scholarly journals Differentiation of Gastric Helicobacter Species Using MALDI-TOF Mass Spectrometry

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 366
Author(s):  
Helena Berlamont ◽  
Chloë De Witte ◽  
Sofie De Bruyckere ◽  
James G. Fox ◽  
Steffen Backert ◽  
...  
Keyword(s):  
Species Identification ◽  
Growth Conditions ◽  
Reference Database ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Animal Pathogens ◽  
H Pylori ◽  
Specific Species ◽  
Individual Mass ◽  
Tof Ms

Gastric helicobacters (Helicobacter (H.) pylori and non-H. pylori Helicobacter species (NHPHs)) colonize the stomach of humans and/or animals. Helicobacter species identification is essential since many of them are recognized as human and/or animal pathogens. Currently, Helicobacter species can only be differentiated using molecular methods. Differentiation between NHPHs using MALDI-TOF MS has not been described before, probably because these species are poorly represented in current MALDI-TOF MS databases. Therefore, we identified 93 gastric Helicobacter isolates of 10 different Helicobacter species using MALDI-TOF MS in order to establish a more elaborate Helicobacter reference database. While the MALDI Biotyper database was not able to correctly identify any of the isolates, the in-house database correctly identified all individual mass spectra and resulted in 82% correct species identification based on the two highest log score matches (with log scores ≥2). In addition, a dendrogram was constructed using all newly created main spectrum profiles. Nine main clusters were formed, with some phylogenetically closely related Helicobacter species clustering closely together and well-defined subclusters being observed in specific species. Current results suggest that MALDI-TOF MS allows rapid differentiation between gastric Helicobacter species, provided that an extensive database is at hand and variation due to growth conditions and agar-medium-related peaks are taken into account.

scholarly journals Performance of Five Commercial Identification Platforms for Identification of Staphylococcus delphini

2019 ◽  
Vol 57 (11) ◽  
Author(s):  
Matthew C. Canver ◽  
Tsigereda Tekle ◽  
Samantha T. Compton ◽  
Katrina Callan ◽  
Eileen M. Burd ◽  
...  
Keyword(s):  
Distinct Species ◽  
Human Infection ◽  
Species Level ◽  
Accurate Identification ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Staphylococcus Intermedius ◽  
Animal Pathogens ◽  
Tof Ms

ABSTRACT The Staphylococcus intermedius group (SIG) is a collection of coagulase-positive staphylococci consisting of four distinct species, namely, Staphylococcus cornubiensis, Staphylococcus delphini, Staphylococcus intermedius, and Staphylococcus pseudintermedius. SIG members are animal pathogens and rare causes of human infection. Accurate identification of S. pseudintermedius has important implications for interpretation of antimicrobial susceptibility testing data and may be important for other members of the group. Therefore, we sought to evaluate the performance of five commercially available identification platforms with 21 S. delphini isolates obtained from a variety of animal and geographic sources. Here, we show that automated biochemical platforms were unable to identify S. delphini to the species level, a function of its omission from their databases, but could identify isolates to the SIG level with various degrees of success. However, all automated systems misidentified at least one isolate as Staphylococcus aureus. One matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) system was able to identify S. delphini to the species level, suggesting that MALDI-TOF MS is the best option for distinguishing members of the SIG. With the exception of S. pseudintermedius, it is unclear if other SIG members should be routinely identified to the species level; however, as our understanding of their role in animal and human diseases increases, it may be necessary and important to do so.

Species identification of Streptococcus bovis group isolates causing bacteremia: a comparison of two MALDI-TOF MS systems

2017 ◽  
Vol 88 (1) ◽  
pp. 23-25 ◽  
Author(s):  
Charlotte N. Agergaard ◽  
Elisa Knudsen ◽  
Rimtas Dargis ◽  
Xiaohui C. Nielsen ◽  
Jens J. Christensen ◽  
...  
Keyword(s):  
Species Identification ◽  
Streptococcus Bovis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

The influence of growth conditions on MALDI-TOF MS spectra of winemaking yeast: Implications for industry applications

2021 ◽  
pp. 106280
Author(s):  
Junwen Zhang ◽  
Jeffrey E. Plowman ◽  
Bin Tian ◽  
Stefan Clerens ◽  
Stephen L.W. On
Keyword(s):  
Growth Conditions ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Industry Applications ◽  
Tof Ms

Black aspergilli: A remaining challenge in fungal taxonomy?

