Differential presence of Campylobacter rectus and Veillonella spp. in pediatric appendicitis: a comparison of emergency and elective surgery cases.

BACKGROUND

Pediatric appendicitis is increasingly recognized as involving dysbiosis of the appendiceal microbiota rather than purely mechanical obstruction. Clinical strategies now include emergency appendectomy and elective surgery after conservative antibiotic therapy, often dictated by institutional policy rather than standardized disease staging. Whether distinct microbial signatures characterize children managed by different surgical pathways remains unclear. This study examined oral and appendiceal microbiota-particularly Campylobacter rectus and Veillonella spp.-and their association with local immune responses in pediatric appendicitis.

METHODS

Nineteen children with appendicitis were prospectively enrolled and categorized into emergency (n = 11) or elective (n = 8) groups according to institutional policies. Saliva and appendiceal contents were collected at surgery. Bacterial communities were characterized by 16S rRNA gene sequencing of the V3-V4 region. FoxP3+ regulatory T cells were quantified by immunohistochemistry.

RESULTS

In total, 297 bacterial species were identified. The emergency group showed significant enrichment of C. rectus in both saliva and appendiceal contents. Veillonella dispar and V. parvula were significantly more abundant in appendiceal samples of the elective group, which also displayed higher overall Veillonella spp. abundance. FoxP3+ cell counts were markedly increased in the elective group. Veillonella spp. abundance positively correlated with FoxP3+ cell numbers, whereas C. rectus showed negative correlation.

CONCLUSION

Pediatric appendicitis exhibits distinct microbial profiles depending on surgical pathway. C. rectus dominance in emergency cases and Veillonella spp. in elective cases suggest opposing microbial signatures associated with inflammatory versus regulated mucosal environments. These taxa may serve as candidate biomarkers for clinical course and progression.