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Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood.

Publication ,  Journal Article
Mirrett, S; Reller, LB
Published in: J Clin Microbiol
October 1979

To determine the reliability of early antimicrobial susceptibility testing, we compared the results of direct and standard single-disk diffusion methods for 581 positive blood cultures processed routinely by the clinical microbiology laboratory. The direct procedure differed from the standard one only in that the 0.5 McFarland inoculum was prepared from 1 ml of turbid broth rather than five isolated colonies from a subculture plate. A major discrepancy in results was defined as a change from susceptible to resistant or vice versa according to interpretive standards for zone diameters, whereas a minor discrepancy was defined as a shift to or from the intermediate category when paired direct and standard tests were compared. The overall agreement between the two methods was 94.6% of 2,308 comparisons. There were 119 minor (5.2%) and 6 major (0.3%) discrepancies. The major discrepancies were seen with three strains of Staphylococcus epidermidis and one strain each of S. aureus, Escherichia coli, and Enterobacter sp. Direct susceptibility testing of positive blood cultures that were pure by gram-stained smear provided reliable results 24 to 36 h earlier than conventional procedures; therefore, we recommended this procedure to guide early antimicrobial therapy in patients with bacterial sepsis.

Duke Scholars

Published In

J Clin Microbiol

DOI

ISSN

0095-1137

Publication Date

October 1979

Volume

10

Issue

4

Start / End Page

482 / 487

Location

United States

Related Subject Headings

  • Species Specificity
  • Microbiology
  • Microbial Sensitivity Tests
  • Humans
  • Drug Resistance, Microbial
  • Blood
  • Bacteria
  • Anti-Bacterial Agents
  • 3207 Medical microbiology
  • 3202 Clinical sciences
 

Citation

APA
Chicago
ICMJE
MLA
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Mirrett, S., & Reller, L. B. (1979). Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood. J Clin Microbiol, 10(4), 482–487. https://doi.org/10.1128/jcm.10.4.482-487.1979
Mirrett, S., and L. B. Reller. “Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood.J Clin Microbiol 10, no. 4 (October 1979): 482–87. https://doi.org/10.1128/jcm.10.4.482-487.1979.
Mirrett, S., and L. B. Reller. “Comparison of direct and standard antimicrobial disk susceptibility testing for bacteria isolated from blood.J Clin Microbiol, vol. 10, no. 4, Oct. 1979, pp. 482–87. Pubmed, doi:10.1128/jcm.10.4.482-487.1979.

Published In

J Clin Microbiol

DOI

ISSN

0095-1137

Publication Date

October 1979

Volume

10

Issue

4

Start / End Page

482 / 487

Location

United States

Related Subject Headings

  • Species Specificity
  • Microbiology
  • Microbial Sensitivity Tests
  • Humans
  • Drug Resistance, Microbial
  • Blood
  • Bacteria
  • Anti-Bacterial Agents
  • 3207 Medical microbiology
  • 3202 Clinical sciences