Pharmacodynamics of linezolid in a clinical isolate of Streptococcus pneumoniae genetically modified to express lux genes.
A bioluminescent clinical isolate of Streptococcus pneumoniae was used to test the real-time effects of the oxazolidinone antibiotic, linezolid, on metabolism compared with effects on cell replication. Viable counts and bioluminescence measurements showed that linezolid has little bactericidal effect, which was similar at minimum (6 mg/L), intermediate (13 mg/L) and maximum (20 mg/L) serum concentrations. The post-antibiotic effect, however, was shorter when measured by light output than by viable counts. The results demonstrate that bioluminescence provides a rapid and sensitive means of measuring the effect of antimicrobials on bacterial metabolism, and that the latter recovers earlier than commencement of cell replication after linezolid exposure.
Alloush
Habib M
HM
Faculty of Applied Science, University of the West of England, Bristol BS16 1QY, UK. habib.alloush@uwe.ac.uk
Salisbury
Vyvyan
V
Lewis
Roger J
RJ
MacGowan
Alasdair P
AP
D000081:Acetamides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003470:Culture Media; D005798:Genes, Bacterial / Q000235:genetics*; D005819:Genetic Markers; D000069349:Linezolid; D008163:Luminescent Measurements; D008826:Microbial Sensitivity Tests; D009876:Operon / Q000235:genetics; D023303:Oxazolidinones / Q000494:pharmacology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000235:genetics*
D000081:Acetamides; D000900:Anti-Bacterial Agents; D003470:Culture Media; D005819:Genetic Markers; D023303:Oxazolidinones; D000069349:Linezolid