often related to major military resources aimed at shielding a specific region from incoming attacks. They are intended to detect, track, intercept, and destruct incoming enemy missiles. These systems vary in cost, efficiency, dependability, and technology. In present times, the possession of these types of systems is associated with large capacity military countries. Demonstrated here are the mathematical techniques behind missile systems which calculate trajectories of incoming missiles and potential intercept positions after initial missile detection. This procedure involved the use of vector-valued functions, systems of equations, and knowledge of projectile motion concepts.

  2. A failure detection and isolation system simulator

    International Nuclear Information System (INIS)

    Assumpcao Filho, E.O.; Nakata, H.

    1990-04-01

    A failure detection and isolation system (FDI) simulation program has been developed for IBM-PC microcomputers. The program, based on the sequential likelihood ratio testing method developed by A. Wald, was implemented with the Monte-Carlo technique. The calculated failure detection rate was favorably compared against the wind-tunnel experimental redundant temperature sensors. (author) [pt

  3. Statistical fault detection in photovoltaic systems

    KAUST Repository

    Garoudja, Elyes; Harrou, Fouzi; Sun, Ying; Kara, Kamel; Chouder, Aissa; Silvestre, Santiago

    2017-01-01

    and efficiency. Here, an innovative model-based fault-detection approach for early detection of shading of PV modules and faults on the direct current (DC) side of PV systems is proposed. This approach combines the flexibility, and simplicity of a one-diode model

  4. Bacterial contamination of table eggs and the influence of housing systems

    NARCIS (Netherlands)

    Reu, de K.; Messens, W.; Heyndrickx, M.; Rodenburg, T.B.; Uyttendaele, M.; Herman, L.

    2008-01-01

    With the introduction of alternative housing systems for laying hens in the EU, recent research has focussed on the bacterial contamination of table eggs, e.g. eggshell and egg content contamination. Contamination of eggshells with aerobic bacteria is generally higher for nest eggs from non-cage

  5. Role of toll like receptors in bacterial and viral diseases – A systemic ...

    African Journals Online (AJOL)

    Background: Toll like receptors are key-receptors of the innate immune system, but their role against bacterial and viral infections are yet to be understood. Aim: The present study is aimed to investigate the diversity and frequency distribution of 10 TLR genes among typhoid fever and HIV+ patients. In this study, 44 samples ...

  6. Statistical fault detection in photovoltaic systems

    KAUST Repository

    Garoudja, Elyes

    2017-05-08

    Faults in photovoltaic (PV) systems, which can result in energy loss, system shutdown or even serious safety breaches, are often difficult to avoid. Fault detection in such systems is imperative to improve their reliability, productivity, safety and efficiency. Here, an innovative model-based fault-detection approach for early detection of shading of PV modules and faults on the direct current (DC) side of PV systems is proposed. This approach combines the flexibility, and simplicity of a one-diode model with the extended capacity of an exponentially weighted moving average (EWMA) control chart to detect incipient changes in a PV system. The one-diode model, which is easily calibrated due to its limited calibration parameters, is used to predict the healthy PV array\\'s maximum power coordinates of current, voltage and power using measured temperatures and irradiances. Residuals, which capture the difference between the measurements and the predictions of the one-diode model, are generated and used as fault indicators. Then, the EWMA monitoring chart is applied on the uncorrelated residuals obtained from the one-diode model to detect and identify the type of fault. Actual data from the grid-connected PV system installed at the Renewable Energy Development Center, Algeria, are used to assess the performance of the proposed approach. Results show that the proposed approach successfully monitors the DC side of PV systems and detects temporary shading.

  7. Bacterial communities associated with an occurrence of colored water in an urban drinking water distribution system.

    Science.gov (United States)

    Wu, Hui Ting; Mi, Zi Long; Zhang, Jing Xu; Chen, Chao; Xie, Shu Guang

    2014-08-01

    This study aimed to investigate bacterial community in an urban drinking water distribution system (DWDS) during an occurrence of colored water. Variation in the bacterial community diversity and structure was observed among the different waters, with the predominance of Proteobacteria. While Verrucomicrobia was also a major phylum group in colored water. Limnobacter was the major genus group in colored water, but Undibacterium predominated in normal tap water. The coexistence of Limnobacter as well as Sediminibacterium and Aquabacterium might contribute to the formation of colored water. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  8. [Development of operation patient security detection system].

    Science.gov (United States)

    Geng, Shu-Qin; Tao, Ren-Hai; Zhao, Chao; Wei, Qun

    2008-11-01

    This paper describes a patient security detection system developed with two dimensional bar codes, wireless communication and removal storage technique. Based on the system, nurses and correlative personnel check code wait operation patient to prevent the defaults. The tests show the system is effective. Its objectivity and currency are more scientific and sophisticated than current traditional method in domestic hospital.

  9. Rapid detection of bacterial contamination in cell or tissue cultures based on Raman spectroscopy

    Science.gov (United States)

    Bolwien, Carsten; Sulz, Gerd; Becker, Sebastian; Thielecke, Hagen; Mertsching, Heike; Koch, Steffen

    2008-02-01

    Monitoring the sterility of cell or tissue cultures is an essential task, particularly in the fields of regenerative medicine and tissue engineering when implanting cells into the human body. We present a system based on a commercially available microscope equipped with a microfluidic cell that prepares the particles found in the solution for analysis, a Raman-spectrometer attachment optimized for non-destructive, rapid recording of Raman spectra, and a data acquisition and analysis tool for identification of the particles. In contrast to conventional sterility testing in which samples are incubated over weeks, our system is able to analyze milliliters of supernatant or cell suspension within hours by filtering relevant particles and placing them on a Raman-friendly substrate in the microfluidic cell. Identification of critical particles via microscopic imaging and subsequent image analysis is carried out before micro-Raman analysis of those particles is then carried out with an excitation wavelength of 785 nm. The potential of this setup is demonstrated by results of artificial contamination of samples with a pool of bacteria, fungi, and spores: single-channel spectra of the critical particles are automatically baseline-corrected without using background data and classified via hierarchical cluster analysis, showing great promise for accurate and rapid detection and identification of contaminants.

  10. Biofilm bacterial communities in urban drinking water distribution systems transporting waters with different purification strategies.

    Science.gov (United States)

    Wu, Huiting; Zhang, Jingxu; Mi, Zilong; Xie, Shuguang; Chen, Chao; Zhang, Xiaojian

    2015-02-01

    Biofilm formation in drinking water distribution systems (DWDS) has many adverse consequences. Knowledge of microbial community structure of DWDS biofilm can aid in the design of an effective control strategy. However, biofilm bacterial community in real DWDS and the impact of drinking water purification strategy remain unclear. The present study investigated the composition and diversity of biofilm bacterial community in real DWDSs transporting waters with different purification strategies (conventional treatment and integrated treatment). High-throughput Illumina MiSeq sequencing analysis illustrated a large shift in the diversity and structure of biofilm bacterial community in real DWDS. Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Nitrospirae, and Cyanobacteria were the major components of biofilm bacterial community. Proteobacteria (mainly Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria) predominated in each DWDS biofilm, but the compositions of the dominant proteobacterial classes and genera and their proportions varied among biofilm samples. Drinking water purification strategy could shape DWDS biofilm bacterial community. Moreover, Pearson's correlation analysis indicated that Actinobacteria was positively correlated with the levels of total alkalinity and dissolved organic carbon in tap water, while Firmicutes had a significant positive correlation with nitrite nitrogen.

  11. IMPROVING CAUSE DETECTION SYSTEMS WITH ACTIVE LEARNING

    Data.gov (United States)

    National Aeronautics and Space Administration — IMPROVING CAUSE DETECTION SYSTEMS WITH ACTIVE LEARNING ISAAC PERSING AND VINCENT NG Abstract. Active learning has been successfully applied to many natural language...

  12. Caltrans fog detection and warning system.

    Science.gov (United States)

    2009-01-01

    The California Department of Transportation (Caltrans) has implemented a fog detection and warning system on Highway 99 near Fresno. The entire central valley region is susceptible to Tule fog, which can reduce visibility tremendously, sometimes to n...

  13. Detection of cardiovascular anomalies: Hybrid systems approach

    KAUST Repository

    Ledezma, Fernando; Laleg-Kirati, Taous-Meriem

    2012-01-01

    In this paper, we propose a hybrid interpretation of the cardiovascular system. Based on a model proposed by Simaan et al. (2009), we study the problem of detecting cardiovascular anomalies that can be caused by variations in some physiological

  14. CRISPR technologies for bacterial systems: Current achievements and future directions

    DEFF Research Database (Denmark)

    Choi, Kyeong Rok; Lee, Sang Yup

    2016-01-01

    Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now revolution......Throughout the decades of its history, the advances in bacteria-based bio-industries have coincided with great leaps in strain engineering technologies. Recently unveiled clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) systems are now...... revolutionizing biotechnology as well as biology. Diverse technologies have been derived from CRISPR/Cas systems in bacteria, yet the applications unfortunately have not been actively employed in bacteria as extensively as in eukaryotic organisms. A recent trend of engineering less explored strains in industrial...... microbiology-metabolic engineering, synthetic biology, and other related disciplines-is demanding facile yet robust tools, and various CRISPR technologies have potential to cater to the demands. Here, we briefly review the science in CRISPR/Cas systems and the milestone inventions that enabled numerous CRISPR...

  15. Detection and intelligent systems for homeland security

    CERN Document Server

    Voeller, John G

    2014-01-01

    Detection and Intelligent Systems for Homeland Security features articles from the Wiley Handbook of Science and Technology for Homeland Security covering advanced technology for image and video interpretation systems used for surveillance, which help in solving such problems as identifying faces from live streaming or stored videos. Biometrics for human identification, including eye retinas and irises, and facial patterns are also presented. The book then provides information on sensors for detection of explosive and radioactive materials and methods for sensing chemical

  16. Doubler system quench detection threshold

    International Nuclear Information System (INIS)

    Kuepke, K.; Kuchnir, M.; Martin, P.

    1983-01-01

    The experimental study leading to the determination of the sensitivity needed for protecting the Fermilab Doubler from damage during quenches is presented. The quench voltage thresholds involved were obtained from measurements made on Doubler cable of resistance x temperature and voltage x time during quenches under several currents and from data collected during operation of the Doubler Quench Protection System as implemented in the B-12 string of 20 magnets. At 4kA, a quench voltage threshold in excess of 5.OV will limit the peak Doubler cable temperature to 452K for quenches originating in the magnet coils whereas a threshold of 0.5V is required for quenches originating outside of coils

  17. Differential effects of interleukin-17 receptor signaling on innate and adaptive immunity during central nervous system bacterial infection

    Directory of Open Access Journals (Sweden)

    Vidlak Debbie

    2012-06-01

    Full Text Available Abstract Although IL-17A (commonly referred to as IL-17 has been implicated in the pathogenesis of central nervous system (CNS autoimmune disease, its role during CNS bacterial infections remains unclear. To evaluate the broader impact of IL-17 family members in the context of CNS infection, we utilized IL-17 receptor (IL-17R knockout (KO mice that lack the ability to respond to IL-17, IL-17F and IL-17E (IL-25. In this article, we demonstrate that IL-17R signaling regulates bacterial clearance as well as natural killer T (NKT cell and gamma-delta (γδ T cell infiltrates during Staphylococcus aureus-induced brain abscess formation. Specifically, when compared with wild-type (WT animals, IL-17R KO mice exhibited elevated bacterial burdens at days 7 and 14 following S. aureus infection. Additionally, IL-17R KO animals displayed elevated neutrophil chemokine production, revealing the ability to compensate for the lack of IL-17R activity. Despite these differences, innate immune cell recruitment into brain abscesses was similar in IL-17R KO and WT mice, whereas IL-17R signaling exerted a greater influence on adaptive immune cell recruitment. In particular, γδ T cell influx was increased in IL-17R KO mice at day 7 post-infection. In addition, NK1.1high infiltrates were absent in brain abscesses of IL-17R KO animals and, surprisingly, were rarely detected in the livers of uninfected IL-17R KO mice. Although IL-17 is a key regulator of neutrophils in other infection models, our data implicate an important role for IL-17R signaling in regulating adaptive immunity during CNS bacterial infection.

  18. A Bacterial-Based Algorithm to Simulate Complex Adaptative Systems

    OpenAIRE

    González Rodríguez, Diego; Hernández Carrión, José Rodolfo

    2014-01-01

    Paper presented at the 13th International Conference on Simulation of Adaptive Behavior which took place at Castellón, Spain in 2014, July 22-25. Bacteria have demonstrated an amazing capacity to overcome envi-ronmental changes by collective adaptation through genetic exchanges. Using a distributed communication system and sharing individual strategies, bacteria propagate mutations as innovations that allow them to survive in different envi-ronments. In this paper we present an agent-based...

  19. Intrusion Detection amp Prevention Systems - Sourcefire Snort

    Directory of Open Access Journals (Sweden)

    Rajesh Vuppala

    2015-08-01

    Full Text Available Information security is a challenging issue for all business organizations today amidst increasing cyber threats. While there are many alternative intrusion detection amp prevention systems available to choose from selecting the best solution to implement to detect amp prevent cyber-attacks is a difficult task. The best solution is of the one that gets the best reviews and suits the organizations needs amp budget. In this review paper we summarize various classes of intrusion detection and prevention systems compare features of alternative solutions and make recommendation for implementation of one as the best solution for business organization in Fiji.

  20. Active fault detection in MIMO systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2014-01-01

    The focus in this paper is on active fault detection (AFD) for MIMO systems with parametric faults. The problem of design of auxiliary inputs with respect to detection of parametric faults is investigated. An analysis of the design of auxiliary inputs is given based on analytic transfer functions...... from auxiliary input to residual outputs. The analysis is based on a singular value decomposition of these transfer functions Based on this analysis, it is possible to design auxiliary input as well as design of the associated residual vector with respect to every single parametric fault in the system...... such that it is possible to detect these faults....

  1. Portable reconfigurable detection and assessment system

    International Nuclear Information System (INIS)

    Blattman, D.A.

    1991-01-01

    Rapidly changing geopolitical issues throughout the world have made the ability to effectively respond to political, military, terrorist and peace-keeping requirements increasingly important. Recent Middle East events indicate a continuing escalation in these activities. These activities are defining the requirements for a rapidly deployable, portable, real-time detection and assessment operational security system that is reconfigurable to site specific threats. This paper describes such a system Mobile Operational Detection and Assessment system (MODAS); a commercially-off-the shelf (COTS) integrated and reconfigurable hardware/software system solution for the ever-changing geopolitical security issues of the Nineties

  2. A Fuzzy Expert System for Distinguishing between Bacterial and Aseptic Meningitis

    Directory of Open Access Journals (Sweden)

    Mostafa Langarizadeh

    2015-05-01

    Full Text Available Introduction Bacterial meningitis is a known infectious disease which occurs at early ages and should be promptly diagnosed and treated. Bacterial and aseptic meningitis are hard to be distinguished. Therefore, physicians should be highly informed and experienced in this area. The main aim of this study was to suggest a system for distinguishing between bacterial and aseptic meningitis, using fuzzy logic.    Materials and Methods In the first step, proper attributes were selected using Weka 3.6.7 software. Six attributes were selected using Attribute Evaluator, InfoGainAttributeEval, and Ranker search method items. Then, a fuzzy inference engine was designed using MATLAB software, based on Mamdani’s fuzzy logic method with max-min composition, prod-probor, and centroid defuzzification. The rule base consisted of eight rules, based on the experience of three specialists and information extracted from textbooks. Results Data were extracted from 106 records of patients with meningitis (42 cases with bacterial meningitis in order to evaluate the proposed system. The system accuracy, specificity, and sensitivity were 89%, 92 %, and 97%, respectively. The area under the ROC curve was 0.93, and Kappa test revealed a good level of agreement (k=0.84, P

  3. The role of the bacterial mismatch repair system in SOS-induced mutagenesis: a theoretical background

    International Nuclear Information System (INIS)

    Belov, O.V.; Kapralov, M.I.; Chuluunbaatar, O.; Sweilam, N.H.

    2012-01-01

    A theoretical study is performed of the possible role of the methyl-directed mismatch repair system in the ultraviolet-induced mutagenesis of Escherichia coli bacterial cells. For this purpose, a mathematical model of the bacterial mismatch repair system is developed. Within this model, the key pathways of this type of repair are simulated on the basis of modern experimental data related to its mechanisms. Here we have modelled in detail five main pathways of DNA misincorporation removal with different DNA exonucleases. Using our calculations, we have tested the hypothesis that the bacterial mismatch repair system is responsible for the removal of the nucleotides misincorporated by DNA polymerase V (the UmuD' 2 C complex) during ultraviolet-induced SOS response. For the theoretical analysis of the mutation frequency, we have combined the proposed mathematical approach with the model of SOS-induced mutagenesis in the E.coli bacterial cell developed earlier. Our calculations support the hypothesis that methyl-directed mismatch repair influences the mutagenic effect of ultraviolet radiation

  4. Anaerobic bacterial systems result in the removal of soluble uranium

    International Nuclear Information System (INIS)

    Thomson, B.M.; Barton, L.L.; Steenhoudt, K.; Tucker, M.D.

    1994-01-01

    Sulfate-reducing bacteria, nitrate-reducing bacteria and bacteria present in sewage sludge were examined for their ability to reduce the level of soluble U(VI) in enriched media. Cultures of Desulfovibrio desulfuricans, D. gigas, and D. vulgaris were grown in sulfate-containing media while Pseudomonas putida and P. denitrificans were cultivated in nitrate media. The amount of U(VI) removed from solution was dependent on metabolism because greater levels of uranium were removed when U(VI) was added to a growing culture than when added to a culture in stationary phase. The presence of vanadate, arsenate, selenate or molybdate at 0.1 and 0.01 M levels in sulfate-reducing cultures, nitrate-respiring cultures or in sludge cultures did not have an effect on the amount of uranium removed. In all cultures the amount of uranium in solution was markedly reduced after 10 to 20 days and reduced uranium, as U(IV), was detected in several cultures. Present in the cultures of D. desulfuricans were crystals of uranium. Examination of these cultures by electron microscopy indicates that the uranium (IV) is deposited outside of the cell and these needle-like crystals are associated with cellular material. X-ray probe analysis with the electron microscope gave an image that was in close agreement with U(IV). With D. desulfuricans in a continuous stirred tank reactor, kinetic parameters have been calculated for uranium reduction. Over a period of 20 to 60 hours, the amount of soluble uranium removed from the bioreactor was proportional to residence time over a period of 20 to 60 hours

  5. Flat Surface Damage Detection System (FSDDS)

    Science.gov (United States)

    Williams, Martha; Lewis, Mark; Gibson, Tracy; Lane, John; Medelius, Pedro; Snyder, Sarah; Ciarlariello, Dan; Parks, Steve; Carrejo, Danny; Rojdev, Kristina

    2013-01-01

    The Flat Surface Damage Detection system (FSDDS} is a sensory system that is capable of detecting impact damages to surfaces utilizing a novel sensor system. This system will provide the ability to monitor the integrity of an inflatable habitat during in situ system health monitoring. The system consists of three main custom designed subsystems: the multi-layer sensing panel, the embedded monitoring system, and the graphical user interface (GUI). The GUI LABVIEW software uses a custom developed damage detection algorithm to determine the damage location based on the sequence of broken sensing lines. It estimates the damage size, the maximum depth, and plots the damage location on a graph. Successfully demonstrated as a stand alone technology during 2011 D-RATS. Software modification also allowed for communication with HDU avionics crew display which was demonstrated remotely (KSC to JSC} during 2012 integration testing. Integrated FSDDS system and stand alone multi-panel systems were demonstrated remotely and at JSC, Mission Operations Test using Space Network Research Federation (SNRF} network in 2012. FY13, FSDDS multi-panel integration with JSC and SNRF network Technology can allow for integration with other complementary damage detection systems.

  6. A new digital correlation flaw detection system

    International Nuclear Information System (INIS)

    Lee, B.B.; Furgason, E.S.

    1981-01-01

    A new portable digital random signal flaw detection system is described which uses a digital delay line to replace the acoustic delay line of the original random signal system. Using this new system, a comparison was made between the two types of transmit signals which have been used in previous systems--m-sequences and random signals. This comparison has not been possible with these previous correlation flaw detection systems. Results indicated that for high-speed short code operation, the m-sequences produced slightly lower range sidelobes than typical samples of a clipped random signal. For normal long code operation, results indicated that system performance is essentially equivalent in resolution and signal-to-noise ratio using either m-sequences or clipped and sampled random signals. Further results also showed that for normal long code operation, the system produces outputs equivalent in resolution to pulse-echo systems, but with the added benefit of signal-to-noise ratio enhancement

  7. Bacterial derived proteoliposome as ideal delivery system and cellular adjuvant.

    Science.gov (United States)

    Rodríguez, Tamara; Pérez, Oliver a; Ugrinovic, Sanja; Bracho, Gustavo; Mastroeni, Pietro

    2006-04-12

    We explored the potential of a proteoliposome (PL) from the outer membrane of N. meningitidis B, as an immunopotentiator and as a vector for antigen delivery to dendritic cells (DC). DC were incubated with PL resulting in up-regulation of MHC-II, CD40, CD80, and CD86 expression and production of TNFalpha and IL12(p70). Ovoalbumin (OVA) was incorporated within PL (PL-OVA). PL-OVA presented OVA-specific peptides to CD4+ and CD8+ OVA-specific T-cell hybridomas. PL exerts an immunomodulatory effect on DC and is a general system to deliver antigens for presentation to CD4+ and CD8+ T-cells possibly implicated in the induction CD8+ cytotoxic T lymphocytes (CTLs) responses.

  8. Preparation and surface functionalisation of poly(styrene maleimide) nanoparticles for bacterial detection

    CSIR Research Space (South Africa)

    Barnard, A

    2012-10-01

    Full Text Available .kashan.co.za] INTRODUCTION The detection of bacteria in water is essential for the prevention of water-borne disease outbreaks. Conventionally, culturing methods are used to detect bacteria in water, whereby the number of bacteria present in a sample is multiplied to a... to the particle surfaces for attachment of fluorescent markers and antibodies. Figure 1: Process diagram of proposed development method of nanoparticles for bacteria detection Particle characterisation was performed with transmission electron microscopy (TEM...

  9. Luciferase-Zinc-Finger System for the Rapid Detection of Pathogenic Bacteria.

    Science.gov (United States)

    Shi, Chu; Xu, Qing; Ge, Yue; Jiang, Ling; Huang, He

    2017-08-09

    Rapid and reliable detection of pathogenic bacteria is crucial for food safety control. Here, we present a novel luciferase-zinc finger system for the detection of pathogens that offers rapid and specific profiling. The system, which uses a zinc-finger protein domain to probe zinc finger recognition sites, was designed to bind the amplified conserved regions of 16S rDNA, and the obtained products were detected using a modified luciferase. The luciferase-zinc finger system not only maintained luciferase activity but also allowed the specific detection of different bacterial species, with a sensitivity as low as 10 copies and a linear range from 10 to 10 4 copies per microliter of the specific PCR product. Moreover, the system is robust and rapid, enabling the simultaneous detection of 6 species of bacteria in artificially contaminated samples with excellent accuracy. Thus, we envision that our luciferase-zinc finger system will have far-reaching applications.

  10. A Transcriptional Regulatory Mechanism Finely Tunes the Firing of Type VI Secretion System in Response to Bacterial Enemies.

    Science.gov (United States)

    Lazzaro, Martina; Feldman, Mario F; García Véscovi, Eleonora

    2017-08-22

    The ability to detect and measure danger from an environmental signal is paramount for bacteria to respond accordingly, deploying strategies that halt or counteract potential cellular injury and maximize survival chances. Type VI secretion systems (T6SSs) are complex bacterial contractile nanomachines able to target toxic effectors into neighboring bacteria competing for the same colonization niche. Previous studies support the concept that either T6SSs are constitutively active or they fire effectors in response to various stimuli, such as high bacterial density, cell-cell contact, nutrient depletion, or components from dead sibling cells. For Serratia marcescens , it has been proposed that its T6SS is stochastically expressed, with no distinction between harmless or aggressive competitors. In contrast, we demonstrate that the Rcs regulatory system is responsible for finely tuning Serratia T6SS expression levels, behaving as a transcriptional rheostat. When confronted with harmless bacteria, basal T6SS expression levels suffice for Serratia to eliminate the competitor. A moderate T6SS upregulation is triggered when, according to the aggressor-prey ratio, an unbalanced interplay between homologous and heterologous effectors and immunity proteins takes place. Higher T6SS expression levels are achieved when Serratia is challenged by a contender like Acinetobacter , which indiscriminately fires heterologous effectors able to exert lethal cellular harm, threatening the survival of the Serratia population. We also demonstrate that Serratia 's RcsB-dependent T6SS regulatory mechanism responds not to general stress signals but to the action of specific effectors from competitors, displaying an exquisite strategy to weigh risks and keep the balance between energy expenditure and fitness costs. IMPORTANCE Serratia marcescens is among the health-threatening pathogens categorized by the WHO as research priorities to develop alternative antimicrobial strategies, and it was

  11. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

    Directory of Open Access Journals (Sweden)

    Chew Chieng Yeo

    2016-02-01

    Full Text Available Toxin-antitoxin (TA systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies.

  12. Heterologous Expression of Toxins from Bacterial Toxin-Antitoxin Systems in Eukaryotic Cells: Strategies and Applications

    Science.gov (United States)

    Yeo, Chew Chieng; Abu Bakar, Fauziah; Chan, Wai Ting; Espinosa, Manuel; Harikrishna, Jennifer Ann

    2016-01-01

    Toxin-antitoxin (TA) systems are found in nearly all prokaryotic genomes and usually consist of a pair of co-transcribed genes, one of which encodes a stable toxin and the other, its cognate labile antitoxin. Certain environmental and physiological cues trigger the degradation of the antitoxin, causing activation of the toxin, leading either to the death or stasis of the host cell. TA systems have a variety of functions in the bacterial cell, including acting as mediators of programmed cell death, the induction of a dormant state known as persistence and the stable maintenance of plasmids and other mobile genetic elements. Some bacterial TA systems are functional when expressed in eukaryotic cells and this has led to several innovative applications, which are the subject of this review. Here, we look at how bacterial TA systems have been utilized for the genetic manipulation of yeasts and other eukaryotes, for the containment of genetically modified organisms, and for the engineering of high expression eukaryotic cell lines. We also examine how TA systems have been adopted as an important tool in developmental biology research for the ablation of specific cells and the potential for utility of TA systems in antiviral and anticancer gene therapies. PMID:26907343

  13. Capacitive system detects and locates fluid leaks

    Science.gov (United States)

    1966-01-01

    Electronic monitoring system automatically detects and locates minute leaks in seams of large fluid storage tanks and pipelines covered with thermal insulation. The system uses a capacitive tape-sensing element that is adhesively bonded over seams where fluid leaks are likely to occur.

  14. Improved biosensor-based detection system

    DEFF Research Database (Denmark)

    2015-01-01

    Described is a new biosensor-based detection system for effector compounds, useful for in vivo applications in e.g. screening and selecting of cells which produce a small molecule effector compound or which take up a small molecule effector compound from its environment. The detection system...... comprises a protein or RNA-based biosensor for the effector compound which indirectly regulates the expression of a reporter gene via two hybrid proteins, providing for fewer false signals or less 'noise', tuning of sensitivity or other advantages over conventional systems where the biosensor directly...

  15. Hydrogen detection systems leak response codes

    International Nuclear Information System (INIS)

    Desmas, T.; Kong, N.; Maupre, J.P.; Schindler, P.; Blanc, D.

    1990-01-01

    A loss in tightness of a water tube inside a Steam Generator Unit of a Fast Reactor is usually monitored by hydrogen detection systems. Such systems have demonstrated in the past their ability to detect a leak in a SGU. However, the increase in size of the SGU or the choice of ferritic material entails improvement of these systems in order to avoid secondary leak or to limit damages to the tube bundle. The R and D undertaken in France on this subject is presented. (author). 11 refs, 10 figs

  16. Multisignal detecting system of pile integrity testing

    Science.gov (United States)

    Liu, Zuting; Luo, Ying; Yu, Shihai

    2002-05-01

    The low strain reflection wave method plays a principal rule in the integrating detection of base piles. However, there are some deficiencies with this method. For example, there is a blind area of detection on top of the tested pile; it is difficult to recognize the defects at deep-seated parts of the pile; there is still the planar of 3D domino effect, etc. It is very difficult to solve these problems only with the single-transducer pile integrity testing system. A new multi-signal piles integrity testing system is proposed in this paper, which is able to impulse and collect signals on multiple points on top of the pile. By using the multiple superposition data processing method, the detecting system can effectively restrain the interference and elevate the precision and SNR of pile integrity testing. The system can also be applied to the evaluation of engineering structure health.

  17. Scalable DNA-Based Magnetic Nanoparticle Agglutination Assay for Bacterial Detection in Patient Samples

    DEFF Research Database (Denmark)

    Mezger, Anja; Fock, Jeppe; Antunes, Paula Soares Martins

    2015-01-01

    and on the introduction of a magnetic incubation scheme. This enables multiplex detection of Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa at clinically relevant concentrations, demonstrating a factor of 30 improvement in sensitivity compared to previous MNP-based detection schemes. Thanks...

