van der Ploeg Koen, de Vogel Corné P, Klaassen Corné H W, Luider Theo M, Zeneyedpour Lona, Mason-Slingerland Bibi C G C, Vos Margreet C, Bruno Marco J, Bexkens Michiel L, Severin Juliëtte A
Dept. of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, the Netherlands.
Dept. of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Rotterdam, the Netherlands.
Biofilm. 2025 Aug 6;10:100310. doi: 10.1016/j.bioflm.2025.100310. eCollection 2025 Dec.
can persistently contaminate endoscopes by forming biofilms within internal channels, complicating both detection and eradication. Current microbiological surveillance methods have limited efficacy and may yield false-negative results. This study aimed to identify proteomic markers of biofilms on endoscope channel material.
Three genetically unrelated isolates from contaminated duodenoscopes and two reference strains (ATCC 27853 and PAO1) were used. Biofilms were grown on disinfected endoscope biopsy channel rings and incubated for 24, 48, and 72 h. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was employed to analyze temporal changes in protein spectra. Peaks of interest were further characterized by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and whole-genome sequencing to identify associated proteins. To further confirm the origin of these peaks, strains naturally lacking the corresponding genes were analyzed.
MALDI-TOF MS revealed distinct time- and strain-specific spectral profiles, with two notable peaks at approximately 2723 m/z and 5450 m/z. LC-MS/MS identified the 5450 m/z peak as PA2146, corresponding to a 5449.1 Da protein after in vivo methionine cleavage. The 2723 m/z peak was confirmed as its doubly charged ion. Both peaks were absent in strains naturally lacking PA2146, confirming it as the source.
PA2146 expression increases during biofilm development on endoscope channel surfaces, indicating its potential as a biomarker for contamination. MALDI-TOF MS could enhance biofilm detection in endoscope surveillance. Further research should assess the clinical utility of proteomic approaches for improving endoscopic microbiological safety.
可通过在内腔道内形成生物膜而持续污染内镜，使检测和根除都变得复杂。当前的微生物监测方法效果有限，可能产生假阴性结果。本研究旨在鉴定内镜通道材料上生物膜的蛋白质组学标志物。
使用从受污染十二指肠镜分离出的三株基因不相关的菌株以及两株参考菌株（ATCC 27853和PAO1）。生物膜在内镜活检通道环上生长，并分别培养24、48和72小时。采用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）分析蛋白质谱的时间变化。通过液相色谱-串联质谱（LC-MS/MS）和全基因组测序对感兴趣的峰进行进一步表征，以鉴定相关蛋白质。为进一步确认这些峰的来源，对天然缺乏相应基因的菌株进行了分析。
MALDI-TOF MS显示出不同的时间和菌株特异性光谱特征，在约2723 m/z和5450 m/z处有两个显著峰。LC-MS/MS将5450 m/z峰鉴定为PA2146，体内甲硫氨酸切割后对应一种5449.1 Da的蛋白质。2723 m/z峰被确认为其双电荷离子。天然缺乏PA2146的菌株中均未出现这两个峰，证实其为来源。
PA2146的表达在内镜通道表面生物膜形成过程中增加，表明其作为污染生物标志物的潜力。MALDI-TOF MS可增强内镜监测中生物膜的检测。进一步研究应评估蛋白质组学方法在提高内镜微生物安全性方面的临床实用性。
