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Evaluation of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry Bruker Biotyper for identification of Penicillium marneffei, Paecilomyces species, Fusarium solani, Rhizopus species, and Pseudallescheria boydii.

Chen YS, Liu YH, Teng SH, Liao CH, Hung CC, Sheng WH, Teng LJ, Hsueh PR - Front Microbiol (2015)

Bottom Line: Sequencing analysis of these 22 non-P. marneffei isolates of molds revealed seven Paecilomyces variotii, six F. solani, four Paecilomyces lilacinus, and one each of Paecilomyces sinensis, Rhizopus arrhizus, R. oryzae, R. microspores, and P. boydii.Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, the score values of these isolates were all of <1.700.Therefore, it is necessary to continuously update the MALDI-TOF MS databases.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Department of Internal Medicine, Cardinal Tien Hospital New Taipei City, Taiwan.

ABSTRACT
We evaluated the performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), the MALDI Bruker Biotyper system (microflex LT; Bruker Daltonik GmbH, Bremen, Germany), on the identification of 50 isolates of clinically encountered molds, including Penicillium marneffei (n = 28), Paecilomyces species (n = 12), Fusarium solani (n = 6), Rhizopus species (n = 3), and Pseudallescheria boydii (n = 1). The isolates were identified to species levels by sequence analysis of the internal transcribed spacer (ITS) regions using primers ITS1 and ITS4. None of the 28 genetically well characterized isolates of P. marneffei were identified as P. marneffei by MALDI-TOF MS, because P. marneffei was not present in either Bruker general library (DB 5627) or Bruker filamentous fungi library V1.0. However, the rate of accurate identification as P. marneffei (score value ≥ 2.000) was 85.7% based on newly created database from one P. marneffei strain (NTUH-3370) by MALDI Biotyper system. Sequencing analysis of these 22 non-P. marneffei isolates of molds revealed seven Paecilomyces variotii, six F. solani, four Paecilomyces lilacinus, and one each of Paecilomyces sinensis, Rhizopus arrhizus, R. oryzae, R. microspores, and P. boydii. Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, the score values of these isolates were all of <1.700. This study indicated that the MALDI Bruker Biotyper is ineffective for identifying P. marneffei and other unusual molds because of the current database limitations. Therefore, it is necessary to continuously update the MALDI-TOF MS databases.

No MeSH data available.


Related in: MedlinePlus

Spectra of Paecilomyces variotii, Fusarium solani, Paecilomyces lilacinus, Paecilomyces sinensis, Rhizopus arrhizus, Rhizopus oryzae, Rhizopus microspores, and Pseudallescheria boydii generated by the MALDI-TOF Bruker Biotyper. The absolute intensities of the ions are shown on the y axis, and the masses (m/z) of the ions are shown on the x axis. The m/z values represent the mass-to-charge ratio.
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Figure 3: Spectra of Paecilomyces variotii, Fusarium solani, Paecilomyces lilacinus, Paecilomyces sinensis, Rhizopus arrhizus, Rhizopus oryzae, Rhizopus microspores, and Pseudallescheria boydii generated by the MALDI-TOF Bruker Biotyper. The absolute intensities of the ions are shown on the y axis, and the masses (m/z) of the ions are shown on the x axis. The m/z values represent the mass-to-charge ratio.

Mentions: Among these 22 non-P. marneffei isolates of molds, only one isolate of F. solani could be correctly identified by MALDI-TOF MS with score value of ≥2.0 (Table 2). Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, all the score values of these isolates were of <1.700 (Table 2). Four of the seven P. variotii isolates, three of the six F. solani, the R. microspores isolate, and none of other molds tested could be correctly identified with lowering the cut-off value of 1.4. These characteristic MALDI Biotyper spectra of non-P. marneffei isolates are shown in Figure 3.


Evaluation of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry Bruker Biotyper for identification of Penicillium marneffei, Paecilomyces species, Fusarium solani, Rhizopus species, and Pseudallescheria boydii.

