Nosocomial infections due to Serratia marcescens--clinical findings, antibiotic susceptibility patterns and fine typing.

We report on nosocomial infections caused by Serratia marcescens occurring in a neonatal intensive care unit and a children's ward for cardiac intensive care. According to the plasmid pattern analysis, all isolated epidemic strains belonged to one clone. Multi-drug resistance, even to cephalosporins of the third generation and amikacin, was characteristic for all strains. Certain markers of S. marcescens (haemolysin, proteases, siderophores) which are thought to be related to virulence were studied but will require further investigation.