  18. Auto-production of biosurfactants reverses the coffee ring effect in a bacterial system

    Science.gov (United States)

    Sempels, Wouter; de Dier, Raf; Mizuno, Hideaki; Hofkens, Johan; Vermant, Jan

    2013-04-01

    The deposition of material at the edge of evaporating droplets, known as the ‘coffee ring effect’, is caused by a radially outward capillary flow. This phenomenon is common to a wide array of systems including colloidal and bacterial systems. The role of surfactants in counteracting these coffee ring depositions is related to the occurrence of local vortices known as Marangoni eddies. Here we show that these swirling flows are universal, and not only lead to a uniform deposition of colloids but also occur in living bacterial systems. Experiments on Pseudomonas aeruginosa suggest that the auto-production of biosurfactants has an essential role in creating a homogeneous deposition of the bacteria upon drying. Moreover, at biologically relevant conditions, intricate time-dependent flows are observed in addition to the vortex regime, which are also effective in reversing the coffee ring effect at even lower surfactant concentrations.

  19. Detecting bacterial magnetite in sediments: strengths and limitations of FMR spectroscopy

    Science.gov (United States)

    Winklhofer, M.

    2012-04-01

    Ferromagnetic resonance spectroscopy (FMR) is increasingly being used as a diagnostic tool for identifying bacterial magnetite in sediments [e.g., Kopp et al. 2007; Kind et al. 2011, Roberts et al. 2011 ], the reason being that magnetic bacteria have a characteristic FMR fingerprint which is not known from inorganic geological samples [Kopp & Kirschvink, 2008]. The diagnostic FMR features of single-stranded magnetite chains are a g-value 2, quite opposite to what we know from single-stranded chains. Therefore, in order to better understand possible biogenic FMR fingerprints and to refine the screen, there is a clear need to acquire FMR spectra of magnetic bacteria with different chain configurations and, in particular, of greigite producing bacteria.

  20. Detection of Bundle Branch Block using Adaptive Bacterial Foraging Optimization and Neural Network

    Directory of Open Access Journals (Sweden)

    Padmavthi Kora

    2017-03-01

    Full Text Available The medical practitioners analyze the electrical activity of the human heart so as to predict various ailments by studying the data collected from the Electrocardiogram (ECG. A Bundle Branch Block (BBB is a type of heart disease which occurs when there is an obstruction along the pathway of an electrical impulse. This abnormality makes the heart beat irregular as there is an obstruction in the branches of heart, this results in pulses to travel slower than the usual. Our current study involved is to diagnose this heart problem using Adaptive Bacterial Foraging Optimization (ABFO Algorithm. The Data collected from MIT/BIH arrhythmia BBB database applied to an ABFO Algorithm for obtaining best(important feature from each ECG beat. These features later fed to Levenberg Marquardt Neural Network (LMNN based classifier. The results show the proposed classification using ABFO is better than some recent algorithms reported in the literature.

  1. Network Intrusion Detection System using Apache Storm

    Directory of Open Access Journals (Sweden)

    Muhammad Asif Manzoor

    2017-06-01

    Full Text Available Network security implements various strategies for the identification and prevention of security breaches. Network intrusion detection is a critical component of network management for security, quality of service and other purposes. These systems allow early detection of network intrusion and malicious activities; so that the Network Security infrastructure can react to mitigate these threats. Various systems are proposed to enhance the network security. We are proposing to use anomaly based network intrusion detection system in this work. Anomaly based intrusion detection system can identify the new network threats. We also propose to use Real-time Big Data Stream Processing Framework, Apache Storm, for the implementation of network intrusion detection system. Apache Storm can help to manage the network traffic which is generated at enormous speed and size and the network traffic speed and size is constantly increasing. We have used Support Vector Machine in this work. We use Knowledge Discovery and Data Mining 1999 (KDD’99 dataset to test and evaluate our proposed solution.

  2. Obstacle detection system for underground mining vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, P.; Polotski, V.; Piotte, M.; Melamed, F. [Ecole Polytechnique de Montreal, Montreal, PQ (Canada)

    1998-01-01

    A device for detecting obstacles by autonomous vehicles navigating in mine drifts is described. The device is based upon structured lighting and the extraction of relevant features from images of obstacles. The system uses image profile changes, ground and wall irregularities, disturbances of the vehicle`s trajectory, and impaired visibility to detect obstacles, rather than explicit three-dimensional scene reconstruction. 7 refs., 5 figs.

  3. Device for detecting failure of reactor system

    International Nuclear Information System (INIS)

    Miyazawa, Tatsuo.

    1979-01-01

    Purpose: To make it possible to rapidly detect any failure in a reactor system prior to the leakage of coolants. Constitution: The dose of beta line is computed from the difference between the power of a detector for reacting with both beta and gamma lines and a detector for reacting only with gamma line to detect the failure of a reactor system, thereby to raise the detection speed and improve the detection accuracy. More specifically, a radiation detector A detects gamma and beta lines by means of piezoelectric elements. A radiation detector B caused the opening of the detector A to be covered with a metal, and detects only gamma line. The detected values of detectors A and B are amplified by an amplifier and applied to a rate meter and a counter, the values being converted into DC and introduced into a comparison circuit, where the outputs of the rate meter are compared with each other. When the difference is more than the predetermined range, it is supplied as output to an alarm circuit where an alarm signal is produced. (Nakamura, S.)

  4. Edge detection techniques for iris recognition system

    International Nuclear Information System (INIS)

    Tania, U T; Motakabber, S M A; Ibrahimy, M I

    2013-01-01

    Nowadays security and authentication are the major parts of our daily life. Iris is one of the most reliable organ or part of human body which can be used for identification and authentication purpose. To develop an iris authentication algorithm for personal identification, this paper examines two edge detection techniques for iris recognition system. Between the Sobel and the Canny edge detection techniques, the experimental result shows that the Canny's technique has better ability to detect points in a digital image where image gray level changes even at slow rate

  5. Development and application of an oligonucleotide microarray and real-time quantitative PCR for detection of wastewater bacterial pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dae-Young [National Water Research Institute, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6 (Canada)], E-mail: daeyoung.lee@ec.gc.ca; Lauder, Heather; Cruwys, Heather; Falletta, Patricia [National Water Research Institute, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6 (Canada); Beaudette, Lee A. [Environmental Science and Technology Centre, Environment Canada, 335 River Road South, Ottawa, Ontario, K1A 0H3 (Canada)], E-mail: lee.beaudette@ec.gc.ca

    2008-07-15

    Conventional microbial water quality test methods are well known for their technical limitations, such as lack of direct pathogen detection capacity and low throughput capability. The microarray assay has recently emerged as a promising alternative for environmental pathogen monitoring. In this study, bacterial pathogens were detected in municipal wastewater using a microarray equipped with short oligonucleotide probes targeting 16S rRNA sequences. To date, 62 probes have been designed against 38 species, 4 genera, and 1 family of pathogens. The detection sensitivity of the microarray for a waterborne pathogen Aeromonas hydrophila was determined to be approximately 1.0% of the total DNA, or approximately 10{sup 3}A. hydrophila cells per sample. The efficacy of the DNA microarray was verified in a parallel study where pathogen genes and E. coli cells were enumerated using real-time quantitative PCR (qPCR) and standard membrane filter techniques, respectively. The microarray and qPCR successfully detected multiple wastewater pathogen species at different stages of the disinfection process (i.e. secondary effluents vs. disinfected final effluents) and at two treatment plants employing different disinfection methods (i.e. chlorination vs. UV irradiation). This result demonstrates the effectiveness of the DNA microarray as a semi-quantitative, high throughput pathogen monitoring tool for municipal wastewater.

  6. A sensitive, support-vector-machine method for the detection of horizontal gene transfers in viral, archaeal and bacterial genomes.

    Science.gov (United States)

    Tsirigos, Aristotelis; Rigoutsos, Isidore

    2005-01-01

    In earlier work, we introduced and discussed a generalized computational framework for identifying horizontal transfers. This framework relied on a gene's nucleotide composition, obviated the need for knowledge of codon boundaries and database searches, and was shown to perform very well across a wide range of archaeal and bacterial genomes when compared with previously published approaches, such as Codon Adaptation Index and C + G content. Nonetheless, two considerations remained outstanding: we wanted to further increase the sensitivity of detecting horizontal transfers and also to be able to apply the method to increasingly smaller genomes. In the discussion that follows, we present such a method, Wn-SVM, and show that it exhibits a very significant improvement in sensitivity compared with earlier approaches. Wn-SVM uses a one-class support-vector machine and can learn using rather small training sets. This property makes Wn-SVM particularly suitable for studying small-size genomes, similar to those of viruses, as well as the typically larger archaeal and bacterial genomes. We show experimentally that the new method results in a superior performance across a wide range of organisms and that it improves even upon our own earlier method by an average of 10% across all examined genomes. As a small-genome case study, we analyze the genome of the human cytomegalovirus and demonstrate that Wn-SVM correctly identifies regions that are known to be conserved and prototypical of all beta-herpesvirinae, regions that are known to have been acquired horizontally from the human host and, finally, regions that had not up to now been suspected to be horizontally transferred. Atypical region predictions for many eukaryotic viruses, including the alpha-, beta- and gamma-herpesvirinae, and 123 archaeal and bacterial genomes, have been made available online at http://cbcsrv.watson.ibm.com/HGT_SVM/.

  7. Simultaneous Detection of Key Bacterial Pathogens Related to Pneumonia and Meningitis Using Multiplex PCR Coupled With Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2018-04-01

    Full Text Available Pneumonia and meningitis continue to present an enormous public health burden and pose a major threat to young children. Among the causative organisms of pneumonia and meningitis, bacteria are the most common causes of serious disease and deaths. It is challenging to accurately and rapidly identify these agents. To solve this problem, we developed and validated a 12-plex PCR coupled with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS method (bacterial pathogen-mass spectrometry, BP-MS that can be used to simultaneously screen for 11 key bacterial pathogens related to pneumonia and meningitis. Forty-six nasopharyngeal swabs and 12 isolates were used to determine the specificity of the method. The results showed that, using the BP-MS method, we could accurately identify the expected bacteria without cross-reactivity with other pathogens. For the 11 target bacterial pathogens, the analytical sensitivity of the BP-MS method was as low as 10 copies/reaction. To further evaluate the clinical effectiveness of this method, 204 nasopharyngeal swabs from hospitalized children with suspected pneumonia were tested using this method. In total, 81.9% (167/204 of the samples were positive for at least one of the 11 target pathogens. Among the 167 bacteria-positive samples, the rate of multiple infections was 55.7% (93/167, and the most frequent combination was Streptococcus pneumoniae with Haemophilus influenzae, representing 46.2% (43/93 two-pathogen mixed infections. We used real-time PCR and nested PCR to confirm positive results, with identical results obtained for 81.4% (136/167 of the samples. The BP-MS method is a sensitive and specific molecular detection technique in a multiplex format and with high sample throughput. Therefore, it will be a powerful tool for pathogen screening and antibiotic selection at an early stage of disease.

  8. Detection of bacterial endotoxin in food: New planar interdigital sensors based approach

    KAUST Repository

    Abdul Rahman, Mohd Syaifudin; Mukhopadhyay, Subhas Chandra; Yu, Paklam; Goicoechea, J.; Matias, Ignacio R.; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2013-01-01

    coating thickness on sensor sensitivity, selectivity and stability. Different food samples contaminated with endotoxin were also tested to verify that the interdigital sensing approach is able to be used for endotoxin detection. © 2012 Elsevier Ltd. All

  9. DETECTION OF BACTERIAL BIOFILM ON STAINLESS STEEL BY HYPERSPECTRAL FLUORESCENCE IMAGING

    Science.gov (United States)

    In this study, hyperspectral fluorescence imaging techniques were investigated for detection of microbial biofilm on stainless steel plates typically used to manufacture food processing equipment. Stainless steel coupons were immersed in bacterium cultures consisting of nonpathogenic E. coli, Pseudo...

  10. A locked nucleic acid (LNA-based real-time PCR assay for the rapid detection of multiple bacterial antibiotic resistance genes directly from positive blood culture.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available Bacterial strains resistant to various antibiotic drugs are frequently encountered in clinical infections, and the rapid identification of drug-resistant strains is highly essential for clinical treatment. We developed a locked nucleic acid (LNA-based quantitative real-time PCR (LNA-qPCR method for the rapid detection of 13 antibiotic resistance genes and successfully used it to distinguish drug-resistant bacterial strains from positive blood culture samples. A sequence-specific primer-probe set was designed, and the specificity of the assays was assessed using 27 ATCC bacterial strains and 77 negative blood culture samples. No cross-reaction was identified among bacterial strains and in negative samples, indicating 100% specificity. The sensitivity of the assays was determined by spiking each bacterial strain into negative blood samples, and the detection limit was 1-10 colony forming units (CFU per reaction. The LNA-qPCR assays were first applied to 72 clinical bacterial isolates for the identification of known drug resistance genes, and the results were verified by the direct sequencing of PCR products. Finally, the LNA-qPCR assays were used for the detection in 47 positive blood culture samples, 19 of which (40.4% were positive for antibiotic resistance genes, showing 91.5% consistency with phenotypic susceptibility results. In conclusion, LNA-qPCR is a reliable method for the rapid detection of bacterial antibiotic resistance genes and can be used as a supplement to phenotypic susceptibility testing for the early detection of antimicrobial resistance to allow the selection of appropriate antimicrobial treatment and to prevent the spread of resistant isolates.

  11. Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach.

    Science.gov (United States)

    Bordron, Philippe; Latorre, Mauricio; Cortés, Maria-Paz; González, Mauricio; Thiele, Sven; Siegel, Anne; Maass, Alejandro; Eveillard, Damien

    2016-02-01

    Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans, we first reconstructed a global metabolic network. Next, using a parsimony assumption, we deciphered sets of genes, called Sets from Genome Segments (SGS), that (1) are close on their respective genomes, (2) take an active part in metabolic pathways and (3) whose associated metabolic reactions are also closely connected within metabolic networks. Overall, this SGS paradigm depicts genomic functional units that emphasize respective roles of bacterial strains to catalyze metabolic pathways and environmental processes. Our analysis suggested that only few functional metabolic genes are horizontally transferred within the consortium and that no single bacterial strain can accomplish by itself the whole copper bioleaching. The use of SGS pinpoints a functional compartmentalization among the investigated species and exhibits putative bacterial interactions necessary for promoting these pathways. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  12. BSim: an agent-based tool for modeling bacterial populations in systems and synthetic biology.

    Directory of Open Access Journals (Sweden)

    Thomas E Gorochowski

    Full Text Available Large-scale collective behaviors such as synchronization and coordination spontaneously arise in many bacterial populations. With systems biology attempting to understand these phenomena, and synthetic biology opening up the possibility of engineering them for our own benefit, there is growing interest in how bacterial populations are best modeled. Here we introduce BSim, a highly flexible agent-based computational tool for analyzing the relationships between single-cell dynamics and population level features. BSim includes reference implementations of many bacterial traits to enable the quick development of new models partially built from existing ones. Unlike existing modeling tools, BSim fully considers spatial aspects of a model allowing for the description of intricate micro-scale structures, enabling the modeling of bacterial behavior in more realistic three-dimensional, complex environments. The new opportunities that BSim opens are illustrated through several diverse examples covering: spatial multicellular computing, modeling complex environments, population dynamics of the lac operon, and the synchronization of genetic oscillators. BSim is open source software that is freely available from http://bsim-bccs.sf.net and distributed under the Open Source Initiative (OSI recognized MIT license. Developer documentation and a wide range of example simulations are also available from the website. BSim requires Java version 1.6 or higher.

  13. A Phosphorylation Switch on Lon Protease Regulates Bacterial Type III Secretion System in Host

    Directory of Open Access Journals (Sweden)

    Xiaofeng Zhou

    2018-01-01

    Full Text Available Most pathogenic bacteria deliver virulence factors into host cytosol through type III secretion systems (T3SS to perturb host immune responses. The expression of T3SS is often repressed in rich medium but is specifically induced in the host environment. The molecular mechanisms underlying host-specific induction of T3SS expression is not completely understood. Here we demonstrate in Xanthomonas citri that host-induced phosphorylation of the ATP-dependent protease Lon stabilizes HrpG, the master regulator of T3SS, conferring bacterial virulence. Ser/Thr/Tyr phosphoproteome analysis revealed that phosphorylation of Lon at serine 654 occurs in the citrus host. In rich medium, Lon represses T3SS by degradation of HrpG via recognition of its N terminus. Genetic and biochemical data indicate that phosphorylation at serine 654 deactivates Lon proteolytic activity and attenuates HrpG proteolysis. Substitution of alanine for Lon serine 654 resulted in repression of T3SS gene expression in the citrus host through robust degradation of HrpG and reduced bacterial virulence. Our work reveals a novel mechanism for distinct regulation of bacterial T3SS in different environments. Additionally, our data provide new insight into the role of protein posttranslational modification in the regulation of bacterial virulence.

  14. Bacterial-based systems for expression and purification of recombinant Lassa virus proteins of immunological relevance

    Directory of Open Access Journals (Sweden)

    Cashman Kathleen A

    2008-06-01

    Full Text Available Abstract Background There is a significant requirement for the development and acquisition of reagents that will facilitate effective diagnosis, treatment, and prevention of Lassa fever. In this regard, recombinant Lassa virus (LASV proteins may serve as valuable tools in diverse antiviral applications. Bacterial-based systems were engineered for expression and purification of recombinant LASV nucleoprotein (NP, glycoprotein 1 (GP1, and glycoprotein 2 (GP2. Results Full-length NP and the ectodomains of GP1 and GP2 were generated as maltose-binding protein (MBP fusions in the Rosetta strains of Escherichia coli (E. coli using pMAL-c2x vectors. Average fusion protein yields per liter of culture for MBP-NP, MBP-GP1, and MBP-GP2 were 10 mg, 9 mg, and 9 mg, respectively. Each protein was captured from cell lysates using amylose resin, cleaved with Factor Xa, and purified using size-exclusion chromatography (SEC. Fermentation cultures resulted in average yields per liter of 1.6 mg, 1.5 mg, and 0.7 mg of purified NP, GP1 and GP2, respectively. LASV-specific antibodies in human convalescent sera specifically detected each of the purified recombinant LASV proteins, highlighting their utility in diagnostic applications. In addition, mouse hyperimmune ascitic fluids (MHAF against a panel of Old and New World arenaviruses demonstrated selective cross reactivity with LASV proteins in Western blot and enzyme-linked immunosorbent assay (ELISA. Conclusion These results demonstrate the potential for developing broadly reactive immunological assays that employ all three arenaviral proteins individually and in combination.

  15. Maximum Temperature Detection System for Integrated Circuits

    Science.gov (United States)

    Frankiewicz, Maciej; Kos, Andrzej

    2015-03-01

    The paper describes structure and measurement results of the system detecting present maximum temperature on the surface of an integrated circuit. The system consists of the set of proportional to absolute temperature sensors, temperature processing path and a digital part designed in VHDL. Analogue parts of the circuit where designed with full-custom technique. The system is a part of temperature-controlled oscillator circuit - a power management system based on dynamic frequency scaling method. The oscillator cooperates with microprocessor dedicated for thermal experiments. The whole system is implemented in UMC CMOS 0.18 μm (1.8 V) technology.

  16. Speed and Displacement Control System of Bearingless Brushless DC Motor Based on Improved Bacterial Foraging Algorithm

    Directory of Open Access Journals (Sweden)

    Diao Xiaoyan

    2016-01-01

    Full Text Available To solve the deficiencies of long optimization time and poor precision existing in conventional bacterial foraging algorithm (BFA in the process of parameter optimization, an improved bacterial foraging algorithm (IBFA is proposed and applied to speed and displacement control system of bearingless brushless DC (Bearingless BLDC motors. To begin with the fundamental principle of BFA, the proposed method is introduced and the individual intelligence is efficiently used in the process of parameter optimization, and then the working principle of bearingless BLDC motors is expounded. Finally, modeling and simulation of the speed and displacement control system of bearingless BLDC motors based on the IBFA are carried out by taking the software of MATLAB/Simulink as a platform. Simulation results show that, speed overshoot, torque ripple and rotor position oscillation are dramatically reduced, thus the proposed method has good application prospects in the field of bearingless motors.

  17. Automatic Emergence Detection in Complex Systems

    Directory of Open Access Journals (Sweden)

    Eugene Santos

    2017-01-01

    Full Text Available Complex systems consist of multiple interacting subsystems, whose nonlinear interactions can result in unanticipated (emergent system events. Extant systems analysis approaches fail to detect such emergent properties, since they analyze each subsystem separately and arrive at decisions typically through linear aggregations of individual analysis results. In this paper, we propose a quantitative definition of emergence for complex systems. We also propose a framework to detect emergent properties given observations of its subsystems. This framework, based on a probabilistic graphical model called Bayesian Knowledge Bases (BKBs, learns individual subsystem dynamics from data, probabilistically and structurally fuses said dynamics into a single complex system dynamics, and detects emergent properties. Fusion is the central element of our approach to account for situations when a common variable may have different probabilistic distributions in different subsystems. We evaluate our detection performance against a baseline approach (Bayesian Network ensemble on synthetic testbeds from UCI datasets. To do so, we also introduce a method to simulate and a metric to measure discrepancies that occur with shared/common variables. Experiments demonstrate that our framework outperforms the baseline. In addition, we demonstrate that this framework has uniform polynomial time complexity across all three learning, fusion, and reasoning procedures.

  18. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Stoica-Guzun, Anicuta [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)], E-mail: astoica@mt.pub.ro; Stroescu, Marta; Tache, Florin [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania); Zaharescu, Traian [Advanced Research Institute for Electrical Engineering, 313 Splaiul Unirii, 030138 Bucharest (Romania)], E-mail: zaharescut@icpe-ca.ro; Grosu, Elena [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)

    2007-12-15

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of {gamma}-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  19. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    International Nuclear Information System (INIS)

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-01-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell

  20. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Science.gov (United States)

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-12-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  1. Bacterial toxin-antitoxin gene system as containment control in yeast cells

    DEFF Research Database (Denmark)

    Kristoffersen, P.; Jensen, G. B.; Gerdes, K.

    2000-01-01

    The potential of a bacterial toxin-antitoxin gene system for use in containment control in eukaryotes was explored. The Escherichia coli relE and relB genes were expressed in the yeast Saccharomyces cerevisiae, Expression of the relE gene was highly toxic to yeast cells. However, expression...... fermentation processes in which the escape of genetically modified cells would be considered highly risky....

  2. Detecting signatures of a sponge-associated lifestyle in bacterial genomes.

    Science.gov (United States)

    Díez-Vives, Cristina; Esteves, Ana I S; Costa, Rodrigo; Nielsen, Shaun; Thomas, Torsten

    2018-04-30

    Sponges interact with diverse and rich communities of bacteria that are phylogenetically often distinct from their free-living counterparts. Recent genomics and metagenomic studies have indicated that bacterial sponge symbionts also have distinct functional features from free-living bacteria, however it is unclear, if such genome-derived functional signatures are common and present in different symbiont taxa. We therefore compared here a large set of genomes from cultured (Pseudovibrio, Ruegeria, Aquimarina) and yet-uncultivated (Synechococcus) bacteria found either in sponge-associated or free-living sources. Our analysis revealed only very few genera-specific functions that could be correlated with a sponge-associated lifestyle. Using different sets of sponge-associated and free-living bacteria for each genus, we could however show that the functions identified as "sponge-associated" are dependent on the reference comparison being made. Using simulation approaches we show how this influences the robustness of identifying functional signatures and how evolutionary divergence and genomic adaptation can be distinguished. Our results highlight the future need for robust comparative analyses to define genomic signatures of symbiotic lifestyles, whether it is for symbionts of sponges or other host organisms. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Detection of antibodies to bacterial cell wall peptidoglycan in human sera

    International Nuclear Information System (INIS)

    Heymer, B.; Schleifer, K.H.; Read, S.; Zabriskie, J.B.; Krause, R.M.

    1976-01-01

    A radioimmunoassay has been developed for the measurement of antibodies to peptidoglycan in human sera including patients with rheumatic feaver and juvenile rheumatoid arthritis. The assay is based on the percentage of binding of the hapten 125 I-L-Ala-γ-D-Glu-L-Lys-D-Ala-D-Ala, the major peptide determinant of peptidoglycan. Because of differences in the avidity of the antibodies in different sera, the amount of antibody was expressed as pentapeptide hapten-binding capacity (pentapeptide-HBC in ng/ml of serum). Fourteen out of 105 normal blood donors had a pentapeptide-HBC value greater than or equal to 75 ng/ml serum. Values in healthy children 5 to 18 years of age were less than or equal to 50 ng/ml. Sixty-eight percent of the individuals with rheumatic fever had values greater than or equal to 75 ng/ml, an indication that streptococcal infections can stimulate an immune response to peptidoglycan. Thirty-five percent of the patients with juvenile rheumatoid arthritis had values greater than or equal to 75 ng/ml. Such a finding points to a possible association between bacterial infections and juvenile rheumatoid arthritis

  4. Coaxial direct-detection lidar-system

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a coaxial direct-detection LIDAR system for measuring velocity, temperature and/or particulate density. The system comprises a laser source for emitting a laser light beam having a lasing center frequency along an emission path. The system further comprises an optical....... Finally, the system comprises a detector system arranged to receive the return signal from the optical delivery system, the detector system comprising a narrowband optical filter and a detector, the narrowband optical filter having a filter center frequency of a pass-band, wherein the center lasing...... frequency and/or the center filter frequency may be scanned. The invention further relates to an aircraft airspeed measurement device, and a wind turbine airspeed measurement device comprising the LIDAR system....

  5. Bacterial Community Structure Shifted by Geosmin in Granular Activated Carbon System of Water Treatment Plants.

    Science.gov (United States)

    Pham, Ngoc Dung; Lee, Eun-Hee; Chae, Seon-Ha; Cho, Yongdeok; Shin, Hyejin; Son, Ahjeong

    2016-01-01

    We investigated the relation between the presence of geosmin in water and the bacterial community structure within the granular activated carbon (GAC) system of water treatment plants in South Korea. GAC samples were collected in May and August of 2014 at three water treatment plants (Sungnam, Koyang, and Yeoncho in Korea). Dissolved organic carbon and geosmin were analyzed before and after GAC treatment. Geosmin was found in raw water from Sungnam and Koyang water treatment plants but not in that from Yeoncho water treatment plant. Interestingly, but not surprisingly, the 16S rRNA clone library indicated that the bacterial communities from the Sungnam and Koyang GAC systems were closely related to geosmin-degrading bacteria. Based on the phylogenetic tree and multidimensional scaling plot, bacterial clones from GAC under the influence of geosmin were clustered with Variovorax paradoxus strain DB 9b and Comamonas sp. DB mg. In other words, the presence of geosmin in water might have inevitably contributed to the growth of geosmin degraders within the respective GAC system.

  6. Profiling bacterial communities associated with sediment-based aquaculture bioremediation systems under contrasting redox regimes

    Science.gov (United States)

    Robinson, Georgina; Caldwell, Gary S.; Wade, Matthew J.; Free, Andrew; Jones, Clifford L. W.; Stead, Selina M.

    2016-12-01

    Deposit-feeding invertebrates are proposed bioremediators in microbial-driven sediment-based aquaculture effluent treatment systems. We elucidate the role of the sediment reduction-oxidation (redox) regime in structuring benthic bacterial communities, having direct implications for bioremediation potential and deposit-feeder nutrition. The sea cucumber Holothuria scabra was cultured on sediments under contrasting redox regimes; fully oxygenated (oxic) and redox stratified (oxic-anoxic). Taxonomically, metabolically and functionally distinct bacterial communities developed between the redox treatments with the oxic treatment supporting the greater diversity; redox regime and dissolved oxygen levels were the main environmental drivers. Oxic sediments were colonised by nitrifying bacteria with the potential to remediate nitrogenous wastes. Percolation of oxygenated water prevented the proliferation of anaerobic sulphate-reducing bacteria, which were prevalent in the oxic-anoxic sediments. At the predictive functional level, bacteria within the oxic treatment were enriched with genes associated with xenobiotics metabolism. Oxic sediments showed the greater bioremediation potential; however, the oxic-anoxic sediments supported a greater sea cucumber biomass. Overall, the results indicate that bacterial communities present in fully oxic sediments may enhance the metabolic capacity and bioremediation potential of deposit-feeder microbial systems. This study highlights the benefits of incorporating deposit-feeding invertebrates into effluent treatment systems, particularly when the sediment is oxygenated.

  7. Methods and systems for detection of radionuclides

    Science.gov (United States)

    Coates, Jr., John T.; DeVol, Timothy A.

    2010-05-25

    Disclosed are materials and systems useful in determining the existence of radionuclides in an aqueous sample. The materials provide the dual function of both extraction and scintillation to the systems. The systems can be both portable and simple to use, and as such can beneficially be utilized to determine presence and optionally concentration of radionuclide contamination in an aqueous sample at any desired location and according to a relatively simple process without the necessity of complicated sample handling techniques. The disclosed systems include a one-step process, providing simultaneous extraction and detection capability, and a two-step process, providing a first extraction step that can be carried out in a remote field location, followed by a second detection step that can be carried out in a different location.

