Antibiotic Resistance in Pseudomonas
Alicia Fajardo and José L. Martínez
from: Pseudomonas: Genomics and Molecular Biology (Edited by: Pierre Cornelis). Caister Academic Press, U.K. (2008)
Abstract
Pseudomonas aeruginosa is a highly relevant opportunistic pathogen. One of the most worrisome characteristics of P. aeruginosa consists in its low antibiotic susceptibility. This low susceptibility is attributable to a concerted action of multidrug efflux pumps with chromosomally-encoded antibiotic resistance genes and the low permeability of the bacterial cellular envelopes. Besides intrinsic resistance, P. aeruginosa easily develop acquired resistance either by mutation in chromosomally-encoded genes, either by the horizontal gene transfer of antibiotic resistance determinants. Development of multidrug resistance by P. aeruginosa isolates requires several different genetic events that include acquisition of different mutations and/or horizontal transfer of antibiotic resistance genes. Hypermutation favours the selection of mutation-driven antibiotic resistance in P. aeruginosa strains producing chronic infections, whereas the clustering of several different antibiotic resistance genes in integrons favours the concerted acquisition of antibiotic resistance determinants. Some recent studies have shown that phenotypic resistance associated to biofilm formation or to the emergence of small-colony-variants may be important in the response of P. aeruginosa populations to antibiotics treatment. The presence of antibiotic resistance genes in other Pseudomonas species like P. putida, P. fluorescens and P. stutzeri will be discussed as well along this chapter read more ...
