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 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 Rapid Identification of Clinically Relevant Members of the Genus Exophiala by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and Description of Two Novel Species, Exophiala campbellii and Exophiala lavatrina

2017 ◽  
Vol 55 (4) ◽  
pp. 1162-1176 ◽  
Author(s):  
Andrew M. Borman ◽  
Mark Fraser ◽  
Adrien Szekely ◽  
Daniel E. Larcombe ◽  
Elizabeth M. Johnson
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Content Type ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT Exophiala is a ubiquitous pleomorphic genus comprising at least 40 species, many of which have been associated with superficial, visceral, or systemic infections in humans, other mammals, or cold-blooded animals. In this study, we investigated the potential of matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS) for the identification of Exophiala species. A total of 89 isolates (including 50 human and 4 animal clinical isolates) stored in the National Collection of Pathogenic Fungi were identified by PCR amplification and sequencing of internal transcribed spacer region 1. Eighty-three of the isolates corresponded to 16 known species within Exophiala/Rhinocladiella . The remaining six isolates are shown by phylogenetic analyses based on four loci to represent two novel Exophiala species. Four isolates from domestic bathrooms which form a sister species with Exophiala lecanii-corni are described here as Exophiala lavatrina sp. nov. The remaining two isolates, both from subcutaneous infections, are distantly related to Exophiala oligosperma and are described here as Exophiala campbellii sp. nov. The triazoles and terbinafine exhibited low MICs against all Exophiala isolates in vitro . MALDI-TOF MS successfully distinguished all 18 species and identified all isolates after appropriate reference spectra were created and added to commercial databases. Intraspecific mean log scores ranged from 1.786 to 2.584 and were consistently significantly higher than interspecific scores (1.193 to 1.624), with the exception of E. lecanii-corni and E. lavatrina , for which there was considerable log score overlap. In summary, MALDI-TOF MS allows the rapid and accurate identification of a wide range of clinically relevant Exophiala species.

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 Genotyping of Plasmodium falciparum Pyrimethamine Resistance by Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry

2004 ◽  
Vol 48 (2) ◽  
pp. 466-472 ◽  
Author(s):  
Florian Marks ◽  
Christian G. Meyer ◽  
Jürgen Sievertsen ◽  
Christian Timmann ◽  
Jennifer Evans ◽  
...  
Keyword(s):  
Dna Sequencing ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT Increasing resistance, recrudescences, and treatment failure have led to the replacement of chloroquine with the combination of pyrimethamine (PYR) and sulfadoxine (SDX) as the first-line antimalarial drugs for treatment of uncomplicated Plasmodium falciparum malaria in several areas where this disease is endemic. The development of resistance to PYR-SDX is favored by incomplete treatment courses or by subtherapeutic levels in plasma. PYR-SDX resistance has been associated with several single-nucleotide polymorphisms (SNPs) in the P. falciparum dihydrofolate reductase (pfdhfr) and the P. falciparum dihydropteroate synthetase (pfdhps) genes. We have established assays based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) that conveniently allow the identification of SNPs associated with PYR resistance. Variants occurring at codon positions 16, 51, 59, and 108 of the pfdhfr gene were analyzed by MALDI-TOF MS in synthetic oligonucleotides to determine the detection threshold. In addition, 63 blood samples from subjects with P. falciparum parasitemia of various degrees were analyzed. The results were compared to those obtained by DNA sequencing of the respective gene fragment. The results of MALDI-TOF MS and DNA sequencing were consistent in 40 samples. In 23 samples two or three pfdhfr variants were detected by MALDI-TOF assays, whereas DNA-sequencing revealed one variant only. Simultaneous detection of two different mutations by biplex assays was, in principle, feasible. As demonstrated by the example of PYR resistance, MALDI-TOF MS allows for rapid and automated high-throughput assessment of drug sensitivity in P. falciparum malaria.

scholarly journals Speciation of Campylobacter coli, C. jejuni, C. helveticus, C. lari, C. sputorum, and C. upsaliensis by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

