[EXPRESS IDENTIFICATION OF POSITIVE BLOOD CULTURES USING DIRECT MALDI-TOF MASS SPECTROMETRY].

OBJECTIVE: To evaluate the effectiveness of direct identification of pathogens of bacteremia by direct matrix assisted laser desorption ionization time-flight mass spectrometry (mALDI-TOF) compared to routine method. MATERIAL AND METHODS: A prospective study included 211 positive blood cultures obtained from 116 patients (106 adults and 10 children, aged from 2 weeks to 77 years old in the ICU after open heart surgery. Incubation was carried out under aerobic vials with a sorbent for antibiotics Analyzer BacT/ALERT 3D 120 (bioMerieux, France) in parallel with the primary sieving blood cultures on solid nutrient media with subsequent identification of pure cultures using MALDI-TOF mass spectrometry analyzer Vitek MS, bioMerieux, France routine method), after appropriate sample preparation we carried out a direct (without screening) MALDI-TOF mass spectrometric study of monocomponental blood cultures (n = 201). RESULTS: using a routine method in 211 positive blood cultures we identified 23 types of microorganisms (Staphylococcus (n = 87), Enterobacteria- ceae (n = 71), Enterococci (n = 20), non-fermentative Gram-negative bacteria (n = 18), others (n = 5). The average time of incubation of samples to obtain a signal of a blood culture growth was 16.2 ± 7.4 h (from 3.75 to 51 hours.) During the first 12 hours of incubation, growth was obtained in 32.4% of the samples, and on the first day in 92.2%. In the direct mass spectrometric analysis mnonocomponental blood cultures (n = 201) is well defined up to 153 species of the sample (76.1%), while the share of successful identification of Gram-negative bacteria was higher than that of Gram-positive (85.4 and 69, 1%, respectively p = 0.01). The high degree of consistency in the results of standard and direct method of identifying blood cultures using MALDI-TOF mass spectrometry (κ = 0.96, p < 0.001; the samples included in the calculation for which both option given result). Duration of the direct mass spectrometric analysis, including sample preparation, was no longer than 1 hour: CONCLUSION: The method of direct MALDI-TOF mass spectrometry allows to significantly speed up the identification of blood cultures that may contribute as much as possible early appointment effective regimes of starting antibiotic therapy.

[Procalcitonin as a predictor of bacteremia in postoperative cardiosurgery patients].

PURPOSE OF THE STUDY: To define diagnostics ability of procalcitonin (PCT) test for prediction of bacteremia of different etiology in cardio-surgical patients. MATERIALS AND METHODS: 10158 pairs of blood examples from cardio-surgical patients in early postoperative period were studied from 2007 to 2012. Results of PCT test were compared with blood cultures. The data is presented as absolute values and proportions. Furthermore a mean and standard error of the mean is presented. Differences in compared groups with p < 0.05 are considered statistically significant. RESULTS: In average a bacteremia occurred on a 6th day of postoperative period. Frequency of the positive blood cultures was 20.7%. 972 cases of bacteremia (46.2%) was caused by Gram-positive cocci, 702 cases (33.3%) by Gram-negative bacteria and 338 (16.1%) by yeast-like fungi. Mixt-cultures were defined in 93 cases (4.4%). Monocultural bacteremia was analyzed only (n = 2012). Average level of PCT was higher (statistically significant) in cases with blood cultures than in cases without it (14.35 +/- 0.91 ng per ml vs. 7.35 +/- 0.26 ng per ml, p = 0). The highest PCT was fixed in cases of bacteremia caused by Gram-negative bacteria (26.03 +/- 2.13 ng per ml). There was no significant difference between bacteremia due to enterobacteria and non-fermenting agents (30.56 +/- 4.05 ng per ml u 22.79 +/- 0.21 ng per ml, p = 0.07). Statistically significant differences according to the average PCT were defined between bacteremia caused by Gram-negative bacteria (26.03 +/- 2.13 ng per ml), Gram-positive cocci (7.24 +/- 0.88 ng per ml, p = 0), Candida species (9.02 +/- 1.84 ng per ml, p = 0), and cases of contamination (9.92 +/- 2.79 ng per ml, p = 0). Average PCT was not significantly different in cases of bacteremia due to coagulase-negative staphylococci (5.94 +/- 0.87 ng per ml), S. aureus (4.04 +/- 0.9 ng per ml), enterococci (15.72 +/- 3.52 ng per ml), Candida species (9.02 +/- 1.84 ng per ml), in cases of contamination (9.92 +/- 2.79 ng per ml) and in cases of the negative blood cultures (7.35 +/- 0.26 ng per ml). According to ROC-analysis the optimal cut-off point for PCT as a predictor of Gram-negative bacteremia was 2.47 ng per ml, AUC 0.7 (95% DI 0.68-0.72). Index of sensitivity was 64%. CONCLUSIONS: PCT level in blood plasma of patients with bacteremia higher (statistically significant) than in patients with negative blood cultures. Gram-negative infection is more likely in cases when PCT higher than 2.47 ng per ml.

[SCD14-ST (presepsin) level monitoring in cardiac surgical patients during perioperative period].

UNLABELLED: Purpose of the study was to define prognostic ability of presepsin (sCD14-ST) as a predictor of complications in cardiac surgical patients during perioperative period. METHODS: Patients operated for acquired heart valvular diseases with cardiopulmonary bypass were involved in the study (n = 51, age 58 +/- 11 years). Following parameters were studied; demographic data, duration of cardiopulmonary bypass, time of aorta clamping, severity-of-disease by APACHE II scale before surgery, on 1st, 2nd, 3rd and 6th day after surgery, routine clinical laboratory data and sCD14-ST. RESULTS: there were no clinical laboratory evidences of inflammation before surgery in all patients. There was no difference between biomarkers in patients who had normal condition during postoperative period and in patients who had complications and/or untoward outcomes during postoperative period. Presepsin level in 6 patients (11.8%) was 543 (519-602) ng/ml, maximal 1597 ng/ml. Infection complications accrued in 19 patients (37%). Hospital mortality was 13.7% (7 patients), all cases of death was in group of patients with infection complications. Statistically significant differences in the level of presepsin and severity-of-disease by APACHE II in groups of patients with infection complications and without accrued on 1st and 2nd days of postoperative period. Optimal split point were 702 ng/ml, 8.5 points and 3.3 ng/ml. Increased postoperative level of presepsin is associated with a risk of infection complications and untoward outcomes. CONCLUSION: sCD14-ST monitoring with the use of severity-of-disease scales and recent biomarkers allow to identify patients with high risk of infection complications and untoward outcomes.