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Abstract
SUMMARY: The occurrence of intergeneric transformation between staphylococci as DNA donors and Streptococcus strain challis as recipient was controlled. By various methods 126 DNA preparations were isolated from 21 staphylococcal strains resistant to different antibiotics (18 produced coagulase and DNase; three were white and did not produce coagulase or DNase). Eight of these preparations, originating from four strains of Staphylococcus aureus were active in intergeneric transformation. The streptomycin-resistance marker was transferred, the yield being 0.001-0.017% of that of homospecific reaction. The authors did not succeed in transferring the penicillin-, novobiocin-, erythromycin- and oxytetracyclin-resistance markers. Repeated isolations were required to produce active DNA preparations and none of the various methods yielded active preparations consistently. The staphylococcal streptomycin-resistance marker re-isolated from the transformants of strain challis was transferred to challis with the same or even higher yield than the homospecific marker.
In the staphylococcal strains from which active preparations were obtained, the GC content was 32.7-37.6% and was lower by 4.9-9% from that in strain challis (41.8%).
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