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The Journal of the Japanese Society for Clinical Microbiology |
Biblioraphy Information
| ArticleTitle |
Examination of biochemical characteristics for the differentiation of clinically isolated strains identified as Haemophilus haemolyticus using MALDI-TOF MS |
| Language |
J |
| AuthorList |
Hitoshi Kuramae1), Natsuko Matsui1), Tomomi Inukai1), Yuki Nakamura1), Kouhei Kawaguchi2), Kiyotada Nakamura1) |
| Affiliation |
1) Department of Clinical Laboratory Pathology, Kariya Toyota General Hospital
2) Biochemical Research Laboratory-1, Eiken Chemical Co., Ltd. |
| Publication |
J.J.C.M.: 28 (2), 106-111, 2018 |
| Received |
April 17, 2017 |
| Accepted |
October 20, 2017 |
| Abstract |
Among bacteria of the genus Haemophilus isolated from clinical samples between April and August 2016 in our hospital, 75 strains identified as Haemophilus haemolyticus using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were investigated to determine diversity in their biochemical characteristics for species differentiation. Only six strains (8.0%) exhibited typical diagnostic characteristics of requiring X and V factors and also displayed hemolysis on house blood agar, whereas 26 isolates (34.7%) were non-hemolytic strains requiring X and V factors. Moreover, 43 strains (57.3%) requiring only V factor were isolated, revealing diverse characteristics of H. haemolyticus. Despite the particular importance of identification of H. influenzae, it is difficult to distinguish non-hemolytic types of H. haemolyticus from H. influenzae based on requirement for X and V factors and hemolysis in routine tests. However, the glycolysis test employing sucrose and mannose, which was performed in this investigation, revealed that all strains of H. haemolyticus requiring only V factor metabolized sucrose, whereas 62.5% of strains requiring X and V factors metabolized mannose, which proved to be valuable as a characteristic for differentiation of H. haemolyticus from H. influenzae. The glycolysis test was a feasible differentiation method that improves accuracy of identification of H. influenzae in biochemical characteristics tests. |
| Keywords |
Haemophilus haemolyticus, MALDI-TOF MS |
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