Chen YS, Liu YH, Teng SH, Liao CH, Hung CC, Sheng WH, Teng LJ, Hsueh PR - Front Microbiol (2015)

Spectra of Paecilomyces variotii, Fusarium solani, Paecilomyces lilacinus, Paecilomyces sinensis, Rhizopus arrhizus, Rhizopus oryzae, Rhizopus microspores, and Pseudallescheria boydii generated by the MALDI-TOF Bruker Biotyper. The absolute intensities of the ions are shown on the y axis, and the masses (m/z) of the ions are shown on the x axis. The m/z values represent the mass-to-charge ratio.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495555&req=5

Figure 3: Spectra of Paecilomyces variotii, Fusarium solani, Paecilomyces lilacinus, Paecilomyces sinensis, Rhizopus arrhizus, Rhizopus oryzae, Rhizopus microspores, and Pseudallescheria boydii generated by the MALDI-TOF Bruker Biotyper. The absolute intensities of the ions are shown on the y axis, and the masses (m/z) of the ions are shown on the x axis. The m/z values represent the mass-to-charge ratio.
Mentions: Among these 22 non-P. marneffei isolates of molds, only one isolate of F. solani could be correctly identified by MALDI-TOF MS with score value of ≥2.0 (Table 2). Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, all the score values of these isolates were of <1.700 (Table 2). Four of the seven P. variotii isolates, three of the six F. solani, the R. microspores isolate, and none of other molds tested could be correctly identified with lowering the cut-off value of 1.4. These characteristic MALDI Biotyper spectra of non-P. marneffei isolates are shown in Figure 3.

Bottom Line: Sequencing analysis of these 22 non-P. marneffei isolates of molds revealed seven Paecilomyces variotii, six F. solani, four Paecilomyces lilacinus, and one each of Paecilomyces sinensis, Rhizopus arrhizus, R. oryzae, R. microspores, and P. boydii.Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, the score values of these isolates were all of <1.700.Therefore, it is necessary to continuously update the MALDI-TOF MS databases.

View Article: PubMed Central - PubMed

Affiliation: Division of Infectious Diseases, Department of Internal Medicine, Cardinal Tien Hospital New Taipei City, Taiwan.

ABSTRACT
We evaluated the performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), the MALDI Bruker Biotyper system (microflex LT; Bruker Daltonik GmbH, Bremen, Germany), on the identification of 50 isolates of clinically encountered molds, including Penicillium marneffei (n = 28), Paecilomyces species (n = 12), Fusarium solani (n = 6), Rhizopus species (n = 3), and Pseudallescheria boydii (n = 1). The isolates were identified to species levels by sequence analysis of the internal transcribed spacer (ITS) regions using primers ITS1 and ITS4. None of the 28 genetically well characterized isolates of P. marneffei were identified as P. marneffei by MALDI-TOF MS, because P. marneffei was not present in either Bruker general library (DB 5627) or Bruker filamentous fungi library V1.0. However, the rate of accurate identification as P. marneffei (score value ≥ 2.000) was 85.7% based on newly created database from one P. marneffei strain (NTUH-3370) by MALDI Biotyper system. Sequencing analysis of these 22 non-P. marneffei isolates of molds revealed seven Paecilomyces variotii, six F. solani, four Paecilomyces lilacinus, and one each of Paecilomyces sinensis, Rhizopus arrhizus, R. oryzae, R. microspores, and P. boydii. Although all the seven P. variotii isolates, four of the six F. solani, two of the four P. lilacinus, and two of the three isolates of Rhizopus species, and the P. boydii isolate had concordant identification results between MALDI-TOF MS and sequencing analysis, the score values of these isolates were all of <1.700. This study indicated that the MALDI Bruker Biotyper is ineffective for identifying P. marneffei and other unusual molds because of the current database limitations. Therefore, it is necessary to continuously update the MALDI-TOF MS databases.

No MeSH data available.


Related in: MedlinePlus