Delafloxacin In Vitro Broth Microdilution and Disk Diffusion Antimicrobial Susceptibility Testing Guidelines: Susceptibility Breakpoint Criteria and Quality Control Ranges for an Expanded-Spectrum Anionic Fluoroquinolone
| Autor: | S. P. McCurdy, M. A. Pfaller, Rn Jones, Robert K. Flamm, Dee Shortridge, Chris M. Pillar |
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| Rok vydání: | 2018 |
| Předmět: |
disk diffusion
Quality Control 0301 basic medicine Microbiology (medical) Staphylococcus 030106 microbiology Antimicrobial susceptibility broth microdilution Microbial Sensitivity Tests Staphylococcus lugdunensis medicine.disease_cause susceptibility Enterococcus faecalis Microbiology 03 medical and health sciences chemistry.chemical_compound delafloxacin Enterobacteriaceae medicine Humans fluoroquinolones Microbial Viability biology business.industry Broth microdilution Bacteriology biology.organism_classification testing criteria Anti-Bacterial Agents chemistry Staphylococcus aureus Streptococcus pyogenes Skin structure Delafloxacin business susceptible breakpoints |
| Zdroj: | Journal of Clinical Microbiology |
| ISSN: | 1098-660X 0095-1137 |
| DOI: | 10.1128/jcm.00339-18 |
| Popis: | Delafloxacin, a recently approved anionic fluoroquinolone, was tested within an international resistance surveillance program. The in vitro susceptibilities of 7,914 indicated pathogens causing acute bacterial skin and skin structure infections (ABSSSI) were determined using Clinical and Laboratory Standards Institute (CLSI) broth microdilution MIC testing methods. Delafloxacin, a recently approved anionic fluoroquinolone, was tested within an international resistance surveillance program. The in vitro susceptibilities of 7,914 indicated pathogens causing acute bacterial skin and skin structure infections (ABSSSI) were determined using Clinical and Laboratory Standards Institute (CLSI) broth microdilution MIC testing methods. The U.S. Food and Drug Administration (FDA) susceptibility testing breakpoints and quality control ranges for routine broth microdilution and disk diffusion methods were confirmed. The delafloxacin MIC50/90 (% susceptibility) results were as follows: Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), 0.008/0.25 μg/ml (92.8%); Staphylococcus lugdunensis, 0.016/0.03 μg/ml (99.3%); Streptococcus pyogenes, 0.016/0.03 μg/ml (100.0%); Streptococcus anginosus group, 0.008/0.016 μg/ml (100.0%); Enterococcus faecalis, 0.12/1 μg/ml (66.2%); and Enterobacteriaceae, 0.12/4 μg/ml (69.5%). The FDA clinical breakpoints were used to assess intermethod test agreement between delafloxacin MIC and disk diffusion methods for the indicated pathogens. The intermethod susceptibility test categorical agreement for delafloxacin was acceptable, with only 0.4% very major, false-susceptible errors among S. aureus strains. Across all FDA-indicated species, the selected breakpoints produced only 0.0 to 1.7% rates of serious (very major and major errors) intermethod error. Quality control ranges for these standardized delafloxacin susceptibility test methods were calculated from three multilaboratory (12 total sites) studies for six control organisms. In conclusion, the application of FDA MIC breakpoints for delafloxacin against contemporary (2014 to 2016) isolates of ABSSSI pathogens provides additional support for the use of delafloxacin in the treatment of adults with ABSSSI. Delafloxacin MIC and disk diffusion susceptibility testing methods have been standardized for clinical application, achieving high intermethod categorical agreement. |
| Databáze: | OpenAIRE |
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