Use of a ribosomal RNA gene probe for the epidemiological study of methicillin and ciprofloxacin resistantStaphylococcus aureus

Abstract

Conventional bacteriophage typing was combined with ribotyping in the analysis of methicillin and ciprofloxacin resistant Staphylococcus aureus strains isolated in increasing frequency since the introduction of the new 4-quinolones as therapeutic agents in the Tel-Aviv Medical Center. Whole-cell DNA was digested with EcoRI and HindIII restriction endonucleases. Agarose gel electrophoresis, Southern blotting, and hybridization by biotinylated probe DNA coding for ribosomal RNA revealed 7 to 14 bands. Analysis of the patterns established a single DNA type in EcoRI as well as in HindIII digests for all strains except one. Control strains from other sources differed in their band patterns. Bacteriophage typing confirmed the results of DNA typing. Thus, the frequent occurrence of staphylococcal isolates resistant to 4-quinolones in the hospital was not due to mutational development of resistance in many strains, but to the spread of a resistant strain.

A comparative study of ribotyping and arbitrarily primed polymerase chain reaction for investigation of hospital outbreaks of Acinetobacter baumannii infection

“…Ribotyping with labelled E. cofi rRNA used to probe the ubiquitous and polymorphic rRNA l0ci~~3 25 has acquired wide acceptance as a powerful epidemiological tool. Ribotyping has several advantages, including patterns which are easy to interpret because of the limited number of hybridised fragments, and ribotypes that are stable and reproducible after continued subculture.…”

Use of ribotyping in epidemiological surveillance of nosocomial outbreaks

“…Hadorn et al combined conventional bacteriophage typing and ribotyping for the analysis of methicillin-and ciprofloxacin-resistant S. aureus strains that had been isolated with increasing frequency since the introduction of the new 4-quinolones at the Tel Aviv Medical Center (64). Ribotypes were established after digestion of bacterial DNA with EcoRI and HindlIl.…”

Ribotyping ofStaphylococcus aureus: an assessment using well–defined strains

“…This observation, in conjunction with the occurrence in England and Australia of a methicillin-resistant strain which was poorly typable by the international phages [6], has led to the belief that multi-resistant strains of S. aureus, whether methicillin-resistant of susceptible, are non-phage typable. In consequence, molecular methods, particularly so-called genotyping methods, though slower and more costly than conventional methods have been used to type hospital strains of S. aureus [4,[7][8][9][10].…”

“…The typability by molecular methods is high, essentially 100%, and with the predominance of a single strain of S. aureus in any given hospital outbreak the second criterion has been adequately investigated [e.g. 4,9]. There remains, however the question of discrimination, especially within sets of unrelated strains of the same phage group.…”