Matrix-assisted laser desorption/ionisation time of-flight mass spectrometry (MALDI-TOF MS) is a fast and reliable method for the identification of bacteria from agar media. Direct identification from positive blood cultures should decrease the time to obtaining the result. In this study, three different processing methods for the rapid direct identification of bacteria from positive blood culture bottles were compared. In total, 101 positive aerobe BacT/ALERT bottles were included in this study. Aliquots from all bottles were used for three bacterial processing methods, i.e. the commercially available Bruker's MALDI Sepsityper kit, the commercially available Molzym's MolYsis Basic5 kit and a centrifugation/washing method. In addition, the best method was used to evaluate the possibility of MALDI application after a reduced incubation time of 7 h of Staphylococcus aureus- and Escherichia coli-spiked (1,000, 100 and 10 colony-forming units [CFU]) aerobe BacT/ALERT blood cultures. Sixty-six (65%), 51 (50.5%) and 79 (78%) bottles were identified correctly at the species level when the centrifugation/washing method, MolYsis Basic 5 and Sepsityper were used, respectively. Incorrect identification was obtained in 35 (35%), 50 (49.5%) and 22 (22%) bottles, respectively. Gram-positive cocci were correctly identified in 33/52 (64%) of the cases. However, Gram-negative rods showed a correct identification in 45/47 (96%) of all bottles when the Sepsityper kit was used. Seven hours of pre-incubation of S. aureus- and E. coli-spiked aerobe BacT/ALERT blood cultures never resulted in reliable identification with MALDI-TOF MS. Sepsityper is superior for the direct identification of microorganisms from aerobe BacT/ALERT bottles. Gram-negative pathogens show better results compared to Gram-positive bacteria. Reduced incubation followed by MALDI-TOF MS did not result in faster reliable identification.
This study replicates previous research that investigated the influence of rapid identification information on the interpretation of a crime scene conducted with English crime scene investigators (CSIs). Given the special circumstances under which CSIs in one country operate, the present study investigates the robustness and generalisability of the previous findings by studying whether identical decision-making phenomena are found in a replication study within a different police environment. Dutch CSIs (N = 65) participated in the same study and results are compared with the English findings. The utility of the replication study is reflected in both the revealed robustness and differences in the findings. First, the results demonstrate the robustness of the previous finding that ID information influenced the interpretation of the crime scene, even more when this information was provided after CSIs had constructed a provisional scenario. Secondly, this study revealed differences in decision-making: English CSIs used ID information to make efficient decisions by prioritising traces with direct progression opportunities for the case and disregarding those without direct opportunities, which led to a form of tunnel vision, namely the ignorance of the involvement of a second offender. Dutch CSIs showed to be less prone to bias towards traces that produced database matches.Dutch CSIs seemed to be more focused on the relation of the trace with the crime, while English CSIs are more focused on the database match.Consequently, important information was overlooked. We question whether the emphasis on efficiency in England goes at the expense of the quality of an investigation.
Non-invasive, rapid, on-site detection and identification of body fluids is highly desired in forensic investigations. The use of fluorescence-based methods for body fluid identification, have so far remain relatively unexplored. As such, the fluorescent properties of semen, serum, urine, saliva and fingermarks over time were investigated, by means of fluorescence spectroscopy, to identify specific fluorescent signatures for body fluid identification. The samples were excited at 81 different excitation wavelengths ranging from 200 to 600 nm and for each excitation wavelength the emission was recorded between 220 and 700 nm. Subsequently, the total emitted fluorescence intensities of specific fluorescent signatures in the UV–visible range were summed and principal component analysis was performed to cluster the body fluids. Three combinations of four principal components allowed specific clustering of the body fluids, except for fingermarks. Blind testing showed that 71.4% of the unknown samples could be correctly identified. This pilot study shows that the fluorescent behavior of ageing body fluids can be used as a new non-invasive tool for body fluid identification, which can improve the current guidelines for the detection of body fluids in forensic practice and provide the robustness of methods that rely on fluorescence.
