C-Reactive Protein Monitoring and Clinical Presentation of Fever as Predictive Factors of Prolonged Febrile Neutropenia and Blood Culture Positivity after Autologous Hematopoietic Stem Cell Transplantation—Single-Center Real-Life Experience

Background: Febrile neutropenia (FN) is a medical emergency that requires urgent evaluation, timely administration of empiric broad-spectrum antibiotics and careful monitoring in order to optimize the patient’s outcome, especially in the setting of both allogeneic and autologous hematopoietic stem cell transplant (ASCT). Methods: In this real-life retrospective study, a total of 49 consecutive episodes of FN were evaluated in 40 adult patients affected by either multiple myeloma (thirty-eight) or lymphoma (eleven), following ASCT, with nine patients having fever in both of the tandem transplantations. Results: Febrile neutropenia occurred a median of 7 days from ASCT. Median duration of FN was 2 days, with 25% of population that had fever for at least four days. Ten patients had at least one fever spike superior to 39 °C, while the median number of daily fever spikes was two. Twenty patients had positive blood cultures with XDR germs, namely Pseudomonas aeruginosa and Klebsiella pneumoniae, present in seven cases. ROC analysis of peak C-reactive protein (CRP) values was conducted based on blood culture positivity and a value of 12 mg/dL resulted significant. Onset of prolonged fever with a duration greater than 3 days was associated with the presence of both a peak number of three or more daily fever spikes (p = 0.02) and a body temperature greater than 39 °C (p = 0.04) based on odds ratio (OR). Blood culture positivity and peak CRP values greater than 12 mg/dL were also associated with prolonged fever duration, p = 0.04, and p = 0.03, respectively. The probability of blood culture positivity was also greater in association with fever greater than 39 °C (p = 0.04). Furthermore, peak CRP values below the cut-off showed less probability of positive blood culture (p = 0.02). Conclusions: In our study, clinical characteristics of fever along with peak CRP levels were associated with a higher probability of both prolonged fever duration and positive blood culture, needing extended antibiotic therapy.

Procalcitonin levels in patients with suspected sepsis

Background: Procalcitonin (PCT) was found to be a valuable and reliable biomarker for sepsis, especially in critical care patients for whom early recognition and prompt treatment could reduce mortality. Aims and Objectives: This study was aimed at correlating the levels of PCT as diagnostic marker for sepsis in relation to the culture positivity of various samples from blood, respiratory, urine, and exudates from patients admitted in a tertiary care hospital. Materials and Methods: Results of PCT level along with bacterial culture results of blood, respiratory, urine, and exudates were analyzed from 780 patients for a period of 1 year. Results: High PCT values ranging from 0.52 to 200 ng/ml were found in 331 patients admitted with suspected sepsis. Out of 135 cases of sepsis, 85 had blood culture positivity alone and 50 had culture positivity in blood and in other sites with the same organism. Among the 85 cases of bloodstream infections, in which no localized infections were identified, the median PCT was 33 for Gram-negative bacteremia, which was significantly higher as compared with a median of 16 for Gram-positive cocci. In UTI with bacteremia, the median PCT was 45.34 and in UTI without bacteremia, it was 5. Conclusion: From this study, we concluded that PCT values may be useful to distinguish Gram-negative and Gram-positive bacteremia, and furthermore, a high PCT value for patients with UTI may be helpful in predicting bacteremia.

Real World Evaluation of the Impact of Implementation of the VIRTUO Blood Culture System in a Tertiary Care Hospital

The bioMerieux BACT/ALERT VIRTUO (VIRTUO) blood culture system used in combination with resin-containing media may enhance the growth of microorganisms. Our objective was to assess the impact of transitioning to the VIRTUO system in comparison to the VersaTREK blood culture system at a tertiary care medical center. We retrospectively reviewed all blood cultures performed at a 1250-bed academic medical center between January-December 2018 (VersaTREK) and January-December 2019 (VIRTUO). Blood culture positivity rates and contamination rates were compared pre- versus post-VIRTUO implementation. Of 101,438 blood cultures performed during the study period, 48,839 (48.1%) were processed pre-implementation and 52,599 (51.9%) post-implementation. The blood culture positivity rate increased from 8.1% pre-implementation to 11.7% post-implementation (p<0.001). Staphylococcus aureus was the most frequently isolated species in both time periods and had higher recovery rate post-implementation (1.5% of all blood cultures obtained pre- vs. 3.4% post-implementation, p<0.001). A higher recovery rate in the post-implementation period was also noted for coagulase-negative staphylococci (1.9% pre- vs. 2.7% post-implementation, p<0.001), as well as modest but statistically significant changes for E. coli (0.8% vs. 1.0%, p<0.001), K. pneumoniae (0.4% vs. 0.5%, p=0.005) and Candida albicans . (0.1% vs. 0.2%, p=0.038). The inpatient blood culture contamination rate was higher post-implementation (1.5% pre- vs. 1.9% post-implementation, p<0.001). The VIRTUO blood culture system was associated with a higher observed proportion of positive blood cultures compared to the previous VersaTREK system. Future studies are needed to assess whether an increased rate of positive blood cultures is associated with changes in clinical outcomes.

