scholarly journals Using MALDI-TOF spectra in epidemiological surveillance for the detection of bacterial subgroups with a possible epidemic potential

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Audrey Giraud-Gatineau ◽  
Gaetan Texier ◽  
Pierre-Edouard Fournier ◽  
Didier Raoult ◽  
Hervé Chaudet
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epidemiological Surveillance ◽  
Routine Activity ◽  
Spectra Analysis ◽  
Essential Information ◽  
Maldi Tof ◽  
Analysis Process ◽  
Close Proximity ◽  
Reference Databases ◽  
Real Time Identification

Abstract Background For the purpose of epidemiological surveillance, the Hospital University Institute Méditerranée infection has implemented since 2013 a system named MIDaS, based on the systematic collection of routine activity materials, including MALDI-TOF spectra, and results. The objective of this paper is to present the pipeline we use for processing MALDI-TOF spectra during epidemiological surveillance in order to disclose proteinic cues that may suggest the existence of epidemic processes in complement of incidence surveillance. It is illustrated by the analysis of an alarm observed for Streptococcus pneumoniae. Methods The MALDI-TOF spectra analysis process looks for the existence of clusters of spectra characterized by a double time and proteinic close proximity. This process relies on several specific methods aiming at contrasting and clustering the spectra, presenting graphically the results for an easy epidemiological interpretation, and for determining the discriminating spectra peaks with their possible identification using reference databases. Results The use of this pipeline in the case of an alarm issued for Streptococcus pneumoniae has made it possible to reveal a cluster of spectra with close proteinic and temporal distances, characterized by the presence of three discriminant peaks (5228.8, 5917.8, and 8974.3 m/z) and the absence of peak 4996.9 m/z. A further investigation on UniProt KB showed that peak 5228.8 is possibly an OxaA protein and that the absent peak may be a transposase. Conclusion This example shows this pipeline may support a quasi-real time identification and characterization of clusters that provide essential information on a potentially epidemic situation. It brings valuable information for epidemiological sensemaking and for deciding on the continuation of the epidemiological investigation, in particular the involving of additional costly resources to confirm or invalidate the alarm. Clinical trials registration NCT03626987.

scholarly journals Using MALDI-TOF spectra in epidemiological surveillance for the detection of bacterial subgroups with a possible epidemic potential

2021 ◽  
Author(s):  
Audrey Giraud-Gatineau ◽  
Gaetan Texier ◽  
Pierre-Edouard Fournier ◽  
Didier Raoult ◽  
Hervé Chaudet
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epidemiological Surveillance ◽  
Routine Activity ◽  
Spectra Analysis ◽  
Essential Information ◽  
Maldi Tof ◽  
Analysis Process ◽  
Data Protection Authority ◽  
Reference Databases ◽  
Real Time Identification

Abstract Background For the purpose of epidemiological surveillance, the Hospital University Institute Méditerranée infection has implemented since 2013 a system named MIDaS, based on the systematic collection of routine activity materials, including MALDI-TOF spectra, and results. The objective of this paper is to present the pipeline we use for processing MALDI-TOF spectra during epidemiological surveillance in order to disclose proteinic cues that may suggest the existence of epidemic processes in complement of incidence surveillance. It is illustrated by the analysis of an alarm observed for Streptococcus pneumoniae.Methods The MALDI-TOF spectra analysis process looks for the existence of clusters of spectra characterized by a double time and proteinic close proximity. This process relies on several specific methods aiming at contrasting and clustering the spectra, presenting graphically the results for an easy epidemiological interpretation, and for determining the discriminating spectra peaks with their possible identification using reference databases. Results The use of this pipeline in the case of an alarm issued for Streptococcus pneumoniae has made it possible to reveal a cluster of spectra with close proteinic and temporal distances, characterized by the presence of three discriminant peaks (5228.8, 5917.8, and 8974.3 m/z) and the absence of peak 4996.9 m/z. A further investigation on UniProt KB showed that peak 5228.8 is possibly an OxaA protein and that the absent peak may be a transposase.Conclusion This example shows this pipeline may support a quasi-real time identification and characterization of clusters that provide essential information on a potentially epidemic situation. It brings valuable information for epidemiological sensemaking and for deciding on the continuation of the epidemiological investigation, in particular the involving of additional costly resources to confirm or invalidate the alarm. Clinical trials registration. NCT03626987Study authorization. This study has been allowed by the French Data Protection Authority (CNIL decision DR-2018-177).

