Linezolid versus omadacycline in diabetic soft tissue infections: a signal of different adjunctive immunological properties?

Recent understanding of antimicrobial chemotherapy has expanded to appreciate significant impacts on the host-pathogen relationship by antibiotics. Omadacycline statistically outperformed linezolid in treating acute bacterial skin and skin structure infections in patients with diabetes mellitus in a recent post-hoc analysis of the OASIS-1 and OASIS-2 clinical trials. This difference may speak directly or indirectly to neutrophil dysfunction in diabetes. Neutrophil dysfunction increases the likelihood of Gram-negative bacterial infection, whereby diabetics may benefit from the broader spectrum of omadacycline compared with linezolid. Indirectly, oxazolidinones like linezolid have been shown to be dependent on neutrophil function, potentially compromising the potency of this drug class in diabetics. Finally, tetracyclines like omadacycline have collateral anti-inflammatory properties that have not been seen in other antibiotic drug classes. These differences may impact clinical outcomes in the treatment of infections that are not predicted by their antimicrobial activities alone, as measured in standard susceptibility testing assays.