Maki's Technique Research Articles

Adding vortexing to the Maki technique provides no benefit for the diagnosis of catheter colonization or catheter-related bacteremia.

A previous study compared vortexing and Maki techniques for the diagnosis of catheter-related bloodstream infection (CRBSI), and concluded that vortexing was not superior to Maki method. To determine whether the combined use of vortexing and Maki techniques provides profitability versus the Maki technique for the diagnosis of catheter tip colonization (CTC) and CRBSI. Observational and prospective study carried out in an Intensive Care Unit. Patients with suspected catheter-related infection (CRI) and with one central venous catheter for at least 7 days were included. The area under the curve (AUC) of the Maki technique, the vortexing technique and the combination of both techniques for the diagnosis of CTC and CRBSI were compared. We included 136 episodes of suspected CRI. We found 21 cases of CTC of which 10 were also CRBSI cases. Of the 21 CTC episodes, 18 (85.7%) were diagnosed by Maki technique and vortexing technique, 3 (14.3%) only by the technique of Maki, and none only by technique of vortexing. Of the 10 CRBSI episodes, 9 (90.0%) were diagnosed by the techniques of Maki and vortexing, 1 (10.0%) was diagnosed only by the technique of Maki, and none only by the technique of vortexing. We no found differences in the comparison of AUC between the technique of Maki and the combination of Maki and vortexing techniques for the diagnosis of CTC (P = 0.99) and CRBSI (P = 0.99). The novel finding of our study was that the combined use of vortexing and Maki techniques did not provide profitability to the technique of Maki alone to CRBSI diagnosis of.

Sonication did not provide reliability to Maki technique for catheter related bloodstream infection diagnosis.

ObjectiveThe aim of our study was to analyze sonication and Maki techniques for diagnosis of catheter tip colonization and catheter-related bloodstream infection (CRBSI) on patients admitted to ICU.Material and methodsObservational and prospective study in one Intensive Care Unit. Patients with some central venous catheter (CVC) at least for 7 days and catheter-related infection (CRI) suspicion (new episode of fever or sepsis) were included. We performed Maki technique followed by sonication of catheter tip. We compared area under the curve (AUC) of Maki, sonication, and techniques combination to diagnosis catheter tip colonization and CRBSI.ResultsWe included 94 CVC from 87 CRI suspicion episodes. We found 14 cases of catheter tip colonization and 10 cases of CRBSI. Of the 14 catheter tip colonization cases, 7 (50.0%) were detected by Maki and sonication techniques, 6 (42.9%) were detected only by Maki technique, and 1 (7.1%) was detected only by sonication technique. Of the 10 CRBSI, 6 (60.0%) were detected by Maki and sonication techniques, 4 (40.0%) were detected only by Maki technique, and any only by sonication technique. We found higher AUC in Maki technique than in sonication technique to diagnosis of CRBSI (p=0.02) and to diagnosis of catheter tip colonization (p=0.03). No significant differences were found in AUC between Maki technique and combination techniques for diagnosis of catheter tip colonization (p=0.32) and of CRBSI (p=0.32).Conclusion.:Sonication did not provide reliability to Maki technique for diagnosis of catheter tip colonization and CRBSI.

Sonicating multi-lumen sliced catheter tips after the roll-plate technique improves the detection of catheter colonization in adults

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 3months, 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 5ml of BHI followed by culture of 100μl 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.

