R factors in gentamicin-resistant organisms causing hospital infection.

An abrupt increase in gentamicin-resistant isolates was noted in the Manhattan Veterans Administration Hospital in 1973 and 1974. Bacteraemic infection occurred in 17 patients, 9 of whom died. R factors mediating gentamicin resistance were demonstrated in 34 of 36 strains. Organisms from 9 of 11 patients transferred a resistance pattern common to all other isolates from that patient, suggesting in-vivo interbacterial spread of the R factor.