RESUMO
A total of 46 clinical isolates of Klebsiella pneumoniae were studied. Of these, 33 were from "Hospital Infantil de Mexico" (HIM) and 13 from "Hospital General de Mexico" (HGM). The susceptibility of these strains to five antibiotics, as well as the plasmid DNA profiles, were determined for each group. Antibiotic susceptibility profiles were very similar in strains from both hospitals; however, most of the strains analyzed exhibited heterogeneous plasmid DNA profiles. Results showed that strains isolated in the two hospitals did not differ regarding morphology, biochemical profiles, antibiotic susceptibility or plasmid populations, and these characteristics may not be used as markers to differentiate Klebsiella pneumoniae strains from different hospitals