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Updated: May 6, 2026
Automated Separation of C. elegans Variably Colonized by a Bacterial Pathogen
Published on: March 21, 2014
PemB, a type III secretion effector in Pseudomonas aeruginosa, affects Caenorhabditis elegans life span
Shira Zelikman1,2, Reut Dudkevich1, Hadar Korenfeld-Tzemach1,2
1The Mina & Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Max and Anna Webb, 5290002, Ramat Gan, Israel.
Abstract:
Pseudomonas aeruginosa is one of the leading nosocomial opportunistic pathogens causing acute and chronic infections. Among its main virulent factors is the Type III secretion system (T3SS) which enhances disease severity by delivering effectors to the host in a highly regulated manner. Despite its importance for virulence, only six T3SS-dependent effectors have been discovered so far. Previously, we identified two new potential effectors using a machine-learning algorithm approach. Here we demonstrate that one of these effectors, PemB, is indeed virulent. Using a live Caenorhabditis elegans infection model, we demonstrate this effector damages the integrity of the intestine barrier leading to the death of the host. Implementing a high-throughput assay using Saccharomyces cerevisiae, we identified several candidate proteins that interact with PemB. One of them, EFT1, has an ortholog in C. elegans (eef-2) and is also an essential gene and a well-known target utilized by different pathogens to induce toxicity to the worm. Accordingly, we found that by silencing the eef-2 gene in C. elegans, PemB could no longer induce its toxic effect. The current study further uncovers the complex machinery assisting P. aeruginosa virulence and may provide novel insight how to manage infection associated with this hard-to-treat pathogen.
Insights
Pseudomonas aeruginosa
Area of Science:
- Microbiology
- Molecular Biology
- Pathogen Research
Background:
- Pseudomonas aeruginosa is a major opportunistic pathogen responsible for numerous infections.
- The Type III secretion system (T3SS) is a key virulence factor in P. aeruginosa, delivering effector proteins into host cells.
- Only a limited number of T3SS effectors have been identified, highlighting the need for further discovery.
Purpose of the Study:
- To validate the virulence of a newly identified T3SS effector, PemB, from P. aeruginosa.
- To investigate the molecular mechanisms underlying PemB-mediated virulence.
- To identify host factors that interact with PemB and contribute to pathogenesis.
Main Methods:
- Utilized a Caenorhabditis elegans infection model to assess PemB virulence.
- Employed a high-throughput yeast-based screen to identify PemB-interacting proteins.
- Investigated the role of identified interacting proteins in PemB-induced toxicity.
Main Results:
- PemB was confirmed as a virulent effector, causing intestinal barrier damage and host death in C. elegans.
- Identified EFT1, a protein interacting with PemB, with an ortholog (eef-2) in C. elegans.
- Demonstrated that silencing eef-2 in C. elegans abrogated PemB's toxic effects, indicating eef-2 is essential for PemB virulence.
Conclusions:
- PemB is a novel virulent T3SS effector of Pseudomonas aeruginosa.
- The interaction between PemB and the host factor eef-2 is critical for P. aeruginosa pathogenesis.
- This study provides new insights into P. aeruginosa virulence mechanisms and potential therapeutic targets.