scholarly journals Development of a novel MALDI-TOF MS-based bile solubility test for rapid discrimination of Streptococcus pneumoniae

2020 ◽  
Vol 310 (3) ◽  
pp. 151413 ◽  
Author(s):  
Evgeny A. Idelevich ◽  
Andreas Schlattmann ◽  
Markus Kostrzewa ◽  
Karsten Becker
Keyword(s):  
Streptococcus Pneumoniae ◽  
Solubility Test ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Rapid Discrimination ◽  
Tof Ms

MALDI-TOF MS protein profiling for the rapid identification of Chagas disease triatomine vectors and application to the triatomine fauna of French Guiana

Parasitology ◽  
2017 ◽  
Vol 145 (5) ◽  
pp. 665-675 ◽  
Author(s):  
MAUREEN LAROCHE ◽  
JEAN-MICHEL BÉRENGER ◽  
GLADYS GAZELLE ◽  
DENIS BLANCHET ◽  
DIDIER RAOULT ◽  
...  
Keyword(s):  
Chagas Disease ◽  
French Guiana ◽  
Protein Profiling ◽  
Epidemiological Surveillance ◽  
Human Populations ◽  
Morphological Identification ◽  
Correct Identification ◽  
Major Step ◽  
Blind Test ◽  
Maldi Tof

SUMMARYTriatomines are haematophagous insects involved in the transmission of Trypanosoma cruzi, the aetiological agent of Chagas disease. The vector competence of these arthropods can be highly variable, depending on the species. A precise identification is therefore crucial for the epidemiological surveillance of T. cruzi and the determination of at-risk human populations. To circumvent the difficulties of morphological identification and the lack of comprehensiveness of the GenBank database, we hereby propose an alternative method for triatomine identification. The femurs of the median legs of triatomines from eight different species from French Guiana were subjected to matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis. Method evaluation was performed on fresh specimens and was applied to dry specimens collected between 1991 and 2003. Femur-derived protein extracts provided reproducible spectra within the same species along with significant interspecies heterogeneity. Validation of the study by blind test analysis provided 100% correct identification of the specimens in terms of the species, sex and developmental stage. MALDI-TOF mass spectrometry appears to be a powerful tool for triatomine identification, which is a major step forward in the fight against Chagas disease.

scholarly journals Growth of Streptococcus pneumoniae on Human Glycoconjugates Is Dependent upon the Sequential Activity of Bacterial Exoglycosidases

2007 ◽  
Vol 190 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Amanda M. Burnaugh ◽  
Laura J. Frantz ◽  
Samantha J. King
Keyword(s):  
Streptococcus Pneumoniae ◽  
Host Defense ◽  
Sole Source ◽  
Epithelial Surface ◽  
Human Host ◽  
Close Proximity ◽  
Defense Molecules

