Epidemiology, drug resistance, and clinical risk factors of peritoneal dialysis-associated peritonitis: a five-year multicenter study.

Background: Peritoneal dialysis-associated peritonitis (PDAP) remains a major complication in long-term dialysis patients, leading to significant morbidity and healthcare burden. This study aimed to investigate the microbial spectrum, antimicrobial resistance patterns, and clinical risk factors associated with PDAP in hospitalized patients in Anhui, China, over the past five years.

Methods: A retrospective analysis was conducted on 438 peritoneal dialysis (PD) patients from three PD centers in Anhui from 2020 to early 2025. Of these, 238 patients were diagnosed with PDAP and 200 served as controls without peritonitis. Peritoneal effluents were cultured and microbiologically identified using MALDI-TOF MS and VITEK 2 systems. Antimicrobial susceptibility testing followed CLSI M100 standards. Clinical and laboratory data were statistically analyzed using SPSS v26.0, and multivariate logistic regression model was used to determine independent risk factors.

Results: Significant differences were observed between the PDAP and control cohorts in sex, age, hospitalization time, PD duration, red blood cell count, total protein, albumin, blood glucose, and concomitant conditions (e.g., hepatitis B, autoimmune diseases, and hyperthyroidism) (p < 0.05). Laboratory infectious markers including peripheral blood white blood cell (WBC) count, neutrophil percentage, procalcitonin (PCT), C-reactive protein, peritoneal dialysate WBC and multinucleated cell counts, were significantly elevated in the PDAP population compared to controls, with serum PCT and dialysate WBCs presented as significant predictors after multivariate adjustment. Staphylococcus species showed predominant methicillin resistance (47.22% oxacillin-susceptible) with moxifloxacin outperforming other fluoroquinolones, while carbapenems demonstrated near-universal efficacy against Enterobacterales (esp., for ertapenem). Candida species mounted variable antifungal responses, with optimal activities of amphotericin B/flucytosine except fluconazole, underscoring both therapeutic opportunities and emerging resistance threats across bacterial and fungal pathogens.

Conclusion: The multicenter study confirmed elevated serum PCT and peritoneal dialysate leukocytes as robust independent clinical predictors for PDAP, with other risk factors significantly increasing disease susceptibility. The diverse microbial spectrum and antimicrobial resistance features shed light on the importance of updated local microbial surveillance to guide empirical treatment and clinical management strategies on PDAP.