Antibiotic-resistant gram-negative pathogens in the hospital environment

Gram-negative pathogens in the hospital environment belong to such distinct families as Enterobacteriaceae, Pseudomonas, Acinetobacter and Stenotrophomonas. They differ in virulence but all present natural (or intrinsic) resistance and the capacity to develop rapidly acquired resistance? the main factor in their selection in the hospital environment. Dissemination of resistance is due either to dissemination of a clonal strain or dissemination of the gene of resistance amongst bacteria belonging to unrelated species. In medical practice, the development of resistance poses various problems: a therapeutic problem for the physician who must prescribe an active antibiotic that does not select resistant mutants; a microbiological problem in relation to the difficulty of detecting particular resistances such as the production of extended spectrum beta -lactamase; a problem for the infection control team whose task is to limit the dissemination of multi-resistant bacteria. Against the complexity and efficacy of bacterial resistance strategies against antimicrobial agents, the combined competences of clinicians, microbiologists and the infection control team are needed.