Resistance-Transfer Factor in Enterobacteriaceae

Abstract

IN recent years pathogenic enterobacteriaceae have become increasingly resistant to many antibiotics.§ ^{1 2 3} Japanese workers showed in 1959 that resistance to multiple antibiotics in many strains of shigella was infectious — that is, that it could be transmitted by conjugation from resistant shigellas to sensitive strains of Escherichia coli.¹ Further investigation showed this to be due to the transfer of an extrachromosomal genetic element, the resistance-transfer factor. The factor which is reproduced in the progeny endows them with resistance to multiple antibiotics. Similarly, infectious resistance has been demonstrated in many strains of salmonella, Esch. coli and other gram-negative bacilli . . .