Distribution of type three secretion system genes and their association with the diarrheagenicity of genus Providencia

2023 Fiscal Year Research-status Report

• Project/Area Number: 23KF0152
• Research Institution: Osaka University
• Principal Investigator: 飯田 哲也 大阪大学, 微生物病研究所, 教授 (90221746)
• Co-Investigator(Kenkyū-buntansha): HASSAN JAYEDUL 大阪大学, 微生物病研究所, 外国人特別研究員
• Project Period (FY): 2023-09-27 – 2026-03-31
• Keywords: Providencia / T3SS / whole genome sequencing / mutant

Outline of Annual Research Achievements

The objective of the research was to examine the existence and locations of T3SS genes in Providencia, as well as to functionally characterize the injectosome. Initially, we screened Providencia isolates in our collection using PCR, followed by whole genome sequencing (WGS) to pinpoint the locations of T3SS genes. Through WGS, we identified the presence and precise locations of T3SS-related genes. Next, we are preparing mutants and complementary strains using various strategies for the functional analysis of the T3SS. Although no definitive conclusions can be drawn at this stage, we anticipate reporting interesting findings by the conclusion of this study.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

The present study aimed to ascertain the presence of T3SS genes in Providencia. As intended, we examined several Providencia isolates and verified the presence of T3SS genes in some of them. To proceed with our next steps, we are currently preparing mutants and complementary strains to elucidate the functional traits of the T3SSs. At this juncture, we are optimistic about uncovering the role of T3SS in these Providencia strains and arriving at our final conclusions as scheduled. Hence, we anticipate that our work is advancing smoothly.

Strategy for Future Research Activity

We're currently proceeding to step-2 of our research, involving a series of in vitro and in vivo experiments. We've selected specific genes and are now in the process of creating deletion mutants and constructing complementary strains. Our upcoming plan entails assessing the invasiveness and diarrheagenicity of the prepared strains through both in vitro and in vivo experiments. Once we've uncovered these traits, our goal shifts to understanding the role of T3SS genes in the interaction between Providencia strains (wild type, mutants, and complementary strains) and their host. To achieve this, we'll utilize live cell imaging and fluorescent microscopy techniques.

Causes of Carryover

試薬類等の物品費の支出を予定していたが、効率的な試薬の使用により物品費を節約することができた。次年度以降については当初計画以上の研究の進展が期待できるので、今年度生じた残金について来年度以降の実験で使い切る予定である。