Pseudomonas aeruginosa may accumulate drug resistance mechanisms without losing its ability to cause bloodstream infections.

Archive ouverte

Hocquet, Didier | Berthelot, Philippe | Roussel-Delvallez, Micheline | Favre, Roger | Jeannot, Katy | Bajolet, Odile | Marty, Nicole | Grattard, Florence | Mariani-Kurkdjian, Patricia | Bingen, Edouard | Husson, Marie-Odile | Couetdic, Gérard | Plésiat, Patrick

Edité par CCSD ; American Society for Microbiology -

International audience. In this study, we systematically investigated the resistance mechanisms to beta-lactams, aminoglycosides, and fluoroquinolones of 120 bacteremic strains of Pseudomonas aeruginosa. Pulsed-field gel electrophoresis genotyping showed that 97 of these strains were represented by a single isolate, 10 by 2 and 1 by 3 clonally related isolates, respectively. Seventy-five percent (90 out of 120) of the bacteremic P. aeruginosa strains displayed a significant resistance to one or more of the tested antimicrobials (up to 11 for 1 strain). These strains were found to harbor a great diversity of resistance mechanisms (up to 7 in 1 strain), leading to various levels of drug resistance. Interestingly, 11 and 36% of the isolates appeared to overproduce the MexAB-OprM and MexXY-OprM efflux systems, respectively. Altogether, our results show that P. aeruginosa may accumulate intrinsic (overproduction of cephalosporinase AmpC, increased drug efflux, fluoroquinolone target mutations, and deficient production of porin OprD) and exogenous (production of secondary beta-lactamases and aminoglycoside-modifying enzymes) resistance mechanisms without losing its ability to generate severe bloodstream infections. Consequently, clinicians should be aware that multidrug-resistant P. aeruginosa may remain fully pathogenic.

Consulter en ligne

Suggestions

Du même auteur

Proficiency Program for Real-Time PCR Diagnosis of Bordetella pertussis Infections in French Hospital Laboratories and at the French National Reference Center for Whooping Cough and other Bordetelloses

Archive ouverte | Caro, Valérie | CCSD

International audience. With the support of a ministerial program for innovative and expensive technologies, dedicated to the economic evaluation of laboratory diagnosis of pertussis by real-time PCR, external quali...

MexAB-OprM- and MexXY-overproducing mutants are very prevalent among clinical strains of Pseudomonas aeruginosa with reduced susceptibility to ticarcillin.

Archive ouverte | Hocquet, Didier | CCSD

International audience

Cumulative effects of several nonenzymatic mechanisms on the resistance of Pseudomonas aeruginosa to aminoglycosides.

Archive ouverte | El'Garch, Farid | CCSD

International audience. Screening of a Tn5-Hg insertional library (12,000 clones) constructed in wild-type Pseudomonas aeruginosa strain PAO1 identified four genes (namely, galU, nuoG, mexZ, and rplY) whose disrupti...

Chargement des enrichissements...