Impact of amoxicillin therapy on resistance selection in patients with community-acquired lower respiratory tract infections: a randomized, placebo-controlled study.

Objectives To determine the effect of amoxicillin treatment on resistance selection in patients with community-acquired lower respiratory tract infections in a randomized, placebo-controlled trial. Methods Patients were prescribed amoxicillin 1 g, three times daily (n=52) or placebo (n=50) for 7 days. Oropharyngeal swabs obtained before, within 48 h post-treatment and at 28–35 days were assessed for proportions of amoxicillin-resistant (ARS; amoxicillin MIC ≥2 mg/L) and -non-susceptible (ANS; MIC ≥0.5 mg/L) streptococci. Alterations in amoxicillin MICs and in penicillin-binding-proteins were also investigated. ITT and PP analyses were conducted. Results ARS and ANS proportions increased 11- and 2.5-fold, respectively, within 48 h post-amoxicillin treatment compared with placebo [ARS mean increase (MI) 9.46, 95% CI 5.57–13.35; ANS MI 39.87, 95% CI 30.96–48.78; P0.1588). ARS/ANS were grouped by pbp mutations. Group 1 strains exhibited significantly lower amoxicillin resistance (mean MIC 2.8 mg/L, 95% CI 2.6–3.1) than group 2 (mean MIC 9.3 mg/L, 95% CI 8.1–10.5; P Conclusions By utilizing oropharyngeal streptococci as model organisms this study provides the first prospective, experimental evidence that resistance selection in patients receiving amoxicillin is modest and short-lived, probably due to ‘fitness costs’ engendered by high-level resistance-conferring mutations. This evidence further supports European guidelines that recommend amoxicillin when an antibiotic is indicated for community-acquired lower respiratory tract infections.</p

The worldwide antibiotic resistance and prescribing in european children (ARPEC) point prevalence survey: developing hospital-quality indicators of antibiotic prescribing for children

Objectives: Previously, web-based tools for cross-sectional antimicrobial point prevalence surveys (PPSs) have been used in adults to develop indicators of quality improvement. We aimed to determine the feasibility of developing similar quality indicators of improved antimicrobial prescribing focusing specifically on hospitalized neonates and children worldwide. Methods: A standardized antimicrobial PPS method was employed. Included were all inpatient children and neonates receiving an antimicrobial at 8:00 am on the day of the PPS. Denominators included the total number of inpatients. A web-based application was used for data entry, validation and reporting. We analysed 2012 data from 226 hospitals (H) in 41 countries (C) from Europe (174H; 24C), Africa (6H; 4C), Asia (25H; 8C), Australia (6H), Latin America (11H; 3C) and North America (4H). Results: Of 17 693 admissions, 6499 (36.7%) inpatients received at least one antimicrobial, but this varied considerably between wards and regions. Potential indicators included very high broad-spectrum antibiotic prescribing in children of mainly ceftriaxone (ranked first in Eastern Europe, 31.3%; Asia, 13.0%; Southern Europe, 9.8%), cefepime (ranked third in North America, 7.8%) and meropenem (ranked first in Latin America, 13.1%). The survey identified worryingly high use of critically important antibiotics for hospital-acquired infections in neonates (34.9%; range from 14.2% in Africa to 68.0% in Latin America) compared with children (28.3%; range from 14.5% in Africa to 48.9% in Latin America). Parenteral administration was very common among children in Asia (88%), Latin America (81%) and Europe (67%). Documentation of the reasons for antibiotic prescribing was lowest in Latin America (52%). Prolonged surgical prophylaxis rates ranged from 78% (Europe) to 84% (Latin America). Conclusions: Simple web-based PPS tools provide a feasible method to identify areas for improvement of antibiotic use, to set benchmarks and to monitor future interventions in hospitalized neonates and children. To our knowledge, this study has derived the first global quality indicators for antibiotic use in hospitalized neonates and children

Impact of amoxicillin therapy on resistance selection in patients with community-acquired lower respiratory tract infections : A randomized, placebo-controlled study

Objectives: To determine the effect of amoxicillin treatment on resistance selection in patients with community-acquired lower respiratory tract infections in a randomized, placebo-controlled trial. Methods: Patients were prescribed amoxicillin 1 g, three times daily (n = 52) or placebo (n = 50) for 7 days. Oropharyngeal swabs obtained before, within 48 h post-treatment and at 28-35 days were assessed for proportions of amoxicillin-resistant (ARS; amoxicillin MIC ≥2 mg/L) and -non-susceptible (ANS; MIC ≥0.5 mg/L) streptococci. Alterations in amoxicillin MICs and in penicillin-binding-proteins were also investigated. ITT and PP analyses were conducted. Results: ARS and ANS proportions increased 11- and 2.5-fold, respectively, within 48 h post-amoxicillin treatment compared with placebo [ARS mean increase (MI) 9.46, 95% CI 5.57-13.35; ANS MI 39.87, 95% CI 30.96-48.78; P 0.1588). ARS/ANS were grouped by pbp mutations. Group 1 strains exhibited significantly lower amoxicillin resistance (mean MIC 2.8 mg/L, 95% CI 2.6-3.1) than group 2 (mean MIC 9.3 mg/L, 95% CI 8.1-10.5; P <0.0001). Group 2 strains predominated immediately post-treatment (61.07%) and although decreased by days 28-35 (30.71%), proportions remained higher than baseline (18.70%; P = 0.0004). Conclusions: By utilizing oropharyngeal streptococci as model organisms this study provides the first prospective, experimental evidence that resistance selection in patients receiving amoxicillin is modest and short-lived, probably due to 'fitness costs' engendered by high-level resistance-conferring mutations. This evidence further supports European guidelines that recommend amoxicillin when an antibiotic is indicated for community-acquired lower respiratory tract infections