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The microbiology of bacterial peritonitis due to appendicitis in children
1Department of Surgery, Portiuncula Hospital, Ballinasloe, Ireland, obinnaobinwa@rcsi.ie.
Insights
This study found Escherichia coli and anaerobes are common in pediatric appendicitis peritonitis. Inadequate antibiotic treatment and resistant E. coli increase post-operative infections, guiding better antimicrobial strategies.
Area of Science:
- Pediatric Surgery
- Infectious Diseases
- Microbiology
Background:
- Secondary bacterial peritonitis is a complication of appendicitis.
- Understanding the causative microorganisms and antibiotic susceptibility is crucial for effective treatment.
Purpose of the Study:
- To investigate the microbiology of secondary bacterial peritonitis in pediatric appendicitis.
- To evaluate the appropriateness of current antimicrobial practices.
Main Methods:
- A 14-year retrospective single-centre study analyzed 69 pediatric patients with appendicitis-related peritonitis.
- Peritoneal cultures, microbiology, antibiotic susceptibility, and post-operative outcomes were examined.
Main Results:
- Escherichia coli (81%) and anaerobes (54%) were predominant. Amoxicillin-clavulanate resistance was noted in E. coli and anaerobes.
- Pseudomonas aeruginosa and streptococci were less common and generally susceptible to standard antibiotics.
- Current combination therapy (amoxicillin-clavulanate and aminoglycoside) is appropriate for 99% of cases; adding metronidazole ensures 100% coverage.
Conclusions:
- E. coli and mixed anaerobes are key pathogens in pediatric appendicitis-related peritonitis.
- Inadequate empirical antibiotics and amoxicillin-clavulanate resistant E. coli are linked to post-operative infections.
- This study provides evidence for optimal combination therapy in pediatric bacterial peritonitis.
Aim:
The aim of this study was to investigate the microbiology of secondary bacterial peritonitis due to appendicitis and the appropriateness of current antimicrobial practice in one institution.
Methods:
A 14-year retrospective single-centre study of 69 consecutive paediatric patients (age 1-14 years) with appendicitis-related peritonitis and positive peritoneal specimen cultures was conducted. Post-operative outcomes, microbiology and antibiotic susceptibility of peritoneal isolates were analysed in all patients.
Results:
Escherichia coli was identified in 56/69 (81 %) peritoneal specimens; four isolates were resistant to amoxicillin-clavulanate, and one other isolate was resistant to gentamicin. Anaerobes were identified in 37/69 (54 %) peritoneal specimens; two anaerobic isolates were resistant to amoxicillin-clavulanate and one isolate was resistant to metronidazole. Pseudomonas aeruginosa was identified in 4/69 (6 %) peritoneal specimens, and all were susceptible to gentamicin. Streptococcal species (two Group F streptococci and three β-haemolytic streptococci) were identified in 5/69 (7 %) specimens, and all were susceptible to amoxicillin-clavulanate. Combination therapy involving amoxicillin-clavulanate and aminoglycoside is appropriate empirical treatment in 68/69 (99 %) patients. Addition of metronidazole to this regime would provide 100 % initial empirical coverage. Inadequate initial empiric antibiotic treatment and the presence of amoxicillin-clavulanate resistant E. coli were independent predictors of the post-operative infectious complications observed in 14/69 (20 %) patients.
Conclusion:
E. coli and mixed anaerobes are the predominant organisms identified in secondary peritonitis from appendicitis in children. Inadequate initial empirical antibiotic and amoxicillin-clavulanate resistant E. coli may contribute to increased post-operative infectious complications. This study provides evidence-based information on choice of combination therapy for paediatric appendicitis-related bacterial peritonitis.
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