Lee R M, Kozarek R A, Sumida S E, Raltz S L
Department of Internal Medicine, Virginia Mason Medical Center, Seattle, Washington 98101, USA.
Gastrointest Endosc. 1998 May;47(5):377-81. doi: 10.1016/s0016-5107(98)70222-6.
Previous studies have shown that pathogens may persist within bacterial biofilms in endoscope accessory channels despite high-level disinfection. Breaching the gastrointestinal mucosa with biopsy forceps contaminated at time of passage has the potential to cause cross-infection between patients.
We studied contamination risk of sterilized biopsy forceps passed through endoscopes after high-level disinfection. For each trial, five video colonoscopes, duodenoscopes, and gastroscopes were used. All endoscopes had been previously processed and stored for 10 or more hours. Sterile biopsy forceps were inserted and retrieved followed by vortexing the tips in 15 mL of soy broth. Under a laminar flow hood, the broth was filtered through a 0.2 microm millipore membrane and plated. Because of minimal bacterial growth resulting from the above, soy broth (> 20 mL) was flushed through two video colonoscopes, duodenoscopes, and gastroscopes on two occasions and collected. The effluent was plated using a sample of 0.1 mL dilution. The remaining suspension was passed through a millipore filter, and the filter was cultured. All cultures were incubated more than 48 hours.
Biopsy forceps underwent a total of 24 anaerobic and 75 aerobic cultures. Microbacterial growth occurred on 17 plates: 7 from gastroscopes, 5 from colonoscopes, and 5 from duodenoscopes. Fifteen plates grew staphylococcus for a total of 21 colonies, 1 plate grew 1 colony of propionibacter, 2 plates grew diphtheroids for a total of 4 colonies, and 1 plate grew a single colony of lactobacillus. Cultures from soy broth flushed through the various endoscopes grew on 5 plates: 3 from gastroscopes and 2 from duodenoscopes grew a total of 8 colonies of staphylococcus.
With proper cleaning technique, a 20-minute soak in 2% glutaraldehyde is effective in disinfecting endoscopes. Although current procedures for endoscope disinfection remain imperfect, we found that in this clinical setting, infection of pathogenic gastrointestinal flora is unlikely when using sterile biopsy forceps.
先前的研究表明，尽管进行了高水平消毒，但病原体仍可能在内窥镜附件通道的细菌生物膜中持续存在。使用在通过时被污染的活检钳穿透胃肠道黏膜有可能导致患者之间的交叉感染。
我们研究了经过高水平消毒后通过内窥镜的无菌活检钳的污染风险。每次试验使用五台视频结肠镜、十二指肠镜和胃镜。所有内窥镜先前都已处理并储存了10个或更多小时。插入并取出无菌活检钳，然后将钳尖在15毫升大豆肉汤中涡旋。在层流罩下，将肉汤通过0.2微米的微孔膜过滤并接种平板。由于上述操作导致细菌生长极少，两次用超过20毫升的大豆肉汤冲洗两台视频结肠镜、十二指肠镜和胃镜并收集流出液。使用0.1毫升稀释液的样本接种平板。将剩余的悬浮液通过微孔过滤器，对过滤器进行培养。所有培养物均孵育超过48小时。
活检钳共进行了24次厌氧菌培养和75次需氧菌培养。在17个平板上出现了微生物生长：7个来自胃镜，5个来自结肠镜，5个来自十二指肠镜。15个平板上生长了葡萄球菌，共21个菌落，1个平板上生长了1个丙酸杆菌菌落，2个平板上生长了类白喉杆菌，共4个菌落，1个平板上生长了1个乳酸杆菌菌落。通过各种内窥镜冲洗的大豆肉汤培养物在5个平板上生长：3个来自胃镜，2个来自十二指肠镜生长了总共8个葡萄球菌菌落。
采用适当的清洁技术，在2%戊二醛中浸泡20分钟可有效消毒内窥镜。尽管目前的内窥镜消毒程序仍不完善，但我们发现在这种临床环境中，使用无菌活检钳时致病性胃肠道菌群感染的可能性不大。
