Antimicrobic susceptibility and plasmid profile analysis as identity tests for multiple blood isolates of coagulase-negative staphylococci

J Clin Microbiol. 1987 Apr;25(4):589-93. doi: 10.1128/jcm.25.4.589-593.1987.

Abstract

We compared a disk diffusion antimicrobic susceptibility panel with plasmid DNA profiles as tests for identity of 106 isolates of coagulase-negative staphylococci cultured from the blood of 45 patients on multiple occasions. The antimicrobic panel included penicillin, oxacillin, clindamycin, trimethoprim-sulfamethoxazole, chloramphenicol, tetracycline, tobramycin, kanamycin, and gentamicin. Nineteen patterns of antimicrobic susceptibility were found. The most common pattern was present in 25% of the isolates, and at least one isolate from 31% of the patients had this pattern. Forty-seven distinct plasmid DNA profiles were found. The most common plasmid profile was present in 8.5% of the isolates, and at least one isolate from 15% of the patients had this profile. Twenty-eight patients had multiple isolates that were identical by plasmid profile analysis. Twenty-seven (96%) of these patients had isolates that were also identical by antimicrobic susceptibility. Nineteen patients had multiple isolates that were different by plasmid profile analysis. In 18 (95%) of these patients, the isolates were also different by antimicrobic susceptibility. Although plasmid DNA profile analysis is a more discriminating tool, these data confirm that a selected disk diffusion antimicrobic susceptibility panel may be used to screen multiple blood isolates of coagulase-negative staphylococci for identity or differences.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Blood / microbiology*
  • Coagulase
  • DNA, Bacterial / analysis
  • Electrophoresis, Agar Gel
  • Humans
  • Microbial Sensitivity Tests
  • Plasmids*
  • Staphylococcus / classification*
  • Staphylococcus / drug effects
  • Staphylococcus / genetics
  • Staphylococcus / isolation & purification

Substances

  • Anti-Bacterial Agents
  • Coagulase
  • DNA, Bacterial