Identification of Burkholderia pseudomallei by Use of the Vitek Mass Spectrometer

Abstract

Burkholderia pseudomallei is the causative agent of melioidosis. This condition most often presents as pneumonia and bacteremia, with mortality rates of 9% to 70%. Therefore, early identification of this organism may aid in directing appropriate management. This study aimed to use the Vitek matrix-assisted laser desorption ionization–time of flight mass spectrometer to create a spectrum for the rapid identification of B. pseudomallei. Spectra from 85 isolate cultures were acquired using the Vitek mass spectrometer research mode. A SuperSpectrum was created using peak matching and subsequently activated for analysis of organism identification. All 85 isolates were correctly identified as B. pseudomallei. A total of 899 spectra were analyzed and demonstrated a specificity of 99.8%. Eighty-one clinical isolates were used, of which 10 were neuromelioidosis, and no discernible spectrum difference was appreciated. Spectrum acquisition from a single spot was only successful in 374/899 (41%) of isolates. This increased to 100% when 3 spots of the same extract were analyzed. The Vitek mass spectrometer can be used for the rapid identification of B. pseudomallei with a high level of specificity.

Human Melioidosis

“…A novel diagnostic method is matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Compared with other techniques, the advantages include reduced analysis time, high sensitivity and specificity, minimal technical requirements, and relatively simple staff training for implementation (241)(242)(243)(244). Two commercially available MALDI-TOF MS instruments, Bruker Microflex Biotyper (Bruker Daltonik GmbH, Bremen, Germany) and biomérieux Vitek MS (biomérieux, Marcy l'Etoile, France), are both certified for identification of clinical isolates.…”

The Epidemiology of Melioidosis and Its Association with Diabetes Mellitus: A Systematic Review and Meta-Analysis

“…It was perceived that farmers were more exposed to B. pseudomallei contaminated soil and flood water while working in the paddy fields during the monsoon [46]. Excessive alcohol consumption was observed to increase the risk of contracting melioidosis in Australia, Thailand, Cambodia, and India [15,31,40,89,90,99]. S2).…”

Methodological tools to study species of the genus Burkholderia

“…The greatest obstacle in the correct identification of these pathogens is the high similarity among these species (Furlan et al 2019 ; Jin et al 2020 ; Martinucci et al 2016 ; Wang et al 2020 ). Different methods can be used for the identification of these bacteria (Table 1 ), such as the sequencing of 16S rRNA , 23S rRNA , recA , hisA , rpsU genes, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) (Wong et al 2020 ; Fergusson et al 2020 ; Gassiep et al 2019 ; Furlan et al 2019 ; Haeckl et al 2019 ; Frickmann et al, 2014 ).…”

“…Different methods can be used for the identification of these bacteria (Table 1 ), such as the sequencing of 16S rRNA , 23S rRNA , recA , hisA , rpsU genes, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) (Wong et al 2020 ; Fergusson et al 2020 ; Gassiep et al 2019 ; Furlan et al 2019 ; Haeckl et al 2019 ; Frickmann et al, 2014 ).…”

“…Recent automated system MALDI-TOF MS (VITEK 2, VITEK MS, and Bruker Biotyper) emerged as sensitive, practical, rapid and inexpensive tools for bacterial identification in most clinical microbiology laboratories. The identification technique is based on spectral analysis of ribosomal and heat shock proteins of the bacterial cell (Fergusson et al 2020 ; Wong et al 2020 ; Depoorter et al 2020 ; Gassiep et al 2019 ; Wattal et al 2017 ). It was reported that determination of Burkholderia bacteria by MALDI-TOF MS at the genus level was reliable and the accuracy ranged between 97 and 100% for all bacteria samples.…”