| Project/Area Number |
17591049
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
膠原病・アレルギー・感染症内科学
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| Research Institution | Kurume University (2006)
Nagasaki University (2005) |
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Principal Investigator |
WATANABE Hiroshi Kurume University, School of Medicine, Professor, 医学部, 教授 (90295080)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Kiwao Nagasaki University, Institute of Tropical Medicine, Assistant Professor, 熱帯医学研究所, 助手 (20220874)
大石 和徳 大阪大学, 微生物病研究所, 特任教授 (80160414)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2005: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Haemophilus influenzae / biofilm / BLNAR / BLNAR / Nontypeable H.influenzae / H. influenzae type b |
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| Research Abstract |
To evaluate the biofilm formation between Nontypeable Haemophilus influenzae (NTHi) and H. influenzae type b (Hib), we conducted the following comparative study. After serotyping and performing PCR to identify β-lactamase-negative ampicillin (AMP)-susceptible (BLNAS) NTHi, β-lactamase-negative AMP-resistant (BLNAR) NTHi, TEM-1 type β-lactamase-producing AMP-resistant (BLPAR) NTHi and Hib, we conducted biofilm production assays and scanning electron microscopy (SEM). The biofilm production assay and SEM showed that NTHi, including the BLNAR, BLNAS and BLPAR strains were similar in terms of forming biofilms, whereas in most of the Hib strains biofilm formation was decreased, compared to NTHi except for a few biofilm-producing strains. PCR to identify the type b cap gene and sequences indicated that 5 of the biofilm-producing Hib strains had lost their b capsule. Also, we compared anti-biofilm effect by several antibiotics between BLNAR and BLNAS strains using biofilm production assays. The assay indicates that penicillin and cephalosporin do not have anti-biofilm effect, but macrolide and quinolone have anti-biofilm effect against BLNAR and BLNAS strains dose-dependently. Our data indicate that most Hib strains form biofilms to a lesser extent than NTHi, whereas biofilm formation among BLNAR, BLNAS and BLPAR NTHi are variable and almost similar, and that the loss of b capsule expression in H. influenzae may result in enhanced biofilm formation. Also, our data demonstrate that macrolide and quinolone may inhibit biofilm formed by Haemophilus influenzae.
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