  8. Diversity of ribosomal 16S DNA- and RNA-based bacterial community in an office building drinking water system.

    Science.gov (United States)

    Inkinen, J; Jayaprakash, B; Santo Domingo, J W; Keinänen-Toivola, M M; Ryu, H; Pitkänen, T

    2016-06-01

    Next-generation sequencing of 16S ribosomal RNA genes (rDNA) and ribosomal RNA (rRNA) was used to characterize water and biofilm microbiome collected from a drinking water distribution system of an office building after its first year of operation. The total bacterial community (rDNA) and active bacterial members (rRNA) sequencing databases were generated by Illumina MiSeq PE250 platform. As estimated by Chao1 index, species richness in cold water system was lower (180-260) in biofilms (Sphingomonas spp., Methylobacterium spp., Limnohabitans spp., Rhizobiales order) than in waters (250-580), (also Methylotenera spp.) (P = 0·005, n = 20). Similarly species richness (Chao1) was slightly higher (210-580) in rDNA libraries compared to rRNA libraries (150-400; P = 0·054, n = 24). Active Mycobacterium spp. was found in cross-linked polyethylene (PEX), but not in corresponding copper pipeline biofilm. Nonpathogenic Legionella spp. was found in rDNA libraries but not in rRNA libraries. Microbial communities differed between water and biofilms, between cold and hot water systems, locations in the building and between water rRNA and rDNA libraries, as shown by clear clusters in principal component analysis (PcoA). By using the rRNA method, we found that not all bacterial community members were active (e.g. Legionella spp.), whereas other members showed increased activity in some locations; for example, Pseudomonas spp. in hot water circulations' biofilm and order Rhizobiales and Limnohabitans spp. in stagnated locations' water and biofilm. rRNA-based methods may be better than rDNA-based methods for evaluating human health implications as rRNA methods can be used to describe the active bacterial fraction. This study indicates that copper as a pipeline material might have an adverse impact on the occurrence of Mycobacterium spp. The activity of Legionella spp. maybe questionable when detected solely by using DNA-based methods. © 2016 The Society for Applied

  9. Direct detection of single-nucleotide polymorphisms in bacterial DNA by SNPtrap

    DEFF Research Database (Denmark)

    Grønlund, Hugo Ahlm; Moen, Birgitte; Hoorfar, Jeffrey

    2011-01-01

    A major challenge with single-nucleotide polymorphism (SNP) fingerprinting of bacteria and higher organisms is the combination of genome-wide screenings with the potential of multiplexing and accurate SNP detection. Single-nucleotide extension by the minisequencing principle represents a technolo...

  10. Detection of bacterial DNA in blood samples from febrile patients: underestimated infection or emerging contamination?

    NARCIS (Netherlands)

    Peters, Remco P. H.; Mohammadi, Tamimount; Vandenbroucke-Grauls, Christina M. J. E.; Danner, Sven A.; van Agtmael, Michiel A.; Savelkoul, Paul H. M.

    2004-01-01

    We applied real-time broad-range polymerase chain reaction (PCR) to detect bacteraemia in blood from febrile patients. Interpretation of amplification results in relation to clinical data and blood culture outcome was complex, although the reproducibility of the PCR results was good. Sequencing

  11. Defense islands in bacterial and archaeal genomes and prediction of novel defense systems.

    Science.gov (United States)

    Makarova, Kira S; Wolf, Yuri I; Snir, Sagi; Koonin, Eugene V

    2011-11-01

    The arms race between cellular life forms and viruses is a major driving force of evolution. A substantial fraction of bacterial and archaeal genomes is dedicated to antivirus defense. We analyzed the distribution of defense genes and typical mobilome components (such as viral and transposon genes) in bacterial and archaeal genomes and demonstrated statistically significant clustering of antivirus defense systems and mobile genes and elements in genomic islands. The defense islands are enriched in putative operons and contain numerous overrepresented gene families. A detailed sequence analysis of the proteins encoded by genes in these families shows that many of them are diverged variants of known defense system components, whereas others show features, such as characteristic operonic organization, that are suggestive of novel defense systems. Thus, genomic islands provide abundant material for the experimental study of bacterial and archaeal antivirus defense. Except for the CRISPR-Cas systems, different classes of defense systems, in particular toxin-antitoxin and restriction-modification systems, show nonrandom clustering in defense islands. It remains unclear to what extent these associations reflect functional cooperation between different defense systems and to what extent the islands are genomic "sinks" that accumulate diverse nonessential genes, particularly those acquired via horizontal gene transfer. The characteristics of defense islands resemble those of mobilome islands. Defense and mobilome genes are nonrandomly associated in islands, suggesting nonadaptive evolution of the islands via a preferential attachment-like mechanism underpinned by the addictive properties of defense systems such as toxins-antitoxins and an important role of horizontal mobility in the evolution of these islands.

  12. Agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia in dogs and cats with hepatobiliary disease.

    Science.gov (United States)

    Pashmakova, Medora B; Piccione, Julie; Bishop, Micah A; Nelson, Whitney R; Lawhon, Sara D

    2017-05-01

    OBJECTIVE To evaluate the agreement between results of microscopic examination and bacterial culture of bile samples from dogs and cats with hepatobiliary disease for detection of bactibilia. DESIGN Cross-sectional study. ANIMALS 31 dogs and 21 cats with hepatobiliary disease for which subsequent microscopic examination and bacterial culture of bile samples was performed from 2004 through 2014. PROCEDURES Electronic medical records of included dogs and cats were reviewed to extract data regarding diagnosis, antimicrobials administered, and results of microscopic examination and bacterial culture of bile samples. Agreement between these 2 diagnostic tests was assessed by calculation of the Cohen κ value. RESULTS 17 (33%) dogs and cats had bactibilia identified by microscopic examination of bile samples, and 11 (21%) had bactibilia identified via bacterial culture. Agreement between these 2 tests was substantial (percentage agreement [positive and negative results], 85%; κ = 0.62; 95% confidence interval, 0.38 to 0.89) and improved to almost perfect when calculated for only animals that received no antimicrobials within 24 hours prior to sample collection (percentage agreement, 94%; κ = 0.84; 95% confidence interval, 0.61 to 1.00). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that agreement between microscopic examination and bacterial culture of bile samples for detection of bactibilia is optimized when dogs and cats are not receiving antimicrobials at the time of sample collection. Concurrent bacterial culture and microscopic examination of bile samples are recommended for all cats and dogs evaluated for hepatobiliary disease.

  13. Digital detection systems for projection radiography

    International Nuclear Information System (INIS)

    Schulz, R.F.

    2001-01-01

    This article gives a survey of digital X-ray detection systems for projection radiography. The different principles are compared and some general characteristics are derived. The basic conversion mechanisms in the absorption layers are described. The basic principles of solid state X-ray detectors and their general characteristics are elucidated as well as some similarities with detectors for computed tomography. Some important application and system aspects are considered. An outlook on further possible developments in this field is given. (orig.) [de

  14. Statistics of multi-tube detecting systems

    International Nuclear Information System (INIS)

    Grau Carles, P.; Grau Malonda, A.

    1994-01-01

    In this paper three new statistical theorems are demonstrated and applied. These theorems simplify very much the obtention of the formulae to compute the counting efficiency when the detection system is formed by several photomultipliers associated in coincidence and sume. These theorems are applied to several photomultiplier arrangements in order to show their potential and the application. way

  15. An FPGA-Based People Detection System

    Directory of Open Access Journals (Sweden)

    James J. Clark

    2005-05-01

    Full Text Available This paper presents an FPGA-based system for detecting people from video. The system is designed to use JPEG-compressed frames from a network camera. Unlike previous approaches that use techniques such as background subtraction and motion detection, we use a machine-learning-based approach to train an accurate detector. We address the hardware design challenges involved in implementing such a detector, along with JPEG decompression, on an FPGA. We also present an algorithm that efficiently combines JPEG decompression with the detection process. This algorithm carries out the inverse DCT step of JPEG decompression only partially. Therefore, it is computationally more efficient and simpler to implement, and it takes up less space on the chip than the full inverse DCT algorithm. The system is demonstrated on an automated video surveillance application and the performance of both hardware and software implementations is analyzed. The results show that the system can detect people accurately at a rate of about 2.5 frames per second on a Virtex-II 2V1000 using a MicroBlaze processor running at 75 MHz, communicating with dedicated hardware over FSL links.

  16. The deep sea Acoustic Detection system AMADEUS

    International Nuclear Information System (INIS)

    Naumann, Christopher Lindsay

    2008-01-01

    As a part of the ANTARES neutrino telescope, the AMADEUS (ANTARES Modules for Acoustic Detection Under the Sea) system is an array of acoustical sensors designed to investigate the possibilities of acoustic detection of ultra-high energy neutrinos in the deep sea. The complete system will comprise a total of 36 acoustic sensors in six clusters on two of the ANTARES detector lines. With an inter-sensor spacing of about one metre inside the clusters and between 15 and 340 metres between the different clusters, it will cover a wide range of distances as will as provide a considerable lever arm for point source triangulation. Three of these clusters have already been deployed in 2007 and have been in operation since, currently yielding around 2GB of acoustic data per day. The remaining three clusters are scheduled to be deployed in May 2008 together with the final ANTARES detector line. Apart from proving the feasibility of operating an acoustic detection system in the deep sea, the main aim of this project is an in-depth survey of both the acoustic properties of the sea water and the acoustic background present at the detector site. It will also serve as a platform for the development and refinement of triggering, filtering and reconstruction algorithms for acoustic particle detection. In this presentation, a description of the acoustic sensor and read-out system is given, together with examples for the reconstruction and evaluation of the acoustic data.

  17. Detection of cardiovascular anomalies: Hybrid systems approach

    KAUST Repository

    Ledezma, Fernando

    2012-06-06

    In this paper, we propose a hybrid interpretation of the cardiovascular system. Based on a model proposed by Simaan et al. (2009), we study the problem of detecting cardiovascular anomalies that can be caused by variations in some physiological parameters, using an observerbased approach. We present the first numerical results obtained. © 2012 IFAC.

  18. Statistics of multi-tube detecting systems

    International Nuclear Information System (INIS)

    Grau Carles, P.; Grau Malonda, A.

    1994-01-01

    In this paper three new statistical theorems are demonstrated and applied. These theorems simplify very much the obtention of the formulae to compute the counting efficiency when the detection system is formed by several photomultipliers associated in coincidence and sum. These theorems are applied to several photomultiplier arrangements in order to show their potential and the application way. (Author) 6 refs

  19. Bacterial Membrane Depolarization-Linked Fuel Cell Potential Burst as Signal for Selective Detection of Alcohol.

    Science.gov (United States)

    Kaushik, Sharbani; Goswami, Pranab

    2018-06-06

    The biosensing application of microbial fuel cell (MFC) is hampered by its long response time, poor selectivity, and technical difficulty in developing portable devices. Herein, a novel signal form for rapid detection of ethanol was generated in a photosynthetic MFC (PMFC). First, a dual chambered (100 mL each) PMFC was fabricated by using cyanobacteria-based anode and abiotic cathode, and its performance was examined for detection of alcohols. A graphene-based nanobiocomposite matrix was layered over graphite anode to support cyanobacterial biofilm growth and to facilitate electron transfer. Injection of alcohols into the anodic chamber caused a transient potential burst of the PMFC within 60 s (load 1000 Ω), and the magnitude of potential could be correlated to the ethanol concentrations in the range 0.001-20% with a limit of detection (LOD) of 0.13% ( R 2 = 0.96). The device exhibited higher selectivity toward ethanol than methanol as discerned from the corresponding cell-alcohol interaction constant ( K i ) of 780 and 1250 mM. The concept was then translated to a paper-based PMFC (p-PMFC) (size ∼20 cm 2 ) wherein, the cells were merely immobilized over the anode. The device with a shelf life of ∼3 months detected ethanol within 10 s with a dynamic range of 0.005-10% and LOD of 0.02% ( R 2 = 0.99). The fast response time was attributed to the higher wettability of ethanol on the immobilized cell surface as validated by the contact angle data. Alcohols degraded the cell membrane on the order of ethanol > methanol, enhanced the redox current of the membrane-bound electron carrier proteins, and pushed the anodic band gap toward more negative value. The consequence was the potential burst, the magnitude of which was correlated to the ethanol concentrations. This novel approach has a great application potential for selective, sensitive, rapid, and portable detection of ethanol.

  20. Plant Pest Detection Using an Artificial Nose System: A Review

    Directory of Open Access Journals (Sweden)

    Shaoqing Cui

    2018-01-01

    Full Text Available This paper reviews artificial intelligent noses (or electronic noses as a fast and noninvasive approach for the diagnosis of insects and diseases that attack vegetables and fruit trees. The particular focus is on bacterial, fungal, and viral infections, and insect damage. Volatile organic compounds (VOCs emitted from plants, which provide functional information about the plant’s growth, defense, and health status, allow for the possibility of using noninvasive detection to monitor plants status. Electronic noses are comprised of a sensor array, signal conditioning circuit, and pattern recognition algorithms. Compared with traditional gas chromatography–mass spectrometry (GC-MS techniques, electronic noses are noninvasive and can be a rapid, cost-effective option for several applications. However, using electronic noses for plant pest diagnosis is still in its early stages, and there are challenges regarding sensor performance, sampling and detection in open areas, and scaling up measurements. This review paper introduces each element of electronic nose systems, especially commonly used sensors and pattern recognition methods, along with their advantages and limitations. It includes a comprehensive comparison and summary of applications, possible challenges, and potential improvements of electronic nose systems for different plant pest diagnoses.

  1. Plant Pest Detection Using an Artificial Nose System: A Review.

    Science.gov (United States)

    Cui, Shaoqing; Ling, Peter; Zhu, Heping; Keener, Harold M

    2018-01-28

    This paper reviews artificial intelligent noses (or electronic noses) as a fast and noninvasive approach for the diagnosis of insects and diseases that attack vegetables and fruit trees. The particular focus is on bacterial, fungal, and viral infections, and insect damage. Volatile organic compounds (VOCs) emitted from plants, which provide functional information about the plant's growth, defense, and health status, allow for the possibility of using noninvasive detection to monitor plants status. Electronic noses are comprised of a sensor array, signal conditioning circuit, and pattern recognition algorithms. Compared with traditional gas chromatography-mass spectrometry (GC-MS) techniques, electronic noses are noninvasive and can be a rapid, cost-effective option for several applications. However, using electronic noses for plant pest diagnosis is still in its early stages, and there are challenges regarding sensor performance, sampling and detection in open areas, and scaling up measurements. This review paper introduces each element of electronic nose systems, especially commonly used sensors and pattern recognition methods, along with their advantages and limitations. It includes a comprehensive comparison and summary of applications, possible challenges, and potential improvements of electronic nose systems for different plant pest diagnoses.

  2. Chemical detection, identification, and analysis system

    International Nuclear Information System (INIS)

    Morel, R.S.; Gonzales, D.; Mniszewski, S.

    1990-01-01

    The chemical detection, identification, and analysis system (CDIAS) has three major goals. The first is to display safety information regarding chemical environment before personnel entry. The second is to archive personnel exposure to the environment. Third, the system assists users in identifying the stage of a chemical process in progress and suggests safety precautions associated with that process. In addition to these major goals, the system must be sufficiently compact to provide transportability, and it must be extremely simple to use in order to keep user interaction at a minimum. The system created to meet these goals includes several pieces of hardware and the integration of four software packages. The hardware consists of a low-oxygen, carbon monoxide, explosives, and hydrogen sulfide detector; an ion mobility spectrometer for airborne vapor detection; and a COMPAQ 386/20 portable computer. The software modules are a graphics kernel, an expert system shell, a data-base management system, and an interface management system. A supervisory module developed using the interface management system coordinates the interaction of the other software components. The system determines the safety of the environment using conventional data acquisition and analysis techniques. The low-oxygen, carbon monoxide, hydrogen sulfide, explosives, and vapor detectors are monitored for hazardous levels, and warnings are issued accordingly

  3. Dynamics of immune system gene expression upon bacterial challenge and wounding in a social insect (Bombus terrestris.

    Directory of Open Access Journals (Sweden)

    Silvio Erler

    2011-03-01

    Full Text Available The innate immune system which helps individuals to combat pathogens comprises a set of genes representing four immune system pathways (Toll, Imd, JNK and JAK/STAT. There is a lack of immune genes in social insects (e.g. honeybees when compared to Diptera. Potentially, this might be compensated by an advanced system of social immunity (synergistic action of several individuals. The bumble bee, Bombus terrestris, is a primitively eusocial species with an annual life cycle and colonies headed by a single queen. We used this key pollinator to study the temporal dynamics of immune system gene expression in response to wounding and bacterial challenge.Antimicrobial peptides (AMP (abaecin, defensin 1, hymenoptaecin were strongly up-regulated by wounding and bacterial challenge, the latter showing a higher impact on the gene expression level. Sterile wounding down-regulated TEP A, an effector gene of the JAK/STAT pathway, and bacterial infection influenced genes of the Imd (relish and JNK pathway (basket. Relish was up-regulated within the first hour after bacterial challenge, but decreased strongly afterwards. AMP expression following wounding and bacterial challenge correlates with the expression pattern of relish whereas correlated expression with dorsal was absent. Although expression of AMPs was high, continuous bacterial growth was observed throughout the experiment.Here we demonstrate for the first time the temporal dynamics of immune system gene expression in a social insect. Wounding and bacterial challenge affected the innate immune system significantly. Induction of AMP expression due to wounding might comprise a pre-adaptation to accompanying bacterial infections. Compared with solitary species this social insect exhibits reduced immune system efficiency, as bacterial growth could not be inhibited. A negative feedback loop regulating the Imd-pathway is suggested. AMPs, the end product of the Imd-pathway, inhibited the up-regulation of the

  4. Multi-sensor explosive detection system

    International Nuclear Information System (INIS)

    Gozani, T.; Shea, P.M.; Sawa, Z.P.

    1992-01-01

    This patent describes an explosive detection system. It comprises a source of neutrons; a detector array comprising a plurality of gamma ray detectors, each of the gamma ray detectors providing a detection signal in the event a gamma ray is captured by the detector, and at least one neutron detector, the neutron detector providing a neutron detection signal in the event a neutron is captured by the neutron detector; means for irradiating an object being examined with neutrons from the neutron source and for positioning the detector array relative to the object so that gamma rays emitted from the elements within the object as a result of the neutron irradiation are detected by the gamma ray detectors of the detector array; and parallel distributed processing means responsive to the detection signals of the detector array for discriminating between objects carrying explosives and objects not carrying explosives, the parallel distributed processing means including an artificial neural system (ANS), the ANS having a parallel network of processors, each processor of the parallel network of processors, each processor of the parallel network of processors including means for receiving at least one input signal, and means for generating an output signal as a function of the at least one input signal

  5. Application of Biomaterials and Inkjet Printing to Develop Bacterial Culture System

    Directory of Open Access Journals (Sweden)

    Tithimanan Srimongkon

    2015-01-01

    Full Text Available We created an automated bioassay system based on inkjet printing. Compared to conventional manual bacterial culture systems our printing approach improves the quality as well as the processing speed. A hydrophobic/hydrophilic pattern as a container supporting a culture medium was built on filter paper using a toluene solution of polystyrene for hydrophobization, followed by toluene printing to create several hydrophilic areas. As culture media we used a novel poly(vinyl alcohol based hydrogel and a standard calcium alginate hydrogel. The poly(vinyl alcohol hydrogel was formed by physical crosslinking poly(vinyl alcohol with adipic acid dihydrazide solutions. The conditions of poly(vinyl alcohol gelation were optimized for inkjet printability and the optimum mixture ratio was determined. The calcium alginate hydrogel was formed by chemical reaction between sodium alginate and CaCl2 solutions. Together with nutrients both hydrogel solutions were successfully printed on paper by means of the modified inkjet printer. The amount of each solution was demanded simply by outputting CMYK values. In the last step bacterial cells were printed on both hydrogel media. For both media we achieved a stable bacteria growth which was confirmed by microscopical imaging of the developed bacterial colonies.

  6. Effect of Electron-Beam Irradiation on Bacterial Cellulose Membranes Used as Transdermal Drug Delivery Systems

    International Nuclear Information System (INIS)

    Stoica-Guzun, A.

    2006-01-01

    Multiple methods are used to modify material surfaces. Radiation is an effective tool for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. Bacterial cellulose is a promising biomaterial synthesized by Acetobacter xylinum. It has a distinctive ultrafine reticulated structure that may become a perfect matrix as an optimal wound healing environment. In this work, high energy irradiation (γ rays from 137 C s) was applied to modify bacterial cellulose membranes. The effect of varying irradiation doses on membranes permeability was studied. Tetracycline was involved in the study of diffusivity as model drug. Release and permeation of drug from irradiated and non-irradiated membranes were done using a diffusion cell. The membrane permeability was determined using a psudo-steady state analysis based on Fick's law

  7. Application of a microcomputer-based system to control and monitor bacterial growth.

    Science.gov (United States)

    Titus, J A; Luli, G W; Dekleva, M L; Strohl, W R

    1984-02-01

    A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO(2), and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.

  8. Influence of the Biliary System on Biliary Bacteria Revealed by Bacterial Communities of the Human Biliary and Upper Digestive Tracts.

    Directory of Open Access Journals (Sweden)

    Fuqiang Ye

    Full Text Available Biliary bacteria have been implicated in gallstone pathogenesis, though a clear understanding of their composition and source is lacking. Moreover, the effects of the biliary environment, which is known to be generally hostile to most bacteria, on biliary bacteria are unclear. Here, we investigated the bacterial communities of the biliary tract, duodenum, stomach, and oral cavity from six gallstone patients by using 16S rRNA amplicon sequencing. We found that all observed biliary bacteria were detectable in the upper digestive tract. The biliary microbiota had a comparatively higher similarity with the duodenal microbiota, versus those of the other regions, but with a reduced diversity. Although the majority of identified bacteria were greatly diminished in bile samples, three Enterobacteriaceae genera (Escherichia, Klebsiella, and an unclassified genus and Pyramidobacter were abundant in bile. Predictive functional analysis indicated enhanced abilities of environmental information processing and cell motility of biliary bacteria. Our study provides evidence for the potential source of biliary bacteria, and illustrates the influence of the biliary system on biliary bacterial communities.

  9. [A simple method for the rapid detection of bacterial hyaluronidase in K hyaluronate-containing gel].

    Science.gov (United States)

    Balke, E; Weiss, R

    1984-08-01

    For detection of hyaluronidase activities we investigated several groups of bacteria. The bacteria were inoculated on a 1,5% agarose gel in Petri plates of 4 cm diameter or gel discs of 7 mm diameter, containing 0,1% of K-hyaluronate as well as nutritient medium, and were incubated for 2-20 h at 37 degrees C in a moist chamber. Subsequently some ml of a 10% solution of cetylpyridiniumchloride were poured on the gel to precipitate the polymere hyaluronate. If the hyaluronate was depolymerized by hyaluronidase, a translucent area was visible around the colonies. We found out, that a gel layer of 1 mm was sufficient to detect the small amounts of hyaluronidase, which were produced by bacteria within an incubation time of 2 h. These results were confirmed by incubation for 20 h and in some cases 36 h. The hyaluronidase production by different anaerobic Clostridium strains was always proved after a 20 h growth period. The bacteria were inoculated with the whole loop of a self made platin sowing wire loop. By this method quantitative differences of hyaluronidase activities between different strains of bacteria could be detected.

  10. 46 CFR 108.405 - Fire detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fire detection system. 108.405 Section 108.405 Shipping... EQUIPMENT Fire Extinguishing Systems § 108.405 Fire detection system. (a) Each fire detection system and each smoke detection system on a unit must— (1) Be approved by the Commandant; and (2) Have a visual...

  11. Encyclopedia of bacterial gene circuits whose presence or absence correlate with pathogenicity--a large-scale system analysis of decoded bacterial genomes.

    Science.gov (United States)

    Shestov, Maksim; Ontañón, Santiago; Tozeren, Aydin

    2015-10-13

    Bacterial infections comprise a global health challenge as the incidences of antibiotic resistance increase. Pathogenic potential of bacteria has been shown to be context dependent, varying in response to environment and even within the strains of the same genus. We used the KEGG repository and extensive literature searches to identify among the 2527 bacterial genomes in the literature those implicated as pathogenic to the host, including those which show pathogenicity in a context dependent manner. Using data on the gene contents of these genomes, we identified sets of genes highly abundant in pathogenic but relatively absent in commensal strains and vice versa. In addition, we carried out genome comparison within a genus for the seventeen largest genera in our genome collection. We projected the resultant lists of ortholog genes onto KEGG bacterial pathways to identify clusters and circuits, which can be linked to either pathogenicity or synergy. Gene circuits relatively abundant in nonpathogenic bacteria often mediated biosynthesis of antibiotics. Other synergy-linked circuits reduced drug-induced toxicity. Pathogen-abundant gene circuits included modules in one-carbon folate, two-component system, type-3 secretion system, and peptidoglycan biosynthesis. Antibiotics-resistant bacterial strains possessed genes modulating phagocytosis, vesicle trafficking, cytoskeletal reorganization, and regulation of the inflammatory response. Our study also identified bacterial genera containing a circuit, elements of which were previously linked to Alzheimer's disease. Present study produces for the first time, a signature, in the form of a robust list of gene circuitry whose presence or absence could potentially define the pathogenicity of a microbiome. Extensive literature search substantiated a bulk majority of the commensal and pathogenic circuitry in our predicted list. Scanning microbiome libraries for these circuitry motifs will provide further insights into the complex

  12. Development of a portable radon detection system

    International Nuclear Information System (INIS)

    Allen, J.W.

    1976-09-01

    The presence of radon-222 in soil gas and ground water can indicate the existence of nearby uranium deposits even when heavy overburdens completely absorb the associated gamma radiation. Techniques to detect and measure radon have evolved during the past several years to the point where radon prospecting is routinely employed in a number of countries. A program to develop and field test a prototype system for measuring radon from soil gas and water is described. A prototype system employing a flow through scintillation detector was designed and constructed, utilizing standard commercial components, to provide a fieldworthy unit for testing the system concepts. Laboratory and preliminary field tests of this unit indicate that it can detect anomalous radon levels of less than 10 picoCuries per liter (pCi/l) in soil gas and ground water

  13. Evaluation of pipeline leak detection systems

    International Nuclear Information System (INIS)

    Glauz, W.D.; Flora, J.D.; Hennon, G.J.

    1993-01-01

    Leaking underground storage tank system presents an environmental concern and a potential health hazard. It is well known that leaks in the piping associated with these systems account for a sizeable fraction of the leaks. EPA has established performance standards for pipeline leak detection systems, and published a document presenting test protocols for evaluating these systems against the standards. This paper discusses a number of facets and important features of evaluating such systems, and presents results from tests of several systems. The importance of temperature differences between the ground and the product in the line is shown both in theory and with test data. The impact of the amount of soil moisture present is addressed, along with the effect of frozen soil. These features are addressed both for line tightness test systems, which must detect leaks of 0.10 gal/h (0.38 L/h) at 150% of normal line pressure, or 0.20 gal/h (0.76 L/h) at normal line pressure, and for automatic line leak detectors that must detect leaks of 3 gal/h (11 L/h) at 10 psi (69 kPa) within an hour of the occurrence of the leak. This paper also addresses some statistical aspects of the evaluation of these systems. Reasons for keeping the evaluation process ''blind'' to the evaluated company are given, along with methods for assuring that the tests are blind. Most importantly, a test procedure is presented for evaluating systems that report a flow rate (not just a pass/fail decision) that is much more efficient than the procedure presented in the EPA protocol, and is just as stringent

  14. Leak rate measurements and detection systems

    International Nuclear Information System (INIS)

    Kupperman, D.; Shack, W.J.; Claytor, T.

    1983-10-01

    A research program is under way to evaluate and develop improve leak detection systems. The primary focus of the work has been on acoustic emission detection of leaks. Leaks from artificial flaws, laboratory-generated IGSCCs and thermal fatigue cracks, and field-induced intergranular stress corrosion cracks (IGSCCs) from reactor piping have been examined. The effects of pressure, temperature, and leak rate and geometry on the acoustic signature are under study. The use of cross-correlation techniques for leak location and pattern recognition and autocorrelation for source discrimination is also being considered

  15. Dynamics of highly polydisperse colloidal suspensions as a model system for bacterial cytoplasm.

    Science.gov (United States)

    Hwang, Jiye; Kim, Jeongmin; Sung, Bong June

    2016-08-01

    There are various kinds of macromolecules in bacterial cell cytoplasm. The size polydispersity of the macromolecules is so significant that the crystallization and the phase separation could be suppressed, thus stabilizing the liquid state of bacterial cytoplasm. On the other hand, recent experiments suggested that the macromolecules in bacterial cytoplasm should exhibit glassy dynamics, which should be also affected significantly by the size polydispersity of the macromolecules. In this work, we investigate the anomalous and slow dynamics of highly polydisperse colloidal suspensions, of which size distribution is chosen to mimic Escherichia coli cytoplasm. We find from our Langevin dynamics simulations that the diffusion coefficient (D_{tot}) and the displacement distribution functions (P(r,t)) averaged over all colloids of different sizes do not show anomalous and glassy dynamic behaviors until the system volume fraction ϕ is increased up to 0.82. This indicates that the intrinsic polydispersity of bacterial cytoplasm should suppress the glass transition and help maintain the liquid state of the cytoplasm. On the other hand, colloids of each kind show totally different dynamic behaviors depending on their size. The dynamics of colloids of different size becomes non-Gaussian at a different range of ϕ, which suggests that a multistep glass transition should occur. The largest colloids undergo the glass transition at ϕ=0.65, while the glass transition does not occur for smaller colloids in our simulations even at the highest value of ϕ. We also investigate the distribution (P(θ,t)) of the relative angles of displacement for macromolecules and find that macromolecules undergo directionally correlated motions in a sufficiently dense system.

