Bacterial pathogens and antimicrobial susceptibility profiles in acute appendicitis in children: a retrospective study at a tertiary hospital in Ningbo, China

Résumé fourni par la source

Objective To investigate the distribution of bacterial pathogens in intraoperative specimens from children with acute appendicitis, characterize the antimicrobial resistance profiles of predominant Gram-negative bacteria, and compare microbiological differences between non-gangrenous and gangrenous appendicitis. Methods We retrospectively reviewed records of patients aged below 18 years who underwent appendectomy for pathologically confirmed acute appendicitis at a tertiary hospital in Ningbo, China, between January 2019 and December 2024. Intraoperative pus, peritoneal fluid, or drainage fluid was cultured aerobically, and isolates were identified and tested for antimicrobial susceptibility. Pathology-stratified analyses compared infection type and major pathogen detection between non-gangrenous and gangrenous appendicitis. Escherichia coli resistance outcomes were additionally compared across age groups. Results Among 1,981 children, 1,393 (70.31%) had positive cultures, yielding 1,903 isolates. Gram-negative organisms accounted for 81.14%. The three most common Gram-negative pathogens were Escherichia coli (55.12%), Pseudomonas aeruginosa (13.14%), and Comamonas testosteroni (5.41%). E. coli showed high resistance to ampicillin (84.56%), trimethoprim-sulfamethoxazole (55.67%), and ceftriaxone (48.85%), while resistance to piperacillin/tazobactam and imipenem was low (0.19% and 0.67%). ESBL-positive E. coli rates were similar across the 1–5, 6–11, and 12–17 years age groups (45.98%, 47.81%, and 47.64%, respectively; P = 0.910), and no significant age-group differences were observed for the selected resistance outcomes. P. aeruginosa resistance to all tested agents was ≤2%. C. testosteroni exhibited high resistance to ciprofloxacin (72.82%) but remained susceptible to piperacillin/tazobactam and imipenem. In pathology-stratified cases ( n = 1,311), polymicrobial infection was more common in gangrenous than non-gangrenous appendicitis (42.07% vs. 33.70%, P = 0.046), and P. aeruginosa was detected more frequently (26.21% vs. 17.50%, P = 0.011). Conclusion In Ningbo, E. coli was the predominant bacterial pathogen isolated from intraoperative specimens collected from children with acute appendicitis, often co-occurring with P. aeruginosa ; C. testosteroni ranked the third. Substantial resistance in E. coli suggested that empiric reliance on third-generation cephalosporins may be insufficient, while age stratification did not identify any age group of children with significantly higher E. coli resistance. Broader Gram-negative coverage may be warranted for gangrenous disease.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.