Comparative analysis on two Leptospira interrogans strains which exhibit different severity to humans

2015 Fiscal Year Final Research Report

• Project/Area Number: 25460557
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Bacteriology (including mycology)
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Koizumi Nobuo 国立感染症研究所, 細菌第一部, 主任研究官 (10333361)
• Co-Investigator(Renkei-kenkyūsha): Sugiyama Hiromu 国立感染症研究所, 寄生動物部, 室長 (00145822)
• Research Collaborator: Fujita Rie ; Tomizawa Rina ; Satou Kazuhito
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: レプトスピラ / レプトスピラ症 / 病原性

Outline of Final Research Achievements

To clarify the mechanism underlying the difference in virulence of the various Leptospira strains, experimental infections of hamsters with strains of two L. interrogans serovars Manilae (highly virulent: HV) and Hebdomadis (less virulent: LV) were performed.Severe disruption of renal tubules in kidney tissues and hemorrhage in lung tissues were observed in HV-infected hamsters. A significantly higher bacterial burden was observed in liver tissues of hamsters infected with HV than those infected with LV. The expression levels of multiple cytokine genes in blood, liver, and lung tissue were also significantly higher in hamsters infected with HV than those infected with LV.These results demonstrate that HV multiplied more efficiently in liver tissues and induced significantly higher expression of genes encoding pro- and anti-inflammatory cytokines than LV. In addition, our results suggest a HV-specific mechanism responsible for inducing severe damage in kidneys and hemorrhage in lung.

Free Research Field

細菌学