  16. Linearmycins Activate a Two-Component Signaling System Involved in Bacterial Competition and Biofilm Morphology

    Science.gov (United States)

    2017-01-01

    ABSTRACT Bacteria use two-component signaling systems to adapt and respond to their competitors and changing environments. For instance, competitor bacteria may produce antibiotics and other bioactive metabolites and sequester nutrients. To survive, some species of bacteria escape competition through antibiotic production, biofilm formation, or motility. Specialized metabolite production and biofilm formation are relatively well understood for bacterial species in isolation. How bacteria control these functions when competitors are present is not well studied. To address fundamental questions relating to the competitive mechanisms of different species, we have developed a model system using two species of soil bacteria, Bacillus subtilis and Streptomyces sp. strain Mg1. Using this model, we previously found that linearmycins produced by Streptomyces sp. strain Mg1 cause lysis of B. subtilis cells and degradation of colony matrix. We identified strains of B. subtilis with mutations in the two-component signaling system yfiJK operon that confer dual phenotypes of specific linearmycin resistance and biofilm morphology. We determined that expression of the ATP-binding cassette (ABC) transporter yfiLMN operon, particularly yfiM and yfiN, is necessary for biofilm morphology. Using transposon mutagenesis, we identified genes that are required for YfiLMN-mediated biofilm morphology, including several chaperones. Using transcriptional fusions, we found that YfiJ signaling is activated by linearmycins and other polyene metabolites. Finally, using a truncated YfiJ, we show that YfiJ requires its transmembrane domain to activate downstream signaling. Taken together, these results suggest coordinated dual antibiotic resistance and biofilm morphology by a single multifunctional ABC transporter promotes competitive fitness of B. subtilis. IMPORTANCE DNA sequencing approaches have revealed hitherto unexplored diversity of bacterial species in a wide variety of environments that

  17. Characterization of the bacterial metagenome in an industrial algae bioenergy production system

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shi [Chinese Academy of Sciences; Fulbright, Scott P [Colorado State University; Zeng, Xiaowei [Chinese Academy of Sciences; Yates, Tracy [Solix Biofuels; Wardle, Greg [Solix Biofuels; Chisholm, Stephen T [Colorado State University; Xu, Jian [Chinese Academy of Sciences; Lammers, Peter [New Mexico State University

    2011-03-16

    Cultivation of oleaginous microalgae for fuel generally requires growth of the intended species to the maximum extent supported by available light. The presence of undesired competitors, pathogens and grazers in cultivation systems will create competition for nitrate, phosphate, sulfate, iron and other micronutrients in the growth medium and potentially decrease microalgal triglyceride production by limiting microalgal health or cell density. Pathogenic bacteria may also directly impact the metabolism or survival of individual microalgal cells. Conversely, symbiotic bacteria that enhance microalgal growth may also be present in the system. Finally, the use of agricultural and municipal wastes as nutrient inputs for microalgal production systems may lead to the introduction and proliferation of human pathogens or interfere with the growth of bacteria with beneficial effects on system performance. These considerations underscore the need to understand bacterial community dynamics in microalgal production systems in order to assess microbiome effects on microalgal productivity and pathogen risks. Here we focus on the bacterial component of microalgal production systems and describe a pipeline for metagenomic characterization of bacterial diversity in industrial cultures of an oleaginous alga, Nannochloropsis salina. Environmental DNA was isolated from 12 marine algal cultures grown at Solix Biofuels, a region of the 16S rRNA gene was amplified by PCR, and 16S amplicons were sequenced using a 454 automated pyrosequencer. The approximately 70,000 sequences that passed quality control clustered into 53,950 unique sequences. The majority of sequences belonged to thirteen phyla. At the genus level, sequences from all samples represented 169 different genera. About 52.94% of all sequences could not be identified at the genus level and were classified at the next highest possible resolution level. Of all sequences, 79.92% corresponded to 169 genera and 70 other taxa. We

  18. Vibrio vulnificus Type 6 Secretion System 1 Contains Anti-Bacterial Properties.

    Directory of Open Access Journals (Sweden)

    Selina R Church

    Full Text Available Vibrio vulnificus is a bacterium responsible for severe gastroenteritis, sepsis and wound infections. Gastroenteritis and sepsis are commonly associated with the consumption of raw oysters, whereas wound infection is often associated with the handling of contaminated fish. Although classical virulence factors of this emerging pathogen are well characterised, there remains a paucity of knowledge regarding the general biology of this species. To investigate the presence of previously unreported virulence factors, we applied whole genome sequencing to a panel of ten V. vulnificus strains with varying virulence potentials. This identified two novel type 6 secretion systems (T6SSs, systems that are known to have a role in bacterial virulence and population dynamics. By utilising a range of molecular techniques and assays we have demonstrated the functionality of one of these T6SSs. Furthermore, we have shown that this system is subject to thermoregulation and is negatively regulated by increasing salinity concentrations. This secretion system was also shown to be involved in the killing of V. vulnificus strains that did not possess this system and a model is proposed as to how this interaction may contribute to population dynamics within V. vulnificus strains. In addition to this intra-species killing, this system also contributes to the killing of inter bacterial species and may have a role in the general composition of Vibrio species in the environment.

  19. Subsea leak detection systems - recommended practice

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Kristin Nergaard

    2010-07-01

    It is known in the industry that occasional leakages occur in subsea production systems. In spite of efforts to apply subsea leak detectors, the experience is that most leakages are either detected by ROV during routine inspections or interventions or as oil slicks on the surface . Operators and authority awareness towards the environmental impact of oil and gas production is increasing. The regulatory bodies in Norway, EU and USA specify requirements for detection of acute pollution. This paper presents the development of a Recommended Practice (RP) sponsored by OLF (The Norwegian Oil Industry Association). The JIP includes several major oil and gas operators. The objective of the RP is to serve as a technical and practical reference in the field of subsea leak detection. (Author)

  20. Easiness of use and validity testing of VS-SENSE device for detection of abnormal vaginal flora and bacterial vaginosis.

    Science.gov (United States)

    Donders, Gilbert G G; Marconi, Camila; Bellen, Gert

    2010-01-01

    Accessing vaginal pH is fundamental during gynaecological visit for the detection of abnormal vaginal flora (AVF), but use of pH strips may be time-consuming and difficult to interpret. The aim of this study was to evaluate the VS-SENSE test (Common Sense Ltd, Caesarea, Israel) as a tool for the diagnosis of AVF and its correlation with abnormal pH and bacterial vaginosis (BV). The study population consisted of 45 women with vaginal pH ≥ 4.5 and 45 women with normal pH. Vaginal samples were evaluated by VS-SENSE test, microscopy and microbiologic cultures. Comparing with pH strips results, VS-SENSE test specificity was 97.8% and sensitivity of 91%. All severe cases of BV and aerobic vaginitis (AV) were detected by the test. Only one case with normal pH had an unclear result. Concluding, VS-SENSE test is easy to perform, and it correlates with increased pH, AVF, and the severe cases of BV and AV.

  1. Easiness of Use and Validity Testing of VS-SENSE Device for Detection of Abnormal Vaginal Flora and Bacterial Vaginosis

    Directory of Open Access Journals (Sweden)

    Gilbert G. G. Donders

    2010-01-01

    Full Text Available Accessing vaginal pH is fundamental during gynaecological visit for the detection of abnormal vaginal flora (AVF, but use of pH strips may be time-consuming and difficult to interpret. The aim of this study was to evaluate the VS-SENSE test (Common Sense Ltd, Caesarea, Israel as a tool for the diagnosis of AVF and its correlation with abnormal pH and bacterial vaginosis (BV. The study population consisted of 45 women with vaginal pH ≥ 4.5 and 45 women with normal pH. Vaginal samples were evaluated by VS-SENSE test, microscopy and microbiologic cultures. Comparing with pH strips results, VS-SENSE test specificity was 97.8% and sensitivity of 91%. All severe cases of BV and aerobic vaginitis (AV were detected by the test. Only one case with normal pH had an unclear result. Concluding, VS-SENSE test is easy to perform, and it correlates with increased pH, AVF, and the severe cases of BV and AV.

  2. A Bacterial Analysis Platform: An Integrated System for Analysing Bacterial Whole Genome Sequencing Data for Clinical Diagnostics and Surveillance

    DEFF Research Database (Denmark)

    Thomsen, Martin Christen Frølund; Ahrenfeldt, Johanne; Bellod Cisneros, Jose Luis

    2016-01-01

    and made publicly available, providing easy-to-use automated analysis of bacterial whole genome sequencing data. The platform may be of immediate relevance as a guide for investigators using whole genome sequencing for clinical diagnostics and surveillance. The platform is freely available at: https://cge.cbs.dtu.dk/services...... and antimicrobial resistance genes. A short printable report for each sample will be provided and an Excel spreadsheet containing all the metadata and a summary of the results for all submitted samples can be downloaded. The pipeline was benchmarked using datasets previously used to test the individual services...

  3. Programmable removal of bacterial strains by use of genome-targeting CRISPR-Cas systems.

    Science.gov (United States)

    Gomaa, Ahmed A; Klumpe, Heidi E; Luo, Michelle L; Selle, Kurt; Barrangou, Rodolphe; Beisel, Chase L

    2014-01-28

    CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems in bacteria and archaea employ CRISPR RNAs to specifically recognize the complementary DNA of foreign invaders, leading to sequence-specific cleavage or degradation of the target DNA. Recent work has shown that the accidental or intentional targeting of the bacterial genome is cytotoxic and can lead to cell death. Here, we have demonstrated that genome targeting with CRISPR-Cas systems can be employed for the sequence-specific and titratable removal of individual bacterial strains and species. Using the type I-E CRISPR-Cas system in Escherichia coli as a model, we found that this effect could be elicited using native or imported systems and was similarly potent regardless of the genomic location, strand, or transcriptional activity of the target sequence. Furthermore, the specificity of targeting with CRISPR RNAs could readily distinguish between even highly similar strains in pure or mixed cultures. Finally, varying the collection of delivered CRISPR RNAs could quantitatively control the relative number of individual strains within a mixed culture. Critically, the observed selectivity and programmability of bacterial removal would be virtually impossible with traditional antibiotics, bacteriophages, selectable markers, or tailored growth conditions. Once delivery challenges are addressed, we envision that this approach could offer a novel means to quantitatively control the composition of environmental and industrial microbial consortia and may open new avenues for the development of "smart" antibiotics that circumvent multidrug resistance and differentiate between pathogenic and beneficial microorganisms. Controlling the composition of microbial populations is a critical aspect in medicine, biotechnology, and environmental cycles. While different antimicrobial strategies, such as antibiotics, antimicrobial peptides, and lytic bacteriophages, offer partial solutions

  4. Clone tag detection in distributed RFID systems

    Science.gov (United States)

    Kamaludin, Hazalila; Mahdin, Hairulnizam

    2018-01-01

    Although Radio Frequency Identification (RFID) is poised to displace barcodes, security vulnerabilities pose serious challenges for global adoption of the RFID technology. Specifically, RFID tags are prone to basic cloning and counterfeiting security attacks. A successful cloning of the RFID tags in many commercial applications can lead to many serious problems such as financial losses, brand damage, safety and health of the public. With many industries such as pharmaceutical and businesses deploying RFID technology with a variety of products, it is important to tackle RFID tag cloning problem and improve the resistance of the RFID systems. To this end, we propose an approach for detecting cloned RFID tags in RFID systems with high detection accuracy and minimal overhead thus overcoming practical challenges in existing approaches. The proposed approach is based on consistency of dual hash collisions and modified count-min sketch vector. We evaluated the proposed approach through extensive experiments and compared it with existing baseline approaches in terms of execution time and detection accuracy under varying RFID tag cloning ratio. The results of the experiments show that the proposed approach outperforms the baseline approaches in cloned RFID tag detection accuracy. PMID:29565982

  5. The synchronous active neutron detection assay system

    International Nuclear Information System (INIS)

    Pickrell, M.M.; Kendall, P.K.

    1994-01-01

    We have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit a 14-MeV neutron generator developed by Schlumberger. The technique, termed synchronous active neutron detection (SAND), follows a method used routinely in other branches of physics to detect very small signals in presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed ''lock-in'' amplifiers. We have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. The Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. Results are preliminary but promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly; it also appears resilient to background neutron interference. The interrogating neutrons appear to be non-thermal and penetrating. Work remains to fully explore relevant physics and optimize instrument design

  6. Clone tag detection in distributed RFID systems.

    Science.gov (United States)

    Kamaludin, Hazalila; Mahdin, Hairulnizam; Abawajy, Jemal H

    2018-01-01

    Although Radio Frequency Identification (RFID) is poised to displace barcodes, security vulnerabilities pose serious challenges for global adoption of the RFID technology. Specifically, RFID tags are prone to basic cloning and counterfeiting security attacks. A successful cloning of the RFID tags in many commercial applications can lead to many serious problems such as financial losses, brand damage, safety and health of the public. With many industries such as pharmaceutical and businesses deploying RFID technology with a variety of products, it is important to tackle RFID tag cloning problem and improve the resistance of the RFID systems. To this end, we propose an approach for detecting cloned RFID tags in RFID systems with high detection accuracy and minimal overhead thus overcoming practical challenges in existing approaches. The proposed approach is based on consistency of dual hash collisions and modified count-min sketch vector. We evaluated the proposed approach through extensive experiments and compared it with existing baseline approaches in terms of execution time and detection accuracy under varying RFID tag cloning ratio. The results of the experiments show that the proposed approach outperforms the baseline approaches in cloned RFID tag detection accuracy.

  7. Recent trends of modern bacterial insecticides for pest control practice in integrated crop management system.

    Science.gov (United States)

    Chattopadhyay, Pritam; Banerjee, Goutam; Mukherjee, Sayantan

    2017-05-01

    Food security and safety are the major concern in ever expanding human population on the planet earth. Each and every year insect pests cause a serious damage in agricultural field that cost billions of dollars annually to farmers. The loss in term of productivity and high cost of chemical pesticides enhance the production cost. Irrespective use of chemical pesticides (such as Benzene hexachloride, Endosulfan, Aldicarb, and Fenobucarb) in agricultural field raised several types of environmental issues. Furthermore, continuous use of chemical pesticides creates a selective pressure which helps in emerging of resistance pest. These excess chemical pesticide residues also contaminate the environment including the soil and water. Therefore, the biological control of insect pest in the agricultural field gains more importance due to food safety and environment friendly nature. In this regard, bacterial insecticides offer better alternative to chemical pesticides. It not only helps to establish food security through fighting against insect pests but also ensure the food safety. In this review, we have categorized insect pests and the corresponding bacterial insecticides, and critically analyzed the importance and mode of action of bacterial pesticides. We also have summarized the use of biopesticides in integrated pest management system. We have tried to focus the future research area in this field for the upcoming scientists.

  8. Handheld microwave bomb-detecting imaging system

    Science.gov (United States)

    Gorwara, Ashok; Molchanov, Pavlo

    2017-05-01

    Proposed novel imaging technique will provide all weather high-resolution imaging and recognition capability for RF/Microwave signals with good penetration through highly scattered media: fog, snow, dust, smoke, even foliage, camouflage, walls and ground. Image resolution in proposed imaging system is not limited by diffraction and will be determined by processor and sampling frequency. Proposed imaging system can simultaneously cover wide field of view, detect multiple targets and can be multi-frequency, multi-function. Directional antennas in imaging system can be close positioned and installed in cell phone size handheld device, on small aircraft or distributed around protected border or object. Non-scanning monopulse system allows dramatically decrease in transmitting power and at the same time provides increased imaging range by integrating 2-3 orders more signals than regular scanning imaging systems.

  9. Detection of bacterial infection of agave plants by laser-induced fluorescence

    Science.gov (United States)

    Cervantes-Martinez, Jesus; Flores-Hernandez, Ricardo; Rodriguez-Garay, Benjamin; Santacruz-Ruvalcaba, Fernando

    2002-05-01

    Greenhouse-grown plants of Agave tequilana Weber var. azul were inoculated with Erwinia carotovora, the causal agent of stem soft rot. We investigated the laser-induced fluorescence (LIF) of agave plants to determine whether LIF can be used as a noninvasive sensing tool for pathological studies. The LIF technique was also investigated as a means of detecting the effect of the polyamine biosynthesis inhibitor beta-hydroxyethylhydrazine as a bactericide against the pathogenic bacterium Erwinia carotovora. A He-Ne laser at 632.8 nm was used as the excitation source, and in vivo fluorescence emission spectra were recorded in the 660-790-range. Fluorescence maxima were at 690 and 740 nm. The infected plants that were untreated with the bactericide showed a definite increase in fluorescence intensity at both maxima within the first three days after infection. Beginning on the fifth day, a steady decrease in fluorescence intensity was observed, with a greater effect at 740 than at 690 nm. After 30 days there was no fluorescence. The infected plants that had been treated with the bactericide showed no significant change in fluorescence compared with that of the uninfected plants. The ratio of fluorescence intensities was determined to be F 690 nm/F 740 nm for all treatments. These studies indicate that LIF measurements of agave plants may be used for the early detection of certain types of disease and for determining the effect of a bactericide on bacteria. The results also showed that fluorescence intensity ratios can be used as a reliable indicator of the progress of disease.

  10. Detection of bacterial endotoxin in food: New planar interdigital sensors based approach

    KAUST Repository

    Abdul Rahman, Mohd Syaifudin

    2013-02-01

    Food poisoning caused by endotoxins or Lipopolysaccharide (LPS) are associated with Gram-negative bacteria. Two major food-borne pathogens, Escherichia coli and Salmonella are examples of Gram-negative bacteria which cause a large number of outbreaks of food poisoning. New types of planar interdigital sensors have been fabricated with different coating materials to assess their response to endotoxins. A carboxyl-functional polymer, APTES (3-Aminopropyltriethoxysilane) and Thionine were chosen to be coated onto FR4 interdigital sensors. The chosen coating materials have carboxylic or amine functional groups, which were optimized to be stable in water. All coated sensors were immobilized with PmB (Polymyxin B) which has specific binding properties to LPS. The sensors were tested with different concentrations of LPS O111:B4, ranging from 0.1 to 1000 μg/ml. Analyses of sensors\\' performance were based on the impedance spectroscopy method. The impedance spectra were modeled using a constant phase-element (CPE) equivalent circuit, and a principal component analysis (PCA) was used for data classification. Sensor coated with APTES has shown better selectivity for LPS detection. The experiments were repeated by coating APTES and immobilizing PmB to a new improve designed of novel interdigital sensors (thin film silicon based sensors). These sensors were observed to have better sensitivity and selectivity to the target biomolecules of LPS. Further experiments were conducted to study the effect of different coating thickness on sensor sensitivity, selectivity and stability. Different food samples contaminated with endotoxin were also tested to verify that the interdigital sensing approach is able to be used for endotoxin detection. © 2012 Elsevier Ltd. All rights reserved.

  11. 29 CFR 1910.164 - Fire detection systems.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Fire detection systems. 1910.164 Section 1910.164 Labor... detection systems. (a) Scope and application. This section applies to all automatic fire detection systems... detection systems and components to normal operating condition as promptly as possible after each test or...

  12. Multichannel Digital Emulator of Radiation Detection Systems

    International Nuclear Information System (INIS)

    Abba, A.; Caponio, F.; Geraci, A.

    2013-06-01

    A digital system for emulating in real time signals from generic setups for radiation detection is presented. The instrument is not a pulse generator of recorded shapes but a synthesizer of random pulses compliant to programmable statistics for energy and occurrence time. Completely programmable procedures for emulation of noise, disturbances and reference level variation can be implemented. The instrument has been realized and fully tested. (authors)

  13. Perimeter intrusion detection and assessment system

    International Nuclear Information System (INIS)

    Eaton, M.J.; Jacobs, J.; McGovern, D.E.

    1977-11-01

    To obtain an effective perimeter intrusion detection system requires careful sensor selection, procurement, and installation. The selection process involves a thorough understanding of the unique site features and how these features affect the performance of each type of sensor. It is necessary to develop procurement specifications to establish acceptable sensor performance limits. Careful explanation and inspection of critical installation dimensions is required during on-site construction. The implementation of these activities at a particular site is discussed

  14. Bacterial community radial-spatial distribution in biofilms along pipe wall in chlorinated drinking water distribution system of East China.

    Science.gov (United States)

    Liu, Jingqing; Ren, Hongxing; Ye, Xianbei; Wang, Wei; Liu, Yan; Lou, Liping; Cheng, Dongqing; He, Xiaofang; Zhou, Xiaoyan; Qiu, Shangde; Fu, Liusong; Hu, Baolan

    2017-01-01

    Biofilms in the pipe wall may lead to water quality deterioration and biological instability in drinking water distribution systems (DWDSs). In this study, bacterial community radial-spatial distribution in biofilms along the pipe wall in a chlorinated DWDS of East China was investigated. Three pipes of large diameter (300, 600, and 600 mm) were sampled in this DWDS, including a ductile cast iron pipe (DCIP) with pipe age of 11 years and two gray cast iron pipes (GCIP) with pipe ages of 17 and 19 years, and biofilms in the upper, middle, and lower parts of each pipe wall were collected. Real-time quantitative polymerase chain reaction (qPCR) and culture-based method were used to quantify bacteria. 454 pyrosequencing was used for bacterial community analysis. The results showed that the biofilm density and total solid (TS) and volatile solid (VS) contents increased gradually from the top to the bottom along the pipe wall. Microorganisms were concentrated in the upper and lower parts of the pipe wall, together accounting for more than 80 % of the total biomass in the biofilms. The bacterial communities in biofilms were significantly different in different areas of the pipe wall and had no strong interaction. Compared with the upper and lower parts of the pipe wall, the bacterial community in the middle of the pipe wall was distributed evenly and had the highest diversity. The 16S rRNA genes of various possible pathogens, including Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Salmonella enterica, were detected in the biofilms, and the abundances of these possible pathogens were highest in the middle of the pipe wall among three areas. The detachment of the biofilms is the main reason for the deterioration of the water quality in DWDSs. The results of this study suggest that the biofilms in the middle of the pipe wall have highly potential risk for drinking water safety, which provides new ideas for the study of the microbial ecology in

  15. Exposure to bacterial DNA before hemorrhagic shock strongly aggravates systemic inflammation and gut barrier loss via an IFN-gamma-dependent route

    NARCIS (Netherlands)

    Luyer, Misha D.; Buurman, Wim A.; Hadfoune, M.'hamed; Wolfs, T.; van't Veer, Cornelis; Jacobs, Jan A.; Dejong, Cornelis H.; Greve, Jan Willem M.

    2007-01-01

    OBJECTIVE: To investigate the role of bacterial DNA in development of an excessive inflammatory response and loss of gut barrier loss following systemic hypotension. SUMMARY BACKGROUND DATA: Bacterial infection may contribute to development of inflammatory complications following major surgery;

  16. A systematic approach for the assessment of bacterial growth-controlling factors linked to biological stability of drinking water in distribution systems

    KAUST Repository

    Prest, E. I.; Hammes, F.; Kotzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    A systematic approach is presented for the assessment of (i) bacterial growth-controlling factors in drinking water and (ii) the impact of distribution conditions on the extent of bacterial growth in full-scale distribution systems. The approach

  17. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    International Nuclear Information System (INIS)

    Huang, Manhong; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-01-01

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge

  18. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Manhong, E-mail: egghmh@163.com; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-11-15

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge.

  19. In-Situ Wire Damage Detection System

    Science.gov (United States)

    Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor); Tate, Lanetra C. (Inventor); Smith, Trent M. (Inventor); Gibson, Tracy L. (Inventor); Jolley, Scott T. (Inventor); Medelius, Pedro J. (Inventor)

    2014-01-01

    An in-situ system for detecting damage in an electrically conductive wire. The system includes a substrate at least partially covered by a layer of electrically conductive material forming a continuous or non-continuous electrically conductive layer connected to an electrical signal generator adapted to delivering electrical signals to the electrically conductive layer. Data is received and processed to identify damage to the substrate or electrically conductive layer. The electrically conductive material may include metalized carbon fibers, a thin metal coating, a conductive polymer, carbon nanotubes, metal nanoparticles or a combination thereof.

  20. The remote atmospheric and ionospheric detection system

    International Nuclear Information System (INIS)

    McCoy, R.P.; Wolfram, K.D.; Meier, R.R.

    1986-01-01

    The Remote Atmospheric and Ionospheric Detection System (RAIDS) experiment, to fly on a TIROS spacecraft in the late 1980's, consists of a comprehensive set of one limb imaging and seven limb scanning optical sensors. These eight instruments span the spectral range from the extreme ultraviolet to the near infrared, allowing simultaneous observations of the neutral and ion composition on the day and night side as well as in the auroral region. The primary objective of RAIDS is to demonstrate a system for remote sensing of the ionosphere to produce global maps of the electron density, peak altitude and critical frequency

  1. Assessment of the extent of bacterial growth in reverse osmosis system for improving drinking water quality.

    Science.gov (United States)

    Park, Se-keun; Hu, Jiang Yong

    2010-01-01

    This study was carried out to assess reverse osmosis (RO) treatment efficacy of drinking water in terms of biological stability in the distribution system. Two flat-sheet RO membranes were used in this study. Experiments were designed to investigate the growth of biofilm and bulk phase bacteria for the RO-treated water flowing through a model distribution system under controlled conditions without disinfectants. RO membranes improved the water quality of drinking water in terms of inorganic, organic and bacterial contents. Organic matter including the fraction available for microbes was efficiently removed by the RO membranes tested. More than 99% of bacterial cells in the tap water was retained by the RO membranes, leaving water. In spite of the low nutrient contents and few cells in the RO permeates, monitoring of the model distribution systems receiving the RO permeates showed that remarkable biofilm accumulation and bulk cell growth occurred in the RO permeate water. In quasi-steady state, the total cell numbers in the biofilm and bulk water were of order 10(3) cells/cm(2) and 10(3) cells/mL, respectively, which were about 2 orders of magnitude lower than those grown in the tap water produced from conventional water treatment. The culturable heterotrophic bacteria constituted a significant part of the total cells (20.7-32.1% in biofilms and 21.3-46.3% in bulk waters). Biofilm maximum density and production rate were of the order 10(4) cells/cm(2) and 10(2) cells/cm(2)/day, respectively. The specific cell growth rate of bacteria in the biofilms was found to be much lower than those in the bulk waters (0.04-0.05 day(-1) versus 0.28-0.36 day(-1)). The overall specific cell growth rate which indicates the growth potential in the whole system was calculated as 0.07-0.08 day(-1), representing a doubling time of 9.1-10.1 days. These observations can be indicative of possibilities for bacterial growth in the RO permeate water with easily assimilable organic carbon

  2. Systemic cytokine signaling via IL-17 in smokers with obstructive pulmonary disease: a link to bacterial colonization?

    Science.gov (United States)

    Andelid, Kristina; Tengvall, Sara; Andersson, Anders; Levänen, Bettina; Christenson, Karin; Jirholt, Pernilla; Åhrén, Christina; Qvarfordt, Ingemar; Ekberg-Jansson, Ann; Lindén, Anders

    2015-01-01

    We examined whether systemic cytokine signaling via interleukin (IL)-17 and growth-related oncogene-α (GRO-α) is impaired in smokers with obstructive pulmonary disease including chronic bronchitis (OPD-CB). We also examined how this systemic cytokine signaling relates to bacterial colonization in the airways of the smokers with OPD-CB. Currently smoking OPD-CB patients (n=60, corresponding to Global initiative for chronic Obstructive Lung Disease [GOLD] stage I–IV) underwent recurrent blood and sputum sampling over 60 weeks, during stable conditions and at exacerbations. We characterized cytokine protein concentrations in blood and bacterial growth in sputum. Asymptomatic smokers (n=10) and never-smokers (n=10) were included as control groups. During stable clinical conditions, the protein concentrations of IL-17 and GRO-α were markedly lower among OPD-CB patients compared with never-smoker controls, whereas the asymptomatic smoker controls displayed intermediate concentrations. Notably, among OPD-CB patients, colonization by opportunistic pathogens was associated with markedly lower IL-17 and GRO-α, compared with colonization by common respiratory pathogens or oropharyngeal flora. During exacerbations in the OPD-CB patients, GRO-α and neutrophil concentrations were increased, whereas protein concentrations and messenger RNA for IL-17 were not detectable in a reproducible manner. In smokers with OPD-CB, systemic cytokine signaling via IL-17 and GRO-α is impaired and this alteration may be linked to colonization by opportunistic pathogens in the airways. Given the potential pathogenic and therapeutic implications, these findings deserve to be validated in new and larger patient cohorts. PMID:25848245

  3. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

  4. [Risk factors associated with bacterial growth in derivative systems from cerebrospinal liquid in pediatric patients].

