MALDI-TOF analysis of seasonal dynamics of Lactic Acid Bacteria from Algerian Goat Milk suggests predominance of Enterococcus Genus

2018 ◽  
Vol 7 (4) ◽  
pp. 173-180
Author(s):  
Nawal Benkrizi ◽  
Abdelkader Homrani ◽  
Ahmed Bekada ◽  
Naima Meghoufel ◽  
Djilali Benbouziane ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Goat Milk ◽  
Laser Desorption ◽  
Spectrometry Method ◽  
Maldi Tof ◽  
The Matrix ◽  
Aroma Production ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

The goat milk is considered as nutraceutical due to its several beneficial com-pounds that increase its value. The purpose of this study was to investigate the variation of the goat milk’s lactic profile during winter and spring (2015). Several tests were realised. First, the isolation of the lactic acid bacteria con-tained in goat milk was realised by three specific media: the MRS, the M17, and the MSE. Second, a screening by the study of the proteolysis at two different concentration of casein (2%, 5%) and the study of aroma production were made to highlight performing isolates. These performing isolates were identified by using a precision spectrometry method which is called the Matrix Assisted Laser Desorption Ionisation Time-of-flight (MALDI-TOF). The identification with mass spectrometry «MALDI-TOF» technique revealed that those seasons had a more quantitative effect than a qualitative one. As a result, an average of 48% of lactic acid bacteria was identified for both sea-sons with a decrease of 6% observed in winter. In addition, it was revealed that Enterococcus was the most dominant genus in the Algerian goat milk. Therefore, lactic strains of this milk were proved to be technologically com-petent in terms of proteolysis and aroma production.

Tannins analysis from different medicinal plants extracts using MALDI-TOF and MEKC

2016 ◽  
Vol 70 (4) ◽  
Author(s):  
Alina Oana Matei ◽  
Florentina Gatea ◽  
Eugenia Dumitra Teodor ◽  
Gabriel Lucian Radu
Keyword(s):  
Mass Spectrometry ◽  
Micellar Electrokinetic Chromatography ◽  
Epigallocatechin Gallate ◽  
Laser Desorption ◽  
Epicatechin Gallate ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
The Matrix ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

AbstractThe matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF) and micellar electrokinetic chromatography (MEKC) methods were used to identify and quantify five tannins, (+)-catechin, (–)-epigallocatechin, (–)-epigallocatechin gallate, (–)-epicatechin gallate and (–)-epicatechin, from aqueous, ethanolic and acetonic extracts of

scholarly journals Identification of Adult Fasciola spp. Using Matrix-Assisted Laser/Desorption Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry

2020 ◽  
Vol 9 (1) ◽  
pp. 82
Author(s):  
Issa Sy ◽  
Lena Margardt ◽  
Emmanuel O. Ngbede ◽  
Mohammed I. Adah ◽  
Saheed T. Yusuf ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Specific Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Species Specific ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Fascioliasis is a neglected trematode infection caused by Fasciola gigantica and Fasciola hepatica. Routine diagnosis of fascioliasis relies on macroscopic identification of adult worms in liver tissue of slaughtered animals, and microscopic detection of eggs in fecal samples of animals and humans. However, the diagnostic accuracy of morphological techniques and stool microscopy is low. Molecular diagnostics (e.g., polymerase chain reaction (PCR)) are more reliable, but these techniques are not routinely available in clinical microbiology laboratories. Matrix-assisted laser/desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) is a widely-used technique for identification of bacteria and fungi; yet, standardized protocols and databases for parasite detection need to be developed. The purpose of this study was to develop and validate an in-house database for Fasciola species-specific identification. To achieve this goal, the posterior parts of seven adult F. gigantica and one adult F. hepatica were processed and subjected to MALDI-TOF MS to create main spectra profiles (MSPs). Repeatability and reproducibility tests were performed to develop the database. A principal component analysis revealed significant differences between the spectra of F. gigantica and F. hepatica. Subsequently, 78 Fasciola samples were analyzed by MALDI-TOF MS using the previously developed database, out of which 98.7% (n = 74) and 100% (n = 3) were correctly identified as F. gigantica and F. hepatica, respectively. Log score values ranged between 1.73 and 2.23, thus indicating a reliable identification. We conclude that MALDI-TOF MS can provide species-specific identification of medically relevant liver flukes.

