2021 Fiscal Year Annual Research Report
Identification and characterization of novel virulence factors of Staphylococcus aureus USA300 using silkworm model.
| Project/Area Number |
19K16653
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
PAUDEL ATMIKA 北海道大学, 人獣共通感染症国際共同研究所, 助教 (80832774)
|
|---|
| Project Period (FY) |
2019-04-01 – 2022-03-31
|
| Keywords | Bacillus cereus / Staphylococcus aureus / pathogenecity / silkworm / pathogenesis |
|---|
| Outline of Annual Research Achievements |
We expanded the research from Staphylococcus aureus to Bacillus anthracis and Bacillus cereus. Our aim was to find any correlation among these two bacteria because they belonged to the same group of Gram-positive bacteria and have several conserved regions and genes that might have role in pathogenesis. We established silkworm infection models of Bacillus anthracis and Bacillus cereus infections. We employed several gene-disruptant mutants to demonstrate that the known-virulence gene deletion mutants have attenuated virulence in silkworms. Using AmCyan1 expressing Bacillus anthracis and Bacillus cereus, we showed that bacteria proliferated inside silkworm hemolymph over time and antibiotic treatment can halt this proliferation. Constructing a mutant library of Bacillus cereus, we found one gene X to have role in virulence in silkworm. We then used the mutants with transposon inserted in the gene X from the NTML library of S. aureus and found that the disruption of the gene X made S. aureus hyper virulent. Thus, we found that although the gene was conserved among S. aureus and B. cereus and had role in virulence, the mechanism of virulence seems to be different which needs to be further confirmed.
|