    Science.gov (United States)

    de Jesús Vargas-Lares, José; Andrade-Aguilera, Angélica Rocío; Díaz-Peña, Rafael; Barrera de León, Juan Carlos

    2015-01-01

    To determine risk factors associated with bacterial growth in systems derived from cerebrospinal fluid in pediatric patients. Case and controls study from January to December 2012, in patients aged <16 years who were carriers of hydrocephalus and who required placement or replacement of derivative system. Cases were considered as children with cultures with bacterial growth and controls with negative bacterial growth. Inferential statistics with Chi-squared and Mann-Whitney U tests. Association of risk with odds ratio. We reviewed 746 registries, cases n=99 (13%) and controls n=647 (87%). Masculine gender 58 (57%) vs. feminine gender 297 (46%) (p=0.530). Age of cases: median, five months and controls, one year (p=0.02). Median weight, 7 vs. 10 kg (p=0.634). Surgical interventions: median n=2 (range, 1-8) vs. n=1 (range, 1-7). Infection rate, 13.2%. Main etiology ductal stenosis, n=29 (29%) vs. n=50 (23%) (p=0.530). Non-communicating, n=50 (51%) vs. 396 (61%) (p=0.456). Predominant microorganisms: enterobacteria, pseudomonas, and enterococcus. Non-use of iodized dressing OR=2.6 (range, 1.8-4.3), use of connector OR=6.8 (range, 1.9-24.0), System replacement OR=2.0 (range, 1.3-3.1), assistant without surgical facemask OR=9.7 (range, 2.3-42.0). Being a breastfeeding infant, of low weight, non-application of iodized dressing, use of connector, previous derivation, and lack of adherence to aseptic technique were all factors associated with ependymitis.

  5. PCR-based detection of bacterial DNA after antimicrobial treatment is indicative of persistent, viable bacteria in the chinchilla model of otitis media.

    Science.gov (United States)

    Post, J C; Aul, J J; White, G J; Wadowsky, R M; Zavoral, T; Tabari, R; Kerber, B; Doyle, W J; Ehrlich, G D

    1996-01-01

    Bacterial deoxyribonucleic acid (DNA) has been previously detected by polymerase chain reactions (PCR) in a significant percentage of culturally-sterile pediatric middle-ear effusions. The current study was designed to determine whether this represents the existence of viable bacteria or the persistence of residual DNA in the middle-ear cleft. The middle-ear cavities of two sets of chinchillas were inoculated with either: 1) 100 colony-forming units (CFU) of live Haemophilus influenzae, 2.2 x 10(6) CFU of pasteurized Moraxella catarrhalis, and 1000 ng of DNA (>10(8) genomic equivalents) from Streptococcus pneumoniae; or 2) 100 CFU of live S pneumoniae, 2.2 x 10(6) CFU of pasteurized M catarrhalis and 1000 ng of purified DNA from H influenzae. Animals were treated with ampicillin for 5 days beginning on day 3. A single-point longitudinal study design was used for sampling to eliminate the possibility of contamination. No DNA was detectable from the heat-killed bacteria or the purified DNA after day 3. However, DNA from the live bacteria persisted through day 21, even though all specimens were culture-negative following the initiation of antimicrobial therapy. These findings indicate that purified DNA and DNA from intact but nonviable bacteria do not persist in the middle-ear cleft in the presence of an effusion, even following high copy inoculation. In contrast, antibiotic-treated bacteria persist in some viable state for weeks as evidenced by the differential ability of the PCR-based assay systems to detect the live bacteria, but not detect the heat-killed organisms.

  6. Automating Vendor Fraud Detection in Enterprise Systems

    Directory of Open Access Journals (Sweden)

    Kishore Singh

    2013-06-01

    Full Text Available Fraud is a multi-billion dollar industry that continues to grow annually. Many organisations are poorly prepared to prevent and detect fraud. Fraud detection strategies are intended to quickly and efficiently identify fraudulent activities that circumvent preventative measures. In this paper we adopt a Design-Science methodological framework to develop a model for detection of vendor fraud based on analysis of patterns or signatures identified in enterprise system audit trails. The concept is demonstrated be developing prototype software. Verification of the prototype is achieved by performing a series of experiments. Validation is achieved by independent reviews from auditing practitioners. Key findings of this study are: i automating routine data analytics improves auditor productivity and reduces time taken to identify potential fraud, and ii visualisations assist in promptly identifying potentially fraudulent user activities. The study makes the following contributions: i a model for proactive fraud detection, ii methods for visualising user activities in transaction data, iii a stand-alone MCL-based prototype.

  7. [Studies on the repair of damaged DNA in bacteriophage, bacterial and mammalian systems]: Final report

    International Nuclear Information System (INIS)

    Friedberg, E.C.

    1987-08-01

    This study sought to exploit the use of uv radiation as a source of genomic damage. We explored the molecular mechanism of the repair of DNA damage at a number of different levels of biological organization, by investigating bacteriophage, bacterial, yeast and mammalian cells. Not only have observations obtained in one biological system suggested specific experimental approaches in others, but we have also learned that some biochemical pathways for DNA repair are unique to specific organisms. Our studies are summarized in terms of 4 major areas of research activity that span the past 16 years. 86 refs

  8. Fungal–bacterial consortia increase diuron degradation in water-unsaturated systems

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea; Knudsen, Berith Elkær; Johansen, Anders

    2014-01-01

    organism. In addition, fungal hyphae may function as transport vectors for bacteria, thereby facilitating a more effective spreading of degrader organisms in the soil. A more rapid mineralization of the phenylurea herbicide diuron was found in sand with added microbial consortia consisting of both...... degrading bacteria and fungi. Facilitated transport of bacteria by fungal hyphae was demonstrated using a system where herbicide-spiked sand was separated from the consortium by a layer of sterile glass beads. Several fungal–bacterial consortia were investigated by combining different diuron...

  9. Incipient fault detection and power system protection for spaceborne systems

    Science.gov (United States)

    Russell, B. Don; Hackler, Irene M.

    1987-01-01

    A program was initiated to study the feasibility of using advanced terrestrial power system protection techniques for spacecraft power systems. It was designed to enhance and automate spacecraft power distribution systems in the areas of safety, reliability and maintenance. The proposed power management/distribution system is described as well as security assessment and control, incipient and low current fault detection, and the proposed spaceborne protection system. It is noted that the intelligent remote power controller permits the implementation of digital relaying algorithms with both adaptive and programmable characteristics.

  10. A complete low cost radon detection system

    International Nuclear Information System (INIS)

    Bayrak, A.; Barlas, E.; Emirhan, E.; Kutlu, Ç.; Ozben, C.S.

    2013-01-01

    Monitoring the 222 Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center. - Author-Highlights: • Low cost radon detection. • Integrated GSM modem for early warning of radon anomalies. • Radon detection in environment

  11. High sensitivity neutron bursts detecting system

    International Nuclear Information System (INIS)

    Shyam, A.; Kaushik, T.C.; Srinivasan, M.; Kulkarni, L.V.

    1993-01-01

    Technique and instrumentation to detect multiplicity of fast neutrons, emitted in sharp bursts, has been developed. A bank of 16 BF 3 detectors, in an appropriate thermalising assembly, efficiency ∼ 16%, is used to detect neutron bursts. The output from this setup, through appropriate electronics, is divided into two paths. The first is directly connected to a computer controlled scalar. The second is connected to another similar scalar through a delay time unit (DTU). The DTU design is such that once it is triggered by a count pulse than it does not allow any counts to be recorded for a fixed dead time set at ∼ 100 μs. The difference in counts recorded directly and through DTU gives the total number of neutrons produced in bursts. This setup is being used to study lattice cracking, anomalous effects in solid deuterium systems and various reactor physics experiments. (author). 3 refs., 1 fig

  12. System and method for anomaly detection

    Science.gov (United States)

    Scherrer, Chad

    2010-06-15

    A system and method for detecting one or more anomalies in a plurality of observations is provided. In one illustrative embodiment, the observations are real-time network observations collected from a stream of network traffic. The method includes performing a discrete decomposition of the observations, and introducing derived variables to increase storage and query efficiencies. A mathematical model, such as a conditional independence model, is then generated from the formatted data. The formatted data is also used to construct frequency tables which maintain an accurate count of specific variable occurrence as indicated by the model generation process. The formatted data is then applied to the mathematical model to generate scored data. The scored data is then analyzed to detect anomalies.

  13. Collision Detection for Underwater ROV Manipulator Systems

    Directory of Open Access Journals (Sweden)

    Satja Sivčev

    2018-04-01

    Full Text Available Work-class ROVs equipped with robotic manipulators are extensively used for subsea intervention operations. Manipulators are teleoperated by human pilots relying on visual feedback from the worksite. Operating in a remote environment, with limited pilot perception and poor visibility, manipulator collisions which may cause significant damage are likely to happen. This paper presents a real-time collision detection algorithm for marine robotic manipulation. The proposed collision detection mechanism is developed, integrated into a commercial ROV manipulator control system, and successfully evaluated in simulations and experimental setup using a real industry standard underwater manipulator. The presented collision sensing solution has a potential to be a useful pilot assisting tool that can reduce the task load, operational time, and costs of subsea inspection, repair, and maintenance operations.

  14. Evaluation of an Internally Controlled Multiplex Tth Endonuclease Cleavage Loop-Mediated Isothermal Amplification (TEC-LAMP Assay for the Detection of Bacterial Meningitis Pathogens

    Directory of Open Access Journals (Sweden)

    Owen Higgins

    2018-02-01

    Full Text Available Bacterial meningitis infection is a leading global health concern for which rapid and accurate diagnosis is essential to reduce associated morbidity and mortality. Loop-mediated isothermal amplification (LAMP offers an effective low-cost diagnostic approach; however, multiplex LAMP is difficult to achieve, limiting its application. We have developed novel real-time multiplex LAMP technology, TEC-LAMP, using Tth endonuclease IV and a unique LAMP primer/probe. This study evaluates the analytical specificity, limit of detection (LOD and clinical application of an internally controlled multiplex TEC-LAMP assay for detection of leading bacterial meningitis pathogens: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae. Analytical specificities were established by testing 168 bacterial strains, and LODs were determined using Probit analysis. The TEC-LAMP assay was 100% specific, with LODs for S. pneumoniae, N. meningitidis and H. influenzae of 39.5, 17.3 and 25.9 genome copies per reaction, respectively. Clinical performance was evaluated by testing 65 archived PCR-positive samples. Compared to singleplex real-time PCR, the multiplex TEC-LAMP assay demonstrated diagnostic sensitivity and specificity of 92.3% and 100%, respectively. This is the first report of a single-tube internally controlled multiplex LAMP assay for bacterial meningitis pathogen detection, and the first report of Tth endonuclease IV incorporation into nucleic acid amplification diagnostic technology.

  15. Evaluation of an Internally Controlled Multiplex Tth Endonuclease Cleavage Loop-Mediated Isothermal Amplification (TEC-LAMP) Assay for the Detection of Bacterial Meningitis Pathogens

    Science.gov (United States)

    Clancy, Eoin; Cormican, Martin; Boo, Teck Wee; Cunney, Robert

    2018-01-01

    Bacterial meningitis infection is a leading global health concern for which rapid and accurate diagnosis is essential to reduce associated morbidity and mortality. Loop-mediated isothermal amplification (LAMP) offers an effective low-cost diagnostic approach; however, multiplex LAMP is difficult to achieve, limiting its application. We have developed novel real-time multiplex LAMP technology, TEC-LAMP, using Tth endonuclease IV and a unique LAMP primer/probe. This study evaluates the analytical specificity, limit of detection (LOD) and clinical application of an internally controlled multiplex TEC-LAMP assay for detection of leading bacterial meningitis pathogens: Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae. Analytical specificities were established by testing 168 bacterial strains, and LODs were determined using Probit analysis. The TEC-LAMP assay was 100% specific, with LODs for S. pneumoniae, N. meningitidis and H. influenzae of 39.5, 17.3 and 25.9 genome copies per reaction, respectively. Clinical performance was evaluated by testing 65 archived PCR-positive samples. Compared to singleplex real-time PCR, the multiplex TEC-LAMP assay demonstrated diagnostic sensitivity and specificity of 92.3% and 100%, respectively. This is the first report of a single-tube internally controlled multiplex LAMP assay for bacterial meningitis pathogen detection, and the first report of Tth endonuclease IV incorporation into nucleic acid amplification diagnostic technology. PMID:29425124

  16. Metabolic Regulation of a Bacterial Cell System with Emphasis on Escherichia coli Metabolism

    Science.gov (United States)

    Shimizu, Kazuyuki

    2013-01-01

    It is quite important to understand the overall metabolic regulation mechanism of bacterial cells such as Escherichia coli from both science (such as biochemistry) and engineering (such as metabolic engineering) points of view. Here, an attempt was made to clarify the overall metabolic regulation mechanism by focusing on the roles of global regulators which detect the culture or growth condition and manipulate a set of metabolic pathways by modulating the related gene expressions. For this, it was considered how the cell responds to a variety of culture environments such as carbon (catabolite regulation), nitrogen, and phosphate limitations, as well as the effects of oxygen level, pH (acid shock), temperature (heat shock), and nutrient starvation. PMID:25937963

  17. 46 CFR 108.413 - Fusible element fire detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Fusible element fire detection system. 108.413 Section... UNITS DESIGN AND EQUIPMENT Fire Extinguishing Systems § 108.413 Fusible element fire detection system. (a) A fusible element fire detection system may be installed. (b) The arrangements for the system...

  18. 46 CFR 108.411 - Smoke detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Smoke detection system. 108.411 Section 108.411 Shipping... EQUIPMENT Fire Extinguishing Systems § 108.411 Smoke detection system. Each smoke accumulator in a smoke detection system must be located on the overhead of the compartment protected by the system in a location...

  19. Intelligent Flamefinder Detection and Alert System (IFDAS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Current hydrogen flame detection systems exhibit shortcomings ranging from limited detection range, to localization inaccuracy, limited sensitivity, false alarms,...

  20. Detection of a Reproducible, Single-Member Shift in Soil Bacterial Communities Exposed to Low Levels of Hydrogen▿

    Science.gov (United States)

    Osborne, Catherine A.; Peoples, Mark B.; Janssen, Peter H.

    2010-01-01

    Soil is exposed to hydrogen when symbiotic rhizobia in legume root nodules cannot recycle the hydrogen that is generated during nitrogen fixation. The hydrogen emitted is most likely taken up by free-living soil bacteria that use hydrogen as an energy source, though the bacteria that do this in situ remain unclear. In this study, we investigated the effect of hydrogen exposure on the bacteria of two different soils in a microcosm setup designed to simulate hydrogen-emitting root nodules. Although the size and overall composition of the soil bacterial community did not significantly alter after hydrogen exposure, one ribotype increased in relative abundance within each soil. This single-ribotype shift was identified by generating multiple terminal restriction fragment length polymorphism (T-RFLP) profiles of 16S rRNA genes from each soil sample, with gene sequence confirmation to identify terminal restriction fragments. The increased abundance of a single ribotype after hydrogen exposure, within an otherwise similar community, was found in replicate samples taken from each microcosm and was reproducible across replicate experiments. Similarly, only one member of the soil bacterial community increased in abundance in response to hydrogen exposure in soil surrounding the root nodules of field-grown soybean (Glycine max). The ribotypes that increased after hydrogen exposure in each soil system tested were all from known hydrogen-oxidizing lineages within the order Actinomycetales. We suggest that soil actinomycetes are important utilizers of hydrogen at relevant concentrations in soil and could be key contributors to soil's function as a sink in the global hydrogen cycle. PMID:20061453

  1. Radon detection system, design, test and performance

    International Nuclear Information System (INIS)

    Balcazar, M.; Chavez, A.; Pina-Villalpando, G.; Navarrete, M.

    1999-01-01

    A portable radon detection system (α-Inin) has been designed and constructed for using it in adverse environmental conditions where humidity, temperature and chemical vaporous are present. The minimum integration time is in periods of 15 min during 41 days. A 12 V battery and a photovoltaic module allow the α-Inin autonomy in field measurements. Data is collected by means of a laptop computer where data processing and α-Inin programming are carried out. α-Inin performance was simultaneously tested in a controlled radon chamber, together with a commercial α-Meter

  2. The DinJ/RelE Toxin-Antitoxin System Suppresses Bacterial Proliferation and Virulence of Xylella fastidiosa in Grapevine.

    Science.gov (United States)

    Burbank, Lindsey P; Stenger, Drake C

    2017-04-01

    Xylella fastidiosa, the causal agent of Pierce's disease of grapes, is a slow-growing, xylem-limited, bacterial pathogen. Disease progression is characterized by systemic spread of the bacterium through xylem vessel networks, causing leaf-scorching symptoms, senescence, and vine decline. It appears to be advantageous to this pathogen to avoid excessive blockage of xylem vessels, because living bacterial cells are generally found in plant tissue with low bacterial cell density and minimal scorching symptoms. The DinJ/RelE toxin-antitoxin system is characterized here for a role in controlling bacterial proliferation and population size during plant colonization. The DinJ/RelE locus is transcribed from two separate promoters, allowing for coexpression of antitoxin DinJ with endoribonuclease toxin RelE, in addition to independent expression of RelE. The ratio of antitoxin/toxin expressed is dependent on bacterial growth conditions, with lower amounts of antitoxin present under conditions designed to mimic grapevine xylem sap. A knockout mutant of DinJ/RelE exhibits a hypervirulent phenotype, with higher bacterial populations and increased symptom development and plant decline. It is likely that DinJ/RelE acts to prevent excessive population growth, contributing to the ability of the pathogen to spread systemically without completely blocking the xylem vessels and increasing probability of acquisition by the insect vector.

  3. Molecular Epidemiologic Typing Systems of Bacterial Pathogens: Current Issues and Perpectives

    Directory of Open Access Journals (Sweden)

    Struelens Marc J

    1998-01-01

    Full Text Available The epidemiologic typing of bacterial pathogens can be applied to answer a number of different questions: in case of outbreak, what is the extent and mode of transmission of epidemic clone(s ? In case of long-term surveillance, what is the prevalence over time and the geographic spread of epidemic and endemic clones in the population? A number of molecular typing methods can be used to classify bacteria based on genomic diversity into groups of closely-related isolates (presumed to arise from a common ancestor in the same chain of transmission and divergent, epidemiologically-unrelated isolates (arising from independent sources of infection. Ribotyping, IS-RFLP fingerprinting, macrorestriction analysis of chromosomal DNA and PCR-fingerprinting using arbitrary sequence or repeat element primers are useful methods for outbreak investigations and regional surveillance. Library typing systems based on multilocus sequence-based analysis and strain-specific probe hybridization schemes are in development for the international surveillance of major pathogens like Mycobacterium tuberculosis. Accurate epidemiological interpretation of data obtained with molecular typing systems still requires additional research on the evolution rate of polymorphic loci in bacterial pathogens.

  4. Autonomous system for pathogen detection and identification

    International Nuclear Information System (INIS)

    Belgrader, P.; Benett, W.; Langlois, R.; Long, G.; Mariella, R.; Milanovich, F.; Miles, R.; Nelson, W.; Venkateswaran, K.

    1998-01-01

    This purpose of this project is to build a prototype instrument that will, running unattended, detect, identify, and quantify BW agents. In order to accomplish this, we have chosen to start with the world s leading, proven, assays for pathogens: surface-molecular recognition assays, such as antibody-based assays, implemented on a high-performance, identification (ID)-capable flow cytometer, and the polymerase chain reaction (PCR) for nucleic-acid based assays. With these assays, we must integrate the capability to: l collect samples from aerosols, water, or surfaces; l perform sample preparation prior to the assays; l incubate the prepared samples, if necessary, for a period of time; l transport the prepared, incubated samples to the assays; l perform the assays; l interpret and report the results of the assays. Issues such as reliability, sensitivity and accuracy, quantity of consumables, maintenance schedule, etc. must be addressed satisfactorily to the end user. The highest possible sensitivity and specificity of the assay must be combined with no false alarms. Today, we have assays that can, in under 30 minutes, detect and identify stimulants for BW agents at concentrations of a few hundred colony-forming units per ml of solution. If the bio-aerosol sampler of this system collects 1000 Ymin and concentrates the respirable particles into 1 ml of solution with 70% processing efficiency over a period of 5 minutes, then this translates to a detection/ID capability of under 0.1 agent-containing particle/liter of air

  5. A polarization system for persistent chemical detection

    Science.gov (United States)

    Craven-Jones, Julia; Appelhans, Leah; Couphos, Eric; Embree, Todd; Finnegan, Patrick; Goldstein, Dennis; Karelitz, David; LaCasse, Charles; Luk, Ting S.; Mahamat, Adoum; Massey, Lee; Tanbakuchi, Anthony; Washburn, Cody; Vigil, Steven

    2015-09-01

    We report on the development of a prototype polarization tag based system for detecting chemical vapors. The system primarily consists of two components, a chemically sensitive tag that experiences a change in its optical polarization properties when exposed to a specific chemical of interest, and an optical imaging polarimeter that is used to measure the polarization properties of the tags. Although the system concept could be extended to other chemicals, for the initial system prototype presented here the tags were developed to be sensitive to hydrogen fluoride (HF) vapors. HF is used in many industrial processes but is highly toxic and thus monitoring for its presence and concentration is often of interest for personnel and environmental safety. The tags are periodic multilayer structures that are produced using standard photolithographic processes. The polarimetric imager has been designed to measure the degree of linear polarization reflected from the tags in the short wave infrared. By monitoring the change in the reflected polarization signature from the tags, the polarimeter can be used to determine if the tag was exposed to HF gas. In this paper, a review of the system development effort and preliminary test results are presented and discussed, as well as our plan for future work.

  6. Acoustic leak detection in piping systems, 4

    International Nuclear Information System (INIS)

    Kitajima, Akira; Naohara, Nobuyuki; Aihara, Akihiko

    1983-01-01

    To monitor a high-pressure piping of nuclear power plants, a possibility of acoustic leak detection method has been experimentally studied in practical field tests and laboratory tests. Characteristics of background noise in field test and the results of experiment are summarized as follows: (1) The level of background noise in primary loop (PWR) was almost constant under actual plant operation. But it is possible that it rises at the condition of the pressure in primary loop. (2) Based on many experience of laboratory tests and practical field tests. The leak monitoring system for practical field was designed and developed. To improve the reliability, a judgment of leak on this system is used three factors of noise level, duration time of phenomena and frequency spectrum of noise signal emitted from the leak point. (author)

  7. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1980-01-01

    This study deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the 13 N content in the containment atmosphere. 13 N is produced from the oxygen of the reactor water via the recoil proton nuclear process Hl+016/yields/ 13 N+ 4 He. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium 13 N concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m/sup -3/ and 7 kBq m/sup -3/ for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge(Li) flow detector assembly operated at elevated pressure. 8 refs

  8. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1980-01-01

    This study deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the N13 content in the containment atmosphere. N13 is produced from the oxygen of the reactor water via the recoil proton nuclear process Hl+016/yields/Nl3+He4. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium N13 concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m/sup -3/ and 7 kBq m/sup -3/ for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge(Li) flow detector assembly operated at elevated pressure. 8 refs

  9. Reactor coolant pressure boundary leakage detection system

    International Nuclear Information System (INIS)

    Dissing, E.; Svansson, L.

    1979-08-01

    The present paper deals with a system for monitoring the leakage of reactor coolant. This system is based primarily on the detection of the N13 content in the containment atmosphere. N13 is produced from the oxygen of the reactor water via the recoil proton nuclear process H1+016 → N13+He4. The generation is therefore independent of fuel element leakage and of the corrosion product content in the water. It is solely related to the neutron flux level in the reactor core. Typical figures for the equilibrium N13 concentration in the containment atmosphere following a 4 kg/minute coolant leakage are 5 kBq m -3 and 7 kBq m -3 for BWR and PWR respectively. These levels are readily measured with a 10 liter Ge (Li) flow detector assembly operated at elevated pressure. (Auth.)

  10. The Environics Mobile CBRN Detection System

    International Nuclear Information System (INIS)

    Jaakkola, T.

    2007-01-01

    Environics Oy has developed a novel monitoring system for detection of Chemical, Biological, Radiological and Nuclear compounds. The system is portable and rapidly installed into a monitoring location. It will allow real time monitoring and alarming of: Chemical Warfare agents (Nerve, Blister, Blood), Toxic industrial chemicals (General toxic-alarm), Biological warfare agents (Bacteria, viruses, toxins), Radiological agents such as alpha and gamma radiation. Monitoring Station makes continuously measurements. Sensor data is processed and stored to local database by the Master Module (MM) that is located within the station. The MM sends the data to the Control Centers by using communication network. The Control Center receives and logs the data and shows it in real time on a map interface. The status of each sensor and detector can be seen in real time. (author)

  11. Simulation Model of Mobile Detection Systems

    International Nuclear Information System (INIS)

    Edmunds, T.; Faissol, D.; Yao, Y.

    2009-01-01

    In this paper, we consider a mobile source that we attempt to detect with man-portable, vehicle-mounted or boat-mounted radiation detectors. The source is assumed to transit an area populated with these mobile detectors, and the objective is to detect the source before it reaches a perimeter. We describe a simulation model developed to estimate the probability that one of the mobile detectors will come in to close proximity of the moving source and detect it. We illustrate with a maritime simulation example. Our simulation takes place in a 10 km by 5 km rectangular bay patrolled by boats equipped with 2-inch x 4-inch x 16-inch NaI detectors. Boats to be inspected enter the bay and randomly proceed to one of seven harbors on the shore. A source-bearing boat enters the mouth of the bay and proceeds to a pier on the opposite side. We wish to determine the probability that the source is detected and its range from target when detected. Patrol boats select the nearest in-bound boat for inspection and initiate an intercept course. Once within an operational range for the detection system, a detection algorithm is started. If the patrol boat confirms the source is not present, it selects the next nearest boat for inspection. Each run of the simulation ends either when a patrol successfully detects a source or when the source reaches its target. Several statistical detection algorithms have been implemented in the simulation model. First, a simple k-sigma algorithm, which alarms with the counts in a time window exceeds the mean background plus k times the standard deviation of background, is available to the user. The time window used is optimized with respect to the signal-to-background ratio for that range and relative speed. Second, a sequential probability ratio test [Wald 1947] is available, and configured in this simulation with a target false positive probability of 0.001 and false negative probability of 0.1. This test is utilized when the mobile detector maintains

  12. Simulation Model of Mobile Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Edmunds, T; Faissol, D; Yao, Y

    2009-01-27

    In this paper, we consider a mobile source that we attempt to detect with man-portable, vehicle-mounted or boat-mounted radiation detectors. The source is assumed to transit an area populated with these mobile detectors, and the objective is to detect the source before it reaches a perimeter. We describe a simulation model developed to estimate the probability that one of the mobile detectors will come in to close proximity of the moving source and detect it. We illustrate with a maritime simulation example. Our simulation takes place in a 10 km by 5 km rectangular bay patrolled by boats equipped with 2-inch x 4-inch x 16-inch NaI detectors. Boats to be inspected enter the bay and randomly proceed to one of seven harbors on the shore. A source-bearing boat enters the mouth of the bay and proceeds to a pier on the opposite side. We wish to determine the probability that the source is detected and its range from target when detected. Patrol boats select the nearest in-bound boat for inspection and initiate an intercept course. Once within an operational range for the detection system, a detection algorithm is started. If the patrol boat confirms the source is not present, it selects the next nearest boat for inspection. Each run of the simulation ends either when a patrol successfully detects a source or when the source reaches its target. Several statistical detection algorithms have been implemented in the simulation model. First, a simple k-sigma algorithm, which alarms with the counts in a time window exceeds the mean background plus k times the standard deviation of background, is available to the user. The time window used is optimized with respect to the signal-to-background ratio for that range and relative speed. Second, a sequential probability ratio test [Wald 1947] is available, and configured in this simulation with a target false positive probability of 0.001 and false negative probability of 0.1. This test is utilized when the mobile detector maintains

  13. 46 CFR 108.404 - Selection of fire detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Selection of fire detection system. 108.404 Section 108... DESIGN AND EQUIPMENT Fire Extinguishing Systems § 108.404 Selection of fire detection system. (a) If a... space. (b) The fire detection system must be designed to minimize false alarms. ...

  14. CRISPR-Cas: From the Bacterial Adaptive Immune System to a Versatile Tool for Genome Engineering.

    Science.gov (United States)

    Kirchner, Marion; Schneider, Sabine

    2015-11-09

    The field of biology has been revolutionized by the recent advancement of an adaptive bacterial immune system as a universal genome engineering tool. Bacteria and archaea use repetitive genomic elements termed clustered regularly interspaced short palindromic repeats (CRISPR) in combination with an RNA-guided nuclease (CRISPR-associated nuclease: Cas) to target and destroy invading DNA. By choosing the appropriate sequence of the guide RNA, this two-component system can be used to efficiently modify, target, and edit genomic loci of interest in plants, insects, fungi, mammalian cells, and whole organisms. This has opened up new frontiers in genome engineering, including the potential to treat or cure human genetic disorders. Now the potential risks as well as the ethical, social, and legal implications of this powerful new technique move into the limelight. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Smart sensor systems for outdoor intrusion detection

    International Nuclear Information System (INIS)

    Lynn, J.K.

