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We analyzed by MALDI-TOF MS 80 catheter tips after 6h and 12h of incubation and the sensitivity of each incubation period for the identification of colonization and C-RBSI was, respectively, 9.5%-NA and 42.9%-28.6%. Despite MALDI-TOF MS cannot be used to predict catheter colonization, it may rule out C-RBSI., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The Maki technique is the standard method for detecting catheter tip (CT) colonization. However, some "multi-lumen" catheters finish in a vaulted fornix and end at different distances from the CT. Therefore, we compared the traditional Maki technique with the sonication method using several cross-cut fragments of the CT. Our objective was to assess the yield of the Maki technique followed by sonication in the detection of adult CT colonization and catheter-related bloodstream infection (C-RBSI). For 3 months, we prospectively performed CT cultures of polyurethane catheters from adult patients admitted to our institution. First, we performed CT culture using the Maki technique on blood agar plates and then sonicated small fragments of CTs in 5 ml of BHI followed by culture of 100 μl of the sonicate. We included a total of 252 CVCs, with overall colonization and C-RBSI rates of 14.3% (36/252) and 5.9% (15/252). Of the 36 colonized CVCs, 21 (58.3%) were detected both by Maki and sonication, 6 (16.7%) were detected only by Maki technique, and 9 (25.0%) only by sonication method. Among 15 episodes with concomitant bacteremia, both techniques were positive and concordant in 9 cases (60.0%), the result of the Maki was positive in only 1 (6.7%), and sonication in 5 (33.3%). Our study shows that both techniques are complementary. We recommend sonicating fragments of the CT from patients with bacteremia of unknown origin and a negative CT culture by the Maki technique., (Copyright © 2016 Elsevier B.V. All rights reserved.)

We evaluated the colonization of stickers used to identify intravenous access lines in a clinical practice setting. We isolated the same microorganisms in colonized catheters and on the stickers in 77.8% of cases. Therefore, stickers could be a portal of entry of microorganisms through the catheter. Alternative methods for labeling intravenous lines are required., (Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

This study assessed in an in vitro model the effect of 2% alcohol clorhexidine for the disinfection of stickers used for intravenous line identification. Nonadhesive sticker sides were associated with higher numbers of colony-forming units when manipulation was performed without 2% alcohol clorhexidine disinfection. Future clinical studies are needed to validate these data and design policies for daily sticker disinfection., (Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.)

Background. Escherichia coli commonly causes catheter-related bloodstream infection (C-RBSI) in specific populations. The differential time to positivity (DTTP) technique is the recommended conservative procedure for diagnosing C-RBSIs. Methods. We conducted a retrospective study of episodes in which E. coli was isolated from catheter lumens obtained using the DTTP technique. Microbiological and clinical data were obtained based on the DTTP technique as either catheter colonization, C-RBSI, or non-C-RBSI. Results. A total of 89 catheter blood cultures were included, classified as follows: catheter colonization, 33.7%; C-RBSI, 9.0%; and non-C-RBSI, 57.3%. Only 15.7% of the catheters were withdrawn, with no positive catheter-tip cultures. We found no statistically significant differences in catheter type, antibiotic treatment, or clinical outcome among the groups, except for the frequency of catheter lock therapy or in the frequency of successful treatment. Mortality was associated with C-RBSI in only one patient. Conclusion. E. coli bacteremia diagnosed by the DTTP technique was classified as non-catheter-related in most patients. As the majority of the catheters were retained, E. coli bacteremia could not be microbiologically confirmed as catheter-related by the catheter-tip culture. Future studies are needed to assess the profitability of the DTTP technique for diagnosing E. coli C-RBSIs. [ABSTRACT FROM AUTHOR]

We assessed the success rate of vancomycin catheter lock therapy (VLT) in combination with systemic antimicrobials in patients with staphylococcal catheter‐related bloodstream infection (C‐RBSI). Over a 6‐year period, we retrospectively collected clinical and microbiological data from patients with long‐term central venous catheters and staphylococcal C‐RBSI who were treated with systemic antimicrobials and VLT. We then assessed the success rate of VLT based on two criteria: 1) catheter retention time> 3 months and 2) catheter in place until end of use. We found 217 staphylococcal C‐RBSI episodes, 115 (53.0%) of which were managed with conservative therapy. Of these, 76 (66.1%) were treated with VLT (85.5% coagulase‐negative staphylococci and 14.5% Staphylococcus aureus). The success rate of VLT was 42.1% with criterion 1 and 71.1% with criterion 2. We did not find statistically significant differences between success and failure in the majority of the clinical data recorded. We only found differences for crude mortality in criterion 1 and for parenteral nutrition in criterion 2. The success of catheter retention using VLT was moderate, reaching slightly more than 70% when the catheter was kept in place until the end of use. [ABSTRACT FROM AUTHOR]