Many lithographically created optical components, such as photonic crystals, require the creation of periodically repeated structures [1]. The optical properties depend critically on the consistency of the shape and periodicity of the repeated structure. At the same time, the structure and its period may be similar to, or substantially below that of the optical diffraction limit, making inspection with optical microscopy difficult. Inspection tools must be able to scan an entire wafer (300 mm diameter), and identify wafers that fail to meet specifications rapidly. However, high resolution, and high throughput are often difficult to achieve simultaneously, and a compromise must be made. TeraNova is developing an optical inspection tool that can rapidly image features on wafers. Their product relies on (a) knowledge of what the features should be, and (b) a detailed and accurate model of light diffraction from the wafer surface. This combination allows deviations from features to be identified by modifying the model of the surface features until the calculated diffraction pattern matches the observed pattern. This form of microscopy—known as Fourier microscopy—has the potential to be very rapid and highly accurate. However, the solver, which calculates the wafer features from the diffraction pattern, must be very rapid and precise. To achieve this, a hardware solver will be implemented. The hardware solver must be combined with mechatronic tracking of the absolute wafer position, requiring the automatic identification of fiduciary markers. Finally, the problem of computer obsolescence in instrumentation (resulting in security weaknesses) will also be addressed by combining the digital hardware and software into a system-on-a-chip (SoC) to provide a powerful, yet secure operating environment for the microscope software.
Over a million people in the Netherlands have type 2 diabetes (T2D), which is strongly related to overweight, and many more people are at-risk. A carbohydrate-rich diet and insufficient physical activity play a crucial role in these developments. It is essential to prevent T2D, because this condition is associated with a reduced quality of life, high healthcare costs and premature death due to cardiovascular diseases. The hormone insulin plays a major role in this. This hormone lowers the blood glucose concentration through uptake in body cells. If an excess of glucose is constantly offered, initially the body maintains blood glucose concentration within normal range by releasing higher concentrations of insulin into the blood, a condition that is described as “prediabetes”. In a process of several years, this compensating mechanism will eventually fail: the blood glucose concentration increases resulting in T2D. In the current healthcare practice, T2D is actually diagnosed by recognizing only elevated blood glucose concentrations, being insufficient for identification of people who have prediabetes and are at-risk to develop T2D. Although the increased insulin concentrations at normal glucose concentrations offer an opportunity for early identification/screening of people with prediabetes, there is a lack of effective and reliable methods/devices to adequately measure insulin concentrations. An integrated approach has been chosen for identification of people at-risk by using a prediabetes screening method based on insulin detection. Users and other stakeholders will be involved in the development and implementation process from the start of the project. A portable and easy-to-use demonstrator will be realised, based on rapid lateral flow tests (LFTs), which is able to measure insulin in clinically relevant samples (serum/blood) quickly and reliably. Furthermore, in collaboration with healthcare professionals, we will investigate how this screening method can be implemented in practice to contribute to a healthier lifestyle and prevent T2D.
Routine neuropathology diagnostic methods are limited to histological staining techniques or directed PCR for pathogen detection and microbial cultures of brain abscesses are negative in one-third of the cases. Fortunately, due to improvements in technology, metagenomic sequencing of a conserved bacterial gene could provide an alternative diagnostic method. For histopathological work up, formalin-fixed paraffin-embedded (FFPE) tissue with highly degraded nucleic acids is the only material being available. Innovative amplicon-specific next-generation sequencing (NGS) technology has the capability to identify pathogens based on the degraded DNA within a few hours. This approach significantly accelerates diagnostics and is particularly valuable to identify challenging pathogens. This ensures optimal treatment for the patient, minimizing unnecessary health damage. Within this project, highly conserved primers in a universal PCR will be used, followed by determining the nucleotide sequence. Based on the obtained data, it is then precisely determined which microorganism(s) is/are responsible for the infection, even in cases of co-infection with multiple pathogens. This project will focus to answer the following research question; how can a new form of rapid molecular diagnostics contribute to the identification of microbial pathogens in CNS infections? The SME partner Molecular Biology Systems B.V. (MBS) develops and sells equipment for extremely rapid execution of the commonly used PCR. In this project, the lectorate Analysis Techniques in the Life Sciences (Avans) will, in collaboration with MBS, Westerdijk Institute (WI-KNAW) and the Institute of Neuropathology (Münster, DE) establish a new molecular approach for fast diagnosis within CNS infections using this MBS technology. This enables the monitoring of infectious diseases in a fast and user-friendly manner, resulting in an improved treatment plan.