    1988-01-01

    A major improvement in outdoor perimeter security system probability of detection (PD) and reduction in false alarm rate (FAR) and nuisance alarm rate (NAR) may be obtained by analyzing the indications immediately preceding an event which might be interpreted as an intrusion. Existing systems go into alarm after crossing a threshold. Very slow changes, which accumulate until the threshold is reached, may be assessed falsely as an intrusion. A hierarchial program has begun at Stellar to develop a modular, expandable Smart Sensor system which may be interfaced to most types of sensor and alarm reporting systems. A major upgrade to the SSI Test Site is in progress so that intrusions may be simulated in a controlled and repeatable manner. A test platform is being constructed which will operate in conduction with a mobile instrumentation center with CCTVB, lighting control, weather and data monitoring and remote control of the test platform and intrusion simulators. Additional testing was contracted with an independent test facility to assess the effects of severe winter weather conditions

  16. Evaluation of a pulsed xenon ultraviolet disinfection system to decrease bacterial contamination in operating rooms.

    Science.gov (United States)

    El Haddad, Lynn; Ghantoji, Shashank S; Stibich, Mark; Fleming, Jason B; Segal, Cindy; Ware, Kathy M; Chemaly, Roy F

    2017-10-10

    Environmental cleanliness is one of the contributing factors for surgical site infections in the operating rooms (ORs). To decrease environmental contamination, pulsed xenon ultraviolet (PX-UV), an easy and safe no-touch disinfection system, is employed in several hospital environments. The positive effect of this technology on environmental decontamination has been observed in patient rooms and ORs during the end-of-day cleaning but so far, no study explored its feasibility between surgical cases in the OR. In this study, 5 high-touch surfaces in 30 ORs were sampled after manual cleaning and after PX-UV intervention mimicking between-case cleaning to avoid the disruption of the ORs' normal flow. The efficacy of a 1-min, 2-min, and 8-min cycle were tested by measuring the surfaces' contaminants by quantitative cultures using Tryptic Soy Agar contact plates. We showed that combining standard between-case manual cleaning of surfaces with a 2-min cycle of disinfection using a portable xenon pulsed ultraviolet light germicidal device eliminated at least 70% more bacterial load after manual cleaning. This study showed the proof of efficacy of a 2-min cycle of PX-UV in ORs in eliminating bacterial contaminants. This method will allow a short time for room turnover and a potential reduction of pathogen transmission to patients and possibly surgical site infections.

  17. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens

    Science.gov (United States)

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M.; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host–pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host–pathogen interactions. PMID:25699030

  18. Bacterial composition in a metropolitan drinking water distribution system utilizing different source waters.

    Science.gov (United States)

    Gomez-Alvarez, Vicente; Humrighouse, Ben W; Revetta, Randy P; Santo Domingo, Jorge W

    2015-03-01

    We investigated the bacterial composition of water samples from two service areas within a drinking water distribution system (DWDS), each associated with a different primary source of water (groundwater, GW; surface water, SW) and different treatment process. Community analysis based on 16S rRNA gene clone libraries indicated that Actinobacteria (Mycobacterium spp.) and α-Proteobacteria represented nearly 43 and 38% of the total sequences, respectively. Sequences closely related to Legionella, Pseudomonas, and Vibrio spp. were also identified. In spite of the high number of sequences (71%) shared in both areas, multivariable analysis revealed significant differences between the GW and SW areas. While the dominant phylotypes where not significantly contributing in the ordination of samples, the populations associated with the core of phylotypes (1-10% in each sample) significantly contributed to the differences between both service areas. Diversity indices indicate that the microbial community inhabiting the SW area is more diverse and contains more distantly related species coexisting with local assemblages as compared with the GW area. The bacterial community structure of SW and GW service areas were dissimilar, suggesting that their respective source water and/or water quality parameters shaped by the treatment processes may contribute to the differences in community structure observed.

  19. LAN attack detection using Discrete Event Systems.

    Science.gov (United States)

    Hubballi, Neminath; Biswas, Santosh; Roopa, S; Ratti, Ritesh; Nandi, Sukumar

    2011-01-01

    Address Resolution Protocol (ARP) is used for determining the link layer or Medium Access Control (MAC) address of a network host, given its Internet Layer (IP) or Network Layer address. ARP is a stateless protocol and any IP-MAC pairing sent by a host is accepted without verification. This weakness in the ARP may be exploited by malicious hosts in a Local Area Network (LAN) by spoofing IP-MAC pairs. Several schemes have been proposed in the literature to circumvent these attacks; however, these techniques either make IP-MAC pairing static, modify the existing ARP, patch operating systems of all the hosts etc. In this paper we propose a Discrete Event System (DES) approach for Intrusion Detection System (IDS) for LAN specific attacks which do not require any extra constraint like static IP-MAC, changing the ARP etc. A DES model is built for the LAN under both a normal and compromised (i.e., spoofed request/response) situation based on the sequences of ARP related packets. Sequences of ARP events in normal and spoofed scenarios are similar thereby rendering the same DES models for both the cases. To create different ARP events under normal and spoofed conditions the proposed technique uses active ARP probing. However, this probing adds extra ARP traffic in the LAN. Following that a DES detector is built to determine from observed ARP related events, whether the LAN is operating under a normal or compromised situation. The scheme also minimizes extra ARP traffic by probing the source IP-MAC pair of only those ARP packets which are yet to be determined as genuine/spoofed by the detector. Also, spoofed IP-MAC pairs determined by the detector are stored in tables to detect other LAN attacks triggered by spoofing namely, man-in-the-middle (MiTM), denial of service etc. The scheme is successfully validated in a test bed. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Microfluidic system for the identification of bacterial pathogens causing urinary tract infections

    Science.gov (United States)

    Becker, Holger; Hlawatsch, Nadine; Haraldsson, Tommy; van der Wijngaart, Wouter; Lind, Anders; Malhotra-Kumar, Surbi; Turlej-Rogacka, Agata; Goossens, Herman

    2015-03-01

    Urinary tract infections (UTIs) are among the most common bacterial infections and pose a significant healthcare burden. The growing trend in antibiotic resistance makes it mandatory to develop diagnostic kits which allow not only the determination of a pathogen but also the antibiotic resistances. We have developed a microfluidic cartridge which takes a direct urine sample, extracts the DNA, performs an amplification using batch-PCR and flows the sample over a microarray which is printed into a microchannel for fluorescence detection. The cartridge is injection-molded out of COP and contains a set of two-component injection-molded rotary valves to switch between input and to isolate the PCR chamber during thermocycling. The hybridization probes were spotted directly onto a functionalized section of the outlet microchannel. We have been able to successfully perform PCR of E.coli in urine in this chip and perform a fluorescence detection of PCR products. An upgraded design of the cartridge contains the buffers and reagents in blisters stored on the chip.

  1. The Accuracy of the Sysmex UF-1000i in Urine Bacterial Detection Compared With the Standard Urine Analysis and Culture.

    Science.gov (United States)

    Erdman, Patrick; Anderson, Brian; Zacko, J Christopher; Taylor, Kirk; Donaldson, Keri

    2017-11-01

    - Urinary tract infections are characterized by the presence of microbial pathogens within the urinary tract. They represent one of the most common infections in hospitalized and clinic patients. - To model the parameters of the Sysmex UF-1000i to the gold standard, urine culture, and to compare the detection of dipstick leukocyte esterase and nitrates to urine cultures and UF-1000i results. - Data were compared from urine samples collected in sterile containers for bacterial culture and microscopic analysis. One sample was used to inoculate a 5% sheep blood agar and MacConkey agar plate using a 0.001-mL calibrated loop. The second sample was analyzed by urinalysis-associated microscopy. The media plates were investigated for growth after 18 to 24 hours of aerobic incubation at 37°C. The second sample was analyzed for bacteria and leukocytes with the Sysmex UF-1000i according to the manufacturer's guidelines. Three definitions for culture results, sensitivity, and specificity at different cutoff values were calculated for the UF-1000i. - The negative predictive value for any positive culture in the adult population included in the study was 95.5%, and the negative predictive value for positive cultures containing growth of 100 000 or more colony-forming units was 99.3% using the Sysmex UF-1000i. - Sysmex UF-1000i showed 98% sensitivity and 93.7% specificity with a 95.5% negative predictive value. Thus, a negative screen with the UF-1000i using defined thresholds for white blood cell counts and bacteria was likely to be a true negative, decreasing the need for presumptive antibiotics.

  2. Molecular detection of Candidatus Scalindua pacifica and environmental responses of sediment anammox bacterial community in the Bohai Sea, China.

    Directory of Open Access Journals (Sweden)

    Hongyue Dang

    Full Text Available The Bohai Sea is a large semi-enclosed shallow water basin, which receives extensive river discharges of various terrestrial and anthropogenic materials such as sediments, nutrients and contaminants. How these terrigenous inputs may influence the diversity, community structure, biogeographical distribution, abundance and ecophysiology of the sediment anaerobic ammonium oxidation (anammox bacteria was unknown. To answer this question, an investigation employing both 16S rRNA and hzo gene biomarkers was carried out. Ca. Scalindua bacteria were predominant in the surface sediments of the Bohai Sea, while non-Scalindua anammox bacteria were also detected in the Yellow River estuary and inner part of Liaodong Bay that received strong riverine and anthropogenic impacts. A novel 16S rRNA gene sequence clade was identified, putatively representing an anammox bacterial new candidate species tentatively named "Ca. Scalindua pacifica". Several groups of environmental factors, usually with distinct physicochemical or biogeochemical natures, including general marine and estuarine physicochemical properties, availability of anammox substrates (inorganic N compounds, alternative reductants and oxidants, environmental variations caused by river discharges and associated contaminants such as heavy metals, were identified to likely play important roles in influencing the ecology and biogeochemical functioning of the sediment anammox bacteria. In addition to inorganic N compounds that might play a key role in shaping the anammox microbiota, organic carbon, organic nitrogen, sulfate, sulfide and metals all showed the potentials to participate in the anammox process, releasing the strict dependence of the anammox bacteria upon the direct availability of inorganic N nutrients that might be limiting in certain areas of the Bohai Sea. The importance of inorganic N nutrients and certain other environmental factors to the sediment anammox microbiota suggests that these

  3. The design method and research status of vehicle detection system based on geomagnetic detection principle

    Science.gov (United States)

    Lin, Y. H.; Bai, R.; Qian, Z. H.

    2018-03-01

    Vehicle detection systems are applied to obtain real-time information of vehicles, realize traffic control and reduce traffic pressure. This paper reviews geomagnetic sensors as well as the research status of the vehicle detection system. Presented in the paper are also our work on the vehicle detection system, including detection algorithms and experimental results. It is found that the GMR based vehicle detection system has a detection accuracy up to 98% with a high potential for application in the road traffic control area.

  4. Model-based fault detection algorithm for photovoltaic system monitoring

    KAUST Repository

    Harrou, Fouzi; Sun, Ying; Saidi, Ahmed

    2018-01-01

    Reliable detection of faults in PV systems plays an important role in improving their reliability, productivity, and safety. This paper addresses the detection of faults in the direct current (DC) side of photovoltaic (PV) systems using a

  5. Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure.

    Science.gov (United States)

    Ishaq, Suzanne L; Johnson, Stephen P; Miller, Zach J; Lehnhoff, Erik A; Olivo, Sarah; Yeoman, Carl J; Menalled, Fabian D

    2017-02-01

    Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P soil contained more Chloroflexi and Acidobacteria, while the sterile inoculum soil had more Bacteroidetes, Firmicutes, Gemmatimonadetes, and Verrucomicrobia. Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.

  6. Novel Approaches to Manipulating Bacterial Pathogen Biofilms: Whole-Systems Design Philosophy and Steering Microbial Evolution.

    Science.gov (United States)

    Penn, Alexandra S

    2016-01-01

    Understanding and manipulating bacterial biofilms is crucial in medicine, ecology and agriculture and has potential applications in bioproduction, bioremediation and bioenergy. Biofilms often resist standard therapies and the need to develop new means of intervention provides an opportunity to fundamentally rethink our strategies. Conventional approaches to working with biological systems are, for the most part, "brute force", attempting to effect control in an input and effort intensive manner and are often insufficient when dealing with the inherent non-linearity and complexity of living systems. Biological systems, by their very nature, are dynamic, adaptive and resilient and require management tools that interact with dynamic processes rather than inert artefacts. I present an overview of a novel engineering philosophy which aims to exploit rather than fight those properties, and hence provide a more efficient and robust alternative. Based on a combination of evolutionary theory and whole-systems design, its essence is what I will call systems aikido; the basic principle of aikido being to interact with the momentum of an attacker and redirect it with minimal energy expenditure, using the opponent's energy rather than one's own. In more conventional terms, this translates to a philosophy of equilibrium engineering, manipulating systems' own self-organisation and evolution so that the evolutionarily or dynamically stable state corresponds to a function which we require. I illustrate these ideas with a description of a proposed manipulation of environmental conditions to alter the stability of co-operation in the context of Pseudomonas aeruginosa biofilm infection of the cystic fibrosis lung.

  7. Wireless Falling Detection System Based on Community.

    Science.gov (United States)

    Xia, Yun; Wu, Yanqi; Zhang, Bobo; Li, Zhiyang; He, Nongyue; Li, Song

    2015-06-01

    The elderly are more likely to suffer the aches or pains from the accidental falls, and both the physiology and psychology of patients would subject to a long-term disturbance, especially when the emergency treatment was not given timely and properly. Although many methods and devices have been developed creatively and shown their efficiency in experiments, few of them are suitable for commercial applications routinely. Here, we design a wearable falling detector as a mobile terminal, and utilize the wireless technology to transfer and monitor the activity data of the host in a relatively small community. With the help of the accelerometer sensor and the Google Mapping service, information of the location and the activity data will be send to the remote server for the downstream processing. The experimental result has shown that SA (Sum-vector of all axes) value of 2.5 g is the threshold value to distinguish the falling from other activities. A three-stage detection algorithm was adopted to increase the accuracy of the real alarm, and the accuracy rate of our system was more than 95%. With the further improvement, the falling detecting device which is low-cost, accurate and user-friendly would become more and more common in everyday life.

  8. Optical fiber-applied radiation detection system

    International Nuclear Information System (INIS)

    Nishiura, Ryuichi; Uranaka, Yasuo; Izumi, Nobuyuki

    2001-01-01

    A technique to measure radiation by using plastic scintillation fibers doped radiation fluorescent (scintillator) to plastic optical fiber for a radiation sensor, was developed. The technique contains some superiority such as high flexibility due to using fibers, relatively easy large area due to detecting portion of whole of fibers, and no electromagnetic noise effect due to optical radiation detection and signal transmission. Measurable to wide range of and continuous radiation distribution along optical fiber cable at a testing portion using scintillation fiber and flight time method, the optical fiber-applied radiation sensing system can effectively monitor space radiation dose or apparatus operation condition monitoring. And, a portable type scintillation optical fiber body surface pollution monitor can measure pollution concentration of radioactive materials attached onto body surface by arranging scintillation fiber processed to a plate with small size and flexibility around a man to be tested. Here were described on outline and fundamental properties of various application products using these plastic scintillation fiber. (G.K.)

  9. Stable Carbon Isotope Fractionation during Bacterial Acetylene Fermentation: Potential for Life Detection in Hydrocarbon-Rich Volatiles of Icy Planet(oid)s.

    Science.gov (United States)

    Miller, Laurence G; Baesman, Shaun M; Oremland, Ronald S

    2015-11-01

    We report the first study of stable carbon isotope fractionation during microbial fermentation of acetylene (C2H2) in sediments, sediment enrichments, and bacterial cultures. Kinetic isotope effects (KIEs) averaged 3.7 ± 0.5‰ for slurries prepared with sediment collected at an intertidal mudflat in San Francisco Bay and 2.7 ± 0.2‰ for a pure culture of Pelobacter sp. isolated from these sediments. A similar KIE of 1.8 ± 0.7‰ was obtained for methanogenic enrichments derived from sediment collected at freshwater Searsville Lake, California. However, C2H2 uptake by a highly enriched mixed culture (strain SV7) obtained from Searsville Lake sediments resulted in a larger KIE of 9.0 ± 0.7‰. These are modest KIEs when compared with fractionation observed during oxidation of C1 compounds such as methane and methyl halides but are comparable to results obtained with other C2 compounds. These observations may be useful in distinguishing biologically active processes operating at distant locales in the Solar System where C2H2 is present. These locales include the surface of Saturn's largest moon Titan and the vaporous water- and hydrocarbon-rich jets emanating from Enceladus. Acetylene-Fermentation-Isotope fractionation-Enceladus-Life detection.

  10. Automatic system for detecting pornographic images

    Science.gov (United States)

    Ho, Kevin I. C.; Chen, Tung-Shou; Ho, Jun-Der

    2002-09-01

    Due to the dramatic growth of network and multimedia technology, people can more easily get variant information by using Internet. Unfortunately, it also makes the diffusion of illegal and harmful content much easier. So, it becomes an important topic for the Internet society to protect and safeguard Internet users from these content that may be encountered while surfing on the Net, especially children. Among these content, porno graphs cause more serious harm. Therefore, in this study, we propose an automatic system to detect still colour porno graphs. Starting from this result, we plan to develop an automatic system to search porno graphs or to filter porno graphs. Almost all the porno graphs possess one common characteristic that is the ratio of the size of skin region and non-skin region is high. Based on this characteristic, our system first converts the colour space from RGB colour space to HSV colour space so as to segment all the possible skin-colour regions from scene background. We also apply the texture analysis on the selected skin-colour regions to separate the skin regions from non-skin regions. Then, we try to group the adjacent pixels located in skin regions. If the ratio is over a given threshold, we can tell if the given image is a possible porno graph. Based on our experiment, less than 10% of non-porno graphs are classified as pornography, and over 80% of the most harmful porno graphs are classified correctly.

  11. Decision algorithms in fire detection systems

    Directory of Open Access Journals (Sweden)

    Ristić Jovan D.

    2011-01-01

    Full Text Available Analogue (and addressable fire detection systems enables a new quality in improving sensitivity to real fires and reducing susceptibility to nuisance alarm sources. Different decision algorithms types were developed with intention to improve sensitivity and reduce false alarm occurrence. At the beginning, it was free alarm level adjustment based on preset level. Majority of multi-criteria decision work was based on multi-sensor (multi-signature decision algorithms - using different type of sensors on the same location or, rather, using different aspects (level and rise of one sensor measured value. Our idea is to improve sensitivity and reduce false alarm occurrence by forming groups of sensors that work in similar conditions (same world side in the building, same or similar technology or working time. Original multi-criteria decision algorithms based on level, rise and difference of level and rise from group average are discussed in this paper.

  12. Distributed gas detection system and method

    Science.gov (United States)

    Challener, William Albert; Palit, Sabarni; Karp, Jason Harris; Kasten, Ansas Matthias; Choudhury, Niloy

    2017-11-21

    A distributed gas detection system includes one or more hollow core fibers disposed in different locations, one or more solid core fibers optically coupled with the one or more hollow core fibers and configured to receive light of one or more wavelengths from a light source, and an interrogator device configured to receive at least some of the light propagating through the one or more solid core fibers and the one or more hollow core fibers. The interrogator device is configured to identify a location of a presence of a gas-of-interest by examining absorption of at least one of the wavelengths of the light at least one of the hollow core fibers.

  13. Detection system of sodium oxide vapors

    International Nuclear Information System (INIS)

    Hundal, Rolv.

    1976-01-01

    The description is given of a sodium oxide vapor detection system which comprises a containment, a light source located to send a light beam into and through this containment and a photodetector located to intercept the light from the source after it has covered a given path through the containment. In response to the intensity of the incident light, the photodetector produces an output signal representative of it. The feature of this device is a first polarizer located near the light source, along the path of the light coming from it and designed to polarize the light projected through the containment in a given plane, and a second polarizer located near the photodetector, along the path of the polarized light and designed virtually to prevent all the light rays whose orientation differs from the given polarization plane from reaching the photodetector [fr

  14. Liquid chromatography detection unit, system, and method

    Science.gov (United States)

    Derenzo, Stephen E.; Moses, William W.

    2015-10-27

    An embodiment of a liquid chromatography detection unit includes a fluid channel and a radiation detector. The radiation detector is operable to image a distribution of a radiolabeled compound as the distribution travels along the fluid channel. An embodiment of a liquid chromatography system includes an injector, a separation column, and a radiation detector. The injector is operable to inject a sample that includes a radiolabeled compound into a solvent stream. The position sensitive radiation detector is operable to image a distribution of the radiolabeled compound as the distribution travels along a fluid channel. An embodiment of a method of liquid chromatography includes injecting a sample that comprises radiolabeled compounds into a solvent. The radiolabeled compounds are then separated. A position sensitive radiation detector is employed to image distributions of the radiolabeled compounds as the radiolabeled compounds travel along a fluid channel.

  15. Development of Real-Time PCR Methods for the Detection of Bacterial Meningitis Pathogens without DNA Extraction.

    Directory of Open Access Journals (Sweden)

    Jeni Vuong

    Full Text Available Neisseria meningitidis (Nm, Haemophilus influenzae (Hi, and Streptococcus pneumoniae (Sp are the lead causes of bacterial meningitis. Detection of these pathogens from clinical specimens using traditional real-time PCR (rt-PCR requires DNA extraction to remove the PCR inhibitors prior to testing, which is time consuming and labor intensive. In this study, five species-specific (Nm-sodC and -ctrA, Hi-hpd#1 and -hpd#3 and Sp-lytA and six serogroup-specific rt-PCR tests (A, B, C, W, X, Y targeting Nm capsular genes were evaluated in the two direct rt-PCR methods using PerfeCTa and 5x Omni that do not require DNA extraction. The sensitivity and specify of the two direct rt-PCR methods were compared to TaqMan traditional rt-PCR, the current standard rt-PCR method for the detection of meningitis pathogens. The LLD for all 11 rt-PCR tests ranged from 6,227 to 272,229 CFU/ml for TaqMan, 1,824-135,982 for 5x Omni, and 168-6,836 CFU/ml for PerfeCTa. The diagnostic sensitivity using TaqMan ranged from 89.2%-99.6%, except for NmB-csb, which was 69.7%. For 5x Omni, the sensitivity varied from 67.1% to 99.8%, with three tests below 90%. The sensitivity of these tests using PerfeCTa varied from 89.4% to 99.8%. The specificity ranges of the 11 tests were 98.0-99.9%, 97.5-99.9%, and 92.9-99.9% for TaqMan, 5x Omni, and PerfeCTa, respectively. PerfeCTa direct rt-PCR demonstrated similar or better sensitivity compared to 5x Omni direct rt-PCR or TaqMan traditional rt-PCR. Since the direct rt-PCR method does not require DNA extraction, it reduces the time and cost for processing CSF specimens, increases testing throughput, decreases the risk of cross-contamination, and conserves precious CSF. The direct rt-PCR method will be beneficial to laboratories with high testing volume.

  16. Detection of a Mixed Infection in a Culture-Negative Brain Abscess by Broad-Spectrum Bacterial 16S rRNA Gene PCR ▿ †

    Science.gov (United States)

    Keller, Peter M.; Rampini, Silvana K.; Bloemberg, Guido V.

    2010-01-01

    We describe the identification of two bacterial pathogens from a culture-negative brain abscess by the use of broad-spectrum 16S rRNA gene PCR. Simultaneous detection of Fusobacterium nucleatum and Porphyromonas endodontalis was possible due to a 24-bp length difference of their partially amplified 16S rRNA genes, which allowed separation by high-resolution polyacrylamide gel electrophoresis. PMID:20392909

  17. 49 CFR 1544.213 - Use of explosives detection systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Use of explosives detection systems. 1544.213...: AIR CARRIERS AND COMMERCIAL OPERATORS Operations § 1544.213 Use of explosives detection systems. (a... explosives detection system approved by TSA to screen checked baggage on international flights. (b) Signs and...

  18. 46 CFR 154.1350 - Flammable gas detection system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Flammable gas detection system. 154.1350 Section 154... Equipment Instrumentation § 154.1350 Flammable gas detection system. (a) The vessel must have a fixed flammable gas detection system that has sampling points in: (1) Each cargo pump room; (2) Each cargo...

  19. 75 FR 5009 - Proximity Detection Systems for Underground Mines

    Science.gov (United States)

    2010-02-01

    ... Proximity Detection Systems for Underground Mines AGENCY: Mine Safety and Health Administration, Labor... information regarding whether the use of proximity detection systems would reduce the risk of accidents where... . Information on MSHA-approved proximity detection systems is available on the Internet at http://www.msha.gov...

  20. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus), from India and its possible role in indoxacarb degradation.

    Science.gov (United States)

    Ramya, Shanivarsanthe Leelesh; Venkatesan, Thiruvengadam; Srinivasa Murthy, Kottilingam; Jalali, Sushil Kumar; Verghese, Abraham

    2016-01-01

    Diamondback moth (DBM), Plutella xylostella (Linnaeus), is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n=13) and adults (n=12) of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%), followed by bacilli (15.4%). Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%), bacilli (16.7%) and flavobacteria (16.7%). Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32μmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus - KC985225 and Pantoea agglomerans - KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26μmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  1. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus, from India and its possible role in indoxacarb degradation

    Directory of Open Access Journals (Sweden)

    Shanivarsanthe Leelesh Ramya

    2016-06-01

    Full Text Available Abstract Diamondback moth (DBM, Plutella xylostella (Linnaeus, is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n = 13 and adults (n = 12 of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%, followed by bacilli (15.4%. Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%, bacilli (16.7% and flavobacteria (16.7%. Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32 µmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus – KC985225 and Pantoea agglomerans – KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26 µmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM.

  2. Evidence for alternative quaternary structure in a bacterial Type III secretion system chaperone

    Energy Technology Data Exchange (ETDEWEB)

    Barta, Michael L.; Zhang, Lingling; Picking, Wendy L.; Geisbrecht, Brian V. (UMKC); (OKLU)

    2010-10-05

    Type III secretion systems are a common virulence mechanism in many Gram-negative bacterial pathogens. These systems use a nanomachine resembling a molecular needle and syringe to provide an energized conduit for the translocation of effector proteins from the bacterial cytoplasm to the host cell cytoplasm for the benefit of the pathogen. Prior to translocation specialized chaperones maintain proper effector protein conformation. The class II chaperone, Invasion plasmid gene (Ipg) C, stabilizes two pore forming translocator proteins. IpgC exists as a functional dimer to facilitate the mutually exclusive binding of both translocators. In this study, we present the 3.3 {angstrom} crystal structure of an amino-terminally truncated form (residues 10-155, denoted IpgC10-155) of the class II chaperone IpgC from Shigella flexneri. Our structure demonstrates an alternative quaternary arrangement to that previously described for a carboxy-terminally truncated variant of IpgC (IpgC{sup 1-151}). Specifically, we observe a rotationally-symmetric 'head-to-head' dimerization interface that is far more similar to that previously described for SycD from Yersinia enterocolitica than to IpgC1-151. The IpgC structure presented here displays major differences in the amino terminal region, where extended coil-like structures are seen, as opposed to the short, ordered alpha helices and asymmetric dimerization interface seen within IpgC{sup 1-151}. Despite these differences, however, both modes of dimerization support chaperone activity, as judged by a copurification assay with a recombinant form of the translocator protein, IpaB. Conclusions: From primary to quaternary structure, these results presented here suggest that a symmetric dimerization interface is conserved across bacterial class II chaperones. In light of previous data which have described the structure and function of asymmetric dimerization, our results raise the possibility that class II chaperones may

  3. Changes in symbiotic and associative interrelations in a higher plant-bacterial system during space flight

    Science.gov (United States)

    Kordyum, V. A.; Man'ko, V. G.; Popova, A. F.; Shcherbak, O. H.; Mashinsky, A. L.; Nguen-Hgue-Thyok

    The miniature cenosis consisting of the water fern Azolla with its associated symbiotic nitrogen-fixing cyanobacterium Anabaena and the concomitant bacteria was investigated. Ecological closure was shown to produce sharp quantitative and qualitative changes in the number and type of concomitant bacteria. Changes in the distribution of bacterial types grown on beef-extract broth after space flight were recorded. Anabaena azollae underwent the most significant changes under spaceflight conditions. Its cell number per Azolla biomass unit increased substantially. Thus closure of cenosis resulted in a weakening of control over microbial development by Azolla. This tendency was augmented by spaceflight factors. Reduction in control exerted by macro-organisms over development of associated micro-organisms must be taken into account in constructing closed ecological systems in the state of weightlessness.

  4. Changes in diversity, abundance, and structure of soil bacterial communities in Brazilian Savanna under different land use systems.

