American Society of Hirudotherapy

Identification and characterization of putative Aeromonas spp. T3SS effectors

Genomics study published in PLoS ONE (2019)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportSafety & Infection ControlRangel LT et al. · PloS one, 2019

Abstract

The genetic determinants of bacterial pathogenicity are highly variable between species and strains. However, a factor that is commonly associated with virulent Gram-negative bacteria, including many Aeromonas spp., is the type 3 secretion system (T3SS), which is used to inject effector proteins into target eukaryotic cells. In this study, we developed a bioinformatics pipeline to identify T3SS effector proteins, applied this approach to the genomes of 105 Aeromonas strains isolated from environmental, mutualistic, or pathogenic contexts and evaluated the cytotoxicity of the identified effectors through their heterologous expression in yeast. The developed pipeline uses a two-step approach, where candidate Aeromonas gene families are initially selected using Hidden Markov Model (HMM) profile searches against the Virulence Factors DataBase (VFDB), followed by strict comparisons against positive and negative control datasets, greatly reducing the number of false positives. This approach identified 21 Aeromonas T3SS likely effector families, of which 8 represent known or characterized effectors, while the remaining 13 have not previously been described in Aeromonas. We experimentally validated our in silico findings by assessing the cytotoxicity of representative effectors in Saccharomyces cerevisiae BY4741, with 15 out of 21 assayed proteins eliciting a cytotoxic effect in yeast. The results of this study demonstrate the utility of our approach, combining a novel in silico search method with in vivo experimental validation, and will be useful in future research aimed at identifying and authenticating bacterial effector proteins from other genera.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.
Indexed MeSH termsAeromonasBacterial ProteinsComputational BiologyComputer SimulationGenome, BacterialSaccharomyces cerevisiaeType III Secretion SystemsVirulence Factors

Summary

Genomic identification and characterization of type-III secretion system effectors across Aeromonas spp., with implications for leech-associated virulence.

Why This Matters for Hirudotherapy

This study developed a bioinformatics pipeline combining Hidden Markov Model profile searches against the Virulence Factors Database with strict dataset comparisons to identify type III secretion system (T3SS) effector proteins across 105 Aeromonas strains from environmental, mutualistic, and pathogenic contexts. Twenty-one likely T3SS effector families were identified, including 13 not previously described in Aeromonas, and 15 of 21 assayed proteins elicited cytotoxic effects when heterologously expressed in Saccharomyces cerevisiae. This work is not directly relevant to ASH's domain. The study does not involve leeches, leech therapy, or strains specifically isolated from leech contexts; no hirudotherapy connection is made in the abstract.

Citation

Identification and characterization of putative Aeromonas spp. T3SS effectors.

Rangel LT et al. · PloS one, 2019

DOI

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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