title: Zyvox Annual Appraisal of Potency and Spectrum Program Results for 2006: an activity and spectrum analysis of linezolid using clinical isolates from 16 countries.
abstract: The Zyvox Annual Appraisal of Potency and Spectrum Program has completed its fifth year of monitoring for emerging resistance to linezolid and other Gram-positive active agents on the continents of Europe, Asia, Australia, and Latin America. In 2006, 4216 Gram-positive isolates from 16 nations were submitted for analysis from 6 organism groups including Staphylococcus aureus (54.0%), coagulase-negative staphylococci (CoNS) (14.6%), enterococci (10.0%), Streptococcus pneumoniae (9.4%), viridans group streptococci (5.0%), and beta-hemolytic streptococci (7.0%). Linezolid retained potent activity against S. aureus (MIC(50) and MIC(90), 2 microg/mL; 39.8% methicillin resistant) and CoNS (MIC(50) and MIC(90), 1 microg/mL; 74.3% methicillin resistant). Despite endemicity of vancomycin-resistant enterococci (up to 30.0%) in several nations, linezolid inhibited >99% of strains at </=2 microg/mL (modal MIC, 1 microg/mL). Among streptococci, all linezolid MIC values were </=2 microg/mL. Rare instances of linezolid-resistance were detected in enterococci (2 isolates, China and Germany) and CoNS (3 isolates, Italy and Brazil); 2 CoNS and 1 Enterococcus faecium had documented G2576T mutations. Overall, linezolid remained active against 99.88% of tested strains from this global collection.
authors.affiliation: JMI Laboratories, North Liberty, IA 52317, USA. ronald-jones@jmilabs.com
authors.forename: Ronald N
authors.initials: RN
authors.lastname: Jones
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Fritsche
authors.forename: Helio S
authors.initials: HS
authors.lastname: Sader
authors.forename: James E
authors.initials: JE
authors.lastname: Ross
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D014943:Global Health; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006095:Gram-Positive Cocci / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D000069349:Linezolid; D008826:Microbial Sensitivity Tests; D023303:Oxazolidinones / Q000494:pharmacology*; D011159:Population Surveillance
chemical_list: D000081:Acetamides; D000890:Anti-Infective Agents; D023303:Oxazolidinones; D000069349:Linezolid