Skip to main navigation menu Skip to main content Skip to site footer

Original article

Vol. 149 No. 1718 (2019)

Impact of co-amoxicillin-resistant Escherichia coli and Pseudomonas aeruginosa on the rate of infectious complications in paediatric complicated appendicitis

  • Véronique Andrey
  • Pierre-Alex Crisinel
  • Guy Prod’hom
  • Antony Croxatto
  • Jean-Marc Joseph
Cite this as:
Swiss Med Wkly. 2019;149:w20055



Choice of antibiotics for complicated appendicitis should address local antibiotic resistance patterns. As our local data showed a less than 15% resistance of Escherichia coli to co-amoxicillin (amoxicillin + clavulanic acid), we opted for this antibiotic in 2013. Subsequently, the increasing prevalence of Pseudomonas aeruginosa challenged this choice.


The aim of this study was to describe the bacteriology of peritoneal swabs from cases of complicated appendicitis in our paediatric patients, and to determine the risk of infectious complications (wound and/or intra-abdominal abscesses).


We designed a retrospective cohort study including all children (<18 years old) who had surgery for complicated appendicitis between 1 January 2010 and 31 December 2016 and had a peritoneal swab culture. Microbiological results are presented descriptively. Univariate analyses were performed for potential determinants of infectious complications. All variables with a p-value <0.05 were then included in a multivariable logistic regression model, for which adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated.


One hundred and thirty-three patients were treated for complicated appendicitis and had cultures of peritoneal fluid. Median age was 9.5 years old (IQR 5.7–12.4), and there were 53 girls (40%). E. coli was isolated in 94 patients (71%) and was resistant to co-amoxicillin in 14% of cases. P. aeruginosa was isolated in 31 patients (23%). The rate of infectious complications was 38% (8/21 patients) when the empiric antibiotic did not cover P. aeruginosa and 0% (0/10 patients) when P. aeruginosa was covered adequately (p = 0.03). In a multivariable analysis, only co-amoxicillin-resistant E. coli significantly predicted infectious complications (OR 4.7; 95% CI 1.4–16.6; p = 0.015).


Results of the multivariable analysis of this small, retrospective study revealed a statistically significant increase in the risk of postoperative complications in the presence of co-amoxicillin-resistant E. coli. The choice of antibiotic should be adapted accordingly. More data are needed to justify the systematic coverage of P. aeruginosa in children with complicated appendicitis.


