Abstract

Introduction: Clinical and Laboratory Standards Institute (CLSI) introduced susceptible dose dependent (SDD) in place of intermediate category for selected drug pathogen combinations such as Enterobacteriaceae-cefepime and Enterococcus-daptomycin. For SDD-isolates, the antimicrobial agent can be used in higher-than-normal doses, precluding the use of higher antimicrobials thereby preventing antibiotic resistance. Therefore, this study was undertaken.

Aim of the Study: To know the SDD pattern among Enterobacteriaceae and Enterococcus to cefepime and daptomycin respectively.

Settings and Design: The Enterobacteriaceae and Enterococcus isolates from blood cultures were included in this study between August 2019 to July 2020.

Materials and Methods: After excluding the repeat isolates, antimicrobial susceptibility test was carried out by VITEK 2 system (bioMérieux) and the MIC result obtained was interpreted by using CLSI guideline 2019. The Enterobacteriaceae and Enterococcus isolates showing SDD results for cefepime and daptomycin respectively were determined.

Statistical Analysis Used: Nil.

Results: Total of 545 Enterobacteriaceae and 115 Enterococcus isolates were included in the study. 15.1% of Enterobacteriaceae isolates were SDD to cefepime, majority of which were Escherichia coli and Klebsiella spp. Among the SDD-isolates, 36.6% were found to have MIC of 4 µg/mL and 63.4% exhibited a MIC of 8 µg/mL. Cefepime in increased dose is a better therapeutic option for the SDD isolates rather switching to higher antimicrobials like carbapenems. Among the Enterococcus isolates, 28.7% (all were E. faecalis) were found SDD to daptomycin.

Conclusion: We found there was an increase in isolation of Enterobacteriaceae and Enterococcus isolates that were SDD to cefepime and daptomycin respectively.

Keywords: SDD; MIC; Cefipime; Daptomycin; Enterobacteriaceae; Enterococcus

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Citation

Citation: Apurba Sastry., et al. “Impact of Susceptible-Dose-Dependent (SDD) Minimum Inhibitory Concentration (MIC) on Reporting and Prescribing Antibiotics". Acta Scientific Microbiology 4.1 (2020): 42-46.

Copyright

Copyright: © 2020 Apurba Sastry., et al.. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.