Lighting the Path: Raman Spectroscopy's Journey Through the Microbial Maze.

The rapid and precise identification of microorganisms is essential in environmental science, pharmaceuticals, food safety, and medical diagnostics. Raman spectroscopy, valued for its ability to provide detailed chemical and structural information, has gained significant traction in these fields, especially with the adoption of various excitation wavelengths and tailored optical setups. The choice of wavelength and setup in Raman spectroscopy is influenced by factors such as applicability, cost, and whether bulk or single-cell analysis is performed, each impacting sensitivity and specificity in bacterial detection.

Unveiling Microbial Diversity: Raman Spectroscopy's Discrimination of and Related Genera.

In the clinical environment, the identification of phylogenetic closely related genera and species like and is challenging. Both genera contain representatives of pathogenic and nonpathogenic species that need to be distinguished for a proper diagnostic read-out. Therefore, reliable and accurate detection methods must be employed for the correct identification of these genera and species.

Direct ink writing with dental composites: A paradigm shift toward sustainable chair-side production.

Objectives: To evaluate the dimensional accuracy of occlusal veneers printed using a novel direct ink writing (DIW) system and a clinically approved dental composite.

Methods: A novel three-dimensional printer was developed based on the extrusion-based DIW principle. The printer, constructed primarily with open-source hardware, was calibrated to print with a flowable resin composite (Beautifil Flow Plus).

Raman-Activated, Interactive Sorting of Isotope-Labeled Bacteria.

Due to its high spatial resolution, Raman microspectroscopy allows for the analysis of single microbial cells. Since Raman spectroscopy analyzes the whole cell content, this method is phenotypic and can therefore be used to evaluate cellular changes. In particular, labeling with stable isotopes (SIPs) enables the versatile use and observation of different metabolic states in microbes.

Illuminating the Tiny World: A Navigation Guide for Proper Raman Studies on Microorganisms.

Raman spectroscopy is an emerging method for the identification of bacteria. Nevertheless, a lot of different parameters need to be considered to establish a reliable database capable of identifying real-world samples such as medical or environmental probes. In this review, the establishment of such reliable databases with the proper design in microbiological Raman studies is demonstrated, shining a light into all the parts that require attention.

Simulating a reference medium for determining bacterial growth in hospital wastewater for Raman spectroscopic investigation.

Wastewater is a very complex and diverse medium, which despite low nutrient density still harbors bacteria. Especially the wastewater from hospitals contains a high germ load. However, wastewater is also very variable and differs not only from day to day, but also from house to house.

Investigating the effect of different pre-treatment methods on Raman spectra recorded with different excitation wavelengths.

Raman reference libraries can be used for identification of components in unknown samples as Raman spectroscopy offers fingerprint information of the measured samples. Since Raman libraries often contain many different and/or highly similar spectra, it is important that the spectra are a reliable fingerprint for each compound. However, Raman spectra are highly sensitive to the experimental conditions, and the Raman spectra will change in different conditions even though the same sample is measured.

Molecular Mechanism of Sirtuin 1 Inhibition by Human Immunodeficiency Virus 1 Tat Protein.

Sirtuins are NAD-dependent protein lysine deacylases implicated in metabolic regulation and aging-related dysfunctions. The nuclear isoform Sirt1 deacetylates histones and transcription factors and contributes, e.g.

NMR-Based Metabolite Profiling and the Application of STOCSY toward the Quality and Authentication Assessment of European EVOOs.

Extra virgin olive oil (EVOO) possesses a high-value rank in the food industry, thus making it a common target for adulteration. Hence, several methods have been essentially made available over the years. However, the issue of authentication remains unresolved with national and food safety organizations globally struggling to regulate and control its market.

Use of polymers as wavenumber calibration standards in deep-UVRR.

Deep-UV resonance Raman spectroscopy (UVRR) allows the classification of bacterial species with high accuracy and is a promising tool to be developed for clinical application. For this attempt, the optimization of the wavenumber calibration is required to correct the overtime changes of the Raman setup. In the present study, different polymers were investigated as potential calibration agents.

Comparison of Different Label-Free Raman Spectroscopy Approaches for the Discrimination of Clinical MRSA and MSSA Isolates.

Methicillin-resistant Staphylococcus aureus (MRSA) is classified as one of the priority pathogens that threaten human health. Resistance detection with conventional microbiological methods takes several days, forcing physicians to administer empirical antimicrobial treatment that is not always appropriate. A need exists for a rapid, accurate, and cost-effective method that allows targeted antimicrobial therapy in limited time.

Raman spectroscopy for the differentiation of : a comparison of two methods.

Enterobacteriaceae are the leading cause of urinary tract infections, and include pathogens such as , and Due to their similarity, the correct identification of these pathogens is difficult and time-consuming. Raman spectroscopy has been demonstrated extensively as a tool for rapid microbiological differentiation. However, for pathogenic Enterobacteriaceae the application of Raman spectroscopy has been particularly challenging.

Phenotypic Differentiation of Autotrophic and Heterotrophic Bacterial Cells Using Raman-DO Labeling.

