[Comparison of the incidence of enterobacterial R plasmids in hospitals and ambulatory care facilities].

Bacteriological examination of patients in hospital and ambulatory facilities revealed that in hospitals the investigated diseases of patients are twice as frequently caused by pathogenic enterobacteria which contain R plasmids than pathogenic bacteria detected in subjects who had ambulatory treatment. Comparison of the number of isolated autonomously transmissible R plasmids revealed an even greater disproportion because some bacterial strains, in particular in hospitals, contained several compatible R plasmids. The author assumes that the almost treble number of R plasmids in strains from hospitals is due to a greater opportunity of plasmid transmission in hospitalized patients, and repeatedly hospitalized patients, and is enhanced by the permanent selective pressure of antibiotics.