scholarly journals Characterization of Potential Protein Biomarkers for Major Depressive Disorder Using Matrix-Assisted Laser Desorption Ionization/Time-of-Flight Mass Spectrometry

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4457
Author(s):  
Chieh-Hsin Lin ◽  
Hung Su ◽  
Chung-Chieh Hung ◽  
Hsien-Yuan Lane ◽  
Jentaie Shiea
Keyword(s):  
Mass Spectrometry ◽  
Time Of Flight ◽  
Laser Desorption ◽  
Healthy Controls ◽  
Laser Desorption Ionization ◽  
Major Depressive ◽  
Ionization Time ◽  
Maldi Tof ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometry is a sensitive analytical tool for characterizing various biomolecules in biofluids. In this study, MALDI-TOF was used to characterize potential plasma biomarkers for distinguishing patients with major depressive disorder (MDD) from patients with schizophrenia and healthy controls. To avoid interference from albumin—the predominant protein in plasma—the plasma samples were pretreated using acid hydrolysis. The results obtained by MALDI-TOF were also validated by electrospray ionization-quadrupole time-of-flight (ESI-QTOF) mass spectrometry. The analytical results were further treated with principal component analysis (PCA), hierarchical clustering analysis (HCA), and receiver operating characteristic (ROC) curve analysis. The statistical analyses showed that MDD patients could be distinguished from schizophrenia patients and healthy controls by the lack of apolipoprotein C1 (Apo C1), which, in fact, was detected in healthy controls and schizophrenia patients. This protein is suggested to be a potential plasma biomarker for distinguishing MDD patients from healthy controls and schizophrenia patients. Since sample preparation for MALDI-TOF is very simple, high-throughput plasma apolipoprotein analysis for clinical purposes is feasible.

scholarly journals Performance of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry for Identifying Clinical Malassezia Isolates

2016 ◽  
Vol 55 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Julie Denis ◽  
Marie Machouart ◽  
Florent Morio ◽  
Marcela Sabou ◽  
Catherine Kauffmann-LaCroix ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Time Of Flight ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Content Type ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT The genus Malassezia comprises commensal yeasts on human skin. These yeasts are involved in superficial infections but are also isolated in deeper infections, such as fungemia, particularly in certain at-risk patients, such as neonates or patients with parenteral nutrition catheters. Very little is known about Malassezia epidemiology and virulence. This is due mainly to the difficulty of distinguishing species. Currently, species identification is based on morphological and biochemical characteristics. Only molecular biology techniques identify species with certainty, but they are time-consuming and expensive. The aim of this study was to develop and evaluate a matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) database for identifying Malassezia species by mass spectrometry. Eighty-five Malassezia isolates from patients in three French university hospitals were investigated. Each strain was identified by internal transcribed spacer sequencing. Forty-five strains of the six species Malassezia furfur , M. sympodialis , M. slooffiae , M. globosa , M. restricta , and M. pachydermatis allowed the creation of a MALDI-TOF database. Forty other strains were used to test this database. All strains were identified by our Malassezia database with log scores of >2.0, according to the manufacturer's criteria. Repeatability and reproducibility tests showed a coefficient of variation of the log score values of <10%. In conclusion, our new Malassezia database allows easy, fast, and reliable identification of Malassezia species. Implementation of this database will contribute to a better, more rapid identification of Malassezia species and will be helpful in gaining a better understanding of their epidemiology.

The Identification of Microbial Pathogens Using Matrix Assisted Laser Desorption Ionization Time of Flight in Medical Intensive Care Unit Beni-Suef University Hospital

2021 ◽  
Vol 30 (3) ◽  
pp. 65-69
Author(s):  
Marwa N. Mohamed ◽  
Ahmed F. Azmy ◽  
Ehab M. Fahmy ◽  
Mervat G. Elanany ◽  
Nesreen M. Kamel
Keyword(s):  
Time Of Flight ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Microbial Identification ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Kappa Agreement ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Background: Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) is a novel technique for identification of microbes. This new method led to a new era in microbial identification because of its rapid, accurate, valid, simple and relatively decreased cost. Objectives: The aim of this study was identification of predominant pathogens by MALDI-TOF technique. Methodology: Pathogens were identified by both conventional methods and MALDI-TOF. Results: From July till December 2018, predominant pathogens were Klebsiella pneumoniae (21%), Pseudomonas aeroguinosa and Candida each constitutes (17%), E-coli (10%), Staph. aureus (9%), Acinetobacter (9%). Identification of isolates (from September to December 2018) by MALDI-TOF revealed a total agreement of (94.1%) with conventional method at genus level, (88.2%) at level of species. Kappa agreement revealed almost perfect correlation between both techniques. Conclusion: The MALDI-TOF results might suggest that its’ usage may be dependable for microbiological identification.

