Article Text

Download PDFPDF
Evaluation of in vitro susceptibility of Gram-positive pathogens from a tertiary care hospital in Singapore to a novel oxazolidinone, tedizolid, by a gradient diffusion method and broth microdilution
  1. Saugata Choudhury1,
  2. Lee Kar Mun1,
  3. Esme Ng Chu Xuan1,
  4. Lee Shin Jia1,
  5. Shawn Vasoo2,
  6. Subodha Samanthini Wickramasinghe1,
  7. Long Jen Mee1
  1. 1 Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore, Singapore
  2. 2 Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
  1. Correspondence to Dr Saugata Choudhury, Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore 308433, Singapore; drsaugata{at}


We compared the in vitro antimicrobial activities of tedizolid and linezolid on the Sensititre broth microdilution system for Gram-positive cocci isolates (n=146) from skin and skin structure infections and bloodstream infections, bronchoalveolar lavage and sputum. These pathogens included 40 methicillin-resistant Staphylococcus aureus, 38 coagulase-negative staphylococci, 20 Enterococcus faecalis and 48 beta-haemolytic Streptococcus spp. Susceptibility was simultaneously determined for 48 vanA vancomycin-resistant enterococci isolates 2013–2016 from rectal swabs (23 E. faecalis and 25 E. faecium, of which 4 were linezolid-non-susceptible). MIC90s for tedizolid were fourfold to eightfold lower than linezolid on the Sensititre and ranged from 0.12 to 0.5 µg/mL for the different pathogen groups. All isolates were susceptible to tedizolid except two vanA E. faecium strains (MICs of 1 and 2 µg/mL, respectively). Categorical and essential agreement for tedizolid were 99.48% and 92%, respectively, between Liofilchem gradient diffusion and Sensititre methods. Overall, the drug exhibited excellent activity against the surveyed Gram-positive pathogens.

  • antibiotics
  • antimicrobial resistance
  • bacteriology

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Handling editor Tony Mazzulli.

  • Contributors SC conceived the study and wrote the manuscript. LKM, ENCX, LSJ, SSW and SV helped in manuscript preparation and did most of the bench work. LJM gave intellectual input.

  • Funding This study was sponsored by a grant from Bayer HealthCare. Bayer HealthCare had no involvement in the collection, analysis or interpretation of data.

  • Competing interests None declared.

  • Patient consent Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.