oxazolidinones
Mechanisms of ResistanceTransferable Resistance Gene optrA in Enterococcus faecalis from Swine in BrazilOptrA is an ATP-binding cassette (ABC)-F protein that confers resistance to oxazolidinones and phenicols and can be either plasmid-encoded or chromosomally encoded. Here, we isolated 13 Enterococcus faecalis strains possessing a linezolid MIC of ≥4 mg/liter from nursery pigs in swine herds located across Brazil. Genome sequence comparison showed that these strains...
PharmacologyAccumulation of Major Linezolid Metabolites in Patients with Renal ImpairmentIn patients with renal impairment (n = 22 of 39), the median serum concentrations of linezolid, PNU-142300, and PNU-142586 were 1.6-, 3.3-, 2.8-fold higher, respectively, than in patients without renal impairment. Metabolite concentrations in paired samples were poorly correlated with linezolid concentrations (r2 = 0.26 for PNU-142300 and 0.06 for PNU-142586). Linezolid and its metabolites share potential...
Mechanisms of ResistanceEfflux-Mediated Resistance to New Oxazolidinones and Pleuromutilin Derivatives in Escherichia coli with Class Specificities in the Resistance-Nodulation-Cell Division-Type Drug Transport Pathways...A major contribution of the resistance-nodulation-cell division (RND)-transporter AcrB to resistance to oxazolidinones and pleuromutilin derivatives in Escherichia coli was confirmed. However, we discovered significant differences in efflux inhibitor activities, specificities of the homologous pump YhiV (MdtF), and the impact of AcrB pathway mutations.
Mechanisms of ResistanceTn6674 Is a Novel Enterococcal optrA-Carrying Multiresistance Transposon of the Tn554 FamilyThe novel 12,932-bp nonconjugative multiresistance transposon Tn6674 was identified in the chromosomal DNA of a porcine Enterococcus faecalis strain. Tn6674 belongs to the Tn554 family of transposons. It shares the same arrangement of the transposase genes tnpA, tnpB, and tnpC with Tn554. However, in...
PharmacologyReappraisal of Linezolid Dosing in Renal Impairment To Improve SafetyLinezolid is administered as a fixed dose to all patients despite evidence of increased exposure and myelosuppression in renal impairment. The objectives of these studies were to assess the risk of thrombocytopenia with standard-dose linezolid in renal impairment and to identify an alternate dosing strategy.
Experimental TherapeuticsOxazolidinones Can Replace Clarithromycin in Combination with Rifampin in a Mouse Model of Buruli UlcerRifampin (RIF) plus clarithromycin (CLR) for 8 weeks is now the standard of care for Buruli ulcer (BU) treatment, but CLR may not be an ideal companion for rifamycins due to bidirectional drug-drug interactions. The oxazolidinone linezolid (LZD) was previously shown to be active against Mycobacterium ulcerans infection in mice but has dose- and duration-dependent...
Letter to the EditorMyelosuppression with Oxazolidinones: Are There Differences?
PharmacologyUse of Translational Pharmacokinetic/Pharmacodynamic Infection Models To Understand the Impact of Neutropenia on the Efficacy of Tedizolid PhosphateTedizolid phosphate, the prodrug of the active antibiotic tedizolid, is an oxazolidinone for the treatment of acute bacterial skin and skin structure infections. Studies in a mouse thigh infection model demonstrated that tedizolid has improved potency and pharmacokinetics/pharmacodynamics (PK/PD) compared with those of linezolid.
Mechanisms of ResistanceEmergence and Within-Host Genetic Evolution of Methicillin-Resistant Staphylococcus aureus Resistant to Linezolid in a Cystic Fibrosis PatientMethicillin-resistant Staphylococcus aureus (MRSA) infection has increased in recent years among cystic fibrosis (CF) patients. Linezolid (LZD) is one of the antistaphylococcal antibiotics widely used in this context.
