Checking For Incidence of Extended Spectrum Beta-Lactamase (ESBL) Producing Enterobacteriaceae, Vancomycin Resistant Enterococcus Faecium (VREF) and Methicillin Resistant Staphylococcus Aureus (MRSA) in 26 Centers from 12 European Countries: The Pan-European Antimicrobial Resistance Using Local Surveillance (PEARLS) Study

Background: Resistant isolates found in the hospital environment continue to increase and are of great concern in the treatment of serious infections. This study is part of an ongoing study examining resistance determinants in common pathogens. The current incidence of ESBL producers in selected Enterobacteriaceae, VREF and MRSA were measured in 26 investigative sites from 12 European countries. The information gathered from the PEARLS study will be useful in determining selective pressures that influence the increasing incidence of resistance. Methods: Each site collected consecutive isolates consisting of no more than 50 Enterococcus faecium, 100 Enterobacter species, 75 Escherichia coli, 75 Klebsiella pneumoniae, 25 Staphylococcus aureus. All isolates were tested in a central reference laboratory using broth microdilution following manufacturer's instructions and NCCLS guidelines. ESBL producers were screened for cephalosporin MICs > 1 mcg/ml for cefotaxime, ceftazidime or ceftriaxone and confirmed using NCCLS guidelines. Results: There were 6,217 isolates available for analysis. The overall incidence of VREF and MRSA was 9.2% and 34.6%, respectively. Klebsiella pneumoniae (16.3%) was the highest producer of ESBL followed by Escherichia coli (4.0%). The total ESBL rate for the Enterobacteriaceae (Klebsiella pneumoniae plus Escherichia coli) was 9.6%. ESBL production rates (Klebsiella pneumoniae plus Escherichia coli) were observed in the following countries: Greece, 35.5%; Italy, 18.7%; South Africa, 17.3%; Turkey, 11.7%; Portugal, 9.8%; Spain, 6.9%; Germany, 4.3%; Austria, 3.9%; Switzerland, 3.6%; Belgium, 3.0%; The Netherlands, 2.1%; France, 0.0%. The highest occurrences of VREF were in Portugal (58.6%) and Austria (16.3%). No occurrences of VREF were seen in Belgium, France, Greece, South Africa and Turkey. MRSA rates varied from country to country with a high of 88.5% in Portugal to a low of 2.0% in The Netherlands. Conclusion: Resistant rates are affected by many factors including patient population, prior antimicrobial therapy, prolonged hospitalization, formulary changes and regional differences, among other factors. The rates of these three determinants of resistance are consistent with current literature for VREF, MRSA and ESBL in Europe but vary greatly by country. These data will serve as a baseline for determining the effects of selective pressures that influence resistance rates over time in these centers.