Comparative Performance Evaluation of Real-Time PCR and Dual-Labeled Fluorescence Resonance Energy Transfer Probe-Based Melt Peak Analysis for the Detection of Escherichia coli O157:H7 in Beef Products.

Contaminated beef and beef products remain a frequent vehicle for the transmission of Escherichia coli O157:H7. The current U.S.

Global Pseudomonas aeruginosa biodiversity as reflected in a Belgian river.

The biodiversity of the bacterium Pseudomonas aeruginosa in an aquatic environment (the Woluwe River, Brussels, Belgium) was analysed. Surface water was sampled bimonthly over a 1-year period (2000-2001) at seven sites evenly dispersed over the river. Total bacterial counts were performed and P.

Identification of type II and type III pyoverdine receptors from Pseudomonas aeruginosa.

Pseudomonas aeruginosa produces, under conditions of iron limitation, a high-affinity siderophore, pyoverdine (PVD), which is recognized at the level of the outer membrane by a specific TonB-dependent receptor, FpvA. So far, for P. aeruginosa, three different PVDs, differing in their peptide chain, have been described (types I-III), but only the FpvA receptor for type I is known.

Identification of new, conserved, non-ribosomal peptide synthetases from fluorescent pseudomonads involved in the biosynthesis of the siderophore pyoverdine.

Pyoverdines, the main siderophores of fluorescent pseudomonads, contain a peptide moiety, different for each pyoverdine, and an identical chromophore. While it has been shown that non-ribosomal peptide synthetases (NRPSs) are involved in the biosynthesis of the peptide chain of pyoverdines, this was not demonstrated for the biosynthesis of the chromo-phore part. We found that PvsA, from Pseudomonas fluorescens ATCC 17400, and PvdL (PA2424), from Pseudomonas aeruginosa are similar NRPSs and functional homologues, necessary for the production of pyoverdine.

A relationship between RP4 plasmid acquisition and phenotypic changes in Pseudomonas fluorescens R2fN.

The physiological behaviour of Pseudomonas fluorescens strain R2fN was compared to that of transconjugants [R2fN(RP4)], and two aggregation phenotypes were identified (Agr- and Agr+). Agr+ phenotype is characterized by the appearance of macroscopic aggregates when cells are growing in liquid media. Transconjugants exhibited Agr+ phenotype whereas wild type strain represented Agr-.