28 research outputs found
Reliable detection of Bacillus anthracis, Francisella tularensis and Yersinia pestis by using multiplex qPCR including internal controls for nucleic acid extraction and amplification
Separated by a Common Language: Awareness of Term Usage Differences Between Languages and Disciplines in Biopreparedness
Preparedness for bioterrorism is based on communication between people in organizations who are educated and trained in several disciplines, including law enforcement, health, and science. Various backgrounds, cultures, and vocabularies generate difficulties in understanding and interpretating terms and concepts, which may impair communication. This is especially true in emergency situations, in which the need for clarity and consistency is vital. The EU project AniBio- Threat initiated methods and made a rough estimate of the terms and concepts that are crucial for an incident, and a pilot database with key terms and definitions has been constructed. Analysis of collected terms and sources has shown that many of the participating organizations use various international standards in their area of expertise. The same term often represents different concepts in the standards from different sectors, or, alternatively, different terms were used to represent the same or similar concepts. The use of conflicting terminology can be problematic for decision makers and communicators in planning and prevention or when handling an incident. Since the CBRN area has roots in multiple disciplines, each with its own evolving terminology, it may not be realistic to achieve unequivocal communication through a standardized vocabulary and joint definitions for words from common language. We suggest that a communication strategy should include awareness of alternative definitions and ontologies and the ability to talk and write without relying on the implicit knowledge underlying specialized jargon. Consequently, cross-disciplinary communication skills should be part of training of personnel in the CBRN field. In addition, a searchable repository of terms and definitions from relevant organizations and authorities would be a valuable addition to existing glossaries for improving awareness concerning bioterrorism prevention planning
Cardiovascular RiskprofilE - IMaging and gender-specific disOrders (CREw-IMAGO): rationale and design of a multicenter cohort study
Electron transfer from cytochrome b559 and tyrosineD to the S2 and S3 states of the water oxidizing complex in photosystem II
We have investigated the electron transfer from reduced tyrosine YD (YDred) and cytochrome b559 to the S2 and S3 states of the water oxidizing complex (WOC) in Photosystem II. The EPR signal of oxidized cyt b559, the S2 state multiline EPR signal and the EPR signal from YD@? were measured to follow the electron transfer to the S2 and S3 states at 245 and 275 K. The majority of the S2 centers was reduced directly from YDred but at 245 K we observed oxidation of cyt b559 in about 20% of the centers. Incubation of the YDredS3 state resulted in biphasic changes of the S2 multiline signal. The signal first increased due to reduction of the S3 state. Thereafter, the signal decreased due to decay of the S2 state. In contrast, the YD@? signal increased with a monophasic kinetics at both temperatures. Again, we observed oxidation of cyt b559 in about 20% of the PSII centers at 245 K. This oxidation correlated with the decay of the S2 state. The complex changes can be explained by the conversion of YDredS3 centers (present initially) to YD@?S1 centers, via the intermediate YD@?S2 state. The early increase of the S2 state multiline signal involves electron transfer from YDred to the S3 state resulting in formation of YD@?S2. This state is reduced by cyt b559 resulting in a single exponential oxidation of cyt b559. Taken together, these results indicate that the electron donor to S2 is cyt b559 while cyt b559 is unable to compete with YDred in the reduction of the S3 state in the pre-reduced samples. We also followed the decay of the S2 and S3 states and the oxidation of cyt b559 in samples where YD was oxidized from the start. In this case cyt b559 was able to reduce both the S2 and the S3 states suggesting that different pathways exist for the electron transfer from cyt b559 to the WOC. The activation energies for the YDredS2->YD@?S1 and YDredS3->YD@?S2 transformations are 0.57 and 0.67 eV, respectively, and the reason for these large activation energies is discussed
Reliable detection of <it>Bacillus anthracis</it>, <it>Francisella tularensis </it>and <it>Yersinia pestis </it>by using multiplex qPCR including internal controls for nucleic acid extraction and amplification
Abstract Background Several pathogens could seriously affect public health if not recognized timely. To reduce the impact of such highly pathogenic micro-organisms, rapid and accurate diagnostic tools are needed for their detection in various samples, including environmental samples. Results Multiplex real-time PCRs were designed for rapid and reliable detection of three major pathogens that have the potential to cause high morbidity and mortality in humans: B. anthracis, F. tularensis and Y. pestis. The developed assays detect three pathogen-specific targets, including at least one chromosomal target, and one target from B. thuringiensis which is used as an internal control for nucleic acid extraction from refractory spores as well as successful DNA amplification. Validation of the PCRs showed a high analytical sensitivity, specificity and coverage of diverse pathogen strains. Conclusions The multiplex qPCR assays that were developed allow the rapid detection of 3 pathogen-specific targets simultaneously, without compromising sensitivity. The application of B. thuringiensis spores as internal controls further reduces false negative results. This ensures highly reliable detection, while template consumption and laboratory effort are kept at a minimum</p
Development and Comparison of Two Assay Formats for Parallel Detection of Four Biothreat Pathogens by Using Suspension Microarrays
Microarrays provide a powerful analytical tool for the simultaneous detection of multiple pathogens. We developed diagnostic suspension microarrays for sensitive and specific detection of the biothreat pathogens Bacillus anthracis, Yersinia pestis, Francisella tularensis and Coxiella burnetii. Two assay chemistries for amplification and labeling were developed, one method using direct hybridization and the other using target-specific primer extension, combined with hybridization to universal arrays. Asymmetric PCR products for both assay chemistries were produced by using a multiplex asymmetric PCR amplifying 16 DNA signatures (16-plex). The performances of both assay chemistries were compared and their advantages and disadvantages are discussed. The developed microarrays detected multiple signature sequences and an internal control which made it possible to confidently identify the targeted pathogens and assess their virulence potential. The microarrays were highly specific and detected various strains of the targeted pathogens. Detection limits for the different pathogen signatures were similar or slightly higher compared to real-time PCR. Probit analysis showed that even a few genomic copies could be detected with 95 % confidence. The microarrays detected DNA from different pathogens mixed in different ratios and from spiked or naturally contaminated samples. The assays that were developed have a potential for applicatio
Simplicity in complexity: The photosynthetic reaction center performs as a simple 0.2V battery.
AbstractThe photosynthetic reaction center is one of the most complicated molecular complexes. Transducing photon energy to a transmembrane electrochemical potential difference for protons, it is the direct or indirect energy source for virtually all life. We show here that it operates in a simple, battery-like manner, with a maximum potential of 0.20 V. Intriguingly this is only one fifth of the energy of the absorbed photon
Detection limits of the DH and TSPE-UH suspension array formats.
a<p>Values displayed represent the lowest DNA concentration at which 95% of the positive samples are detected, as calculated by using probit analysis. ND = not determined.</p
Detection of mixed pathogens by using DH and TSPE-UH suspension microarrays.
<p>Genomic DNA from <i>B. anthracis</i> (Ba), <i>F. tularensis</i> (Ft), <i>Y. pestis</i> (Yp), <i>C. burnetii</i> (Cb) was mixed in different ratios and measured by using DH (<b>A</b>) and TSPE-UH (<b>B</b>) microarrays. Mean fluorescence intensity (MFI) is displayed for the different pathogen-specific probes (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0031958#pone-0031958-t001" target="_blank">Table 1</a>). The detection of one pathogen is not impeded by the detection of the other targeted pathogens.</p