Nanocomposites of Boronic Acid-functionalized Magnetic Multi-walled Carbon Nanotubes With Flexible Branched Polymers as a Novel Desorption/Ionization Matrix for the Capture and Direct Detection of cis-diol-flavonoid Compounds Coupled With MALDI-TOF-MS

2021 ◽  
pp. 128055
Author(s):  
FuKai Li ◽  
Min Wang ◽  
Jian Zhou ◽  
MengRui Yang ◽  
TongTong Wang
Keyword(s):  
Carbon Nanotubes ◽  
Boronic Acid ◽  
Direct Detection ◽  
Branched Polymers ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Tof Ms

scholarly journals Assessment of Reproducibility of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Bacterial and Yeast Identification

2015 ◽  
Vol 53 (7) ◽  
pp. 2349-2352 ◽  
Author(s):  
Lars F. Westblade ◽  
Omai B. Garner ◽  
Karen MacDonald ◽  
Constance Bradford ◽  
David H. Pincus ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Microbial Identification ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) has revolutionized the identification of clinical bacterial and yeast isolates. However, data describing the reproducibility of MALDI-TOF MS for microbial identification are scarce. In this study, we show that MALDI-TOF MS-based microbial identification is highly reproducible and can tolerate numerous variables, including differences in testing environments, instruments, operators, reagent lots, and sample positioning patterns. Finally, we reveal that samples of bacterial and yeast isolates prepared for MALDI-TOF MS identification can be repeatedly analyzed without compromising organism identification.

scholarly journals Occurrence of the p019 gene in the blaKPC-harbouring plasmids: adverse clinical impact for direct tracking of KPC-producing Klebsiella pneumoniae by MALDI-TOF MS

2021 ◽  
Author(s):  
Eva Gato ◽  
Ignacio Pedro Constanso ◽  
Bruno Kotska Rodiño-Janeiro ◽  
Paula Guijarro-Sánchez ◽  
Tyler Alioto ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Computational Analysis ◽  
Direct Detection ◽  
Clinical Impact ◽  
Mass Peak ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Direct Tracking ◽  
Geographical Locations ◽  
Tof Ms

MALDI-TOF MS has recently been used for the direct detection of KPC-producing isolates by analysis of the 11,109 Da mass peak representing the P019 protein. In this study we evaluate the presence of the 11,109 Da mass peak in a collection of 435 unduplicated K. pneumoniae clinical isolates. The prevalence of the P019 peak in the blaKPC K. pneumoniae isolates was 49.2% (32/65). The 11,109 Da mass peak was not observed in any of the other carbapenemase (319) or non carbapenemase producers (116). Computational analysis of the presence of the p019 gene was performed in the aforementioned carbapenemase-producing K. pneumoniae isolates fully characterized by WGS and in a further collection of 1,649 K. pneumoniae genomes included in EuSCAPE. Herein, we have demonstrated that the p019 gene is not exclusively linked to the pKpQil plasmid, but it is present in the following plasmids: IncFIB(K)/IncFII(K)/ColRNAI, IncFIB(pQil), IncFIB(pQil)/ColRNAI, IncFIB(pQil)/IncFII(K), IncFIB(K)/IncFII(K) and IncX3. Besides, we have proven the independent movement of the Tn4401 and the ISKpn31, of which the p019 gene is a component. The absence of the p019 gene was obvious in Col440I, Col(pHAD28), IncFIB(K)/IncX3/IncFII(K), IncFIB(K)/IncFII(K) plasmids. In addition, we also observed another plasmid in which neither Tn4401 nor ISKpn31 was found, IncP6. In the EuSCAPE, the occurrence of p019 varied from 0% to 100% among the different geographical locations. The adverse clinical impact of the diminished prevalence of the p019 gene within the plasmid encoding KPC-producing Klebsiella pneumoniae puts forward the need for reconsideration when applying this technique in a clinical setting.

scholarly journals Direct detection of humoral marker corelates of COVID-19, glycated HSA and hyperglycosylated IgG3, by MALDI-ToF mass spectrometry.

2021 ◽  
Author(s):  
Raymond Kruse Iles ◽  
Jason Kruse Iles ◽  
Raminta Zmuidinaite ◽  
Anna Gardiner ◽  
Jonathan Lacey ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Respiratory Distress ◽  
Direct Detection ◽  
Plasma Samples ◽  
Total Blood ◽  
Laser Desorption Mass Spectrometry ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Immune Correlates ◽  
Tof Ms

The prefusion Spike protein of SARS-CoV2 binds advanced glycation end product (AGE) glycated human serum albumin (HSA) and a higher mass, hyperglycosylated/glycated, IgG3, as determined by matrix assisted laser desorption mass spectrometry (MALDI-ToF MS). We set out to investigate if the total blood plasma of patients who had recovered from acute respiratory distress as a result of COVID-19, contained more glycated HSA and higher mass (glycosylated/glycated) IgG3 than those with only clinically mild or asymptomatic infections. A direct dilution and disulphide bond reduction method was development and applied to plasma samples from SARS-CoV2 seronegative (N = 30) and seropositive (N = 31) healthcare workers and 38 convalescent plasma samples from patients who had been admitted with acute respiratory distress syndrome (ARDS) associated with COVID-19. Patients recovering from COVID-19 ARDS had significantly higher mass, AGE-glycated HSA and higher mass IgG3 levels. This would indicate that increased levels and/or ratios of hyper-glycosylation (probably terminal sialic acid) IgG3 and AGE glycated HSA may be predisposition markers for development of ARDS as a result of COVID-19 infection. Furthermore, rapid direct analysis of plasma samples by MALDI-ToF MS for such humoral immune correlates of COVID-19 presents a feasible screening technology for the most at risk; regardless of age or known health conditions.

