[Mechanism of antibiotic resistance in bacteria responsible for respiratory infections].

Bacterial resistance is both a frequent phenomena and in perpetual evolution; currently it effects all antibiotics. The acquisition of resistance is a result of chromosomal mutations or is a contribution of genetic material either as plasmids or transposons. The principle mechanisms which can be isolated or associated can be grouped together under changes of bacterial permeability which alters the target of the anti-infectious agents; or the synthesis of enzymes which inhibit the activity of the antibiotic. Some micro-organisms such as Staphylococcal aureus, Streptococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa, and certain enterobacteria have developed resistance to varying degrees against the antibiotics initially or more recently introduced which pose, in some cases, very real therapeutic problems. The prescribing doctor should recognise the principle bacterial phenotypes which are resistant, as well as the rules of association of the different antibiotics in order to institute an effective anti-infectious regime, which allows the cure of the patient and limits any introduction of resistance or the selection of resistant mutants.