    Science.gov (United States)

    Rampelotto, Pabulo Henrique; de Siqueira Ferreira, Adão; Barboza, Anthony Diego Muller; Roesch, Luiz Fernando Wurdig

    2013-10-01

    The Brazilian Savanna, also known as "Cerrado", is the richest and most diverse savanna in the world and has been ranked as one of the main hotspots of biodiversity. The Cerrado is a representative biome in Central Brazil and the second largest biome in species diversity of South America. Nevertheless, large areas of native vegetation have been converted to agricultural land including grain production, livestock, and forestry. In this view, understanding how land use affects microbial communities is fundamental for the sustainable management of agricultural ecosystems. The aim of this work was to analyze and compare the soil bacterial communities from the Brazilian Cerrado associated with different land use systems using high throughput pyrosequencing of 16S rRNA genes. Relevant differences were observed in the abundance and structure of bacterial communities in soils under different land use systems. On the other hand, the diversity of bacterial communities was not relevantly changed among the sites studied. Land use systems had also an important impact on specific bacterial groups in soil, which might change the soil function and the ecological processes. Acidobacteria, Proteobacteria, and Actinobacteria were the most abundant groups in the Brazilian Cerrado. These findings suggest that more important than analyzing the general diversity is to analyze the composition of the communities. Since soil type was the same among the sites, we might assume that land use was the main factor defining the abundance and structure of bacterial communities.

  5. Design of detection module for smart ligthting system

    OpenAIRE

    Matveev, I. G.; Goponenko, A. S.

    2015-01-01

    The paper considers a smart lighting system based on Beaglebone microcomputer. The analysis of existing motion and presence sensors was carried out and then used as a basis for design of a detection system. The detection system and the corresponding connection solution for a smart lighting system were developed. Using the designed smart lighting system, experimental studies were carried out.

  6. Distributed Impact Detection System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Automated impact detection and characterization on manned spacecraft has been an elusive goal due to the transitory nature of the detectable high-frequency signals....

  7. Reliability of leak detection systems in LWRs

    International Nuclear Information System (INIS)

    Kupperman, D.S.

    1986-10-01

    In this paper, NRC guidelines for leak detection will be reviewed, current practices described, potential safety-related problems discussed, and potential improvements in leak detection technology (with emphasis on acoustic methods) evaluated

  8. Hybrid Intrusion Detection System for DDoS Attacks

    Directory of Open Access Journals (Sweden)

    Özge Cepheli

    2016-01-01

    Full Text Available Distributed denial-of-service (DDoS attacks are one of the major threats and possibly the hardest security problem for today’s Internet. In this paper we propose a hybrid detection system, referred to as hybrid intrusion detection system (H-IDS, for detection of DDoS attacks. Our proposed detection system makes use of both anomaly-based and signature-based detection methods separately but in an integrated fashion and combines the outcomes of both detectors to enhance the overall detection accuracy. We apply two distinct datasets to our proposed system in order to test the detection performance of H-IDS and conclude that the proposed hybrid system gives better results than the systems based on nonhybrid detection.

  9. Frequency of dental caries in active and inactive systemic lupus erythematous patients: salivary and bacterial factors.

    Science.gov (United States)

    Loyola Rodriguez, J P; Galvan Torres, L J; Martinez Martinez, R E; Abud Mendoza, C; Medina Solis, C E; Ramos Coronel, S; Garcia Cortes, J O; Domínguez Pérez, R A

    2016-10-01

    The objective of this study was to determine dental caries frequency and to analyze salivary and bacterial factors associated with active and inactive systemic lupus erythematous (SLE) patients. Also, a proposal to identify dental caries by a surface, teeth, and the patient was developed. A cross-sectional, blinded study that included 60 SLE patients divided into two groups of 30 subjects each, according to the Activity Index for Diagnosis of Systemic Lupus Erythematous (SLEDAI). The decayed, missing, and filled teeth (DMFT) index and Integrative Dental Caries Index (IDCI) were used for analyzing dental caries. The saliva variables recorded were: flow, pH, and buffer capacity. The DNA copies of Streptococcus mutans and Streptococcus sobrinus were estimated by real-time PCR. The caries frequency was 85% for SLE subjects (73.3% for inactive systemic lupus erythematous (ISLE) and 100% for active systemic lupus erythematous (ASLE)); DMFT for the SLE group was 12.6 ± 5.7 and the IDCI was (9.8 ± 5.9). The ASLE group showed a salivary flow of 0.65 compared with 0.97 ml/1 min from the ISLE group; all variables mentioned above showed a statistical difference (p dental caries in epidemiological studies. © The Author(s) 2016.

  10. Multilevel Regulation of Bacterial Gene Expression with the Combined STAR and Antisense RNA System.

    Science.gov (United States)

    Lee, Young Je; Kim, Soo-Jung; Moon, Tae Seok

    2018-03-16

    Synthetic small RNA regulators have emerged as a versatile tool to predictably control bacterial gene expression. Owing to their simple design principles, small size, and highly orthogonal behavior, these engineered genetic parts have been incorporated into genetic circuits. However, efforts to achieve more sophisticated cellular functions using RNA regulators have been hindered by our limited ability to integrate different RNA regulators into complex circuits. Here, we present a combined RNA regulatory system in Escherichia coli that uses small transcription activating RNA (STAR) and antisense RNA (asRNA) to activate or deactivate target gene expression in a programmable manner. Specifically, we demonstrated that the activated target output by the STAR system can be deactivated by expressing two different types of asRNAs: one binds to and sequesters the STAR regulator, affecting the transcription process, while the other binds to the target mRNA, affecting the translation process. We improved deactivation efficiencies (up to 96%) by optimizing each type of asRNA and then integrating the two optimized asRNAs into a single circuit. Furthermore, we demonstrated that the combined STAR and asRNA system can control gene expression in a reversible way and can regulate expression of a gene in the genome. Lastly, we constructed and simultaneously tested two A AND NOT B logic gates in the same cell to show sophisticated multigene regulation by the combined system. Our approach establishes a methodology for integrating multiple RNA regulators to rationally control multiple genes.

  11. Airway fungal colonization compromises the immune system allowing bacterial pneumonia to prevail.

    Science.gov (United States)

    Roux, Damien; Gaudry, Stéphane; Khoy-Ear, Linda; Aloulou, Meryem; Phillips-Houlbracq, Mathilde; Bex, Julie; Skurnik, David; Denamur, Erick; Monteiro, Renato C; Dreyfuss, Didier; Ricard, Jean-Damien

    2013-09-01

    To study the correlation between fungal colonization and bacterial pneumonia and to test the effect of antifungal treatments on the development of bacterial pneumonia in colonized rats. Experimental animal investigation. University research laboratory. Pathogen-free male Wistar rats weighing 250-275 g. Rats were colonized by intratracheal instillation of Candida albicans. Fungal clearance from the lungs and immune response were measured. Both colonized and noncolonized animals were secondarily instilled with different bacterial species (Pseudomonas aeruginosa, Escherichia coli, or Staphylococcus aureus). Bacterial phagocytosis by alveolar macrophages was evaluated in the presence of interferon-gamma, the main cytokine produced during fungal colonization. The effect of antifungal treatments on fungal colonization and its immune response were assessed. The prevalence of P. aeruginosa pneumonia was compared in antifungal treated and control colonized rats. C. albicans was slowly cleared and induced a Th1-Th17 immune response with very high interferon-gamma concentrations. Airway fungal colonization favored the development of bacterial pneumonia. Interferon-gamma was able to inhibit the phagocytosis of unopsonized bacteria by alveolar macrophages. Antifungal treatment decreased airway fungal colonization, lung interferon-gamma levels and, consequently, the prevalence of subsequent bacterial pneumonia. C. albicans airway colonization elicited a Th1-Th17 immune response that favored the development of bacterial pneumonia via the inhibition of bacterial phagocytosis by alveolar macrophages. Antifungal treatment decreased the risk of bacterial pneumonia in colonized rats.

  12. Planet Detectability in the Alpha Centauri System

    Science.gov (United States)

    Zhao, Lily; Fischer, Debra A.; Brewer, John; Giguere, Matt; Rojas-Ayala, Bárbara

    2018-01-01

    We use more than a decade of radial-velocity measurements for α {Cen} A, B, and Proxima Centauri from the High Accuracy Radial Velocity Planet Searcher, CTIO High Resolution Spectrograph, and the Ultraviolet and Visual Echelle Spectrograph to identify the M\\sin i and orbital periods of planets that could have been detected if they existed. At each point in a mass–period grid, we sample a simulated, Keplerian signal with the precision and cadence of existing data and assess the probability that the signal could have been produced by noise alone. Existing data places detection thresholds in the classically defined habitable zones at about M\\sin i of 53 {M}\\oplus for α {Cen} A, 8.4 {M}\\oplus for α {Cen} B, and 0.47 {M}\\oplus for Proxima Centauri. Additionally, we examine the impact of systematic errors, or “red noise” in the data. A comparison of white- and red-noise simulations highlights quasi-periodic variability in the radial velocities that may be caused by systematic errors, photospheric velocity signals, or planetary signals. For example, the red-noise simulations show a peak above white-noise simulations at the period of Proxima Centauri b. We also carry out a spectroscopic analysis of the chemical composition of the α {Centauri} stars. The stars have super-solar metallicity with ratios of C/O and Mg/Si that are similar to the Sun, suggesting that any small planets in the α {Cen} system may be compositionally similar to our terrestrial planets. Although the small projected separation of α {Cen} A and B currently hampers extreme-precision radial-velocity measurements, the angular separation is now increasing. By 2019, α {Cen} A and B will be ideal targets for renewed Doppler planet surveys.

  13. Safe Detection System for Hydrogen Leaks

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, Robert A. [Intelligent Optical Systems, Inc., Torrance, CA (United States); Beshay, Manal [Intelligent Optical Systems, Inc., Torrance, CA (United States)

    2012-02-29

    Hydrogen is an "environmentally friendly" fuel for future transportation and other applications, since it produces only pure ("distilled") water when it is consumed. Thus, hydrogen-powered vehicles are beginning to proliferate, with the total number of such vehicles expected to rise to nearly 100,000 within the next few years. However, hydrogen is also an odorless, colorless, highly flammable gas. Because of this, there is an important need for hydrogen safety monitors that can warn of hazardous conditions in vehicles, storage facilities, and hydrogen production plants. To address this need, IOS has developed a unique intrinsically safe optical hydrogen sensing technology, and has embodied it in detector systems specifically developed for safety applications. The challenge of using light to detect a colorless substance was met by creating chemically-sensitized optical materials whose color changes in the presence of hydrogen. This reversible reaction provides a sensitive, reliable, way of detecting hydrogen and measuring its concentration using light from low-cost LEDs. Hydrogen sensors based on this material were developed in three completely different optical formats: point sensors ("optrodes"), integrated optic sensors ("optical chips"), and optical fibers ("distributed sensors") whose entire length responds to hydrogen. After comparing performance, cost, time-to-market, and relative market need for these sensor types, the project focused on designing a compact optrode-based single-point hydrogen safety monitor. The project ended with the fabrication of fifteen prototype units, and the selection of two specific markets: fuel cell enclosure monitoring, and refueling/storage safety. Final testing and development of control software for these markets await future support.

  14. Detection of contamination of municipal water distribution systems

    Science.gov (United States)

    Cooper, John F [Oakland, CA

    2012-01-17

    A system for the detection of contaminates of a fluid in a conduit. The conduit is part of a fluid distribution system. A chemical or biological sensor array is connected to the conduit. The sensor array produces an acoustic signal burst in the fluid upon detection of contaminates in the fluid. A supervisory control system connected to the fluid and operatively connected to the fluid distribution system signals the fluid distribution system upon detection of contaminates in the fluid.

  15. Research on IPv6 intrusion detection system Snort-based

    Science.gov (United States)

    Shen, Zihao; Wang, Hui

    2010-07-01

    This paper introduces the common intrusion detection technologies, discusses the work flow of Snort intrusion detection system, and analyzes IPv6 data packet encapsulation and protocol decoding technology. We propose the expanding Snort architecture to support IPv6 intrusion detection in accordance with CIDF standard combined with protocol analysis technology and pattern matching technology, and present its composition. The research indicates that the expanding Snort system can effectively detect various intrusion attacks; it is high in detection efficiency and detection accuracy and reduces false alarm and omission report, which effectively solves the problem of IPv6 intrusion detection.

  16. Homologs of the Acinetobacter baumannii AceI transporter represent a new family of bacterial multidrug efflux systems.

    Science.gov (United States)

    Hassan, Karl A; Liu, Qi; Henderson, Peter J F; Paulsen, Ian T

    2015-02-10

    Multidrug efflux systems are a major cause of resistance to antimicrobials in bacteria, including those pathogenic to humans, animals, and plants. These proteins are ubiquitous in these pathogens, and five families of bacterial multidrug efflux systems have been identified to date. By using transcriptomic and biochemical analyses, we recently identified the novel AceI (Acinetobacter chlorhexidine efflux) protein from Acinetobacter baumannii that conferred resistance to the biocide chlorhexidine, via an active efflux mechanism. Proteins homologous to AceI are encoded in the genomes of many other bacterial species and are particularly prominent within proteobacterial lineages. In this study, we expressed 23 homologs of AceI and examined their resistance and/or transport profiles. MIC analyses demonstrated that, like AceI, many of the homologs conferred resistance to chlorhexidine. Many of the AceI homologs conferred resistance to additional biocides, including benzalkonium, dequalinium, proflavine, and acriflavine. We conducted fluorimetric transport assays using the AceI homolog from Vibrio parahaemolyticus and confirmed that resistance to both proflavine and acriflavine was mediated by an active efflux mechanism. These results show that this group of AceI homologs represent a new family of bacterial multidrug efflux pumps, which we have designated the proteobacterial antimicrobial compound efflux (PACE) family of transport proteins. Bacterial multidrug efflux pumps are an important class of resistance determinants that can be found in every bacterial genome sequenced to date. These transport proteins have important protective functions for the bacterial cell but are a significant problem in the clinical setting, since a single efflux system can mediate resistance to many structurally and mechanistically diverse antibiotics and biocides. In this study, we demonstrate that proteins related to the Acinetobacter baumannii AceI transporter are a new class of multidrug

  17. Long-term impact of systemic bacterial infection on the cerebral vasculature and microglia

    Directory of Open Access Journals (Sweden)

    Püntener Ursula

    2012-06-01

    Full Text Available Abstract Background Systemic infection leads to generation of inflammatory mediators that result in metabolic and behavioural changes. Repeated or chronic systemic inflammation leads to a state of innate immune tolerance: a protective mechanism against overactivity of the immune system. In this study, we investigated the immune adaptation of microglia and brain vascular endothelial cells in response to systemic inflammation or bacterial infection. Methods Mice were given repeated doses of lipopolysaccharide (LPS or a single injection of live Salmonella typhimurium. Inflammatory cytokines were measured in serum, spleen and brain, and microglial phenotype studied by immunohistochemistry. To assess priming of the innate immune response in the brain, mice were infected with Salmonella typhimurium and subsequently challenged with a focal unilateral intracerebral injection of LPS. Results Repeated systemic LPS challenges resulted in increased brain IL-1β, TNF-α and IL-12 levels, despite attenuated systemic cytokine production. Each LPS challenge induced significant changes in burrowing behaviour. In contrast, brain IL-1β and IL-12 levels in Salmonella typhimurium-infected mice increased over three weeks, with high interferon-γ levels in the circulation. Behavioural changes were only observed during the acute phase of the infection. Microglia and cerebral vasculature display an activated phenotype, and focal intracerebral injection of LPS four weeks after infection results in an exaggerated local inflammatory response when compared to non-infected mice. Conclusions These studies reveal that the innate immune cells in the brain do not become tolerant to systemic infection, but are primed instead. This may lead to prolonged and damaging cytokine production that may have a profound effect on the onset and/or progression of pre-existing neurodegenerative disease.

  18. Survey of childhood empyema in Asia: Implications for detecting the unmeasured burden of culture-negative bacterial disease

    Directory of Open Access Journals (Sweden)

    Shen Xuzhuang

    2008-07-01

    Full Text Available Abstract Background Parapneumonic empyema continues to be a disease of significant morbidity and mortality among children despite recent advances in medical management. To date, only a limited number of studies have assessed the burden of empyema in Asia. Methods We surveyed medical records of four representative large pediatric hospitals in China, Korea, Taiwan and Vietnam using ICD-10 diagnostic codes to identify children Results During the study period, we identified 1,379 children diagnosed with empyema or pleural effusion (China, n = 461; Korea, n = 134; Taiwan, n = 119; Vietnam, n = 665. Diagnoses of pleural effusion (n = 1,074 were 3.5 times more common than of empyema (n = 305, although the relative proportions of empyema and pleural effusion noted in hospital records varied widely between the four sites, most likely because of marked differences in coding practices. Although pleural effusions were reported more often than empyema, children with empyema were more likely to have a cultured pathogen. In addition, we found that median age and gender distribution of children with these conditions were similar across the four countries. Among 1,379 empyema and pleural effusion specimens, 401 (29% were culture positive. Staphylococcus aureus (n = 126 was the most common organism isolated, followed by Streptococcus pneumoniae (n = 83, Pseudomonas aeruginosa (n = 37 and Klebsiella (n = 35 and Acinetobacter species (n = 34. Conclusion The age and gender distribution of empyema and pleural effusion in children in these countries are similar to the US and Western Europe. S. pneumoniae was the second leading bacterial cause of empyema and pleural effusion among Asian children. The high proportion of culture-negative specimens among patients with pleural effusion or empyema suggests that culture may not be a sufficiently sensitive diagnostic method to determine etiology in the majority of cases. Future prospective studies in different countries would

  19. Distributed Fault Detection for a Class of Nonlinear Stochastic Systems

    Directory of Open Access Journals (Sweden)

    Bingyong Yan

    2014-01-01

    Full Text Available A novel distributed fault detection strategy for a class of nonlinear stochastic systems is presented. Different from the existing design procedures for fault detection, a novel fault detection observer, which consists of a nonlinear fault detection filter and a consensus filter, is proposed to detect the nonlinear stochastic systems faults. Firstly, the outputs of the nonlinear stochastic systems act as inputs of a consensus filter. Secondly, a nonlinear fault detection filter is constructed to provide estimation of unmeasurable system states and residual signals using outputs of the consensus filter. Stability analysis of the consensus filter is rigorously investigated. Meanwhile, the design procedures of the nonlinear fault detection filter are given in terms of linear matrix inequalities (LMIs. Taking the influence of the system stochastic noises into consideration, an outstanding feature of the proposed scheme is that false alarms can be reduced dramatically. Finally, simulation results are provided to show the feasibility and effectiveness of the proposed fault detection approach.

  20. Thermal History Devices, Systems For Thermal History Detection, And Methods For Thermal History Detection

    KAUST Repository

    Caraveo Frescas, Jesus Alfonso; Alshareef, Husam N.

    2015-01-01

    Embodiments of the present disclosure include nanowire field-effect transistors, systems for temperature history detection, methods for thermal history detection, a matrix of field effect transistors, and the like.

  1. Thermal History Devices, Systems For Thermal History Detection, And Methods For Thermal History Detection

    KAUST Repository

    Caraveo Frescas, Jesus Alfonso

    2015-05-28

    Embodiments of the present disclosure include nanowire field-effect transistors, systems for temperature history detection, methods for thermal history detection, a matrix of field effect transistors, and the like.

  2. Towards rationally redesigning bacterial signaling systems using information encoded in abundant sequence data

    Science.gov (United States)

    Cheng, Ryan; Morcos, Faruck; Levine, Herbert; Onuchic, Jose

    2014-03-01

    An important challenge in biology is to distinguish the subset of residues that allow bacterial two-component signaling (TCS) proteins to preferentially interact with their correct TCS partner such that they can bind and transfer signal. Detailed knowledge of this information would allow one to search sequence-space for mutations that can systematically tune the signal transmission between TCS partners as well as re-encode a TCS protein to preferentially transfer signals to a non-partner. Motivated by the notion that this detailed information is found in sequence data, we explore the mutual sequence co-evolution between signaling partners to infer how mutations can positively or negatively alter their interaction. Using Direct Coupling Analysis (DCA) for determining evolutionarily conserved interprotein interactions, we apply a DCA-based metric to quantify mutational changes in the interaction between TCS proteins and demonstrate that it accurately correlates with experimental mutagenesis studies probing the mutational change in the in vitro phosphotransfer. Our methodology serves as a potential framework for the rational design of TCS systems as well as a framework for the system-level study of protein-protein interactions in sequence-rich systems. This research has been supported by the NSF INSPIRE award MCB-1241332 and by the CTBP sponsored by the NSF (Grant PHY-1308264).

  3. ACPR upgrade fuel motion detection system

    International Nuclear Information System (INIS)

    Kelly, J.G.; Stalker, K.T.

    1976-01-01

    Coded aperture imaging techniques are being applied to the problem of fuel motion detection in core disruptive safety experiments in the LMFBR. The upgraded Sandia Annular Core Pulse Reactor will be used for fuel motion studies, and a system is now being developed to image fuel motion through a slot in the core in l- and 7-pin experiments. The γ-rays emitted by the fuel will be modulated by a coded aperture and will form a pseudohologram on a scintillator. This shadowgram will be lens coupled first to an optical image intensifier, and then to a rotating prism framing camera. The goal is to obtain quality images of fuel with approximately 1 mm spatial resolution at about 10 4 frames/sec. Some of the feasibility milestones which have been reached thus far are the following: (1) A fuel pin shaped 252 Cf fission gamma ray source has been imaged through 1.27 cm of steel (simulating reactor containment). (2) A 252 Cf source has been imaged through 1.27 cm of steel with x-ray image intensifier amplification. (3) Collimation and shielding tests indicate that at ACPR it should be possible to obtain adequate signal to noise at the detector when the fuel is observed through a slot in the core

  4. Detection systems for radioactive ion beams

    International Nuclear Information System (INIS)

    Savajols, H.

    2002-01-01

    Two main methods are used to produce radioactive ion beams: -) the ISOL method (isotope separation on-line) in which the stable beam interacts with a thick target, the reaction products diffuse outside the target and are transferred to a source where they are ionized, a mass separator and a post-accelerator drive the selected radioactive ions to the right energy; -) the in-flight fragmentation method in which the stable beam interacts with a thin target, the reaction products are emitted from the target with a restricted angular distribution and a velocity close to that of the incident beam, the experimenter has to take advantage from the reaction kinetics to get the right particle beam. Characteristic time is far longer with the ISOL method but the beam intensity is much better because of the use of a post-accelerator. In both cases, the beam intensity is lower by several orders of magnitude than in the case of a stable beam. This article presents all the constraints imposed by radioactive beams to the detection systems of the reaction products and gives new technical solutions according to the type of nuclear reaction studied. (A.C.)

  5. Fast-neutron detecting system with n, γ discrimination

    International Nuclear Information System (INIS)

    Ouyang Xiaoping; Huang Bao; Cao Jinyun

    1997-11-01

    In the present work, a new type neutron detecting system is reported, which can absolutely measure neutron parameters in n + γ mixed fields and has a long continuance of static high vacuum of 10 -4 Pa. The detecting system, with middle neutron-detecting sensitivity, short time response and big linear current output, has applied successfully in pulsed neutron beam measurement

  6. An efficient tag derived from the common epitope of tospoviral NSs proteins for monitoring recombinant proteins expressed in both bacterial and plant systems.

    Science.gov (United States)

    Cheng, Hao-Wen; Chen, Kuan-Chun; Raja, Joseph A J; Li, Jian-Xian; Yeh, Shyi-Dong

    2013-04-15

    NSscon (23 aa), a common epitope in the gene silencing suppressor NSs proteins of the members of the Watermelon silver mottle virus (WSMoV) serogroup, was previously identified. In this investigation, we expressed different green fluorescent protein (GFP)-fused deletions of NSscon in bacteria and reacted with NSscon monoclonal antibody (MAb). Our results indicated that the core 9 amino acids, "(109)KFTMHNQIF(117)", denoted as "nss", retain the reactivity of NSscon. In bacterial pET system, four different recombinant proteins labeled with nss, either at N- or C-extremes, were readily detectable without position effects, with sensitivity superior to that for the polyhistidine-tag. When the nss-tagged Zucchini yellow mosaic virus (ZYMV) helper component-protease (HC-Pro) and WSMoV nucleocapsid protein were transiently expressed by agroinfiltration in tobacco, they were readily detectable and the tag's possible efficacy for gene silencing suppression was not noticed. Co-immunoprecipitation of nss-tagged and non-tagged proteins expressed from bacteria confirmed the interaction of potyviral HC-Pro and coat protein. Thus, we conclude that this novel nss sequence is highly valuable for tagging recombinant proteins in both bacterial and plant expression systems. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Systems and Methods for Automated Water Detection Using Visible Sensors

    Science.gov (United States)

    Rankin, Arturo L. (Inventor); Matthies, Larry H. (Inventor); Bellutta, Paolo (Inventor)

    2016-01-01

    Systems and methods are disclosed that include automated machine vision that can utilize images of scenes captured by a 3D imaging system configured to image light within the visible light spectrum to detect water. One embodiment includes autonomously detecting water bodies within a scene including capturing at least one 3D image of a scene using a sensor system configured to detect visible light and to measure distance from points within the scene to the sensor system, and detecting water within the scene using a processor configured to detect regions within each of the at least one 3D images that possess at least one characteristic indicative of the presence of water.

  8. Detection technique of targets for missile defense system

    Science.gov (United States)

    Guo, Hua-ling; Deng, Jia-hao; Cai, Ke-rong

    2009-11-01

    Ballistic missile defense system (BMDS) is a weapon system for intercepting enemy ballistic missiles. It includes ballistic-missile warning system, target discrimination system, anti-ballistic-missile guidance systems, and command-control communication system. Infrared imaging detection and laser imaging detection are widely used in BMDS for surveillance, target detection, target tracking, and target discrimination. Based on a comprehensive review of the application of target-detection techniques in the missile defense system, including infrared focal plane arrays (IRFPA), ground-based radar detection technology, 3-dimensional imaging laser radar with a photon counting avalanche photodiode (APD) arrays and microchip laser, this paper focuses on the infrared and laser imaging detection techniques in missile defense system, as well as the trends for their future development.

  9. Biokinetics and bacterial communities of propionate oxidizing bacteria in phased anaerobic sludge digestion systems.

    Science.gov (United States)

    Zamanzadeh, Mirzaman; Parker, Wayne J; Verastegui, Yris; Neufeld, Josh D

    2013-03-15

    Phased anaerobic digestion is a promising technology and may be a potential source of bio-energy production. Anaerobic digesters are widely used for sewage sludge stabilization and thus a better understanding of the microbial process and kinetics may allow increased volatile solids reduction and methane production through robust process operation. In this study, we analyzed the impact of phase separation and operational conditions on the bio-kinetic characteristics and communities of bacteria associated with four phased anaerobic digestion systems. In addition to significant differences between bacterial communities associated with different digester operating temperatures, our results also revealed that bacterial communities in the phased anaerobic digestion systems differed between the 1st and 2nd phase digesters and we identified strong community composition correlations with several measured physicochemical parameters. The maximum specific growth rates of propionate oxidizing bacteria (POB) in the mesophilic and thermophilic 1st phases were 11 and 23.7 mgCOD mgCOD(-1) d(-1), respectively, while those of the mesophilic and thermophilic 2nd-phase digesters were 6.7 and 18.6 mgCOD mgCOD(-1) d(-1), respectively. Hence, the biokinetic characteristics of the POB population were dependent on the digester loading. In addition, we observed that the temperature dependency factor (θ) values were higher for the less heavily loaded digesters as compared to the values obtained for the 1st-phase digesters. Our results suggested the appropriate application of two sets of POB bio-kinetic that reflect the differing growth responses as a function of propionate concentration (and/or organic loading rates). Also, modeling acetogenesis in phased anaerobic sludge digestion systems will be improved considering a population shift in separate phases. On the basis of the bio-kinetic values estimated in various digesters, high levels of propionate in the thermophilic digesters may be

  10. Bacterial Communities of Diverse Drosophila Species: Ecological Context of a Host–Microbe Model System

    Science.gov (United States)

    Bhatnagar, Srijak; Eisen, Jonathan A.; Kopp, Artyom

    2011-01-01

    Drosophila melanogaster is emerging as an important model of non-pathogenic host–microbe interactions. The genetic and experimental tractability of Drosophila has led to significant gains in our understanding of animal–microbial symbiosis. However, the full implications of these results cannot be appreciated without the knowledge of the microbial communities associated with natural Drosophila populations. In particular, it is not clear whether laboratory cultures can serve as an accurate model of host–microbe interactions that occur in the wild, or those that have occurred over evolutionary time. To fill this gap, we characterized natural bacterial communities associated with 14 species of Drosophila and related genera collected from distant geographic locations. To represent the ecological diversity of Drosophilids, examined species included fruit-, flower-, mushroom-, and cactus-feeders. In parallel, wild host populations were compared to laboratory strains, and controlled experiments were performed to assess the importance of host species and diet in shaping bacterial microbiome composition. We find that Drosophilid flies have taxonomically restricted bacterial communities, with 85% of the natural bacterial microbiome composed of only four bacterial families. The dominant bacterial taxa are widespread and found in many different host species despite the taxonomic, ecological, and geographic diversity of their hosts. Both natural surveys and laboratory experiments indicate that host diet plays a major role in shaping the Drosophila bacterial microbiome. Despite this, the internal bacterial microbiome represents only a highly reduced subset of the external bacterial communities, suggesting that the host exercises some level of control over the bacteria that inhabit its digestive tract. Finally, we show that laboratory strains provide only a limited model of natural host–microbe interactions. Bacterial taxa used in experimental studies are rare or absent in

  11. Comparison of bacterial culture and qPCR testing of rectal and pen floor samples as diagnostic approaches to detect enterotoxic Escherichia coli in nursery pigs

    DEFF Research Database (Denmark)

    Weber, N. R.; Nielsen, J. P.; Hjulsager, Charlotte Kristiane

    2017-01-01

    Enterotoxigenic E. coli (ETEC) are a major cause of diarrhoea in weaned pigs. The objective of this study was to evaluate the agreement at pen level among three different diagnostic approaches for the detection of ETEC in groups of nursery pigs with diarrhoea. The diagnostic approaches used were......: bacterial culturing of faecal samples from three pigs (per pen) with clinical diarrhoea and subsequent testing for virulence genes in E. coli isolates; bacterial culturing of pen floor samples and subsequent testing for virulence genes in E. coli isolates; qPCR testing of pen floor samples in order...... to determine the quantity of F18 and F4 genes. The study was carried out in three Danish pig herds and included 31 pens with a pen-level diarrhoea prevalence of > 25%, as well as samples from 93 diarrhoeic nursery pigs from these pens. All E. coli isolates were analysed by PCR and classified as ETEC when genes...