Sensitive dopamine recognition by boronic acid functionalized multi-walled carbon nanotubes

2007 ◽  
pp. 2345 ◽  
Author(s):  
Wei Wu ◽  
Huarui Zhu ◽  
Louzhen Fan ◽  
Dongfang Liu ◽  
Reinhard Renneberg ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Boronic Acid ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals Direct Detection and Identification of Bacterial Pathogens from Urine with Optimized Specimen Processing and Enhanced Testing Algorithm

2017 ◽  
Vol 55 (5) ◽  
pp. 1488-1495 ◽  
Author(s):  
Bin Huang ◽  
Lei Zhang ◽  
Weizheng Zhang ◽  
Kang Liao ◽  
Shihong Zhang ◽  
...  
Keyword(s):  
Predictive Value ◽  
Urine Culture ◽  
Direct Detection ◽  
Bacterial Pathogens ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Detection And Identification ◽  
Specimen Processing ◽  
Tract Infections ◽  
Tof Ms

ABSTRACT Rapid and accurate detection and identification of microbial pathogens causing urinary tract infections allow prompt and specific treatment. We optimized specimen processing to maximize the limit of detection (LOD) by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) and evaluated the capacity of combination of MALDI-TOF MS and urine analysis (UA) for direct detection and identification of bacterial pathogens from urine samples. The optimal volumes of processed urine, formic acid/acetonitrile, and supernatant spotted onto the target plate were 15 ml, 3 μl, and 3 μl, respectively, yielding a LOD of 1.0 × 10 5 CFU/ml. Among a total of 1,167 urine specimens collected from three hospital centers, 612 (52.4%) and 351 (30.1%) were, respectively, positive by UA and urine culture. Compared with a reference method comprised of urine culture and 16S rRNA gene sequencing, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MALDI-TOF MS alone and MALDI-TOF MS coupled with UA were 86.6% versus 93.4% (χ 2 = 8.93; P < 0.01), 91.5% versus 96.3% (χ 2 = 7.06; P < 0.01), 81.5% versus 96.4% (χ 2 = 37.32; P < 0.01), and 94.1% versus 93.1% (χ 2 = 0.40; P > 0.05), respectively. No significant performance differences were revealed among the three sites, while specificity and NPV of MALDI-TOF MS for males were significantly higher than those for females (specificity, 94.3% versus 77.3%, χ 2 = 44.90, P < 0.01; NPV, 95.5% versus 86.1%, χ 2 = 18.85, P < 0.01). Our results indicated that the optimization of specimen processing significantly enhanced analytical sensitivity and that the combination of UA and MALDI-TOF MS provided an accurate and rapid detection and identification of bacterial pathogens directly from urine.

scholarly journals Matrix-Assisted Laser Desorption Ionization–Time of Flight (MALDI-TOF) Mass Spectrometry for Detection of Antibiotic Resistance Mechanisms: from Research to Routine Diagnosis

2013 ◽  
Vol 26 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Jaroslav Hrabák ◽  
Eva Chudáčková ◽  
Radka Walková
Keyword(s):  
Antibiotic Resistance ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

SUMMARYMatrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) has been successfully applied as an identification procedure in clinical microbiology and has been widely used in routine laboratory practice because of its economical and diagnostic benefits. The range of applications of MALDI-TOF MS has been growing constantly, from rapid species identification to labor-intensive proteomic studies of bacterial physiology. The purpose of this review is to summarize the contribution of the studies already performed with MALDI-TOF MS concerning antibiotic resistance and to analyze future perspectives in this field. We believe that current research should continue in four main directions, including the detection of antibiotic modifications by degrading enzymes, the detection of resistance mechanism determinants through proteomic studies of multiresistant bacteria, and the analysis of modifications of target sites, such as ribosomal methylation. The quantification of antibiotics is suggested as a new approach to study influx and efflux in bacterial cells. The results of the presented studies demonstrate that MALDI-TOF MS is a relevant tool for the detection of antibiotic resistance and opens new avenues for both clinical and experimental microbiology.

scholarly journals Effect of Culture Conditions on Microorganism Identification by Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

2005 ◽  
Vol 71 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Nancy Valentine ◽  
Sharon Wunschel ◽  
David Wunschel ◽  
Catherine Petersen ◽  
Karen Wahl
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used to identify bacteria based upon protein signatures. This research shows that while some different proteins are produced by vegetative bacteria when they are cultured in different growth media, positive identification with MALDI-TOF MS is still possible with the protocol established at the Pacific Northwest National Laboratory (K. H. Jarman, S. T. Cebula, A. J. Saenz, C. E. Petersen, N. B. Valentine, M. T. Kingsley, and K. L. Wahl, Anal. Chem. 72:1217-1223, 2000). A core set of small proteins remain constant under at least four different culture media conditions and blood agar plates, including minimal medium M9, rich media, tryptic soy broth (TSB) or Luria-Bertani (LB) broth, and blood agar plates, such that analysis of the intact cells by matrix-assisted laser desorption/ionization mass spectrometry allows for consistent identification.

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