To assess the influence of antifungal therapy on the outcome of non-candidemic adult patients with central vascular catheter (CVC) tips colonized by Candida species. A retrospective analysis of the outcome of patients with Candida colonization of their CVC tip and no concurrent candidemia was made over a 4-year period. Patients who either died or developed candidemia-invasive candidiasis (poor outcome) were compared with those who improved. We finally included 58 patients for analysis. Almost all (91.4%) had to be admitted to the ICU during their hospital stay. Independent predictors for outcome were a McCabe and Jackson score corresponding to ultimately fatal underlying disease [odds ratio (OR) 11.98; 95% confidence interval (CI), 1.37–104.97; P = 0.02], and maximum severity corresponding to severe sepsis, septic shock or multiorgan failure (OR: 6.16, CI 95%: 1.00–37.93; P = 0.05). We were unable to demonstrate that antifungal therapy was an independent variable influencing outcome (OR 0.82; 95% CI, 0.27–2.47; P = 0.73). Our data suggest that, in non-neutropenic critically ill patients with no concomitant candidemia and with CVC tips colonized by Candida, antifungal therapy does not seem to have a significant influence on clinical outcome. [ABSTRACT FROM AUTHOR]

Summary: Propionibacterium spp. are common flora of human skin. Nevertheless, currently recommended culture procedures do not include anaerobic processing with the result that this organism may go undetected on a colonized catheter. To determine the rate of catheter colonization by Propionibacterium spp., a sample of 1000 vascular catheters was processed by the roll-plate technique and, after conventional aerobic processing, all primary culture plates were reincubated in an anaerobic atmosphere. Propionibacterium acnes was detected in significant counts in the vascular catheters of 39 patients. This represents 14.7% (95% CI, 12.5–16.9) of all positive catheters. Propionibacterium is the second most frequent genus-colonizing catheter tips after Staphylococcus spp. Methodological shortcomings impair the detection and proper adscription of P. acnes as a potential cause of catheter-related infections. [Copyright &y& Elsevier]

The Maki technique is the standard method for detecting catheter tip (CT) colonization. However, some “multi-lumen” catheters finish in a vaulted fornix and end at different distances from the CT. Therefore, we compared the traditional Maki technique with the sonication method using several cross-cut fragments of the CT. Our objective was to assess the yield of the Maki technique followed by sonication in the detection of adult CT colonization and catheter-related bloodstream infection (C-RBSI). For 3 months, we prospectively performed CT cultures of polyurethane catheters from adult patients admitted to our institution. First, we performed CT culture using the Maki technique on blood agar plates and then sonicated small fragments of CTs in 5 ml of BHI followed by culture of 100 μl of the sonicate. We included a total of 252 CVCs, with overall colonization and C-RBSI rates of 14.3% (36/252) and 5.9% (15/252). Of the 36 colonized CVCs, 21 (58.3%) were detected both by Maki and sonication, 6 (16.7%) were detected only by Maki technique, and 9 (25.0%) only by sonication method. Among 15 episodes with concomitant bacteremia, both techniques were positive and concordant in 11 cases (73.3%) and in 4 cases (26.7%) sonication was the only positive technique. Our study shows that both techniques are complementary. We recommend sonicating fragments of the CT from patients with bacteremia of unknown origin and a negative CT culture by the Maki technique. [ABSTRACT FROM AUTHOR]

Abstract: Present guidelines recommend culturing only central venous catheter (CVC) tips from patients with suspected catheter-related bloodstream infection (CR-BSI). However, a high proportion of these suspicions are not confirmed. Moreover, CVC tip culture increases laboratory workload, and reports of colonization may be meaningless or misleading for the clinician. Our working hypothesis was that CVC tips should be refrigerated and cultured only in patients with positive blood cultures. We evaluated the effect of 6-day refrigeration of 215 CVC tips. We selected all the catheters with a significant count according to the Maki''s roll-plate technique and randomly assigned them to 2 groups. In group A, the catheters were recultured after 24 h of refrigeration, and in group B, the catheters were recultured after 6 days more of refrigeration, so that the refrigeration time evaluated would be of 6 days. The yield of refrigerated CVC tips that grow significant colony counts of primary culture in group B was compared with the yield of refrigerated catheter tips in group A. The difference showed that 6-day refrigeration reduced the number of significant CVCs by 15.2%. Only 61 CVCs were obtained from patients with CR-BSI, and in most of them, blood cultures were already positive before CVC culture, so only 0.91% of the CR-BSI episodes would have been misdiagnosed as culture negative after refrigeration. Refrigeration of CVC tips sent for culture and culturing only those from patients with positive blood cultures reduce the workload in the microbiology laboratory without misdiagnosing CR-BSI. [Copyright &y& Elsevier]