Bacterial studies of complicated appendicitis over a 20-year period and their impact on empirical antibiotic treatment

Background: Multiresistant bacterial strains tend to develop, especially enterobacteriacae, in intraabdominal infections. The aim of this study was to characterize the evolution of the bacterial biota in complicated appendicitis in children over the past 20 years and their acquired resistance rates to antibiotics. Materials and Methods: All pediatric patients admitted in the emergency unit for complicated appendicitis were retrospectively reviewed during 3 periods: 1989 to 1991, 1999 to 2000, and 2009 to 2010. Results of peritoneal swabs were analyzed regarding bacterial species and resistance to antibiotics. Statistical significance was set at P < .05. Results: Thirty-four, 48, and 85 patients from the 3 periods, respectively, were included, with 1 to 6 bacterial strains found in each peritoneal sample. During the first period, 80% of the biota was composed of enterobacteriacae and anaerobes and then decreased to 65%, whereas streptococci levels increased from 0 to 22%. Pansusceptibility rates remained stable (17%, 16.8%, and 15.6% for the 3 periods, respectively). Piperacillin, vancomycin, ticarcillin-clavulanic acid, and fluoroquinolones were associated with increased resistance rates, unlike antibiotic associations currently used as postoperative treatments. Conclusion: No significant increase in resistance rates of bacteriacae in complicated appendicitis in children was found over the last 20 years. Empirical antibiotherapy protocols currently recommended remain efficient on this particular biota. (c) 2012 Elsevier Inc. All rights reserved.