Mecanismos de resistencia en bacterias gram-negativas

DANIELA CENTRÓN

Panamá

Conferencia; II Congreso Centroamericano del Caribe de Medicina; 2004

Sociedad Panameña de Hematología

Relevance of Topic : Many novel resistance mechanisms such as carbapenemases, extended-spectrum Beta-lactamases, and plasmid-mediated quinolone resistance, when first reported were often confined to single species and/or limited geographic areas.  Several oral presentations and posters (including late-breakers) at the 2004 ICAAC have made it clear that at present there is a rapid geographic spread of these resistances, as well as species-to-species horizontal transfer of their genes.  In Gram-negative bacteria most of these resistance genes are encoded by mobile cassettes of class 1 integrons, many of which are on transposable elements and most of which are on conjugative plasmids.  The proposed symposium would bring together information on the resistance mechanisms themselves (IMP, VIM, and VEB carbapenemases, CTX-M ESBLAs, qnr-mediated quinolone resistance, and AAC-(6’) aminoglycoside resistance to name only a few) and their species and geographic distribution, with information from basic research on the mechanisms underlying a) the exchange of cassettes between large chromosomal integrons and plasmid-mediated class 1 integrons, and b) the formation of new cassettes by juxtaposition of a structural gene and an attC site (59-base element), a phenomenon probably mediated by group II introns.