2005 ◽  
Vol 71 (10) ◽  
pp. 6292-6307 ◽  
Author(s):  
Robert E. Mandrell ◽  
Leslie A. Harden ◽  
Anna Bates ◽  
William G. Miller ◽  
William F. Haddon ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Campylobacter Coli ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACT Multiple strains of Campylobacter coli, C. jejuni, C. helveticus, C. lari, C. sputorum, and C. upsaliensis isolated from animal, clinical, or food samples have been analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Whole bacterial cells were harvested from colonies or confluent growth on agar and transferred directly into solvent and then to a spot of dried 3-methoxy-4-hydroxycinnamic acid (matrix). Multiple ions in the 5,000- to 15,000-Da mass range were evident in spectra for each strain; one or two ions in the 9,500- to 11,000-Da range were consistently high intensity. “Species-identifying” biomarker ions (SIBIs) were evident from analyses of multiple reference strains for each of the six species, including the genome strains C. jejuni NCTC 11168 and C. jejuni RM1221. Strains grown on nine different combinations of media and atmospheres yielded SIBI masses within ±5 Da with external instrument calibration. The highest-intensity C. jejuni SIBIs were cytosolic proteins, including GroES, HU/HCj, and RplL. Multiple intraspecies SIBIs, corresponding probably to nonsynonymous nucleotide polymorphisms, also provided some intraspecies strain differentiation. MALDI-TOF MS analysis of 75 additional Campylobacter strains isolated from humans, poultry, swine, dogs, and cats revealed (i) associations of SIBI type with source, (ii) strains previously speciated incorrectly, and (iii) “strains” composed of more than one species. MALDI-TOF MS provides an accurate, sensitive, and rapid method for identification of multiple Campylobacter species relevant to public health and food safety.

scholarly journals Cost Savings Realized by Implementation of Routine Microbiological Identification by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

2015 ◽  
Vol 53 (8) ◽  
pp. 2473-2479 ◽  
Author(s):  
Anthony Tran ◽  
Kevin Alby ◽  
Alan Kerr ◽  
Melissa Jones ◽  
Peter H. Gilligan
Keyword(s):  
New Technology ◽  
Cost Savings ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry (MS) is an emerging technology for rapid identification of bacterial and fungal isolates. In comparison to conventional methods, this technology is much less labor intensive and can provide accurate and reliable results in minutes from a single isolated colony. We compared the cost of performing the bioMérieux Vitek MALDI-TOF MS with conventional microbiological methods to determine the amount saved by the laboratory by converting to the new technology. Identification costs for 21,930 isolates collected between April 1, 2013, and March 31, 2014, were directly compared for MALDI-TOF MS and conventional methodologies. These isolates were composed of commonly isolated organisms, including commonly encountered aerobic and facultative bacteria and yeast but excluding anaerobes and filamentous fungi. Mycobacterium tuberculosis complex and rapidly growing mycobacteria were also evaluated for a 5-month period during the study. Reagent costs and a total cost analysis that included technologist time in addition to reagent expenses and maintenance service agreement costs were analyzed as part of this study. The use of MALDI-TOF MS equated to a net savings of $69,108.61, or 87.8%, in reagent costs annually compared to traditional methods. When total costs are calculated to include technologist time and maintenance costs, traditional identification would have cost $142,532.69, versus $68,886.51 with the MALDI-TOF MS method, resulting in a laboratory savings of $73,646.18, or 51.7%, annually by adopting the new technology. The initial cost of the instrument at our usage level would be offset in about 3 years. MALDI-TOF MS not only represents an innovative technology for the rapid and accurate identification of bacterial and fungal isolates, it also provides a significant cost savings for the laboratory.

scholarly journals Evaluation of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry in Identification of Nontuberculous Mycobacteria

Chemotherapy ◽  
2016 ◽  
Vol 61 (4) ◽  
pp. 167-170 ◽  
Author(s):  
Ivana Mareković ◽  
Zrinka Bošnjak ◽  
Marko Jakopović ◽  
Zagorka Boras ◽  
Mateja Janković ◽  
...  
Keyword(s):  
Nontuberculous Mycobacteria ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Background/Aims: Species-level identification of nontuberculous mycobacteria (NTM) is important in making decisions about the necessity and choice of antimicrobial treatment. The reason is predictable clinical significance and the susceptibility profile of specific NTM species. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is recognized as a diagnostic tool for routine identification of bacteria and yeasts in the clinical laboratory based on protein fingerprint analysis. The aim of the study was to evaluate MALDI-TOF MS in the identification of NTM. Methods: A total of 25 NTM isolates from liquid cultures were identified with both polymerase chain reaction (PCR)-based hybridization assay and MALDI-TOF MS at the University Hospital Center Zagreb. Results: PCR-based hybridization assay identified 96% (24/25) and MALDI-TOF MS 80% (20/25) of tested NTM isolates. Five isolates with no reliable MALDI-TOF MS identification belonged to the Mycobacterium avium-intracellulare complex. Seventy percent (14/20) of NTM isolates successfully identified with MALDI-TOF MS had a score higher than 2.0, indicating reliable species identification. Conclusion: MALDI-TOF MS is a promising tool for the identification of NTM. With a further improvement of the protein extraction protocol, especially regarding the M. avium-intracellulare complex, MALDI-TOF MS could be an additional standard method for identification of NTM.

