maldi-tofms

Objective: To investigate the drug-resistant gene characteristics and core genome characteristics of carbapenem-resistant Enterobacter cloacae (CR-ECL) in rural residents of Weifang City, Shandong Province. Methods: Fecal samples were collected from rural community residents in Weifang City, Shandong Province in 2017. Drug-resistant strains were screened using a carbapenem-resistant enterobacter chromogenic medium. CR-ECL positive strains were acquired via Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry(MALDI-TOFMS) analysis...

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) is a suitable method for polymer analysis. MALDI is a soft ionization technique that can generate mainly singly charged ions. Therefore, the polymer's molecular weight distribution is easy to analyze, facilitating the calculation of the number average molecular weight and weight average molecular weight and polydispersity. However, there are polymers that are difficult to detect by MALDI-TOFMS. For example, polyacrylic acid includes carboxylic acid in the main chain, which is difficult to measure due to its low ionization efficiency...

When rare bacterial species are identified in blood cultures, determining the clinical significance is sometimes difficult. This study aimed to analyze the clinical significance of rare bacterial species detected in blood cultures using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOFMS) by comparing their contamination rates with those of common species. We retrospectively analyzed medical records of adult patients with positive blood cultures at Kyoto City Hospital from 2014 to 2022...

Balsam sulfide, produced by the reaction of turpentine/rosin and sulfur, has been used as one of the raw materials of liquid gold to decorate ceramics and tableware with thin gold film for more than 100 years. The characterization of balsam sulfide is still insufficient because of its compositional complexity. In this study, balsam sulfide was characterized using pyrolysis-gas chromatography (Py-GC)-mass spectrometry (MS) and Py-GC with sulfur chemiluminescence detection (SCD) as well as matrix-assisted laser desorption/ionization time-of-flight MS (MALDI-TOFMS)...

Vibrio parahaemolyticus causes seafood-borne gastroenteritis infection in human which can even lead to death. The pathogenic strain of V. parahaemolyticus secretes different types of virulence factors that are directly injected into the host cell by a different type of secretion system which helps bacteria to establish its own ecological niche within the organism. Therefore, the aim of this study was to isolate the extracellular secreted proteins from the trh positive strain of V. parahaemolyticus and identify them using two-dimensional gel electrophoresis and MALDI-TOFMS/MS...

RATIONALE: Linear mode of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been routinely used for bacterial identification in the clinic, depending on the pattern analysis of spectral libraries rather than accurate mass measurement of ribosomal proteins (10-15 kDa). However, a demand for more accurate mass analysis of pathogens (e.g. KPC-2 carbapenemase) has been recently increasing for diagnostic purposes. METHODS: We introduced a 6xHIS-tagged KPC-2 (i...

AIMS: In this study, we aimed to investigate previously unrecognized lipid metabolic perturbations in tamoxifen-resistant breast cancer (BC) by conducting comprehensive metabolomics and transcriptomics analysis. We identified the role of 3-hydroxy-3-methylglutary-coenzyme-A-synthase 2 (HMGCS2), a key enzyme responsible for ketogenesis, in tamoxifen-resistant BC growth. MAIN METHODS: Comprehensive metabolomics (CE-TOFMS, LC-TOFMS) and transcriptiomics analysis were performed to characterize metabolic pathways in tamoxifen-resistant BC cells...

This study presents "mouse tissue glycome atlas" representing the profiles of major N-glycans of mouse glycoproteins that may define their essential functions in the surface glycocalyx of mouse organs/tissues and serum-derived extracellular vesicles (exosomes). Cell surface glycocalyx composed of a variety of N-glycans attached covalently to the membrane proteins, notably characteristic "N-glycosylation patterns" of the glycocalyx, plays a critical role for the regulation of cell differentiation, cell adhesion, homeostatic immune response, and biodistribution of secreted exosomes...

Corynebacterium spp. are part of the human microbiome, but can cause the development of inflammatory diseases of various localization. Purpose - to evaluate the relationship between pathogenic properties and resistance to antimicrobial drugs (AMD) of Corynebacterium spp. from patients with inflammatory diseases of the respiratory tract. Strains of Corynebacterium spp. isolated from patients with inflammatory diseases of the respiratory tract (99 pcs.) and practically healthy individuals (33 pcs.). Isolates were identified by mass spectrometric method (MALDI-ToFMS), their adhesive and invasive activity on Hep-2 cells, cytopathic effect (CPE) in CHO-K1 cell culture, and resistance to antimicrobial drugs (AMD) were determined...

Comamonas species are rarely associated with human infections. Recent reports found that Comamonas kerstersii was associated with severe diseases such as abdominal infection and bacteremia. However, Comamonas kerstersii may be confused with Comamonas testosteroni using the automatic bacterial identification systems currently available. An 8-year-old boy who had a right iliac fossa pain and classic migration of pain at the temperature of 38.9°C. The positive strain of aerobic and anaerobic bottles of blood cultures was identified...