Comparison of the roll-plate and sonication techniques in the diagnosis of microbial ureteral stent colonisation: results of the first prospective randomised study

Microbial ureteral stent colonisation (MUSC) is one leading risk factor for complications associated with ureteral stent placement. As MUSC remains frequently undetected by standard urine cultures, its definitive diagnosis depends on microbiological investigation of the stent. However, a standard reference laboratory technique for studying MUSC is still lacking. A total of 271 ureteral stents removed from 199 consecutive patients were investigated. Urine samples were obtained prior to device removal. Stents were divided into four parts. Each part was separately processed by the microbiology laboratory within 6 h. Ureteral stents were randomly allocated to roll-plate or sonication, respectively, and analysed using standard microbiological techniques. Demographic and clinical data were prospectively collected using a standard case-report form. Overall, roll-plate showed a higher detection rate of MUSC compared with sonication (35 vs. 28 %, p < 0.05) and urine culture (35 vs. 8 %, p < 0.05). No inferiority of Maki's technique was observed even when stents were stratified according to indwelling time below or above 30 days. Compared with roll-plate, sonication commonly failed to detect Enterococcus spp., coagulase-negative staphylococci (CoNS) and Enterobacteriaceae. In addition, sonication required more hands-on time, more equipment and higher training than roll-plate in the laboratory. This prospective randomised study demonstrates the superiority of Maki's roll-plate technique over sonication in the diagnosis of MUSC and that urine culture is less sensitive than both methods. The higher detection rate, simplicity and cost-effectiveness render roll-plate the methodology of choice for routine clinical investigation as well as basic laboratory research.

How Should Long-Term Tunneled Central Venous Catheters Be Managed in Microbiology Laboratories in Order To Provide an Accurate Diagnosis of Colonization?

Guidelines recommend the roll-plate technique for short-term central venous catheter (CVC) tip cultures. However, the issue of whether the roll-plate technique is better than the sonication method for long-term CVCs remains unresolved. In addition, no data are available for predicting the value of direct Gram staining in anticipating catheter colonization or catheter-related bloodstream infection (CRBSI) in these long-term CVCs. Our objectives were to compare the roll-plate technique and the sonication method and to define the validity values of Gram staining for the prediction of colonization and CRBSI in patients with long-term tunneled CVCs. During the study period, all tunneled CVCs removed at our institution were prospectively and routinely sent to the microbiology laboratory for Gram staining (first) and tip culture (the Maki technique and sonication, in a random order). We received 149 tunneled CVCs, 39 (26.2%) of which were colonized and 11 (7.4%) of which were associated with CRBSI. Overall, the roll-plate method detected 94.9% of the colonized catheters, whereas sonication detected only 43.6% (P < 0.001). The validity values of Gram staining for the detection of colonization and CRBSI were as follows: a sensitivity of 35.9% to 60.0%, a specificity of 100% to 94.2%, a positive predictive value of 100% to 42.9%, and a negative predictive value of 81.5% to 97.0%. The roll-plate technique proved to be better than sonication for the detection of bacteria in long-term tunneled CVCs. Gram staining of the tips of tunneled CVCs can anticipate a positive culture and rule out CRBSI. In our opinion, direct Gram staining should be incorporated into routine microbiological assessments of long-term catheter tips.

UP-2.51: Comparison of Maki's technique and sonication in the diagnosis of microbial ureteral stent colonization: a randomized prospective study

UP-2.51: Comparison of Maki's technique and sonication in the diagnosis of microbial ureteral stent colonization: a randomized prospective study

A Prospective, Randomized, and Comparative Study of 3 Different Methods for the Diagnosis of Intravascular Catheter Colonization