  1. Emil S, Laberge JM, Mikhail P, Baican L, Flageole H, Nguyen L, et al. Appendicitis in children: a ten-year update of therapeutic recommendations. J Pediatr Surg. 2003;38(2):236–42. doi:.
  2. Emil S, Elkady S, Shbat L, Youssef F, Baird R, Laberge JM, et al. Determinants of postoperative abscess occurrence and percutaneous drainage in children with perforated appendicitis. Pediatr Surg Int. 2014;30(12):1265–71. doi:.
  3. Adibe OO, Barnaby K, Dobies J, Comerford M, Drill A, Walker N, et al. Postoperative antibiotic therapy for children with perforated appendicitis: long course of intravenous antibiotics versus early conversion to an oral regimen. Am J Surg. 2008;195(2):141–3. doi:.
  4. Guillet-Caruba C, Cheikhelard A, Guillet M, Bille E, Descamps P, Yin L, et al. Bacteriologic epidemiology and empirical treatment of pediatric complicated appendicitis. Diagn Microbiol Infect Dis. 2011;69(4):376–81. doi:.
  5. Slusher J, Bates CA, Johnson C, Williams C, Dasgupta R, von Allmen D. Standardization and improvement of care for pediatric patients with perforated appendicitis. J Pediatr Surg. 2014;49(6):1020–4, discussion 1024–5. doi:.
  6. Rentea RM, Peter SD, Snyder CL. Pediatric appendicitis: state of the art review. Pediatr Surg Int. 2017;33(3):269–83. doi:.
  7. Chen C, Botelho C, Cooper A, Hibberd P, Parsons SK. Current practice patterns in the treatment of perforated appendicitis in children. J Am Coll Surg. 2003;196(2):212–21. doi:.
  8. Chan KW, Lee KH, Mou JW, Cheung ST, Sihoe JD, Tam YH. Evidence-based adjustment of antibiotic in pediatric complicated appendicitis in the era of antibiotic resistance. Pediatr Surg Int. 2010;26(2):157–60. doi:.
  9. Obinwa O, Casidy M, Flynn J. The microbiology of bacterial peritonitis due to appendicitis in children. Ir J Med Sci. 2014;183(4):585–91. doi:.
  10. Fallon SC, Hassan SF, Larimer EL, Rodriguez JR, Brandt ML, Wesson DE, et al. Modification of an evidence-based protocol for advanced appendicitis in children. J Surg Res. 2013;185(1):273–7. doi:.
  11. Nadler EP, Reblock KK, Ford HR, Gaines BA. Monotherapy versus multi-drug therapy for the treatment of perforated appendicitis in children. Surg Infect (Larchmt). 2003;4(4):327–33. doi:.
  12. Goldin AB, Sawin RS, Garrison MM, Zerr DM, Christakis DA. Aminoglycoside-based triple-antibiotic therapy versus monotherapy for children with ruptured appendicitis. Pediatrics. 2007;119(5):905–11. doi:.
  13. St Peter SD, Little DC, Calkins CM, Murphy JP, Andrews WS, Holcomb GW, 3rd, et al. A simple and more cost-effective antibiotic regimen for perforated appendicitis. J Pediatr Surg. 2006;41(5):1020–4. doi:.
  14. Holcomb GW, III, St Peter SD. Current management of complicated appendicitis in children. Eur J Pediatr Surg. 2012;22(3):207–12. doi:.
  15. Desai AA, Alemayehu H, Holcomb GW, III, St Peter SD. Safety of a new protocol decreasing antibiotic utilization after laparoscopic appendectomy for perforated appendicitis in children: A prospective observational study. J Pediatr Surg. 2015;50(6):912–4. doi:.
  16. Lee SL, Islam S, Cassidy LD, Abdullah F, Arca MJ ; 2010 American Pediatric Surgical Association Outcomes and Clinical Trials Committee. Antibiotics and appendicitis in the pediatric population: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee systematic review. J Pediatr Surg. 2010;45(11):2181–5. doi:.
  17. Dumont R, Cinotti R, Lejus C, Caillon J, Boutoille D, Roquilly A, et al. The Microbiology of Community-acquired Peritonitis in Children. Pediatr Infect Dis J. 2011;30(2):131–5. doi:.
  18. Schmitt F, Clermidi P, Dorsi M, Cocquerelle V, Gomes CF, Becmeur F. Bacterial studies of complicated appendicitis over a 20-year period and their impact on empirical antibiotic treatment. J Pediatr Surg. 2012;47(11):2055–62. doi:.
  19. Chen CY, Chen YC, Pu HN, Tsai CH, Chen WT, Lin CH. Bacteriology of acute appendicitis and its implication for the use of prophylactic antibiotics. Surg Infect (Larchmt). 2012;13(6):383–90. doi:.
  20. Skarda DE, Schall K, Rollins M, Andrews S, Olson J, Greene T, et al. Response-based therapy for ruptured appendicitis reduces resource utilization. J Pediatr Surg. 2014;49(12):1726–9. doi:.
  21. Solomkin JS, Mazuski JE, Bradley JS, Rodvold KA, Goldstein EJ, Baron EJ, et al. Diagnosis and management of complicated intra-abdominal infection in adults and children: guidelines by the Surgical Infection Society and the Infectious Diseases Society of America. Clin Infect Dis. 2010;50(2):133–64. doi:.
  22. Mazuski JE, Sawyer RG, Nathens AB, DiPiro JT, Schein M, Kudsk KA, et al.; Therapeutic Agents Committee of the Surgical Infections Society. The Surgical Infection Society guidelines on antimicrobial therapy for intra-abdominal infections: an executive summary. Surg Infect (Larchmt). 2002;3(3):161–73. doi:.