Resumen

REDONDO, Carlos  y  ALONSO, Guillermina. Conjugated plasmids isolated from multi resistant strains obtained at four health centers in the Caracas metropolitan area. Rev. Soc. Ven. Microbiol. [online]. 2007, vol.27, n.2, pp.100-107. ISSN 1315-2556.

Abstract Conjugative and movable plasmids are the extra chromosomal structures of greater epidemiological importance, responsible for the horizontal propagation of multiple resistance genes. In this study we evaluated E. coli and K. pneunoniae strains to determine the presence of conjugative plasmids and their relationship with the acquisition, stabilization and dissemination of multiple resistance genes. Using conjugation assays we demonstrated the presence of conjugative plasmids in 67% of the strains analyzed. The analysis of restriction enzyme treatments demonstrated that there were bacterial strains isolated from different hospital areas  with identical restriction patterns. The resistance profiles of the transconjugating strains revealed that there was transfer of resistance determinants against all the antibiotic families analyzed, demonstrating the plasmid contribution to the multiple resistance phenotype. Our results suggest that the E. coli and K. pneumoniae strains isolated from patients in four health centers of the metropolitan areas may have acquired the multi resistance phenotype through the acquisition of plasmids that bear multiple genes that codify resistance to various antimicrobial agents

Palabras clave : plasmids; multi resistance; intra hospital infections.