MALDI-TOF is not useful in the diagnosis of catheter colonization based on superficial cultures: results from an in vitro study

摘要

We compared in an vitro model the yields of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and conventional culture (CC) for the detection of catheter colonization with superficial catheter samples (SS). We used blood culture bottles (BCB) with an inserted cannula and incubated at 37 degrees C. The BCB were manipulated with different contaminations and when a BCB turned positive, SS were obtained to perform both techniques. To compare both techniques we analyzed the mean time to colonization (MTC) and the mean time to a result (MTR). The MTC (SD, days) by CC and MALDI-TOF was as follows: hub, 0.59 (0.79) versus 1.07 (139), P = 0.06; surface: 0.62 (0.67) versus 0.82 (0.81), P < 0.001. The MTR (SD, days) of CC and MALDI-TOF was as follows: hub: 1.58 (0.79) versus 225 (1.48), P = 0.04; surface: 1.62 (0.67) versus 1.95 (0.80), P < 0.001. In general, the use of MALDI-TOF performed directly with SS was no better than CC and did not anticipate colonization results. (C) 2016 Elsevier Inc. All rights reserved.