scholarly journals Bacterial Identification and Monitoring Around Two-Piece Dental Implants by Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS)

2020 ◽  
Vol 12 (01) ◽  
pp. 49-55
Author(s):  
Sonali Saha ◽  
Ajita Meenawat ◽  
Chinmoy Sahu ◽  
Vivek Srivastava ◽  
Shivam Yadav ◽  
...  
Keyword(s):  
Dental Implants ◽  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Abstract Context Early microbiological diagnosis and treatment of periodontal pathogens is important for successful retention of dental implants. Aims This study aimed to identify and monitor oral bacterial colonization after successful two-piece dental implants. Settings and Design In this study, 50 two-piece dental implant subjects were included and assessed clinically, radiographically, and microbiologically. Methods and Material All the parameters were recorded at various stages after prosthesis placement. In each stage, nonadherent (peri-implant sulcular fluid) and adherent (curetted inner threads) samples were collected. Semiquantitative anaerobic culture of the samples were done in Anoxomat system. Bacterial colonies were first identified by routine microbiological methods and then by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) method. Statistical Analysis All the results were analyzed by appropriate statistical methods (Chi-square, one factor analysis of variance, etc.). Results All the bacterial isolates were identified in the MALDI-TOF MS system with no failure. After implant placement for the nonadherent samples, the frequency (%) of Fusobacterium nucleatum, Prevotella melaninogenica, and Propionibacterium acnes decreased whereas frequency (%) of Escherichia coli, Staphylococcus epidermidis, and Streptococcus mitis increased. For adherent samples, the frequency (%) of E. coli, Enterococcus faecalis, Porphyromonas gingivalis, P. melaninogenica, and Veillonella parvula decreased, whereas frequency (%) of S. mitis and Streptococcus mutans increased. The postimplant mean nonadherent and adherent bacterial load increased with time but not significantly over the periods (p = 0.302 and 0.123, respectively). Conclusion Combination of basic (semiquantitative culture method) and advanced microbiological method (MALDI-TOF MS) can be useful for accurate detection and monitoring of potential pathogens around two-piece dental implants.

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 Differentiation of Brachyspira spp. isolated from laying hens using PCR-based methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

2018 ◽  
Vol 30 (4) ◽  
pp. 545-553
Author(s):  
Monika Harms ◽  
Volker Schmidt ◽  
Tilo Heydel ◽  
Jutta Hauptmann ◽  
Christine Ahlers ◽  
...  
Keyword(s):  
Laser Desorption ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Maldi Tof Ms ◽  
Desorption Ionization ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Tof Ms ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

Avian intestinal spirochetosis (AIS), an important but neglected disease in laying hens, is caused by Brachyspira pilosicoli, B. intermedia, and B. alvinipulli. Poultry are also frequently colonized by putatively nonpathogenic species such as B. murdochii and B. innocens. We evaluated the differentiation of Brachyspira species by 3 methods: sequencing of the reduced nicotinamide adenine dinucleotide (NADH) oxidase gene ( nox), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and a new multiplex (m)PCR targeting genes such as the tryptophanase A gene ( tnaA) and the p-aminobenzoyl-glutamate hydrolase subunit B gene ( abgB). Sequencing of 414 bp of the nox PCR amplification products generated from 41 pure cultures of avian Brachyspira isolates allowed presumptive species identification in 33 isolates with at least 99% identity in basic local alignment search tool analysis, including B. pilosicoli, B. intermedia, B. murdochii, B. innocens, and “ B. pulli”. MALDI-TOF MS analysis was found to be a reliable tool for differentiation after extension of the manufacturer’s database. In the mPCR, all isolates identified as B. pilosicoli and B. intermedia were positive for abgB and tnaA, respectively. The mPCR might be very useful in detecting Brachyspira species in mixed cultures including not only nonpathogenic species, such as B. innocens, but also one of the AIS pathogens. We found that MALDI-TOF MS analysis combined with the mPCR targeting tnaA and abgB was suitable for the identification of avian isolates of B. pilosicoli and B. intermedia, 2 important agents of AIS.

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