2018 ◽  
Vol 57 (6) ◽  
pp. 773-780 ◽  
Author(s):  
Elizabet D’hooge ◽  
Pierre Becker ◽  
Dirk Stubbe ◽  
Anne-Cécile Normand ◽  
Renaud Piarroux ◽  
...  
Keyword(s):  
Antifungal Susceptibility ◽  
Identification Accuracy ◽  
Clinical Isolates ◽  
Reference Database ◽  
Data Set ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms

AbstractAspergillus section Nigri is a taxonomically difficult but medically and economically important group. In this study, an update of the taxonomy of A. section Nigri strains within the BCCM/IHEM collection has been conducted. The identification accuracy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was tested and the antifungal susceptibilities of clinical isolates were evaluated. A total of 175 strains were molecularly analyzed. Three regions were amplified (ITS, benA, and caM) and a multi-locus phylogeny of the combined loci was created by using maximum likelihood analysis. The in-house MALDI-TOF MS reference database was extended and an identification data set of 135 strains was run against a reference data set. Antifungal susceptibility was tested for voriconazole, itraconazole, and amphotericin B, using the EUCAST method. Phylogenetic analysis revealed 18 species in our data set. MALDI-TOF MS was able to distinguish between A. brasiliensis, A. brunneoviolaceus, A. neoniger, A. niger, A. tubingensis, and A. welwitschiae of A. sect. Nigri. In the routine clinical lab, isolates of A. sect. Nigri are often identified as A. niger. However, in the clinical isolates of our data set, A. tubingensis (n = 35) and A. welwitschiae (n = 34) are more common than A. niger (n = 9). Decreased antifungal susceptibility to azoles was observed in clinical isolates of the /tubingensis clade. This emphasizes the importance of identification up to species level or at least up to clade level in the clinical lab. Our results indicate that MALDI-TOF MS can be a powerful tool to replace classical morphology.

scholarly journals Effect of trapping method on species identification of phlebotomine sandflies by MALDI-TOF MS protein profiling

2018 ◽  
Vol 32 (3) ◽  
pp. 388-392 ◽  
Author(s):  
P. Halada ◽  
K. Hlavackova ◽  
J. Risueño ◽  
E. Berriatua ◽  
P. Volf ◽  
...  
Keyword(s):  
Species Identification ◽  
Protein Profiling ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Phlebotomine Sandflies ◽  
Trapping Method ◽  
Tof Ms

scholarly journals Reagent-Free Identification of Clinical Yeasts by Use of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

2019 ◽  
Vol 57 (5) ◽  
Author(s):  
Lisa M. T. Lam ◽  
Philippe J. Dufresne ◽  
Jean Longtin ◽  
Jacqueline Sedman ◽  
Ashraf A. Ismail
Keyword(s):  
Fourier Transform ◽  
Ftir Spectroscopy ◽  
Fourier Transform Infrared ◽  
Attenuated Total Reflectance ◽  
Reference Database ◽  
Accurate Identification ◽  
Total Reflectance ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

ABSTRACT Invasive fungal infections by opportunistic yeasts have increased concomitantly with the growth of an immunocompromised patient population. Misidentification of yeasts can lead to inappropriate antifungal treatment and complications. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy is a promising method for rapid and accurate identification of microorganisms. ATR-FTIR spectroscopy is a standalone, inexpensive, reagent-free technique that provides results within minutes after initial culture. In this study, a comprehensive spectral reference database of 65 clinically relevant yeast species was constructed and tested prospectively on spectra recorded (from colonies taken from culture plates) for 318 routine yeasts isolated from various body fluids and specimens received from 38 microbiology laboratories over a 4-month period in our clinical laboratory. ATR-FTIR spectroscopy attained comparable identification performance with matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). In a preliminary validation of the ATR-FTIR method, correct identification rates of 100% and 95.6% at the genus and species levels, respectively, were achieved, with 3.5% unidentified and 0.9% misidentified. By expanding the number of spectra in the spectral reference database for species for which isolates could not be identified or had been misidentified, we were able to improve identification at the species level to 99.7%. Thus, ATR-FTIR spectroscopy provides a new standalone method that can rival MALDI-TOF MS for the accurate identification of a broad range of medically important yeasts. The simplicity of the ATR-FTIR spectroscopy workflow favors its use in clinical laboratories for timely and low-cost identification of life-threatening yeast strains for appropriate treatment.