Carbon cycling is one of the major biogeochemical processes driven by bacteria. Autotrophic bacteria convert carbon dioxide (CO) into organic compounds that are used by heterotrophs. Mixotrophic bacteria can employ both autotrophy and heterotrophy for growth.

Label-free differentiation of clinical E. coli and Klebsiella isolates with Raman spectroscopy.

Raman spectroscopy is a promising spectroscopic technique for microbiological diagnostics. In routine diagnostic, the differentiation of pathogens of the Enterobacteriaceae family remain challenging. In this study, Raman spectroscopy was applied for the differentiation of 24 clinical E.

In Vitro Fiber-Probe-Based Identification of Pathogens in Biofilms by Raman Spectroscopy.

Biofilms are the preferred habitat of microorganisms on living and artificial surfaces. Biofilm-related infections, such as infections of medical implants, are difficult to treat, and due to a reduced cultivability of the included bacteria, difficult to diagnose. Therefore, it is highly important to rapidly identify and investigate biofilms on implant surfaces, e.

Fiber Probe-Based Raman Spectroscopic Identification of Pathogenic Infection Microorganisms on Agar Plates.

Rapid identification of microorganisms is clinically meaningful, and it helps to decelerate the spread of drug resistance and improve patient treatment. In this study, we present a rapid fiber probe-based Raman technique with an excitation wavelength of 785 nm, which is applied to classify and identify nine different species of microorganisms. The cost-effective fiber probe compresses the dimension of the system and provides a more reliable and stable database.

Influence of the preparation design on the survival probability of occlusal veneers.

Objectives: The fracture resistance of ultrathin computer-aided design and computer-aided manufacturing (CAD/CAM) occlusal veneers with different preparation designs was investigated under cycling mechanical loading and via finite element analysis (FEA).

Methods: Eighty molars were prepared with a circular enamel ring until complete exposure of the occlusal dentin occurred. Forty were prepared via additional circular chamfer preparation.

Detection of multi-resistant clinical strains of E. coli with Raman spectroscopy.

In recent years, we have seen a steady rise in the prevalence of antibiotic-resistant bacteria. This creates many challenges in treating patients who carry these infections, as well as stopping and preventing outbreaks. Identifying these resistant bacteria is critical for treatment decisions and epidemiological studies.

Nondestructive 3D imaging and quantification of hydrated biofilm matrix by confocal Raman microscopy coupled with non-negative matrix factorization.

Biofilms are ubiquitous in natural and engineered environments and of great importance in drinking water distribution and biological wastewater treatment systems. Simultaneously acquiring the chemical and structural information of the hydrated biofilm matrix is essential for the cognition and regulation of biofilms in the environmental field. However, the complexity of samples and the limited approaches prevent a holistic understanding of the biofilm matrix.

Bolstering fitness via CO fixation and organic carbon uptake: mixotrophs in modern groundwater.

Current understanding of organic carbon inputs into ecosystems lacking photosynthetic primary production is predicated on data and inferences derived almost entirely from metagenomic analyses. The elevated abundances of putative chemolithoautotrophs in groundwaters suggest that dark CO fixation is an integral component of subsurface trophic webs. To understand the impact of autotrophically fixed carbon, the flux of CO-derived carbon through various populations of subsurface microbiota must first be resolved, both quantitatively and temporally.

Effects of application method on shrinkage vectors and volumetric shrinkage of bulk-fill composites in class-II restorations.

Objectives: Upon initial proximal wall construction, the favorable C-factor of class-II cavities may become unfavorable. This study investigated the application method on bulk-fill resin composite polymerization shrinkage.

Methods: Occluso-proximal class-II cavities were prepared in 40 molars and bonded with a self-etch adhesive (Adhese Universal).

Raman Stable Isotope Probing of Bacteria in Visible and Deep UV-Ranges.

Raman stable isotope probing (Raman-SIP) is an excellent technique that can be used to access the overall metabolism of microorganisms. Recent studies have mainly used an excitation wavelength in the visible range to characterize isotopically labeled bacteria. In this work, we used UV resonance Raman spectroscopy (UVRR) to evaluate the spectral red-shifts caused by the uptake of isotopes (C, N, H(D) and O) in cells.

Isolation of bacteria from artificial bronchoalveolar lavage fluid using density gradient centrifugation and their accessibility by Raman spectroscopy.

Raman spectroscopy is an analytical method to identify medical samples of bacteria. Because Raman spectroscopy detects the biochemical properties of a cell, there are many factors that can influence and modify the Raman spectra of bacteria. One possible influence is a proper method for isolation of the bacteria.

Monitoring Deuterium Uptake in Single Bacterial Cells via Two-Dimensional Raman Correlation Spectroscopy.

Raman-stable isotope labeling using heavy water (Raman-DO) is attracting great interest as a fast technique with various applications ranging from the identification of pathogens in medical samples to the determination of microbial activity in the environment. Despite its widespread applications, little is known about the fundamental processes of hydrogen-deuterium (H/D) exchange, which are crucial for understanding molecular interactions in microorganisms. By combining two-dimensional (2D) correlation spectroscopy and Raman deuterium labeling, we have investigated H/D exchange in bacterial cells under time dependence.