Demonstration of catheter tip colonization is usually performed by use of Maki's semiquantitative technique, although the superiority of quantitative techniques has been claimed on the basis of their purported ability to detect both endoluminal and exoluminal microorganisms. We prospectively compared Maki's semiquantitative technique and the quantitative methods of sonication and vortexing for the detection of colonization of intravascular catheter tips and catheter-related bloodstream infections. All 3 techniques were performed on the tip of each catheter, and the order in which each technique was performed was randomly assigned. Of the 1000 catheter tips that were processed, 329 (32.9%) had positive results for at least 1 of the 3 techniques when a breakpoint of >or=100 colony-forming units (cfu)/catheter segment was used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique. Eighty-two of the catheter tips for which results were positive were from patients with catheter-related bloodstream infections. For each technique, the likelihood of detection decreased progressively depending on the order in which the technique was performed (i.e., second vs. first and third vs. second). The likelihood of detection of catheter colonization for each technique, when the technique was performed first and when 2 breakpoints (>or=100 cfu/catheter segment [criterion B] and >or=1000 cfu/catheter segment [criterion A]) were used for the quantitative techniques and a breakpoint of >or=15 cfu was used for Maki's technique, was as follows: 99.1% and 100% for Maki's technique, 95.1% and 92.9% for sonication, and 93.1% and 72.8% for vortexing (for criteria B and A, respectively). No inferiority of Maki's technique could be demonstrated when results were compared according to whether catheter placement was short term (i.e., <7 days) or long term (i.e., >or=7 days), either for the detection of colonization or for the detection of catheter-related bloodstream infections. According to data from the present study, the quantitative techniques of sonication and vortexing were not superior to Maki's technique under the test conditions used. The greater simplicity of Maki's semiquantitative technique makes it the procedure of choice for routine work in the microbiology laboratory.

Reduction of catheter-related infections in neutropenic patients: a prospective controlled randomized trial using a chlorhexidine and silver sulfadiazine-impregnated central venous catheter

Antiseptic coating of intravascular catheters may be an effective means of decreasing catheter-related colonization and subsequent infection. The purpose of this study was to assess the efficacy of chlorhexidine and silver sulfadiazine (CH-SS)-impregnated central venous catheters (CVCs) to prevent catheter-related colonization and infection in patients with hematological malignancies who were subjected to intensive chemotherapy and suffered from severe and sustained neutropenia. Proven CVC-related bloodstream infection (BSI) was defined as the isolation of the same species from peripheral blood culture and CVC tip (Maki technique). This randomized, prospective clinical trial was carried out in 106 patients and compared catheter-related colonization and BSI using a CH-SS-impregnated CVC (n=51) to a control arm using a standard uncoated triple-lumen CVC (n=55). Patients were treated for acute leukemia (n=89), non-Hodgkin's lymphoma (n=10), and multiple myeloma (n=7). Study groups were balanced regarding to age, sex, underlying diseases, insertion site, and duration of neutropenia. The CVCs were in situ a mean of 14.3+/-8.2 days (mean+/-SD) in the study group versus 16.6+/-9.7 days in the control arm. Catheter-related colonization was observed less frequently in the study group (five vs nine patients; p=0.035). CVC-related BSI were significantly less frequent in the study group (one vs eight patients; p=0.02). In summary, in patients with severe neutropenia, CH-SS-impregnated CVCs yield a significant antibacterial effect resulting in a significantly lower rate of catheter-related colonization as well as CVC-related BSI.

Central venous catheter-related infections

Central venous catheter-related infections

Malassezia furfur-related colonization and infection of central venous catheters

To determine the incidence of Malassezia furfur-related colonization and infection of central venous catheters. Prospective clinical study. A paediatric intensive care unit at a University Hospital. 66 newborns with central venous catheters for parenteral nutrition including lipid emulsions (Intralipid). When a central venous catheter was removed, it was rinsed with 1 ml of physiological saline, transported at ambient temperature to the clinical laboratory and cultured on Dixon's medium. The tip of the central venous catheter was used for a bacteriological study using Maki's technique. In case of suspected sepsis, blood cultures were obtained using an Isolator tube. RESULTS. 74 central venous catheters were included: mean duration of use of a central venous catheters and infusions of lipid emulsion (Intralipid) were 19.3 +/- 10 days and 8.6 +/- 8 days respectively. Only 2 central venous catheters (2.7%) were colonized by Malassezia furfur: (Mf) one in an asymptomatic newborn, and the other in an infected newborn with signs of sepsis, who most probably died at 4 months of age from refractory hypoxia due to pulmonary hypoplasia, but not from Mf sepsis. The incidence of Malassezia furfur-related colonization of central venous catheters appears to be low but not negligible, which warrants the use of specific culture techniques.