2013 Fiscal Year Final Research Report

Analysis on the genetic characteristics and virulence factors of hypervirulent Klebsiella pneumonia isolates from clinical samples

Research Project

Project/Area Number	23791143
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Infectious disease medicine
Research Institution	Toho University
Principal Investigator	HARADA Sohei 東邦大学, 医学部, 非常勤研究生 (30591630)
Project Period (FY)	2011 – 2012
Keywords	肺炎桿菌 / 莢膜血清型 / 病原因子 / MLST / パルスフィールドゲル電気泳動 / rep-PCR
Research Abstract	I explored the epidemiology and pathogenesis of hypervirulent Klebsiella pneumonia infection. K. pneumoniae isolates of capsular genotype K1 and K2 and isolates carrying rmpA gene, which have been identified as hypervirulent strains in other countries, were not rare among clinical isolates in Japan. Despite isolation from different geographic regions, K1 isolates in Japan showed high genetic relatedness. The proportion of the hypervirulent strains mentioned above in K. pneumoniae isolates recovered from blood was similar to that of hypervirulent strains in clinical isolates form various body sites. I performed experiment of Balb/c mouse model of infection with K1 strains isolated in Japan and established the model of infection accompanying the formation of liver abscess similar to the infection in human caused by these strains.