Bleomycin resistance in Staphylococcus aureus clinical isolates

Abstract

Among clinical isolates of Staphylococcus aureus tested for resistance to the antibiotic bleomycin, 197 were found to be resistant; most of them were also resistant to tobramycin and contained plasmids. DNA dot-blot hybridization analysis of the bleomycin resistant isolates with an 171 bp probe derived from plasmid pUB110 indicated that 43 strains (22%) carried pUB110-like bleomycin resistance DNA sequences. Analysis of bacterial cell lysates derived from the bleomycin resistant isolates indicated that many contained bleomycin-binding proteins (BBP), that prevent DNA damage by the antibiotic. Of 13 strains that were analysed by DNA gel electrophoresis and Southern blot DNA hybridization, six were found to carry pUB110-like bleomycin resistance DNA sequences. These studies indicate that there may be more than one genetic determinant for bleomycin resistance in S. aureus whose DNA is protected.