Comparison of multiple-locus variable-number tandem repeat analysis and pulsed-field gel electrophoresis in a setting of polyclonal endemicity of vancomycin-resistant Enterococcus faecium.

In order to assess whether multiple-locus-variable number tandem repeat analysis (MLVA) could replace pulsed-field gel electrophoresis (PFGE) for genotyping vancomycin-resistant isolates of Enterococcus faecium (VREF), this study compared the typeability, discriminatory power, concordance and costs of these methods for VREF isolates obtained from patients, environmental samples and the hands of healthcare workers (HCWs) in a medical intensive care unit (ICU) where VREF was endemic. Over a 58-day period, 393 VREF isolates (373 vanA, one vanA/B, 19 vanB) were cultured from patient rectal swabs (n = 76), the environment (n = 270) and the hands of HCWs (n = 47). PFGE was able to divide 358 (91.1%) isolates into 19 PFGE types (>six bands different) and 24 subtypes (one to three bands different). MLVA was able to type 391 (99.5%) isolates into 11 genotypes. The discriminatory power of PFGE subtypes was 83%, as compared to 68% for MLVA. Concordance between the two methods, based on matched or mismatched MLVA types and PFGE types or subtypes, was 67.5% and 82.8%, respectively. Using PFGE, 13 isolates could be genotyped in 3 days; MLVA genotyped 94 isolates in 2 days. For both methods, the estimated costs were Euro 7 ($10)/isolate. PFGE and MLVA produced highly concordant results when assigning genotypes to nosocomial VREF isolates. MLVA was faster, but PFGE subtyping was more discriminatory.

Value of electrocardiographic scoring systems for the assessment of thrombolytic therapy in acute myocardial infarction. The European Cooperative Study Group for Recombinant Tissue Type Plasminogen Activator.

The value of the Selvester and Cardiac Infarction Injury Scores was assessed in a randomized, placebo-controlled study of intravenous recombinant tissue plasminogen activator (rt-PA) in 721 patients with acute myocardial infarction. Electrocardiograms (ECG) obtained at admission, 6 h and 10 to 22 days after the start of therapy were analysed. Patients with prior myocardial infarction or QRS duration greater than or equal to 120 ms were excluded, leaving 322 in the rt-PA group and 333 in the placebo group. Cumulative 72-h release of alpha-hydroxybutyrate dehydrogenase (HBDH) and global ejection fraction derived from angiography and nuclear scintigraphy were used as independent measures of infarct size. Predischarge results demonstrated a net benefit of rt-PA therapy, with the Selvester Score 11% lower (P less than 0.01) and the Cardiac Infarction Injury Score 5.4% lower (P = NS) in the rt-PA than the control group. Total enzyme release was reduced by 19.2% (P less than 0.001) in the rt-PA group. In patients with inferior infarction, neither enzyme release (r = 0.30 to 0.40) nor ejection fraction (r = 0.22 to 0.31) correlated well with the ECG indices of infarct size. In anterior infarction, the correlations were better, especially between the Selvester Score and enzyme release (r = 0.40 to 0.48) as well as ejection fraction (r = -0.48 to -0.67). It is concluded that ECG scoring systems, especially the Selvester Score, although imperfect are useful to assess thrombolytic therapy in clinical trials. However, their value for the management and assessment of thrombolytic therapy in individual patients is still limited.