scholarly journals Species identification of enterobacteria strains by means of MALDI-TOF MS

2018 ◽  
pp. 110-113
Author(s):  
D.A. Vasiliev ◽  
◽  
N.A. Feoktistova ◽  
A.V. Mastilenko ◽  
E.V. Suldina ◽  
...  
Keyword(s):  
Species Identification ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals Novel attempt at discrimination of a bullet-shaped siphonophore (Family Diphyidae) using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-ToF MS)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nayeon Park ◽  
Jisu Yeom ◽  
Raehyuk Jeong ◽  
Wonchoel Lee
Keyword(s):  
Species Identification ◽  
Morphological Characteristics ◽  
Kuroshio Current ◽  
Northwest Pacific ◽  
Maldi Tof Ms ◽  
Protein Mass ◽  
Maldi Tof ◽  
Morphological Findings ◽  
Flight Mass Spectrometry ◽  
Tof Ms

AbstractOne major difficulty in identifying the gelatinous bodied bullet-shaped Siphonophore, Diphyids, is that their shape is deformed following ethanol fixation. Ethanol often is preferred over other fixatives, since samples fixed in ethanol can be used for molecular studies that can supplement morphological findings. To overcome this problem, we obtained protein mass spectra of ten species of Diphyidae found in the waters of the Kuroshio Current (Northwest Pacific and South Coast of South Korea) to test whether MALDI-ToF MS could be used as a methodology for species identification. In addition, a number of morphological characteristics that can be used with ethanol-treated samples was summarized. Concatenated phylogenetic analysis was also performed to determine the phylogenetic relationship by obtaining partial sequences of four genes (mtCOI, 16S rRNA, 18S rRNA, and ITS regions). Based on our integrative analysis, MALDI-ToF MS was evaluated as a potentially fast, inexpensive, and accurate tool for species identification along with conventional morphological and DNA barcoding for Diphyidae.

scholarly journals Short Incubation of Positive Blood Cultures on Solid Media for Species Identification by MALDI-TOF MS: Which Agar Is the Fastest?

2021 ◽  
Author(s):  
Neele J. Froböse ◽  
Evgeny A. Idelevich ◽  
Frieder Schaumburg
Keyword(s):  
Mass Spectrometry ◽  
Species Identification ◽  
Susceptibility Testing ◽  
Solid Medium ◽  
Blood Cultures ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Solid Media ◽  
Laboratory Results ◽  
Tof Ms

When blood cultures are flagged as positive, they are incubated on solid media to produce enough biomass of the bacterium for identification and susceptibility testing. Rapid turnaround times for laboratory results could save lives, and we wanted to assess which solid medium is best to shorten the time to species identification using MALDI-TOF mass spectrometry.

scholarly journals Identification of Nocardia species using Autof MS 1000 and Bruker MALDI-TOF MS systems: A comparison

2021 ◽  
Author(s):  
Bing Ma ◽  
Yunqi Tian ◽  
Yungang Han ◽  
Lifang Ban ◽  
Junwen Yang ◽  
...  
Keyword(s):  
Species Identification ◽  
Protein Extraction ◽  
Reference Method ◽  
Invasive Disease ◽  
Species Level ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Significant Difference ◽  
Tof Ms

ABSTRACTNocardia is an important cause of clinically invasive disease, but for most clinical laboratories, identification of these isolates to the species level is challenging. Recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used for identification of most bacterial and fungal isolates. In this multicenter study, we evaluated the identification of Nocardia isolates using Autof MS1000 and Bruker Biotyper. A total of 86 non-duplicate Nocardia isolates from 7 hospital laboratories were evaluated. Further, we carried out sequence analysis of 16S rRNA, gyrB, secA1, hsp65, and rpoB genes as a reference method for Nocardia species identification. The 86 isolates were directly spotted on the target plate and plate protein extraction was performed. Data were analyzed by SPSS 19.0. In total, 72 (83.7%) strains (score ≥ 9.0) and 70 (81.4%) strains (score ≥ 2.0) were correctly identified by the Autof MS1000 and Bruker Biotyper systems, respectively, at the species level. There was no significant difference (P > 0.05) between the two systems using the same protein extraction method. In conclusion, the Autof MS 1000 and Bruker MALDI-TOF systems showed no difference in identification of Nocardia spp. to the species level and could meet the most important clinical requirement for species identification.

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