Abstract
One of the most common complications associated with the use of central venous catheters (CVCs) is catheter-associated infection. Traditionally, when an infection is suspected, the CVC is removed and replaced, with the CVC tip being retrospectively analysed. Techniques that involve sampling of the CVC whilst it remains in situ, are hindered by the requirement for conventional laboratory culture of the sample for diagnosis. Some more rapid methods of detecting microorganisms have been developed but none are routinely used CVC management. The aim of this study was to develop a rapid method, which could potentially aid in the diagnosis of catheter-associated infections whilst the CVC remains in situ. The FAS Endoluminal Brush (FASEB)-retrieved sample has high predictive values for the confirmation or elimination of a catheter-associated infection and it was chosen as the sampling device for use in this study. ATP bioluminescence was chosen as a possible detection technique for use in conjunction with FASEB-retrieved samples. Much of the development involved, the exposure and degradation of non-microbial ATP and the subsequent lysis and detection of microbial ATP. A TCA-based extraction method was found to be of little clinical utility when evaluated with FASEB samples retrieved from 114 CVC tips. Further work involving a DTAB-based extraction method in combination with a-cyclodextrin, resulted in a sensitivity and specificity of 70. 6% and 86. 7% respectively, in combination with plate culture, when challenged with 47 FASEB-retrieved samples. This study indicates that ATP bioluminescence is a useful technique that may have an application for use in conjunction with FASEB-retrieved samples. However, further work is required to improve upon the sensitivity and specificity of the technique, with the main emphasis being on the sample preparation so that contaminating ATP is degraded and all microbial cells are exposed to the microbial lysis agent prior to ATP detection.