Triacylglyceride (TAG) profiles of integumentary lipids isolated from three bat species determined by matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI–TOF MS)

2012 ◽  
Vol 90 (9) ◽  
pp. 1117-1127 ◽  
Author(s):  
E.L. Pannkuk ◽  
D.F. Gilmore ◽  
B.J. Savary ◽  
T.S. Risch

Lipids secreted from sebaceous glands in bat integument may play a role in determining host pathogenicity by the fungus Geomyces destructans in white-nose syndrome (WNS). To investigate this, we have determined the triacylglycerol (TAG) profiles for three bat species: eastern red bats ( Lasiurus borealis (Müller, 1776)), evening bats ( Nycticeius humeralis (Rafinesque, 1818)), and big brown bats ( Eptesicus fuscus (Beauvois, 1796)). Neutral lipids extracted from the hair and wing tissue were fractionated by preparative thin-layer chromatography (TLC) into four major lipid bands corresponding to cholesterol, free fatty acids (FFAs), TAGs, and sterol–wax esters. Densitometry showed higher proportions of TAGs in hair than from wing tissue. TAG bands were recovered and analyzed by matrix-assisted laser desorption–ionization time-of-flight mass spectrometry (MALDI–TOF MS). Mass spectra showed sodiated TAG species with variable fatty acyl (FA) moieties range from m/z 715.6–911.8. High intensity ion peaks were consistent with 16:0 and 18:1 as dominant FA moieties, and these were identified as palmitic and oleic acids, respectively, by liquid chromatography electrospray ionization mass spectrometry. We determined significant differences in TAG profiles between three bat species by MALDI–TOF MS, providing the first description of integumentary lipids in bats. In this study, we performed the first TAG profiling of bats, which suggest such profiles may be species-specific in bats.

2019 ◽  
Vol 36 (No. 6) ◽  
pp. 452-458 ◽  
Author(s):  
Štěpán Koudelka ◽  
Tereza Gelbíčová ◽  
Markéta Procházková ◽  
Renáta Karpíšková

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.


2017 ◽  
Vol 55 (4) ◽  
pp. 1162-1176 ◽  
Author(s):  
Andrew M. Borman ◽  
Mark Fraser ◽  
Adrien Szekely ◽  
Daniel E. Larcombe ◽  
Elizabeth M. Johnson

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.


2004 ◽  
Vol 48 (2) ◽  
pp. 466-472 ◽  
Author(s):  
Florian Marks ◽  
Christian G. Meyer ◽  
Jürgen Sievertsen ◽  
Christian Timmann ◽  
Jennifer Evans ◽  
...  

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.


2005 ◽  
Vol 71 (10) ◽  
pp. 6292-6307 ◽  
Author(s):  
Robert E. Mandrell ◽  
Leslie A. Harden ◽  
Anna Bates ◽  
William G. Miller ◽  
William F. Haddon ◽  
...  

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.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4775
Author(s):  
Sachio Tsuchida ◽  
Hiroshi Umemura ◽  
Tomohiro Nakayama

Mass spectrometry (MS), a core technology for proteomics and metabolomics, is currently being developed for clinical applications. The identification of microorganisms in clinical samples using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF MS) is a representative MS-based proteomics application that is relevant to daily clinical practice. This technology has the advantages of convenience, speed, and accuracy when compared with conventional biochemical methods. MALDI-TOF MS can shorten the time used for microbial identification by about 1 day in routine workflows. Sample preparation from microbial colonies has been improved, increasing the accuracy and speed of identification. MALDI-TOF MS is also used for testing blood, cerebrospinal fluid, and urine, because it can directly identify the microorganisms in these liquid samples without prior culture or subculture. Thus, MALDI-TOF MS has the potential to improve patient prognosis and decrease the length of hospitalization and is therefore currently considered an essential tool in clinical microbiology. Furthermore, MALDI-TOF MS is currently being combined with other technologies, such as flow cytometry, to expand the scope of clinical applications.


Chemotherapy ◽  
2016 ◽  
Vol 61 (4) ◽  
pp. 167-170 ◽  
Author(s):  
Ivana Mareković ◽  
Zrinka Bošnjak ◽  
Marko Jakopović ◽  
Zagorka Boras ◽  
Mateja Janković ◽  
...  

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.


2001 ◽  
Vol 67 (11) ◽  
pp. 5069-5076 ◽  
Author(s):  
Jutta Fastner ◽  
Marcel Erhard ◽  
Hans von Döhren

ABSTRACT Besides the most prominent peptide toxin, microcystin, the cyanobacteria Microcystis spp. have been shown to produce a large variety of other bioactive oligopeptides. We investigated for the first time the oligopeptide diversity within a naturalMicrocystis population by analyzing single colonies directly with matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). The results demonstrate a high diversity of known cyanobacterial peptides such as microcystins, anabaenopeptins, microginins, aeruginosins, and cyanopeptolins, but also many unknown substances in the Microcystis colonies. Oligopeptide patterns were mostly related to specificMicrocystis taxa. Microcystis aeruginosa(Kütz.) Kütz. colonies contained mainly microcystins, occasionally accompanied by aeruginosins. In contrast, microcystins were not detected in Microcystis ichthyoblabeKütz.; instead, colonies of this species contained anabaenopeptins and/or microginins or unknown peptides. Within a third group, Microcystis wesenbergii (Kom.) Kom. in Kondr., chiefly a cyanopeptolin and an unknown peptide were found. Similar patterns, however, were also found in colonies which could not be identified to species level. The significance of oligopeptides as a chemotaxonomic tool within the genus Microcystis is discussed. It could be demonstrated that the typing of single colonies by MALDI-TOF MS may be a valuable tool for ecological studies of the genus Microcystis as well as in early warning of toxic cyanobacterial blooms.


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