ABSTRACT In the human host, Streptococcus pneumoniae encounters a variety of glycoconjugates, including mucin, host defense molecules, and glycans associated with the epithelial surface. S. pneumoniae is known to encode a number of glycosidases that may modify these glycoconjugates in vivo. Three exoglycosidases, a neuraminidase (NanA), β-galactosidase (BgaA), and N-acetylglucosaminidase (StrH), have been previously demonstrated to sequentially deglycosylate N-linked glycans on host defense molecules, which coat the pneumococcal surface in vivo. This cleavage is proposed to alter the clearance function of these molecules, allowing pneumococci to persist in the airway. However, we propose that the exoglycosidase-dependent liberation of monosaccharides from these glycoconjugates in close proximity to the pneumococcal surface provides S. pneumoniae with a convenient source of fermentable carbohydrate in vivo. In this study, we demonstrate that S. pneumoniae is able to utilize complex N-linked human glycoconjugates as a sole source of carbon to sustain growth and that efficient growth is dependent upon the sequential deglycosylation of the glycoconjugate substrate by pneumococcal exoglycosidases. In addition to demonstrating a role for NanA, BgaA, and StrH, we have identified a function for the second pneumococcal neuraminidase, NanB, in the deglycosylation of host glycoconjugates and have demonstrated that NanB activity can partially compensate for the loss or dysfunction of NanA. To date, all known functions of pneumococcal neuraminidase have been attributed to NanA. Thus, this study describes the first proposed role for NanB by which it may contribute to S. pneumoniae colonization and pathogenesis.

scholarly journals Interaction of Albumin and Immunoglobulin G with Synthetic Hydroxyapatite

2012 ◽  
Vol 7 (2) ◽  
pp. 143-146
Author(s):  
E. Pylypchuk ◽  
V. Mishchenko ◽  
T. Yu. Gromovoy
Keyword(s):  
Mass Spectrometry ◽  
Ir Spectra ◽  
Phase Analysis ◽  
Immunoglobulin G ◽  
Spectra Analysis ◽  
X Ray ◽  
Maldi Tof Mass Spectrometry ◽  
Partial Dissolution ◽  
Maldi Tof ◽  
Synthetic Hydroxyapatite

It was shown by X-ray phase analysis, IR spectra analysis and MALDI-ToF mass spectrometry methods that interaction of synthetic hydroxyapatite with a solution of immunoglobulin G leads to its partial dissolution due to leaching from the surface of calcium triphosphate which, in our opinion, forms complexes with immunoglobulin G.

scholarly journals Antimicrobial Resistance of Coagulase-Positive Staphylococcus Isolates Recovered in a Veterinary University Hospital

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 752
Author(s):  
Marta Pérez-Sancho ◽  
Sergio Alvarez-Perez ◽  
Teresa Garcia-Seco ◽  
Marta Hernandez ◽  
David Rodríguez-Lázaro ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Good Alternative ◽  
Species Level ◽  
University Hospital ◽  
Epidemiological Surveillance ◽  
Methicillin Resistant ◽  
Maldi Tof ◽  
Level Identification

The Staphylococcus pseudintermedius group (SIG) is an emerging threat in veterinary medicine, particularly methicillin-resistant (MRSP) isolates, which are frequently associated with multidrug resistance. Reliable identification of SIG members is critical to establish correct antimicrobial treatments. However, information on the molecular epidemiology and antimicrobial resistance patterns of MRSP in some regions is still limited. This study aimed to assess the antimicrobial resistance of SIG isolates recovered from animals at the Veterinary Teaching Hospital of Complutense University of Madrid (Spain) during a 10-year period (2007–2016). A total of 139 selected Staphylococcus isolates were subjected to species-level identification by different bioanalytical techniques (PCR, VITEK, MALDI-TOF) and subsequent antimicrobial susceptibility testing. Methicillin-resistant isolates (n = 20) were subjected to whole genome sequencing for further characterization of their antibiotic resistance determinants. Our results showed that there was a good correlation between PCR and MALDI-TOF identification, whereas VITEK showed very divergent results, thus confirming MALDI-TOF as a good alternative for species-level identification of coagulase-positive staphylococci. Notably, S. pseudintermedius, including the epidemic MRSP genotype ST71, was the only SIG species found among canine isolates. In addition, we found a high prevalence of multidrug resistance and resistance to fluoroquinolones, cephalosporins and macrolides. Finally, diverse genes associated with antibiotic resistance were detected among MRSP isolates, although the genetic basis of some of the resistant phenotypes (particularly to fluoroquinolones) could not be determined. In conclusion, our study reveals the circulation of MRSP in the veterinary setting in Spain, thus highlighting the emerging threat posed by this bacterial group and the need for further epidemiological surveillance.

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