scholarly journals Identification of Zoophilic Dermatophytes Using MALDI-TOF Mass Spectrometry

Author(s):  
Christina-Marie Baumbach ◽  
Stefanie Müller ◽  
Maximilian Reuschel ◽  
Silke Uhrlaß ◽  
Pietro Nenoff ◽  
...  

Dermatophytoses represent a major health burden in animals and man. Zoophilic dermatophytes usually show a high specificity to their original animal host but a zoonotic transmission is increasingly recorded. In humans, these infections elicit highly inflammatory skin lesions requiring prolonged therapy even in the immunocompetent patient. The correct identification of the causative agent is often crucial to initiate a targeted and effective therapy. To that end, matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) represents a promising tool. The objective of this study was to evaluate the reliability of species identification of zoophilic dermatophytes using MALDI-TOF MS. The investigation of isolates from veterinary clinical samples suspicious of dermatophytoses suggests a good MALDI-TOF MS based identification of the most common zoophilic dermatophyte Microsporum canis. Trichophyton (T.) spp. usually achieved scores only around the cutoff value for secure species identification because of a small number of reference spectra. Moreover, these results need to be interpreted with caution due to the close taxonomic relationship of dermatophytes being reflected in very similar spectra. In our study, the analysis of 50 clinical samples of hedgehogs revealed no correct identification using the provided databases, nor for zoophilic neither for geophilic causative agents. After DNA sequencing, adaptation of sample processing and an individual extension of the in-house database, acceptable identification scores were achieved (T. erinacei and Arthroderma spp., respectively). A score-oriented distance dendrogram revealed clustering of geophilic isolates of four different species of the genus Arthroderma and underlined the close relationship of the important zoophilic agents T. erinacei, T. verrucosum and T. benhamiae by forming a subclade within a larger cluster including different dermatophytes. Taken together, MALDI-TOF MS proofed suitable for the identification of zoophilic dermatophytes provided fresh cultures are used and the reference library was previously extended with spectra of laboratory-relevant species. Performing independent molecular methods, such as sequencing, is strongly recommended to substantiate the findings from morphologic and MALDI-TOF MS analyses, especially for uncommon causative agents.


Author(s):  
Neele J. Froböse ◽  
Evgeny A. Idelevich ◽  
Frieder Schaumburg

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.



2009 ◽  
Vol 58 (9) ◽  
pp. 1154-1159 ◽  
Author(s):  
Pierre-Edouard Fournier ◽  
Carine Couderc ◽  
Sylvain Buffet ◽  
Christophe Flaudrops ◽  
Didier Raoult

Bacteria of the genus Bartonella are emerging zoonotic bacteria recognized in a variety of human diseases. Due to their poor chemical reactivity, these fastidious bacteria are poorly characterized using routine phenotypic laboratory tests. Identification is usually achieved using molecular techniques that are time-consuming, expensive and technically demanding. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a new technique for bacterial species identification. This study evaluated the use of MALDI-TOF MS for rapid genus and species identification of Bartonella species. Reference strains representing 17 recognized Bartonella species were studied. For each species, MS spectra for four colonies were analysed. The consensus spectrum obtained for each species was unique among spectra obtained for 2843 bacteria within the Bruker database, including 109 alphaproteobacteria. Thirty-nine additional blind-coded Bartonella strains were correctly identified at the species level, including 36 with a significant score. Altogether, these data demonstrate that MS is an accurate and reproducible tool for rapid and inexpensive identification of Bartonella species.



Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 28 ◽  
Author(s):  
Basma Ouarti ◽  
Maureen Laroche ◽  
Souad Righi ◽  
Mohamed Nadir Meguini ◽  
Ahmed Benakhla ◽  
...  

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is now routinely used for the rapid identification of microorganisms isolated from clinical samples and has been recently successfully applied to the identification of arthropods. In the present study, this proteomics tool was used to identify lice collected from livestock and poultry in Algeria. The MALDI-TOF MS spectra of 408 adult specimens were measured for 14 species, including Bovicola bovis, B. ovis, B. caprae, Haematopinus eurysternus, Linognathus africanus, L. vituli, Solenopotes capillatus, Menacanthus stramineus, Menopon gallinae, Chelopistes meleagridis, Goniocotes gallinae, Goniodes gigas, Lipeurus caponis and laboratory reared Pediculus humanus corporis. Good quality spectra were obtained for 305 samples. Spectral analysis revealed intra-species reproducibility and inter-species specificity that were consistent with the morphological classification. A blind test of 248 specimens was performed against the in-lab database upgraded with new spectra and validated using molecular tools. With identification percentages ranging from 76% to 100% alongside high identification scores (mean = 2.115), this study proposes MALDI-TOF MS as an effective tool for discriminating lice species.



