Construction of chimeric bacteria and analysis of host specificity determination mechanism of pathogenic bacteria

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K19446
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 49:Pathology, infection/immunology, and related fields
• Research Institution: Osaka University
• Principal Investigator: Horiguchi Yasuhiko 大阪大学, 微生物病研究所, 教授 (00183939)
• Project Period (FY): 2018-06-29 – 2022-03-31
• Keywords: 細胞融合 / キメラ細菌

Outline of Final Research Achievements

To analyze the mechanism of determining host specificity of pathogenic bacteria at the genetic level, we attempted to generate chimeric bacteria that infect non-human laboratory animals by fusing B. parapertussis, which infects only humans, and B. bronchiseptica, which infects a wide range of mammalian species. As a result, we isolated candidate strains for fused bacterial cells at a rate of about 0.01% of the number of bacteria tested. Of these strains, about 10% showed the potential for genomic hybridization. Unfortunately, however, we were unable to achieve our initial goal due to problems such as recombination occurring in a shorter genomic region than expected and the occurrence of mutant strains with spontaneous inversion of the genomic structure in parental B. bronchiseptica.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

細胞の融合技術は40年以上前に隆盛し、微生物では品種改良の目的で乳酸菌、糸状菌、酵母などで利用されたが、特定の遺伝子を標的にできる、より精細な遺伝子操作技術が発展した現在ではほとんど利用されない。異なる種の真正細菌の細胞融合に関する研究はさらに少なく、種々の方法論が確立される前に研究が衰退してしまったため、現在の科学の動向や水準からみて参考となる知見はほとんどない。本研究課題では所期の目的は達成できなかったが、細胞融合の基準プロトコールと融合候補細菌の遺伝子解析の結果を示すことができた。その成果は、キメラ細菌の作製技術の再理解のための最新の知見を提供すると考えている。