  12. Microbiological quality and bacterial diversity of the tropical oyster Crassostrea rhizophorae in a monitored farming system and from natural stocks.

    Science.gov (United States)

    Silva Neta, M T; Maciel, B M; Lopes, A T S; Marques, E L S; Rezende, R P; Boehs, G

    2015-12-02

    Microbiological evaluation is one of the most important parameters for analyzing the viability of an oyster farming system, which addresses public health and ecological concerns. Here, the microbiological quality of the oyster Crassostrea rhizophorae cultivated in a monitored environment and from natural beds in Bahia, northeastern Brazil, was determined. Bacterial diversity in oysters was measured by polymerase chain reaction-denaturing gradient gel electrophoresis. Sequence analysis revealed that most bacterial species showed similarity with uncultured or unidentified bacteria from environmental samples, and were clustered into the phylum Proteobacteria. Diverse bacteria from cultivated (monitored) oyster samples were grouped in the same cluster with a high similarity index (above 79%). Microbiological analyses revealed that these oysters did not contain pathogens. These results reflect the natural balance of the microbial communities essential to the maintenance of health and in inhibiting pathogen colonization in the oyster. On the other hand, bacterial diversity of samples from native stocks in extractive areas displayed a similarity index varying between 55 and 77%, and all samples were clustered separately from each other and from the cluster of samples derived from the cultivation area. Microbiological analyses showed that oysters from the extractive area were not fit for human consumption. This reflected a different composition of the microbial community in this area, probably resulting from anthropic impact. Our study also demonstrated that low temperatures and high rainfall limits the bacterial concentration in tropical oysters. This is the first study analyzing the total bacterial community profiles of the oyster C. rhizophorae.

  13. Nanomaterial-based sensors for detection of foodborne bacterial pathogens and toxins as well as pork adulteration in meat products

    Directory of Open Access Journals (Sweden)

    B. Stephen Inbaraj

    2016-01-01

    Full Text Available Food safety draws considerable attention in the modern pace of the world owing to rapid-changing food recipes and food habits. Foodborne illnesses associated with pathogens, toxins, and other contaminants pose serious threat to human health. Besides, a large amount of money is spent on both analyses and control measures, which causes significant loss to the food industry. Conventional detection methods for bacterial pathogens and toxins are time consuming and laborious, requiring certain sophisticated instruments and trained personnel. In recent years, nanotechnology has emerged as a promising field for solving food safety issues in terms of detecting contaminants, enabling controlled release of preservatives to extend the shelf life of foods, and improving food-packaging strategies. Nanomaterials including metal oxide and metal nanoparticles, carbon nanotubes, and quantum dots are gaining a prominent role in the design of sensors and biosensors for food analysis. In this review, various nanomaterial-based sensors reported in the literature for detection of several foodborne bacterial pathogens and toxins are summarized highlighting their principles, advantages, and limitations in terms of simplicity, sensitivity, and multiplexing capability. In addition, the application through a noncross-linking method without the need for any surface modification is also presented for detection of pork adulteration in meat products.

  14. Development of an Automated Microfluidic System for DNA Collection, Amplification, and Detection of Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, Bethany S.; Bruckner-Lea, Cynthia J.

    2002-12-01

    This project was focused on developing and testing automated routines for a microfluidic Pathogen Detection System. The basic pathogen detection routine has three primary components; cell concentration, DNA amplification, and detection. In cell concentration, magnetic beads are held in a flow cell by an electromagnet. Sample liquid is passed through the flow cell and bacterial cells attach to the beads. These beads are then released into a small volume of fluid and delivered to the peltier device for cell lysis and DNA amplification. The cells are lysed during initial heating in the peltier device, and the released DNA is amplified using polymerase chain reaction (PCR) or strand displacement amplification (SDA). Once amplified, the DNA is then delivered to a laser induced fluorescence detection unit in which the sample is detected. These three components create a flexible platform that can be used for pathogen detection in liquid and sediment samples. Future developments of the system will include on-line DNA detection during DNA amplification and improved capture and release methods for the magnetic beads during cell concentration.

  15. Modeling of the bacterial mechanism of methicillin-resistance by a systems biology approach.

    Directory of Open Access Journals (Sweden)

    Ida Autiero

    Full Text Available BACKGROUND: A microorganism is a complex biological system able to preserve its functional features against external perturbations and the ability of the living systems to oppose to these external perturbations is defined "robustness". The antibiotic resistance, developed by different bacteria strains, is a clear example of robustness and of ability of the bacterial system to acquire a particular functional behaviour in response to environmental changes. In this work we have modeled the whole mechanism essential to the methicillin-resistance through a systems biology approach. The methicillin is a beta-lactamic antibiotic that act by inhibiting the penicillin-binding proteins (PBPs. These PBPs are involved in the synthesis of peptidoglycans, essential mesh-like polymers that surround cellular enzymes and are crucial for the bacterium survival. METHODOLOGY: The network of genes, mRNA, proteins and metabolites was created using CellDesigner program and the data of molecular interactions are stored in Systems Biology Markup Language (SBML. To simulate the dynamic behaviour of this biochemical network, the kinetic equations were associated with each reaction. CONCLUSIONS: Our model simulates the mechanism of the inactivation of the PBP by methicillin, as well as the expression of PBP2a isoform, the regulation of the SCCmec elements (SCC: staphylococcal cassette chromosome and the synthesis of peptidoglycan by PBP2a. The obtained results by our integrated approach show that the model describes correctly the whole phenomenon of the methicillin resistance and is able to respond to the external perturbations in the same way of the real cell. Therefore, this model can be useful to develop new therapeutic approaches for the methicillin control and to understand the general mechanism regarding the cellular resistance to some antibiotics.

  16. Tetrodotoxin-Producing Bacteria: Detection, Distribution and Migration of the Toxin in Aquatic Systems

    Directory of Open Access Journals (Sweden)

    Timur Yu. Magarlamov

    2017-05-01

    Full Text Available This review is devoted to the marine bacterial producers of tetrodotoxin (TTX, a potent non-protein neuroparalytic toxin. In addition to the issues of the ecology and distribution of TTX-producing bacteria, this review examines issues relating to toxin migration from bacteria to TTX-bearing animals. It is shown that the mechanism of TTX extraction from toxin-producing bacteria to the environment occur through cell death, passive/active toxin excretion, or spore germination of spore-forming bacteria. Data on TTX microdistribution in toxic organs of TTX-bearing animals indicate toxin migration from the digestive system to target organs through the transport system of the organism. The role of symbiotic microflora in animal toxicity is also discussed: despite low toxin production by bacterial strains in laboratory conditions, even minimal amounts of TTX produced by intestinal microflora of an animal can contribute to its toxicity. Special attention is paid to methods of TTX detection applicable to bacteria. Due to the complexity of toxin detection in TTX-producing bacteria, it is necessary to use several methods based on different methodological approaches. Issues crucial for further progress in detecting natural sources of TTX investigation are also considered.

  17. Assessment of cytotoxic and genotoxic potential of refinery waste effluent using plant, animal and bacterial systems.

    Science.gov (United States)

    Gupta, Amit Kumar; Ahmad, Masood

    2012-01-30

    The work described here presents the toxic effect of Mathura refinery wastewater (MRWW) in plant (Allium cepa), bacterial (E. coli K12) and human (blood) system. The samples were collected from adjoining area of Mathura refinery, Dist. Mathura, U.P. (India). Chromosomal aberration test and micronucleus assay in (A. cepa) system, E. coli K12 survival assay as well as hemolysis assay in human blood were employed to assess the toxicity of MRWW. MRWW exposure resulted in the formation of micronuclei and bridges in chromosomes of A. cepa cells. A significant decline occurred in survival of DNA repair defective mutants of E. coli K12 exposed to MRWW. On incubation with MRWW, calf thymus DNA-EtBr fluorescence intensity decreased and percent hemolysis of human blood cells increased. An induction in the MDA levels of MRWW treated A. cepa roots indicated lipid peroxidation also. Collectively, the results demonstrate a significant genotoxic and cytotoxic potential of MRWW. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Sorting of bacterial lipoproteins to the outer membrane by the Lol system.

    Science.gov (United States)

    Narita, Shin-ichiro; Tokuda, Hajime

    2010-01-01

    Bacterial lipoproteins comprise a subset of membrane proteins with a lipid-modified cysteine residue at their amino termini through which they are anchored to the membrane. In Gram-negative bacteria, lipoproteins are localized on either the inner or the outer membrane. The Lol system is responsible for the transport of lipoproteins to the outer membrane.The Lol system comprises an inner-membrane ABC transporter LolCDE complex, a periplasmic carrier protein, LolA, and an outer membrane receptor protein, LolB. Lipoproteins are synthesized as precursors in the cytosol and then translocated across the inner membrane by the Sec translocon to the outer leaflet of the inner membrane, where lipoprotein precursors are processed to mature lipoproteins. The LolCDE complex then mediates the release of outer membrane-specific lipoproteins from the inner membrane while the inner membrane-specific lipoproteins possessing Asp at position 2 are not released by LolCDE because it functions as a LolCDE avoidance signal, causing the retention of these lipoproteins in the inner membrane. A water-soluble lipoprotein-LolA complex is formed as a result of the release reaction mediated by LolCDE. This complex traverses the hydrophilic periplasm to reach the outer membrane, where LolB accepts a lipoprotein from LolA and then catalyzes its incorporation into the inner leaflet of the outer membrane.

  19. DETECTION OF BACTERIAL CYTOTOXIC ACTIVITIES FROM WATER-DAMAGED CEILING TILE MATERIAL FOLLOWING INCUBATION ON BLOOD AGAR

    Science.gov (United States)

    Samples of ceiling tiles with high levels of bacteria exhibited cytotoxic activities on a HEP-2 tissue culture assay. Ceiling tiles containing low levels of bacterial colonization did not show cytotoxic activities on the HEP-2 tissue culture assay. Using a spread plate procedure ...

  20. Portable microfluidic raman system for rapid, label-free early disease signature detection

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meiye [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Davis, Ryan Wesley [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Hatch, Anson [Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

    2015-09-01

    In the early stages of infection, patients develop non-specific or no symptoms at all. While waiting for identification of the infectious agent, precious window of opportunity for early intervention is lost. The standard diagnostics require affinity reagents and sufficient pathogen titers to reach the limit of detection. In the event of a disease outbreak, triaging the at-risk population rapidly and reliably for quarantine and countermeasure is more important than the identification of the pathogen by name. To expand Sandia's portfolio of Biological threat management capabilities, we will utilize Raman spectrometry to analyze immune subsets in whole blood to rapidly distinguish infected from non-infected, and bacterial from viral infection, for the purpose of triage during an emergency outbreak. The goal of this one year LDRD is to determine whether Raman spectroscopy can provide label-free detection of early disease signatures, and define a miniaturized Raman detection system meeting requirements for low- resource settings.

  1. Differences of serum procalcitonin levels between bacterial infection and flare in systemic lupus erythematosus patients

    Science.gov (United States)

    Patrick, J.; Marpaung, B.; Ginting, Y.

    2018-03-01

    Differentiate bacterial infections from flare in SLE patients is difficult to do because clinical symptoms of infection is similar to flare. SLE patients with infection require antibiotic therapy with decreased doses of immunosuppressant while in flare diseases require increased immunosuppressant. Procalcitonin (PCT), a biological marker, increased in serum patients with bacterial infections and expected to be a solution of problem. The aim of this study was to examine the function of PCT serum as marker to differentiate bacterial infection and flare in SLE patients. This cross-sectional study was conducted in Adam Malik Hospital from January-July 2017. We examined 80 patients SLE flare (MEX-SLEDAI>5), screen PCT and culture according to focal infection. Data were statistically analyzed. 80 SLE patients divided into 2 groups: bacterial infection group (31 patients) and non-infection/flare group (49 patients). Median PCT levels of bacterial infection group was 1.66 (0.04-8.45)ng/ml while flare group was 0.12 (0.02-0.81)ng/ml. There was significant difference of serum Procalcitonin level between bacterial infection and flare group in SLE patients (p=0.001). Procalcitonin serum levels can be used as a biomarker to differentiate bacterial infections and flare in SLE patients.

  2. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... act together to generate the force required for plasmid movement during segregation. ParR protein binds cooperatively to the centromeric parC DNA region, thereby forming a complex that interacts with the filament-forming actin-like ParM protein in an ATP-dependent manner, suggesting that plasmid...

  3. A Magnetic Sensor System for Biological Detection

    KAUST Repository

    Li, Fuquan

    2015-01-01

    Magnetic biosensors detect biological targets through sensing the stray field of magnetic beads which label the targets. Commonly, magnetic biosensors employ the “sandwich” method to immobilize biological targets, i.e., the targets are sandwiched

  4. A Magnetic Sensor System for Biological Detection

    KAUST Repository

    Li, Fuquan

    2015-05-01

    Magnetic biosensors detect biological targets through sensing the stray field of magnetic beads which label the targets. Commonly, magnetic biosensors employ the “sandwich” method to immobilize biological targets, i.e., the targets are sandwiched between a bio-functionalized sensor surface and bio-functionalized magnetic beads. This method has been used very successfully in different application, but its execution requires a rather elaborate procedure including several washing and incubation steps. This dissertation investigates a new magnetic biosensor concept, which enables a simple and effective detection of biological targets. The biosensor takes advantage of the size difference between bare magnetic beads and compounds of magnetic beads and biological targets. First, the detection of super-paramagnetic beads via magnetic tunnel junction (MTJ) sensors is implemented. Frequency modulation is used to enhance the signal-to-noise ratio, enabling the detection of a single magnetic bead. Second, the concept of the magnetic biosensor is investigated theoretically. The biosensor consists of an MTJ sensor, which detects the stray field of magnetic beads inside of a trap on top of the MTJ. A microwire between the trap and the MTJ is used to attract magnetic beads to the trapping well by applying a current to it. The MTJ sensor’s output depends on the number of beads inside the trap. If biological targets are in the sample solution, the beads will form bead compounds consisting of beads linked to the biological targets. Since bead compounds are larger than bare beads, the number of beads inside the trapping well will depend on the presence of biological targets. Hence, the output of the MTJ sensor will depend on the biological targets. The dependences of sensor signals on the sizes of the MTJ sensor, magnetic beads and biological targets are studied to find the optimum constellations for the detection of specific biological targets. The optimization is demonstrated

  5. Laser Obstacle Detection System Flight Testing

    National Research Council Canada - National Science Library

    Davis, Timothy

    2003-01-01

    ...). The Aviation Applied Technology Directorate (AATD) was contracted to mount the HELLAS sensor on the nose of a UH-60L Blackhawk helicopter and to conduct flight tests to evaluate the HELLAS obstacle detection sensor...

  6. Optimizing Systems of Threshold Detection Sensors

    National Research Council Canada - National Science Library

    Banschbach, David C

    2008-01-01

    .... Below the threshold all signals are ignored. We develop a mathematical model for setting individual sensor thresholds to obtain optimal probability of detecting a significant event, given a limit on the total number of false positives allowed...

  7. Magnetic biosensor system to detect biological targets

    KAUST Repository

    Li, Fuquan; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    magnetic concentration, magnetic as well as mechanical trapping and magnetic sensing. Target detection is based on the size difference between bare magnetic beads and magnetic beads with targets attached. This method remedies the need for a coating layer

  8. Bacterial Effectors and Their Functions in the Ubiquitin-Proteasome System: Insight from the Modes of Substrate Recognition

    Directory of Open Access Journals (Sweden)

    Minsoo Kim

    2014-08-01

    Full Text Available Protein ubiquitination plays indispensable roles in the regulation of cell homeostasis and pathogenesis of neoplastic, infectious, and neurodegenerative diseases. Given the importance of this modification, it is to be expected that several pathogenic bacteria have developed the ability to utilize the host ubiquitin system for their own benefit. Modulation of the host ubiquitin system by bacterial effector proteins inhibits innate immune responses and hijacks central signaling pathways. Bacterial effectors mimic enzymes of the host ubiquitin system, but may or may not be structurally similar to the mammalian enzymes. Other effectors bind and modify components of the host ubiquitin system, and some are themselves subject to ubiquitination. This review will describe recent findings, based on structural analyses, regarding how pathogens use post-translational modifications of proteins to establish an infection.

  9. Bacterial effectors and their functions in the ubiquitin-proteasome system: insight from the modes of substrate recognition.

    Science.gov (United States)

    Kim, Minsoo; Otsubo, Ryota; Morikawa, Hanako; Nishide, Akira; Takagi, Kenji; Sasakawa, Chihiro; Mizushima, Tsunehiro

    2014-08-18

    Protein ubiquitination plays indispensable roles in the regulation of cell homeostasis and pathogenesis of neoplastic, infectious, and neurodegenerative diseases. Given the importance of this modification, it is to be expected that several pathogenic bacteria have developed the ability to utilize the host ubiquitin system for their own benefit. Modulation of the host ubiquitin system by bacterial effector proteins inhibits innate immune responses and hijacks central signaling pathways. Bacterial effectors mimic enzymes of the host ubiquitin system, but may or may not be structurally similar to the mammalian enzymes. Other effectors bind and modify components of the host ubiquitin system, and some are themselves subject to ubiquitination. This review will describe recent findings, based on structural analyses, regarding how pathogens use post-translational modifications of proteins to establish an infection.

  10. Underwater electric field detection system based on weakly electric fish

    Science.gov (United States)

    Xue, Wei; Wang, Tianyu; Wang, Qi

    2018-04-01

    Weakly electric fish sense their surroundings in complete darkness by their active electric field detection system. However, due to the insufficient detection capacity of the electric field, the detection distance is not enough, and the detection accuracy is not high. In this paper, a method of underwater detection based on rotating current field theory is proposed to improve the performance of underwater electric field detection system. First of all, we built underwater detection system based on the theory of the spin current field mathematical model with the help of the results of previous researchers. Then we completed the principle prototype and finished the metal objects in the water environment detection experiments, laid the foundation for the further experiments.

  11. Fault Detection for Shipboard Monitoring and Decision Support Systems

    DEFF Research Database (Denmark)

    Lajic, Zoran; Nielsen, Ulrik Dam

    2009-01-01

    In this paper a basic idea of a fault-tolerant monitoring and decision support system will be explained. Fault detection is an important part of the fault-tolerant design for in-service monitoring and decision support systems for ships. In the paper, a virtual example of fault detection...... will be presented for a containership with a real decision support system onboard. All possible faults can be simulated and detected using residuals and the generalized likelihood ratio (GLR) algorithm....

  12. Security Enrichment in Intrusion Detection System Using Classifier Ensemble

    Directory of Open Access Journals (Sweden)

    Uma R. Salunkhe

    2017-01-01

    Full Text Available In the era of Internet and with increasing number of people as its end users, a large number of attack categories are introduced daily. Hence, effective detection of various attacks with the help of Intrusion Detection Systems is an emerging trend in research these days. Existing studies show effectiveness of machine learning approaches in handling Intrusion Detection Systems. In this work, we aim to enhance detection rate of Intrusion Detection System by using machine learning technique. We propose a novel classifier ensemble based IDS that is constructed using hybrid approach which combines data level and feature level approach. Classifier ensembles combine the opinions of different experts and improve the intrusion detection rate. Experimental results show the improved detection rates of our system compared to reference technique.

  13. Suggested guidelines for using systemic antimicrobials in bacterial skin infections: part?2? antimicrobial choice, treatment regimens and compliance

    OpenAIRE

    Beco, L.; Guagu?re, E.; M?ndez, C. Lorente; Noli, C.; Nuttall, T.; Vroom, M.

    2013-01-01

    Systemic antimicrobials are critically important in veterinary healthcare, and resistance is a major concern. Antimicrobial stewardship will be important in maintaining clinical efficacy by reducing the development and spread of antimicrobial resistance. Bacterial skin infections are one of the most common reasons for using systemic antimicrobials in dogs and cats. Appropriate management of these infections is, therefore, crucial in any policy for responsible antimicrobial use. The goals of t...

  14. Elevated carbon monoxide in the exhaled breath of mice during a systemic bacterial infection.

    Directory of Open Access Journals (Sweden)

    Alan G Barbour

    Full Text Available Blood is the specimen of choice for most laboratory tests for diagnosis and disease monitoring. Sampling exhaled breath is a noninvasive alternative to phlebotomy and has the potential for real-time monitoring at the bedside. Improved instrumentation has advanced breath analysis for several gaseous compounds from humans. However, application to small animal models of diseases and physiology has been limited. To extend breath analysis to mice, we crafted a means for collecting nose-only breath samples from groups and individual animals who were awake. Samples were subjected to gas chromatography and mass spectrometry procedures developed for highly sensitive analysis of trace volatile organic compounds (VOCs in the atmosphere. We evaluated the system with experimental systemic infections of severe combined immunodeficiency Mus musculus with the bacterium Borrelia hermsii. Infected mice developed bacterial densities of ∼10(7 per ml of blood by day 4 or 5 and in comparison to uninfected controls had hepatosplenomegaly and elevations of both inflammatory and anti-inflammatory cytokines. While 12 samples from individual infected mice on days 4 and 5 and 6 samples from uninfected mice did not significantly differ for 72 different VOCs, carbon monoxide (CO was elevated in samples from infected mice, with a mean (95% confidence limits effect size of 4.2 (2.8-5.6, when differences in CO2 in the breath were taken into account. Normalized CO values declined to the uninfected range after one day of treatment with the antibiotic ceftriaxone. Strongly correlated with CO in the breath were levels of heme oxygenase-1 protein in serum and HMOX1 transcripts in whole blood. These results (i provide further evidence of the informativeness of CO concentration in the exhaled breath during systemic infection and inflammation, and (ii encourage evaluation of this noninvasive analytic approach in other various other rodent models of infection and for utility in

  15. Control of corrosive bacterial community by bronopol in industrial water system.

    Science.gov (United States)

    Narenkumar, Jayaraman; Ramesh, Nachimuthu; Rajasekar, Aruliah

    2018-01-01

    Ten aerobic corrosive bacterial strains were isolated from a cooling tower water system (CWS) which were identified based on the biochemical characterization and 16S rRNA gene sequencing. Out of them, dominant corrosion-causing bacteria, namely, Bacillus thuringiensis EN2, Terribacillus aidingensis EN3, and Bacillus oleronius EN9, were selected for biocorrosion studies on mild steel 1010 (MS) in a CWS. The biocorrosion behaviour of EN2, EN3, and EN9 strains was studied using immersion test (weight loss method), electrochemical analysis, and surface analysis. To address the corrosion problems, an anti-corrosive study using a biocide, bronopol was also demonstrated. Scanning electron microscopy and Fourier-transform infrared spectroscopy analyses of the MS coupons with biofilm developed after exposure to CWS confirmed the accumulation of extracellular polymeric substances and revealed that biofilms was formed as microcolonies, which subsequently cause pitting corrosion. In contrast, the biocide system, no pitting type of corrosion, was observed and weight loss was reduced about 32 ± 2 mg over biotic system (286 ± 2 mg). FTIR results confirmed the adsorption of bronopol on the MS metal surface as protective layer (co-ordination of NH 2 -Fe 3+ ) to prevent the biofilm formation and inhibit the corrosive chemical compounds and thus led to reduction of corrosion rate (10 ± 1 mm/year). Overall, the results from WL, EIS, SEM, XRD, and FTIR concluded that bronopol was identified as effective biocide and corrosion inhibitor which controls the both chemical and biocorrosion of MS in CWS.

  16. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Harel, Elad [Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

    2012-05-07

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  17. Long range excitonic transport in a biomimetic system inspired by the bacterial light-harvesting apparatus

    International Nuclear Information System (INIS)

    Harel, Elad

    2012-01-01

    Photosynthesis, the process by which energy from sunlight drives cellular metabolism, relies on a unique organization of light-harvesting and reaction center complexes. Recently, the organization of light-harvesting LH2 complexes and dimeric reaction center-light-harvesting I-PufX core complexes in membranes of purple non-sulfur bacteria was revealed by atomic force microscopy [S. Bahatyrova et al., Nature (London) 430, 1058 (2004)]. Here, we discuss optimal exciton transfer in a biomimetic system closely modeled on the structure of LH2 and its organization within the membrane using a Markovian quantum model with dissipation and trapping added phenomenologically. In a deliberate manner, we neglect the high level detail of the bacterial light-harvesting complex and its interaction with the phonon bath in order to elucidate a set of design principles that may be incorporated in artificial pigment-scaffold constructs in a supramolecular assembly. We show that our scheme reproduces many of the most salient features found in their natural counterpart and may be largely explained by simple electrostatic considerations. Most importantly, we show that quantum effects act primarily to enforce robustness with respect to spatial and spectral disorder between and within complexes. The implications of such an arrangement are discussed in the context of biomimetic photosynthetic analogs capable of transferring energy efficiently across tens to hundreds of nanometers.

  18. α-Intercalated cells defend the urinary system from bacterial infection.

    Science.gov (United States)

    Paragas, Neal; Kulkarni, Ritwij; Werth, Max; Schmidt-Ott, Kai M; Forster, Catherine; Deng, Rong; Zhang, Qingyin; Singer, Eugenia; Klose, Alexander D; Shen, Tian Huai; Francis, Kevin P; Ray, Sunetra; Vijayakumar, Soundarapandian; Seward, Samuel; Bovino, Mary E; Xu, Katherine; Takabe, Yared; Amaral, Fábio E; Mohan, Sumit; Wax, Rebecca; Corbin, Kaitlyn; Sanna-Cherchi, Simone; Mori, Kiyoshi; Johnson, Lynne; Nickolas, Thomas; D'Agati, Vivette; Lin, Chyuan-Sheng; Qiu, Andong; Al-Awqati, Qais; Ratner, Adam J; Barasch, Jonathan

    2014-07-01

    α-Intercalated cells (A-ICs) within the collecting duct of the kidney are critical for acid-base homeostasis. Here, we have shown that A-ICs also serve as both sentinels and effectors in the defense against urinary infections. In a murine urinary tract infection model, A-ICs bound uropathogenic E. coli and responded by acidifying the urine and secreting the bacteriostatic protein lipocalin 2 (LCN2; also known as NGAL). A-IC-dependent LCN2 secretion required TLR4, as mice expressing an LPS-insensitive form of TLR4 expressed reduced levels of LCN2. The presence of LCN2 in urine was both necessary and sufficient to control the urinary tract infection through iron sequestration, even in the harsh condition of urine acidification. In mice lacking A-ICs, both urinary LCN2 and urinary acidification were reduced, and consequently bacterial clearance was limited. Together these results indicate that A-ICs, which are known to regulate acid-base metabolism, are also critical for urinary defense against pathogenic bacteria. They respond to both cystitis and pyelonephritis by delivering bacteriostatic chemical agents to the lower urinary system.

  19. 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.

  20. The type VI secretion system impacts bacterial invasion and population dynamics in a model intestinal microbiota

    Science.gov (United States)

    Logan, Savannah L.; Shields, Drew S.; Hammer, Brian K.; Xavier, Joao B.; Parthasarathy, Raghuveer

    Animal gastrointestinal tracts are home to a diverse community of microbes. The mechanisms by which microbial species interact and compete in this dense, physically dynamic space are poorly understood, limiting our understanding of how natural communities are assembled and how different communities could be engineered. Here, we focus on a physical mechanism for competition: the type VI secretion system (T6SS). The T6SS is a syringe-like organelle used by certain bacteria to translocate effector proteins across the cell membranes of target bacterial cells, killing them. Here, we use T6SS+ and T6SS- strains of V. cholerae, the pathogen that causes cholera in humans, and light sheet fluorescence microscopy for in vivo imaging to show that the T6SS provides an advantage to strains colonizing the larval zebrafish gut. Furthermore, we show that T6SS+ bacteria can invade and alter an existing population of a different species in the zebrafish gut, reducing its abundance and changing the form of its population dynamics. This work both demonstrates a mechanism for altering the gut microbiota with an invasive species and explores the processes controlling the stability and dynamics of the gut ecosystem. Research Corporation, Gordon and Betty Moore Foundation, and the Simons Foundation.