Author(s):  
T. V. Priputnevich ◽  
A. R. Melkumyan ◽  
L. A. Lyubasovskaya ◽  
V. V. Muravieva ◽  
E. N. Ilina ◽  
...  

Aim. Comparative evaluation of species identification of microorganisms by MALDI-TOF mass-spectrometry and automatic biochemical analyzer VITEK2 Compact30. Materials and methods. Species identification of18 400 isolates of microorganisms (staphylococci, streptococci, enterococci, enterobacteria, nonfermenting gram-negative bacteria, lactobacilli, anaerobes, yeast fungi, neisseriae), isolated from vagina of pregnant and non-pregnant women and from newborns, was carried out. Identification of the isolated microorganisms was carried out by automatic bac-teriologic analyzer VITEK2 Compact30 (BioMerieux, France) and MALDI-TOF-MS analysis method on AutoflexIII (Bruker Daltonics, Germany) mass-spectrometer. Results. Comparative identification of 2005 isolates of microorganisms was carried out. Sequencing of ribosomal RNA was used as a reference method. Authenticity of species identification my MALDI-TOF-MS analysis method was: for staphylococci (95.8%), enterococci (97.5%), enterobacteria (98.4%), nonfermenting gram-negative bacteria (93.6%), P-hemolytic staphylococci (93.8%), lactobacilli (92.8%), yeast fungi (99.9%). Conclusion. Introduction of MALDI-TOF-MS analysis technology into practical work of microbiological laboratories exceeds previously used methods of microbiological testing in terms of speed, cost and authenticity of identification of a wide spectrum of microorganisms.



2013 ◽  
Vol 24 (4) ◽  
pp. 191-194 ◽  
Author(s):  
Manal Tadros ◽  
Astrid Petrich

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to identify bacteria directly from positive blood and sterile fluid cultures. The authors evaluated a commercially available kit – the Sepsityper Kit (Bruker Daltonik, Germany) – and MALDI-TOF MS for the rapid identification of organisms from 80 flagged positive blood culture broths, of which 73 (91.2%) were blood culture specimens and seven (8.7%) were cerebrospinal fluid specimens, in comparison with conventional identification methods. Correct identification to the genus and species levels was obtained in 75 of 80 (93.8%) and 39 of 50 (78%) blood culture broths, respectively. Applying the blood culture analysis module, a newly developed software tool, improved the species identification of Gram-negative organisms from 94.7% to 100% and of Gram-positive organisms from 66.7% to 70%.MALDI-TOF MS is a promising tool for the direct identification of organisms cultured from sterile sites.



2019 ◽  
Vol 31 (3) ◽  
pp. 471-474 ◽  
Author(s):  
Pierre Becker ◽  
Anne-Cécile Normand ◽  
Gerty Vanantwerpen ◽  
Mia Vanrobaeys ◽  
Roel Haesendonck ◽  
...  

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has emerged as a reliable method to identify fungal isolates. The success of this approach relies on the availability of exhaustive databases, but the latter were built with a focus on human pathogens. We assessed a large in-house database of reference spectra and a dedicated web application for their suitability for use in veterinary laboratories. A panel of 290 mold and yeast isolates representing 69 different fungal species was isolated from various animals (including pets, cattle, and zoo animals) and identified using both MALDI-TOF MS and conventional techniques. The performance of the 2 methods was compared, and identifications were confirmed by DNA sequencing. MALDI-TOF MS allowed distinction between some closely related species and achieved 89% correct identification at the species level. In comparison, only 60% of the isolates were correctly identified with conventional approaches. Using this online application, MALDI-TOF MS thus appears to be a relevant alternative for the identification of fungal isolates encountered by animal health professionals.



2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Mohammed AlMogbel ◽  
Mohammed AlBolbol ◽  
Noura Elkhizzi ◽  
Hisham AlAjlan ◽  
John Philip Hays ◽  
...  

