Jean Claude Pechere

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We investigated the regulation of the MexEF-OprN multidrug efflux system of Pseudomonas aeruginosa, which is overexpressed in nfxC-type mutants and confers resistance to quinolones, chloramphenicol and trimethoprim. Sequencing of the DNA region upstream of the mexEF-oprN operon revealed the presence of an open reading frame (ORF) of 304 amino acids encoding(More)
Originally described in bacteria, drug transporters (or efflux pumps) are now recognized as major determinants in the modulation of the accumulation and efflux of antibacterials in virtually all cell types, from prokaroytes to superior eukary-otes. Transport proteins are in fact major cellular products. Based on sequence similarities with known transporters(More)
Quorum-sensing systems are critical regulators of the expression of virulence factors of various organisms, including Pseudomonas aeruginosa. Las and Rhl are two major quorum-sensing components, and they are regulated by their corresponding autoinducers, N-3-oxododecanoyl homoserine lactone (3-oxo-C(12)-HSL) and N-butyryl-L-homoserine lactone (C(4)-HSL).(More)
  • J C Pechère
  • 2001
To better evaluate patient contribution in antibiotic use, we questioned 5379 subjects from 9 countries. Antibiotics are perceived as strong, efficient drugs, but they are believed to undermine immunity. Interviewees believe that most respiratory infections, except the common cold, require antibiotic therapy, and 11% of them had to exaggerate their symptoms(More)
Many patients who present with Pseudomonas aeruginosa bacteremia have been previously exposed to antibiotics. To assess whether resistance of bacteremic strains to antipseudomonal antibiotics (piperacillin, ceftazidime, imipenem, ciprofloxacin, or aminoglycosides) is associated with previous exposure to these drugs, a case-control study including 267 cases(More)
We investigated the unusual susceptibility to meropenem observed for seven imipenem-resistant clinical isolates of Pseudomonas aeruginosa. These strains were genetically closely related, expressed OprD, as determined by Western blot analyses, and were resistant to imipenem (>5 microg/ml) but susceptible to meropenem (<1 microg/ml). The oprD genes from two(More)
The ability of trovafloxacin and ciprofloxacin to select efflux mutants in vivo was studied in a model of acute Pseudomonas aeruginosa pneumonia in rats. Twelve hours after intratracheal inoculation of 10(6) CFU of P. aeruginosa strain PAO1 enmeshed in agar beads, two groups of 12 rats were treated by three intraperitoneal injections of each antibiotic(More)
Suppression of bacterial growth that persists after short exposure of bacteria to antimicro-bial agents, called the postantibiotic effect (PAE), has been observed both in vitro and in vivo. Duration, and even presence or absence of PAE depends upon the organism, the antimicrobial agent and the environmental conditions used for measuring the effect (Craig,(More)
Originally described in bacteria, drug transporters (or efflux pumps) are now recognized as major determinants in the modulation of the accumulation and efflux of antibacterials in virtually all cell types, from prokaroytes to superior eukary-otes. Transport proteins are in fact major cellular products. Based on sequence similarities with known transporters(More)