Les Infections nosocomiales à klebsiella pneumoniae multirésistante et persistante.

Abstract

Klebsiella pneumoniae is a multiresistant and persistent bacterium, responsible for multiple nosocomial infections, a panoply of transferable genetic elements such as integration and conjugation elements, conjugative plasmids, transposons, integrals, which offer this germ new virulence and antibiotic resistance traits, such as “BLSE” and “Carbapenemas” enzymes encoded by acquired chromosomal and plasmid genes responsible for the degradation of β- lactams and carbapenems. Antibiotic resistance is also ensured by point mutations or by acquired genes coding for changing the affinity of the antibiotic for its target or for efflux pumps that reject it, new resistance genes have recently been acquired in this bacterium (blaOXA-48, blaNDM-1) and the emergence of a new carbapenem-resistant strain in Europe called ‘ST23’. The persistence is ensured in Klebsiella pneumoniae by a mechanism called “metabolic dormancy” which is summarized in a reversible metabolic slowdown which itself is done by various mechanisms : Toxin-antitoxin type II, ppGpp, the SOS system, Stopping multiplication and all cellular activity and inhibiting the effect of antibiotics that target different cellular processes such as translation, replication, transcription. Klebsiella pneumoniae also opts for a filamentous form which allows it to grow horizontally while preventing the scissiparity in order to conserve the energy provided during the division and be able to perpetuate. These three adaptive phenomena: resistance, persistence and morphological plasticity have made antibiotic therapy ineffective against this germ ; as a result new treatment techniques have recently been innovated in order to cure Klebsiella pneumoniae infections