Department of Traumatology and Critical Care Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan.
J Hosp Infect. 2010 May;75(1):19-22. doi: 10.1016/j.jhin.2009.11.005. Epub 2010 Mar 12.
Central venous catheter (CVC) tip and blood cultures are generally used to diagnose a catheter-related infection. Such methodology does not confirm the presence of bacterial colonisation on parts of CVCs other than the CVC tip. In order to assess the extent of bacterial colonisation, 10 catheters were examined in detail from patients admitted to intensive care unit. Swabs from the lumen at several sites (hub, indwelling and non-indwelling) were cultured and the intraluminal surface of the device subjected to scanning electron microscopy (SEM). Bacteria were detected on five out of 10 catheters (50%), and bacterial contamination of CVCs was common in the hub area of the device. Deposits (crystallisation) that differed from bacterial colonisation or biofilm were observed on the intraluminal surface of used CVCs. SEM showed bacteria firmly anchored to the deposits. Experimental flow studies demonstrated that deposits were more likely to appear after exposure to solutions such as total parenteral nutrition rather than distilled water. These deposits facilitated bacterial colonisation 30 times more than CVCs free from deposits.
中心静脉导管（CVC）尖端和血液培养通常用于诊断导管相关感染。但这种方法并不能确认 CVC 尖端以外的 CVC 部位是否存在细菌定植。为了评估细菌定植的程度，对重症监护病房收治的 10 例患者的导管进行了详细检查。对导管的多个部位（管毂、留置和非留置部位）的内腔进行了拭子培养，并对器械的内腔表面进行了扫描电子显微镜（SEM）检查。在 10 个导管中有 5 个（50%）检测到了细菌，且导管毂部位的 CVC 细菌污染很常见。在使用后的 CVC 内腔表面观察到与细菌定植或生物膜不同的沉积物（结晶）。SEM 显示，细菌牢固地锚定在沉积物上。实验性流动研究表明，与蒸馏水相比，接触全胃肠外营养等溶液后更容易出现沉积物。这些沉积物使细菌定植的可能性增加了 30 倍，而没有沉积物的 CVC 则没有这种情况。
