Cell-associated hemolysis activity in the clinical strain of Pseudomonas fluorescens MFN1032.

Background: MFN1032 is a clinical Pseudomonas fluorescens strain able to grow at 37 degrees C. MFN1032 cells induce necrosis and apoptosis in rat glial cells at this temperature. This strain displays secretion-mediated hemolytic activity involving phospholipase C and cyclolipopeptides.

Involvement of a phospholipase C in the hemolytic activity of a clinical strain of Pseudomonas fluorescens.

Background: Pseudomonas fluorescens is a ubiquitous Gram-negative bacterium frequently encountered in hospitals as a contaminant of injectable material and surfaces. This psychrotrophic bacterium, commonly described as unable to grow at temperatures above 32 degrees C, is now considered non pathogenic. We studied a recently identified clinical strain of P.

Phylogenetic relationships between environmental and clinical isolates of Pseudomonas fluorescens and related species deduced from 16S rRNA gene and OprF protein sequences.

The major surface protein of the genus Pseudomonas, OprF, is a non-specific porin that plays an important role in maintenance of cell shape, in growth in a low osmolarity environment, and in adhesion to various supports. The objectives of our study were (i) to carry out a comparative analysis of phylogenies obtained from the OprF protein and from the 16S rRNA gene in 41 isolates from various sources (water, soil, milk and the hospital) and (ii) to investigate the physiological characteristics correlated with the phylogeny of OprF. We report here an important incongruence between the phylogenies of the 16S rRNA gene and the OprF protein.

Regulation of the cytotoxic effects of Pseudomonas fluorescens by growth temperature.

We had previously shown that the psychrotrophic bacterium Pseudomonas fluorescens can act as a pathogen, inducing apoptosis and necrosis in neurons and glial cells. In the present study, we investigated the influence of the growth temperature of P. fluorescens on its infectious potential.