We conduct research to understand bacteria (bacteriology and environmental microbiology)and to use bacteria (applied microbiology).

We are welcome overseas graduate students. The link to higher degree programs is shown on the right. If you are interested in our research, feel free to contact uchiyama[a_to]okayama-u.ac.jp.

Research on bacteriology and environemntal mirobiology

 

Microbiota research

We now know that many bacteria live on our body surface and in our intestinal tract. In the intestinal tract, there are as many as 100 trillion bacteria of 1,000 different species. We are conducting research to clarify the actual status of the commensal microflora, to investigate its relationship with diseases, and to determine which bacteria are important for diseases or health. In collaboration with clinical departments, we are investigating the relationship between various diseases and the commensal microbiota.

 

Research on　Helicobacter pylori

H. pylori is known as a bacterium that causes gastritis, gastric ulcer, gastric MALT lymphoma, and gastric cancer in some humans through the process of long-term residence in the stomach. In recent years, drug resistance has become a problem in this bacterium, and countermeasures against drug-resistant bacteria are necessary. Therefore, it is essential to conduct research to prevent cancer caused by H. pylori. The atrophy of the gastric mucosa caused by H. pylori infection leads to a decrease in gastric acid secretion and an increase in indigenous bacteria other than H. pylori. These commensal bacteria include nitrate-reducing bacteria that produce nitrite, which reduces nitrate and is involved in the production of carcinogens. We are conducting research on the possibility that the carcinogenic mechanism of H. pylori is due to the cooperation between H. pylori and nitrite-reducing bacteria.

Research on drug-resistant bacteria

With continued use of antimicrobial drugs, the resistance of bacteria to the drugs increases and the drugs become ineffective. These bacteria that have developed resistance to the drugs are called "drug-resistant bacteria". According to a British economist, it is estimated that 10 million people will die annually by 2050, more than the number who will die of cancer if nothing is done about the current situation. In Japan, where the number of elderly people is expected to increase, infections caused by drug-resistant bacteria will become a particular problem. Therefore, in order to understand the current status of drug-resistant bacteria, we are conducting a survey of drug-resistant bacteria in collaboration with clinical departments.

Research on applied microbiology

Research and developments on bacteriophage therapy

"Bacteriophage (phage) therapy" is a treatment for bacterial infections that utilizes and applies the bactericidal action of bacteriophages. As mentioned above, drug-resistant bacteria have become a problem in recent years, and there is a need for an alternative treatment to chemotherapy. Phage therapy is one of the most promising treatment methods. We are actively engaged in the research and development of phage therapy. Specifically, we are searching for therapeutic phages, creating therapeutic tools using phage molecules, and conducting animal experiments. Our research targets Staphylococcus spp., Enterococcus spp., Group B Streptococcus, Acinetobacter spp., Helicobacter pylori, and Pseudomonas aeruginosa.

 

Research on the use of toxins for regenerative medicine

Collagen is a major protein in the extracellular matrix. It forms insoluble collagen fibers that act as a barrier to the spread of infection. The gastric jaundice group of bacteria produces "collagenase" to destroy connective tissue and rapidly spread the infection. The enzyme binds to and hydrolyzes collagen fibrils with an anchor consisting of a PKD domain and a collagen-binding domain (CBD). When a fusion protein linking this anchor and a growth factor was produced and transplanted to the bone surface by binding to high-density collagen membrane and demineralized bone, significantly more osteogenesis was induced (Patent No. 5512887, US 9,248,164, EP 2,708,246). Preclinical research is being conducted with the aim of clinical application through tissue regeneration of nerves and blood vessels.

 

Research on the use of toxins as painkillers

Clostridium botulinum is a bacterium that produces botulinum toxin that causes food poisoning. The toxin is a neurotoxin, which is the most poisonous biological substances known. We are conducting applied research to elucidate the physiological functions of the toxin in detail and to use the toxin as an analgesic.