Mercury resistance and R plasmids in clinical isolates of Kebsiella pneumoniae.

The mercury and antibiotic resistance of 155 clinical isolates of Klebsiella pneumoniae (K. pneumoniae) was determined. Resistance to mercury tested was found in 64.5% of the total isolates. The frequencies of resistance to SM, TC, CP, KM and GM were 65.8%, 49.0%, 48.4%, 37.4% and 3.9%, respectively. And we selected 94 mercury and drug resistant strains, and they were tested for their ability to transfer the resistance to the mercury and drug sensitive recipients of E. coli K12 ML 1410-Nx and E. coli JE 17-Rif. Among 94 strains of Hg resistant K. pneumoniae, 86 R plasmids with Hg resistance could be demonstrated. It should be noted that transferable R plasmids with Hg resistance were demonstrated in 92% of the Hg-resistant isolates. Furthermore, R (Hg; SM, TC, CP, KM) plasmids were isolated most frequently, followed by R (Hg; SM, TC, CP), R (Hg; SM, KM), and R (Hg; SM, TC) plasmids.