Bacteriological and epidemiological study of multiple amplification of capsulation locus in Haemophilus influenzae type b (Hib).

2015 Fiscal Year Final Research Report

• Project/Area Number: 24591476
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Infectious disease medicine
• Research Institution: Kagoshima University (2014-2015); Tohoku University (2012-2013)
• Principal Investigator: TOKUDA KOICHI 鹿児島大学, 医歯学域医学部・歯学部附属病院, 准教授 (10518400)
• Co-Investigator(Kenkyū-buntansha): NISHI JUNICHIRO 鹿児島大学, 医歯学域医学部, 教授 (40295241)
• Co-Investigator(Renkei-kenkyūsha): IMUTA NAOKO 鹿児島大学, 医歯学域医学部, 助教 (00643470)
• Project Period (FY): 2012-04-01 – 2016-03-31
• Keywords: インフルエンザ菌b型 / ワクチン不全 / capb遺伝子の重複 / 無莢膜型インフルエンザ菌 / バイオフィルム形成能 / 付着遺伝子

Outline of Final Research Achievements

We studied multiple amplification of the capsulation (capb) locus which may influence vaccine efficacy for Haemophilus influenzae type b (Hib) using the strains detected in the patients of invasive Haemophilus influenzae disease (IHD). Our study from 2004 to 2011 revealed increasing trend in the locus amplification prevalence rate (pre-Hib vaccine era, 9.5%; post-vaccine era, 23.1%). Although we conducted the follow-up researches, it is impossible to continue our study because of the dramatic decrease of IHD after introducing Hib vaccine program in 2008.
On the other hand, the invasive infection caused by nontypable Haemophilus influenza (NTHi) have being increasing. We studied 66 strain of NTHi for biofilm formation by a quantitative biofilm assay and for adhesion genes a biofilm-related gene by PCR. Variabilities among isolates were observed in their ability to form biofilms and detection rate of adhesion genes.

Free Research Field

医歯薬学