scholarly journals Lineage and serotype identification of Listeria monocytogenes by matrix-assisted laser desorption ionization-time of flight mass spectrometry

2019 ◽  
Vol 36 (No. 6) ◽  
pp. 452-458 ◽  
Author(s):  
Štěpán Koudelka ◽  
Tereza Gelbíčová ◽  
Markéta Procházková ◽  
Renáta Karpíšková
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Serotype Identification ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

The identification of Listeria species, lineages and serotypes remains a crucial issue not only in epidemic surveys, but also in monitoring of the diversity of bacteria in the food chain. The aim of this study was identification of L. monocytogenes strains at lineage and serotype level using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The performance of MALDI-TOF MS was tested to identify L. monocytogenes into two lineages (I and II) and four serotypes (1/2a, 1/2b, 1/2c and 4b) the most commonly found in humans and food. Total of 227 L. monocytogenes strains from different sources were subjected to the study. Some of strains (112) were used for main spectrum profile (MSP) library creation. Other strains of interest (115) were then correctly identified on the lineage level comparing with the library by MALDI-TOF MS analysis using Biotyper (90%) and ClinPro Tools (100%) software. The serotype identification with 55.7% (Biotyper) and 67.8% (ClinPro Tools) accuracy is rather a proof that under given conditions the method has not big potential to be used for serotyping. However, MALDI-TOF MS has a potential to identify lineages of L. monocytogenes of food and human origin.

scholarly journals An improved simple method for the identification of Mycobacteria by MALDI-TOF MS (Matrix-Assisted Laser Desorption- Ionization mass spectrometry)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Adela Alcolea-Medina ◽  
M. T. Cabezas Fernandez ◽  
N. Montiel ◽  
M. P. Luzón García ◽  
C. Delamo Sevilla ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Ionization Mass ◽  
Laser Desorption Ionization ◽  
Isolation And Identification ◽  
Simple Method ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

AbstractThe aim of this study was to establish a simple method for the rapid identification of Mycobacteria species by MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass spectrometry) using the Bruker MALDI-TOF Biotyper system (Bruker Daltonik, Bremen, Germany). A multicentre, prospective, and single blind study was performed in three European Hospitals, two Spanish and one UK hospital from May to August 2018. The BD BACTEC MGIT (Becton Dickinson, Berks, UK) liquid culture system was used in all three centres for the growth of Mycobacteria. When signal positive, tubes were removed from the analyser and in addition to standard laboratory procedures were subcultured on blood agar plates for MALDI-TOF analysis. Plates were incubated aerobically for 1 to 7 days at 37 °C and inspected every day. Once any growth was visible, it was transferred to the steel target plate, overlaid with 1 μl of neat formic acid and 1 μl HCCA matrix (alpha hydroxyl 4 cinnamic acid), and analysed in a Bruker Biotyper MALDI-TOF. Results given by MALDI-TOF were compared with the reference methods used for identification in the different centres. At two Spanish hospitals, identification by MALDI-TOF was only attempted on presumptive non-tuberculosis mycobacteria (NTM) and the results were initially compared with the results obtained by a commercial reverse hybridisation assay, GenoType CM/AS (Hain Lifescience, Tübingen, Germany). At the UK Hospital, identification of any presumptive mycobacteria was attempted and compared with the results obtained by whole genome sequencing (WGS). Overall in 142/167 (85%) of cases the identifications obtained were concordant; all Mycobacterium tuberculosis (MTB) isolates 43/43 (100%), 57/76 (75%) of the rapid growing nontuberculous mycobacteria (NTM), and 42/48 (85%) slow growing NTM tested were identified correctly. We report a new, easy, cheap and quick method for isolation and identification of Mycobacterium spp. without the need for additional steps or equipment and this method is in routine used in all three centres.

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