Abstract Nocardia cyriacigeorgica (N. cyriacigeorgica) is most frequently associated with human infections, including chronic bronchitis, pulmonary disease and brain abscesses. In general, N. cyriacigeorgica causes infections in immunocompromised individuals and has been reported in clinical samples worldwide. However, the isolation and speciation of N. cyriacigeorgica in the routine diagnostic microbiology laboratory are complicated and time consuming. Recent mass spectrometry techniques such as matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) have been successfully integrated into many routine diagnostic microbiology laboratories, allowing for the rapid, accurate and simple identification and speciation of many different microorganisms, including difficult-to-identify bacterial species. Here, we present a case report of a 65-year-old female patient from the neurology ward of Prince Sultan Military Medical City in Riyadh, Saudi Arabia, who was infected with N. cyriacigeorgica. The bacterium was successfully identified by MALDI-TOF-MS, with species identification subsequently confirmed by sequence analysis of the 16S ribosomal RNA.



2019 ◽  
Vol 89 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Márió Gajdács ◽  
Edit Urbán

Introduction: The group of anaerobic Gram-negative cocci (AGNC) includes the genera Veillonella, Megasphaera, Anaeroglobus, Negativicoccus and Acidaminococcus. These bacteria are an integral part of the microbiome of humans but may be causative agents in various infectious processes. The available data on the epidemiology and significance of AGNCs is scarce. Aims: To assess and compare the prevalence of different species of AGNCs among inpatients and outpatients at the Albert Szent-Györgyi Clinical Center retrospectively, during a 10-year study period. Methods: Isolates containing AGNC were identified retrospectively by reviewing the online microbiology records of the Institute of Clinical Microbiology. Results: The median age of affected patients overall was 52 years (range: 1–90 years), with a male dominance. 59.79% of samples originated from inpatients. 572 individual AGNCs isolates were recovered from clinical samples, most of the isolated GNACs were Veillonella spp. (95.28%), Megasphaera and Acidaminococcus species accounted for a minority of isolates (2.79% and 1.93%, respectively), while Anaeroglobus and Negativicoccus species were not isolated. In the second half of the study period (2013-2017), 91.31% of isolates were identified on the species level (p<0.001) using MALDI-TOF MS. Conclusion: The current study represents a long-term surveillance study on the isolation frequency and trends among anaerobic Gram-negative cocci (AGNCs), isolated in the Southern Great Plain of Hungary, highlighting the beneficial effect of MALDI-TOF MS on the diagnostic efficacy of the laboratories.



Author(s):  
Fatou Kiné Fall ◽  
Maureen Laroche ◽  
Hervé Bossin ◽  
Didier Musso ◽  
Philippe Parola

Mosquitoes are the main arthropod vectors of infectious diseases in humans. The current methods for mosquito identification include morphological and molecular methods. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), now routinely used for bacterial identification, has recently emerged in the field of entomology. The aim of this study was to use MALDI-TOF MS to identify mosquito colonies from French Polynesia. Five hundred specimens from French Polynesia belonging to three species, Aedes aegypti, Aedes polynesiensis, and Culex quinquefasciatus, were included in the study. Testing the legs of these mosquitoes by MALDI-TOF MS revealed a 100% correct identification of all specimens at the species level. The MALDI-TOF MS profiles obtained allowed differentiation of male from female mosquitoes and the specific identification of female mosquito colonies of the same species but different geographic origin.



Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 266-273
Author(s):  
Min Tang ◽  
Jia Yang ◽  
Ying Li ◽  
Luhua Zhang ◽  
Ying Peng ◽  
...  

AbstractMatrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has become one of the most popular methods for the rapid and cost-effective detection of clinical pathogenic microorganisms. This study aimed to evaluate and compare the diagnostic performance of MALDI-TOF MS with that of conventional approaches for the direct identification of pathogens from urine samples. A systematic review was conducted based on a literature search of relevant databases. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve of the combined studies were estimated. Nine studies with a total of 3920 subjects were considered eligible and included in the meta-analysis. The pooled sensitivity was 0.85 (95% CI 0.79-0.90), and the pooled specificity was 0.93 (95% CI 0.82-0.97). The PLR and NLR were 11.51 (95% CI 4.53-29.26) and 0.16 (95% CI 0.11-0.24), respectively. The area under the SROC curve was 0.93 (95% CI 0.91-0.95). Sensitivity analysis showed that the results of this meta-analysis were stable. MALDI-TOF MS could directly identify microorganisms from urine samples with high sensitivity and specificity.



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