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The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
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[Vol.26 No.3 contents] Japanese / English |
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| ArticleTitle | Comparative study of identification methods for NVS by two different MALDI-TOF MS based devices, VITEK 2 and conventional biochemical test |
| Language | J |
| AuthorList | Michiko Furugaito1), Hiroshi Enari3), Atsushi Yoshida4, 6), Katsuko Okuzumi5), Yoshiaki Kawamura7), Kaori Eguchi1), Hirofumi Toda1), Koji Utsunomiya1), Hiromi Matsuura1), Toshihiro Yamaguchi1), Toshinori Kamisako2) |
| Affiliation |
1) Department of Clinical Laboratory, Kindai University Hospital 2) Department of Clinical Laboratory Medicine, Kindai University School of Medicine 3) Division of Anaerobe Research, Life Science Research Center, Gifu University 4) Department of Clinical Laboratory Medicine, Dokkyo Medical University Hospital 5) Division of Infection Control, Dokkyo Medical University Hospital 6) Department of Infectious Diseases, Tokyo Women's Medical University 7) Department of Microbiology, Aichigakuin University, School of Pharmacy |
| Publication | J.J.C.M.: 26 (3), 223-233, 2016 |
| Received | January 15, 2016 |
| Accepted | April 22, 2016 |
| Abstract | Nutritionally variant streptococci (NVS) have been known to be significant causative agents of endocarditis. These organisms have caused major diagnostic difficulties due to fastidious culturing. In this study, we evaluated the performance of 2 matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) systems, VITEK MS (sysmex biomerieux) and MALDI Biotyper (Bruker), and the automatic phenotypic test system VITEK 2 (sysmex biomerieux). Sequence of the 16S rRNA gene was used as the reference method. In addition, we evaluated conventional biochemical tests. Twenty six NVS strains consist of 3 type strains and 3 clinical isolates and 20 isolates from oral cavity of healthy adults were analyzed. As a result, the VITEK MS accurately identified 100% strains, and the Biotyper identified 84.6% strains, but the VITEK 2 could only identify 65.4% strains, compared with 16S rRNA gene sequencing at the species level. When NVS were identified by the MALDI-TOF MS, we should confirm growth ability of these organisms on the sheep blood agar (non-growth, or slowly growth) compared with chocolate agar or anaerobic blood agar or medium for anaerobic bacteria, and gram strain of the colonies (gram-variable, pleomorphic), and catalase test (negative), PYR test (positive) which can perform quickly. But, in the microbiology laboratories where MALDI-TOF MS is not introduced, it is necessary to examine arginine dihydrolase, α-galactosodase, satellitism test et al. in addition to phenotypic tests described above. In conclusion, the MALDI-TOF MS could identify NVS more rapid and accurate than the VITEK 2 system. The rapid and accurate identification of NVS may contribute to various NVS infections. |
| Keywords | nutritionally variant streptococci, Satellitism test |
| Copyright © 2002 The Japanese Society for Clinical Microbiology All rights reserved. |