Transferable Antibiotic Resistance in a General Hospital: A Two Year Survey

Abstract

Summary. For two years transferable antibiotic resistance (TAR) was studied by replicator methods in strains of Enterohacteriaceae isolated in a 900-becI hospital. Transfer to an Escherichia coli recipient was demonstrated in 21% of 7,800 Enterobacteriaaae. Il was most common in Klebsiella (37% of isolates) and least in Acinetobacter (G%). The mean number of phenotypic resistance markers (RMs) transferred was higher from Klebsiella pneumoniae or Enterobacter cloacae than from E. coli or P. mirabilis. K. pneumoniae and E. cloacae especially transferred 7 or more RMs much more often than other species. Some RMs were associated with a particular species, e.g. streptomycin with E. coli. kanamycin or gentamrcin with E. cloacae and kanamycin with P. mirabilis. The same was true of certain patterns of resistance transfer, e.g. Ap-Km and P. mirahilis. Ap-Sm and E. coli. Ap-Km-Om-Tm-Cm and K. pneumoniae. However, many of the commonest resistance phenotypes were transferred from several species and from several biotypes within any given species. Resistance patterns transferred from E. coli were detected sporadically throughout, whereas many of those transferred from Klebsiella. Enierobacter or Proteus were found only for a limited time.

Construction of a gentamicin resistance gene probe for epidemiological studies

“…Earlier studies on a collection of gentamicin-resistant enterobacteria from this hospital and other hospitals in Australia have been limited to descriptions of the patterns of different resistance genes that are transferred by conjugation and have not differentiated between genes that confer resistance to the same antibiotic (1). These studies could not include resistance genes found on nonconjugative plasmids or on the chromosome.…”