Related Experiment Video
Updated: Aug 6, 2026
Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
Published on: February 23, 2014
Positive correlation between in vivo and in vitro assays for the evaluation of Pseudomonas virulence
Andréa L Pimenta1, Patrick Di Martino, Mark A Blight
1Département de Biologie, Laboratoire ERRMECe, Université de Cergy-Pontoise, 95302 Cergy-Pontoise cedex, France. pimenta@u-cergy.fr
Abstract:
Some bacterial phenotypes measured in vitro can be used to access bacterial virulence, on the premise that they are positively correlated with data from in vivo experiments. We show here that in vitro assessment of bacterial phenotypes, such as adherence and cytotoxicity, are positively correlated with data from in vivo experiments in Drosophila and can be used to assess bacterial virulence in vivo. Manipulation of environmental parameters, such as iron availability, induced changes in the phenotypes measured in vitro that correlated with changes in vivo virulence of all strains tested. Applying these assays, we demonstrate the pathogenic potential of a Pseudomonas fluorescens strain, initially isolated as a non-pathogenic milk contaminant. This strain displayed adherence and cytotoxicity comparable to those of the Pseudomonas aeruginosa pathogenic strain PAK, and colonized the infected flies as rapidly as the PAK strain. These results indicate that this "a priori" non-pathogenic bacterium is capable of escaping the host immune response, supporting the use of in vitro tests for screening of potential pathogens.
Insights
In vitro bacterial assays for adherence and cytotoxicity accurately predict in vivo virulence. These methods can identify potential pathogens, even from previously non-pathogenic strains.
Area of Science:
- Microbiology
- Pathogenesis
- Bacterial Virulence
Background:
- Bacterial virulence assessment often relies on in vivo experiments.
- In vitro phenotypes are hypothesized to correlate with in vivo virulence.
Purpose of the Study:
- To validate in vitro bacterial phenotypes (adherence, cytotoxicity) as predictors of in vivo virulence.
- To assess the pathogenic potential of a Pseudomonas fluorescens strain using in vitro assays.
Main Methods:
- Correlation analysis between in vitro measurements and in vivo virulence data in Drosophila.
- Manipulation of environmental factors (e.g., iron availability) to observe phenotypic and virulence changes.
- Comparative analysis of Pseudomonas fluorescens and Pseudomonas aeruginosa PAK strains.
Main Results:
- In vitro adherence and cytotoxicity positively correlated with in vivo virulence in Drosophila.
- Environmental parameter changes mirrored in vitro and in vivo virulence shifts.
- Pseudomonas fluorescens exhibited virulence comparable to Pseudomonas aeruginosa PAK.
Conclusions:
- In vitro assays are reliable tools for assessing bacterial virulence in vivo.
- Environmental factors significantly influence bacterial virulence.
- Previously non-pathogenic bacteria can possess pathogenic potential, highlighting the need for robust screening methods.
More Related Videos
07:28Standardized In vitro Assays to Visualize and Quantify Interactions between Human Neutrophils and Staphylococcus aureus Biofilms
Published on: June 8, 2022
06:43Studying Microbial Communities In Vivo: A Model of Host-mediated Interaction Between Candida Albicans and Pseudomonas Aeruginosa in the Airways
Published on: January 13, 2016