title: Genetic, phenotypic and matrix-assisted laser desorption ionization time-of-flight mass spectrometry-based identification of anaerobic bacteria and determination of their antimicrobial susceptibility at a University Hospital in Japan.
abstract: The accuracies of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the phenotypic method using VITEK 2 were compared to the accuracy of 16S rRNA sequence analysis for the identification of 170 clinically isolated anaerobes. The antimicrobial susceptibility of the isolates was also evaluated. Genetic analysis identified 21 Gram-positive species in 14 genera and 29 Gram-negative species in 11 genera. The most frequently isolated genera were Prevotella spp. (n = 46), Bacteroides spp. (n = 25) and Clostridium spp. (n = 25). MALDI-TOF MS correctly identified more isolates compared with VITEK 2 at the species (80 vs. 58%, respectively; p < 0.01) and genus (85 vs. 71%, respectively; p < 0.01) levels. More than 90% of the isolates of the three major genera identified (Prevotella, Bacteroides, and Clostridium species other than Clostridium difficile) were susceptible to beta-lactam/beta-lactamase inhibitor combinations, carbapenems, metronidazole and chloramphenicol. MALDI-TOF MS provided better identification results than VITEK2. Commonly used anti-anaerobic agents indicated that the isolates of the three most frequently identified anaerobic genera exhibited good antimicrobial susceptibility.
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: tyunoki@kuhp.kyoto-u.ac.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yunoki
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: yazblood@kuhp.kyoto-u.ac.jp.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Matsumura
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: snakano@kuhp.kyoto-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakano
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: karin@kuhp.kyoto-u.ac.jp.
authors.forename: Karin
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: hotta611@kuhp.kyoto-u.ac.jp.
authors.forename: Go
authors.initials: G
authors.lastname: Hotta
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: noguchit@kuhp.kyoto-u.ac.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Noguchi
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: masakiy@kuhp.kyoto-u.ac.jp.
authors.forename: Masaki
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: mnagao@kuhp.kyoto-u.ac.jp.
authors.forename: Miki
authors.initials: M
authors.lastname: Nagao
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: stakakr@kuhp.kyoto-u.ac.jp.
authors.forename: Shunji
authors.initials: S
authors.lastname: Takakura
authors.affiliation: Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. Electronic address: sichiyam@kuhp.kyoto-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ichiyama
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000737:chemistry / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D001424:Bacterial Infections / Q000382:microbiology*; D015373:Bacterial Typing Techniques / Q000379:methods* / Q000592:standards; D015331:Cohort Studies; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007564:Japan; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents
keywords: Anaerobic bacteria; Antimicrobial susceptibility; Identification; MALDI-TOF MS