title: Clinical, microbiologic, and genetic determinants of persistent methicillin-resistant Staphylococcus aureus bacteremia.
abstract: Methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) often persists despite full susceptibility to vancomycin; therefore, associated factors were assessed. A retrospective cohort analysis of 222 patients with MRSAB treated with vancomycin was conducted; patients with persistent MRSAB (pMRSAB) were compared to those with nonpersistent bacteremia (NPB). Incidence of pMRSAB was 9%. More patients with vancomycin MIC = 2 mg/L had pMRSAB (16%) compared to patients with vancomycin MIC <2 mg/L (5%), P = 0.012. SCCmec type and Panton-Valentine leukocidin production were similar between patients with pMRSAB and NPB. There was no difference in vancomycin troughs, time to first dose, or area under the concentration-time curve/MIC between groups. More metastatic complications were observed in pMRSAB 63% versus NPB 32% (P = 0.005). Multivariate analysis found endocarditis (odds ratio [OR], 2.3; P = 0.021), complicated MRSAB (OR, 2.6; P = 0.009), vancomycin MIC = 2 (OR, 2.6; P = 0.009), and septic shock (OR 2.2 P = 0.031), which were independent predictors of pMRSAB.
authors.affiliation: Department of Pharmacy, Cleveland Clinic, Cleveland, OH 44195, USA. neunere@ccf.org
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Neuner
authors.forename: Ed
authors.initials: E
authors.lastname: Casabar
authors.forename: Richard
authors.initials: R
authors.lastname: Reichley
authors.forename: Peggy S
authors.initials: PS
authors.lastname: McKinnon
mesh_terms: D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology* / Q000473:pathology; D014640:Vancomycin / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin