Direct Bacterial Profiling by Matrix-Assisted Laser Desorption−Ionization Time-of-Flight Mass Spectrometry for Identification of Pathogenic Neisseria

Abstract

The present study investigates the suitability of direct bacterial profiling as a tool for the identification and subtyping of pathogenic Neisseria. The genus Neisseria includes two human pathogens , Neisseria meningitidis and Neisseria gonorrhoeae, as well as several nonpathogenic Neisseria species. Here , a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling protocol was optimized using a laboratory strain of E. coli DH5␣ to guarantee high quality and reproducible results. Subsequently , mass spectra for both laboratory and clinical strains of N. gonorrhoeae, N. meningitidis, and several nonpathogenic Neisseria species were collected. Significant interspecies differences but little intraspecies diversity were revealed by means of a visual inspection and bioinformatics examination using the MALDI BioTyper software. Cluster analysis successfully separated mass spectra collected from three groups that corresponded to N. gonorrhoeae , N. meningitidis , and nonpathogenic Neisseria isolates. Requiring only one bacterial colony for testing and using a fast and easy measuring protocol , this approach represents a powerful tool for the rapid identification of pathogenic Neisseria and can be adopted for other microorganisms.

Phenotypical and Mass Spectral Assessment Methods for Identification of Some Contagious Mastitis Pathogens

“…agalactiae and 72% of CNS were identified by API system. The results tabulated in the current study, supported by similar and widespread data for clinical human and veterinary microbiology (Ilina et al, 2009;Lartigue et al, 2009; Science Publications Marklein et al, 2009;Nagy et al, 2009;Barreiro et al, 2010;Dubois et al, 2010;Ilina et al, 2010;Seibold et al, 2010;Moon et al, 2013;Raemy et al, 2013), confirmed that MALDI-TOF MS contributes in the fast identification of bacteria (one day versus five to eight days for conventional identification) and consequently the chance of an earlier treatment of subclinical and clinical mastitis with suitable antimicrobial agents will be carried out. In addition, in the dairy industry, MALDITOF MS can provides a faster, cheaper and more reliable identification of microorganisms isolated from milk of animals witth clinical and subclinical mastitis.…”

“…This technique requires slight Mass Spectral (MS) ability, the utilize of uncomplicated instruments and relatively fast operator training. After comparing mass spectral identification with DNA analysis based technologies, it was found that MALDI-TOF MS requires smaller amounts of biological material and involves simpler sample preparation protocols with no initial assessment, such as Gram staining (Ilina et al, 2009;Chalupová et al, 2014;Tomazia et al, 2014). In the current study, the performance of MALDI-TOF-MS was evaluated comparing with conventional methods for bacterial screening of clinical and subclinical mastitis in dairy cows.…”

Einsatz der Matrix-Assisted Laser Desorption/ionisation-Time of Flight Massenspektrometrie (MALDI-TOF MS) in der mikrobiologischen Routinediagnostik/Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in clinical microbiological routine diagnostics

“…Anders als bei den biochemischen Testsystemen handelt es sich beim MALDI-TOF MS-System um ein offenes, bei dem die Datenbank auch vom Anwender eigenst ä ndig erweitert werden kann. Durch entsprechende Erg ä nzungen der Referenz-Spektren der Datenbanken konnte eine nahezu 100 % Identifi zierungsrate von Neisserien [11] , Clostridien [12] , Mycobakterien [13] , Salmonellen [14] , vergr ü nenden Streptokokken [15] und Helicobacter pylori [16] erreicht werden. W ä hrend das MALDI-TOF MS-System im Vergleich zu biochemischen Testsystemen im Bereich der Differenzierung von Enterobakterien, Staphylokokken und Streptokokken vergleichbar gute Ergebnisse liefert, zeigt es deutliche Vorteile bei der Differenzierung von Gram-positiven St ä bchen [17] , Anaerobiern und einigen Nonfermentern [18,19] .…”

Strain differentiation of staphylococcus aureus by means of direct maldi tof mass spectrometry profiling

“…Впервые использование масс-спектрометрии для идентификации бактерий было предложено в 1975 году [9], сейчас метод прямого MALDI -масс-спектрометрического профилирования используется многими клиническими и научными лабораториями мира для решения задач по исследованию клеточных микроорганизмов [10][11][12][13][14][15][16]. Данный подход основан на накоплении MALDI масс-спектров грубого лизата клеток исследуемого микроорганизма и последующим сопоставлении их с аналогичными масс-спектрами, хранящимися в базах данных или между собой.…”