RATIONALE: Combining matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and Kendrick mass defect (KMD) analysis is a powerful tool for visualizing polymers in complex mass spectra. The identification of minor polymers by KMD analysis requires reduction of the broad noise peaks often observed at low mass region. METHODS: A machine-learning model was created using pix2pixHD. It converts an original mass spectrum to a pseudo-mass spectrum that contains only the original peaks at m/z positions that the model judges as sharp single-component peaks...

New insights into the structure of the hybrid κ/β-carrageenan (κ/β-CRG) of the red alga Tichocarpus crinitus have been obtained. Carrageenan oligosaccharides were prepared through the chemical and enzymatic depolymerization of κ/β-CRG with κ-carrageenase and its the enzyme-resistant fraction. The composition and distribution of the repetition units of κ/β- CRG were investigated by using the negative ion tandem MALDI-TOFMS and ESIMS method, which made it possible to prove and characterize the hybrid structure of this polysaccharide...

RATIONALE: The polyprenols are involved in some essential biosynthetic pathways and serve as ubiquitous components of cellular membranes, so their fingerprinting in natural samples is of great interest. Previous studies indicate that due to the high hydrophobicity of polyprenols their direct analysis by mass spectrometry with soft ionization techniques may be difficult and require preliminary off-line derivatization. Hence, a method for rapid and sensitive screening of polyprenols is required...

Two novel aqueous U IV complexes were synthesized by the interaction between the tetravalent uranium cation and the ( 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetra(methylene phosphonic acid) (DOTP) macrocyclic ligand. Two distinct homonuclear complexes were identified- the first was characterized by X-ray crystallography as a unique "out-of-cage", [U(DOTPH 6 ) 2 ] complex, in which the U IV cation is octa-coordinated to 4 phosphonic arms from each ligand in a square anti-prism geometry, with a C 4 symmetry...

Enterococci is one of a major cause of bloodstream infection (BSI). Because of its intrinsic drug-resistant nature, empiric antibiotic treatment tends to be inappropriate. We conducted a single-center retrospective cohort study to evaluate the impact of Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOFMS) on the improvement of early antibiotic treatment for enterococcal infection. We also investigated the 28-day mortality, length of hospitalization and duration of antibiotic treatment for enterococcal bacteremia...

Pancreatic ductal adenocarcinoma (PDAC) is an intractable malignancy for which novel therapeutic targets are in high demand. To uncover glycans expressed within PDAC, we previously performed glycome profiling of PDAC cell lines using lectin microarray and found that the lectin rBC2LCN with specificity to a Fucα1-2Galβ1-3 motif exhibited strong binding to a PDAC cell line (Capan-1) and to all tumor tissues derived from 69 pancreatic cancer patients. Nevertheless, no information was available as to whether glycans containing the Fucα1-2Galβ1-3 motif are expressed within PDAC...

Lactococci are Gram-positive cocci that occur in short chains or pairs and are traditionally considered to be of low virulence in human. Most species are not associated with human disease. There are few reports regarding Lactococcus isolation in humans and the clinical significance of this rarely-encountered genus is unknown. Here, we report a case of infectious spondylitis due to Lactococcus garvieae confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). A 77-year-old man was admitted to our hospital with back pain that had lasted 5 days...

Catalytic liquefaction of lignin is an attractive process for the production of fuels and chemicals, but it forms a wide range of liquid products from monomers to oligomers. Oligomers represent an important fraction of the products and their analysis is complex. Therefore, rapid characterization methods are needed in order to screen liquefaction conditions based on the distribution in monomers and oligomers. For this purpose, we propose UV spectroscopy as a fast and simple method to assess the composition of lignin-derived liquids...

Polyrotaxane (PR) is a necklace-like supramolecule comprised of cyclic components, such as cyclodextrin (CD), and a threading polymer capped with bulky end groups. PR exhibits peculiar mechanical properties attributed to the intermolecular cross-links with CD. Various CD molecules threaded on a linear PEG chain are often modified with chemical groups to add specific physicochemical properties. In general, the stoichiometry between CD and the PEG chain is a significant parameter that defines the unique physical properties of CD-based polyrotaxane (CD-PR)...

As a prebiotics, lactosucrose plays an important role in maintaining human gastrointestinal homeostasis. In this study, a thermostable enzyme from Arthrobacter sp. 10138 was screened from six β-fructofuranosidase-producing strains for the lactosucrose production and the coding gene was heterologously expressed in Escherichia coli for efficient expression. Recombinant β-fructofuranosidase was purified and biochemically characterized by MALDI-TOFMS spectrometry. The transfructosylation product by this recombinant enzyme was determined to be lactosucrose rather than other oligosaccharides or polysaccharides by HPLC and LC-MS...