Sequential hospitalwide outbreaks of resistant Serratia and Klebsiella infections
F. E. Thomas, R. T. Jackson, A. Melly and R. H. Alford
Late in 1973 at the Nashville Veterans Administration Hospital, an
intrusion of Serratia marcescens infections that were resistant to
gentamicin sulfate and other antimicrobial agents occurred. This abated
somewhat, only to be superseded by another wave of multiply-resistant
infections due to Klebsiella pneumoniae beginning in the spring of 1974.
Approximately 400 patients had substantial infections with these organisms
during the 2 1/4 year period, imposing considerable morbidity and
mortality. Due to the serious and lasting impact that these events imposed
on patient care in our hospital, we sought explanations for the sequential
infectious outbreaks. Both may have arisen because of the same persisting
pressures favoring prevalence of multidrug-resistant bacteria. Indirect
evidence including the sequential order of the outbreaks, similarity of
antibiotograms, transferable multiple drug resistance from Serratia to
Klebsiella, and possession of approximately equal molecular weight plasmids
supported the notion that the two outbreaks were causally related.
