Akiko KUSUMOTO Assistant Professor

ThemeMolecular mechanisms of gliding motility in a fish pathogen, Tenacibaculum maritimum

My DreamReveal novel mechanisms of bacterial motility


Diagnostic Center for Animal Health and Food Safety/Research Unit for MicrobiologyResearch Department/Department of Veterinary Medicine/Division of Veterinary Sciences/Section of Applied Veterinary Sciences
Field Bacteriology, Fish pathology, Biophysics
Keyword Motor protein, Gliding motility, Fish diseases, Foodborne bacteria, Antibiotic resistant bacteria, Bacteriophage


I'm interested in bacterial motility, and in graduate school I studied the flagella of Vibrio and “gliding motility” in Mycoplasma. Currently, I'm studying gliding motility in a fish pathogen Tenacibaculum maritimum.
The T. maritimum bacterium infects various saltwater fish, in which it causes gliding bacterial disease(or tenacibaculosis).The affected fish exhibit erosions and ulcers on their body surface, as well as rot and disintegration in the fins and mouths. (Refer to the photo “Red sea bream fry with gliding bacterial disease.”) Gliding bacterial disease is seen in domestic and overseas fish farms, where it's a serious problem. T. maritimum adheres to solid surfaces, along which it creeps in what is called “gliding motility.” (Refer to the link of the movie on gliding motility in T. maritimum.) Gliding motility in T. maritimum differs from the motility of bacteria with organs such as flagella and fimbria, but the molecular mechanism has yet to be elucidated. I apply molecular biological methods to discover how T. maritimum move.
In bacteria, motility tends to be closely related to pathogenicity. As for T. maritimum, it is expected that adhesion for gliding motility is involved in adhesion to the host. I'd like to develop a novel study on the motility of T. maritimum with the aim of treating gliding bacterial diseases and developing vaccines.
At present, plasmids and the like can't be used for gene recombination in T. maritimum, so gene manipulation isn't possible. If gene manipulation were to become possible, it would lead to the identification of genes involved in gliding motility, catapulting the research forward. Therefore, we're working to develop phage-based gene manipulation technologies. (Refer to the figure “bacteriophage showing clear plaques on the lawn of T. maritimum .”) If we're able to establish this technology, it will contribute to the development of bacteriology through its application to other bacterial species that can't be genetically manipulated.

Red sea bream fry with gliding bacterial disease
T. maritimum colonies
Bacteriophage showing clear plaques on the lawn of T. maritimum

List of current research topics

  • Molecular mechanism of gliding motility in fish pathogen Tenacibaculum maritimum
  • Isolation of bacteriophage infecting Tenacibaculum maritimum
  • Development of genetic modification methods of Tenacibaculum maritimum
  • Tenacibaculosis vaccine development
Related industries Fisheries, Veterinary Medicine
Affiliated academic society The Japanese Society of Fish Pathology, The Japanese Society for Bacteriology, The Japanese Society of Veterinary Science
Academic degree Ph.D. in Science
Self introduction

I'm from Fukuoka. I like traveling to hot spring resorts, and I go to a public hot spring bath almost every day. In summer, I drive around Hokkaido by motorcycle (a Honda XL-Degree). I like drawing. But because I tend to become engrossed in drawing, I haven't done much of it in recent days. My favorite style of comics is that of Junji Ito. I like animals, and at the university, I was in the equestrian club. I have a cat.

Room addressDiagnostic Center for Animal Health and Food Safety
Room number205
Mail address akusumoto atmark obihiro.ac.jp