Identification of viridans streptococci With Matrix-Assisted Laser Desorption & Ionization Time-of-flight Mass Spectrometry by an In-house Method and a Commercially Available System
1
조회
0
다운로드
0
인용
0
참고문헌
키워드
초록
Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All in-house measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chi-square test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species.
Abstract
Two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS)-based methods were compared for their ability to identify viridans streptococci. One approach employed a reference database and software developed in-house. All in-house measurements were performed using an Autoflex II Instrument (Bruker Daltonics GmbH, Germany). The other system, a VITEK-MS (BioMérieux, France) was operated on the commercially available V2.0 Knowledge Base for Clinical Use database. Clinical isolates of viridans streptococci (n=184) were examined. Discrepant results were resolved by 16S rDNA sequencing. Species-level identification percentages were compared by a chi-square test. The in-house method correctly identified 179 (97%) and 175 (95%) isolates to the group and species level respectively. In comparison, the VITEK-MS system correctly identified 145 (79%) isolates to the group and species level. The difference between the two methods was statistically significant at both group and species levels. Using the Autoflex II instrument combined with an extraction method instead of whole cell analysis resulted in more reliable viridans streptococci identification. Our results suggest that combining extraction with powerful analysis software and the careful choice of well-identified strains included into the database was useful for identifying viridans streptococci species.
참고문헌 (9)
- Teles C, "Identification of clinically relevant viridans group streptococci by phenotypic and genotypic analysis", Eur J Clin Microbiol Infect Dis, 30, pp.243~250 (2011)
- Gavin P J, "Evaluation of the Vitek 2 system for rapid identification of clinical isolates of gram-negative bacilli and members of the family Streptococcaceae", Eur J Clin Microbiol Infect Dis, 21, pp.869~874 (2002)
- Ikryanikova LN, "Misidentification of alpha-haemolytic streptococci by routine tests in clinical practice", Infect Genet Evol, 11, pp.1709~1715 (2011)
- Friedrichs C, "Rapid identification of viridans streptococci by mass spectrometric discrimination", J Clin Microbiol, 45, pp.2392~2397 (2007)
- Moon HW, "Performance of the Vitek MS matrix-assisted laser desorption ionization time-of-flight mass spectrometry system for identification of gram-positive cocci routinely isolated in clinical microbiology laboratories", J Med Microbiol, 62, pp.1301~1306 (2013)
- Davies AP, "Identification of clinical isolates of α-hemolytic streptococci by 16S rRNA gene sequencing, matrix-assisted laser desorption ionization-time of flight mass spectrometry using MALDI Biotyper, and conventional phenotypic methods: a comparison", J Clin Microbiol, 50, pp.4087~4090 (2012)
- Kärpänoja P, "Evaluation of two matrix-assisted laser desorption ionization-time of flight mass spectrometry systems for identification of viridans group streptococci", Eur J Clin Microbiol Infect Dis, 33, pp.779~788 (2014)
- Rychert J, "Multicenter evaluation of the VITEK MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of Gram-positive aerobic bacteria", J Clin Microbiol, 51, pp.2225~2231 (2013)
- Dubois D, "Identification of clinical Streptococcus pneumoniae isolates among other alpha and nonhemolytic streptococci by use of the Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system", J Clin Microbiol, 51, pp.1861~1867 (2013)