目的: 探讨维持性腹膜透析(peritoneal dialysis，PD)患者因PD相关性腹膜炎拔除PD导管后，导管细菌生物膜的形成情况及特征。方法: 回顾性分析北京大学人民医院2007年6月至2022年1月期间规律随访的维持性PD患者，选取其中因PD相关性腹膜炎而退出PD、拔除PD导管且行导管扫描电镜检查的患者，总结患者的一般资料、拔管原因、PD导管扫描电镜检查结果以及腹膜透析液的细菌培养结果。结果: 共纳入18例患者，其中女性11例(61.1%)，患者平均年龄(59.1±11.5) 岁，平均透析龄(80.1±47.4)个月。18例患者中，16例(88.9%)存在导管细菌生物膜，细菌生物膜形态均为球菌。腹膜透析液的细菌培养结果显示，最常见的3种病原体分别为大肠埃希菌(Escherichia coli)、甲氧西林敏感的金黄色葡萄球菌(methicillin-sensitive Staphylococcus aureus，MSSA)、表皮葡萄球菌(Staphylococcus epidermidis)。13例患者(72.2%)既往曾经发生腹膜炎，其中9例患者既往腹膜炎的致病菌为球菌。结论: PD导管内细菌生物膜形成在因腹膜炎拔管的PD患者中比较常见，并非所有因腹膜炎拔除的PD导管上都有细菌生物膜存在，细菌生物膜与腹膜炎的致病菌可能不一致。

Objective: Peritoneal dialysis(PD)-associated peritonitis is a common and major complication of PD and the most common cause of technical failure of PD. The presence of bacterial biofilm may be an important factor leading to refractory or recurrence of peritonitis. To investigate the formation and characteristics of bacterial biofilms on PD catheters after peritonitis-associated catheter removal. Methods: The patients with maintenance PD who were regularly followed up in the Peking University People' s Hospital from June 2007 to January 2022 were retrospectively analyzed. The patients who withdrew from PD because of peritonitis and removed the PD catheter in our hospital and underwent the scanning electron microscope examination of the catheter were selected. The general information of the patients, the electron microscope results of the PD catheter and the bacterial culture results of the PD fluid were summarized. Results: (1) A total of 18 patients were included, 11 were female (accounting for 61.1%). The average age of the patients was (59.1±11.5) years, and the average duration of dialysis was (80.1±47.4) months. Primary kidney diseases were predominantly chronic glomerulonephritis (55.6%), followed by diabetic nephropathy (27.8%), and others (16.6%). The reasons for catheters removal in 18 patients were refractory peritonitis in 11 cases, recurrent peritonitis in 5 cases, and fungal peritonitis in 2 cases. (2) 16 of the 18 patients (88.9%) had catheter bacterial biofilm, and the bacterial biofilm forms were all cocci. Some were arranged in grape-like shapes, and their diameters ranged from about 500 nm to 1 000 nm. The bacterial culture results of peritoneal dialysis fluid showed that the three most common pathogens were Escherichia coli, methicillin-sensitive Staphylococcus aureus (MSSA), and Staphylococcus epidermidis. (3) Among the 18 patients enrolled, 13 patients (72.2%) had peritonitis in the past. The causative bacteria of peritonitis in 9 patients were cocci, including coagulase-negative Staphylococci (Staphylococcus suis, Staphylococcus surface, Staphylococcus xylosus, Staphylococcus warneri), Staphylococcus aureus, Streptococcus (Streptococcus salivarius and Aerococus viridans). Conclusion: Bacterial biofilm formation on the inner surface of PD catheter is common in peritonitis-associated catheter removal patients. Not all PD catheters removed due to peritonitis have bacterial biofilms. Bacterial biofilms and peritonitis pathogens may not be consistent.