Neither Blood Culture Positivity nor Time to Positivity is Associated with Mortality among Patients Presenting with Severe Manifestations of Sepsis: The FABLED Cohort Study

Background Sepsis is a leading cause of morbidity, mortality, and health care costs worldwide. Methods We conducted a multi-center, prospective cohort study evaluating the yield of blood cultures drawn before and after empiric antimicrobial administration among adults presenting to the emergency department with severe manifestations of sepsis (ClinicalTrials.gov: NCT01867905). Enrolled patients who had the requisite blood cultures drawn were followed for 90 days. We explored the independent association between blood culture positivity and its time to positivity in relation to 90-day mortality. Findings 325 participants were enrolled; 90-day mortality among the 315 subjects followed-up was 25·4% (80/315). Mortality was associated with age (mean age in those who died was 72·5 ±15·8 vs. 62·9 ±17·7 years among survivors, p&lt;0·0001), greater Charlson Comorbidity Index (2 (IQR 1,3) vs. 1 (IQR 0,3), p=0·008), dementia (13/80 (16·2%) vs. 18/235 (7·7%), p=0·03), cancer (27/80 (33·8%) vs. 47/235 (20·0%), p=0·015), positive qSOFA score (57/80 (71·2%) vs. 129/235 (54·9%), p=0·009), and normal white blood cell counts (25/80 (31·2%) vs. 42/235 (17·9%), p=0·02). The presence of bacteremia, persistent bacteremia after antimicrobial infusion, and shorter time to blood culture positivity were not associated with mortality. Neither the source of infection nor pathogen affected mortality. Interpretation Although severe sepsis is an inflammatory condition triggered by infection, its 90-day survival is not influenced by blood culture positivity nor its time to positivity. Funding Vancouver Coastal Health; St-Paul’s Hospital Foundation Emergency Department Support Fund; the Fonds de Recherche Santé – Québec (CPY); Intramural Research Program of the NIH, Clinical Center (AL); the Maricopa Medical Foundation

A hospital-based study on etiology and prognosis of bacterial meningitis in adults

Bacterial meningitis is a neurological emergency with high morbidity and mortality. We herein investigated clinical features, etiology, antimicrobial susceptibility profiles, and prognosis of bacterial meningitis in adults from a single tertiary center. We retrospectively reviewed medical records of patients with laboratory-confirmed bacterial meningitis from 2007 to 2016. Patients with recent neurosurgery, head trauma, or indwelling neurosurgical devices were classified as having healthcare-related meningitis. Causative microorganisms were identified by analyzing cerebrospinal fluid (CSF) and blood cultures, and antimicrobial susceptibility profiles were evaluated. We performed multiple logistic regression analysis to identify factors associated with unfavorable outcomes. We identified 161 cases (age, 55.9 ± 15.5 years; male, 50.9%), of which 43 had community-acquired and 118 had healthcare-related meningitis. CSF and blood culture positivity rates were 91.3% and 30.4%, respectively. In community-acquired meningitis patients, Klebsiella pneumoniae (25.6%) was the most common isolate, followed by Streptococcus pneumoniae (18.6%) and Listeria monocytogenes (11.6%). The susceptibility rates of K. pneumoniae to ceftriaxone, cefepime, and meropenem were 85.7%, 81.3%, and 100%, respectively. Among healthcare-related meningitis patients, the most common bacterial isolates were coagulase-negative staphylococci (28.0%), followed by Staphylococcus aureus (16.1%) and Enterobacter spp. (13.6%). Neurological complications occurred in 39.1% of the patients and the 3-month mortality rate was 14.8%. After adjusting for covariates, unfavorable outcome was significantly associated with old age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00–1.06), neurological complications (OR 4.53, 95% CI 1.57–13.05), and initial Glasgow coma scale ≤ 8 (OR 19.71, 95% CI 4.35–89.40). Understanding bacterial pathogens and their antibiotic susceptibility may help optimize antimicrobial therapy in adult bacterial meningitis.

Short time to blood culture positivity in Enterococcus faecalis infective endocarditis

Time to blood culture positivity (TTP) is an indirect measure of bacterial concentration in blood. A short TTP has been linked to the presence of infective endocarditis (IE) and to poor prognosis in Staphylococcus aureus bacteremia. We analyze factors influencing TTP in bacteremia with Enterococcus faecalis. This retrospective observational study of medical records included adults diagnosed with monomicrobial E. faecalis bacteremia between 2015 and 2018 in the Skåne region (Sweden). For each episode, the shortest TTP was recorded. Median TTP was compared between patients grouped based on age, sex, comorbidity, site of acquisition, and focus of infection. Using a dichotomized TTP (shorter or longer than 12 h), a multivariable logistic regression for factors associated to TTP was performed. The association between TTP and IE or mortality was evaluated. Three hundred sixty-seven episodes with monomicrobial E. faecalis bacteremia with the corresponding TTP were identified. Median TTP for the entire cohort was 11.6 (IQR 9.9–14.1) h and a significantly shorter TTP was noted for episodes which represented IE (n = 55, 9.4 (IQR 6.4–10.6) h). Only IE remained associated with a short TTP (≤ 12 h) in binary logistic regression analysis. Factors associated with IE were investigated and TTP was associated with IE also when adjusted for age, gender, comorbidity, and nosocomial acquisition. There was no association between TTP and mortality. A low TTP is associated with IE in E. faecalis bacteremia and could be used as a help in determining the need for echocardiography in patients with this condition.

Evaluation of Brucella Coombs Gel Test with Blood Culture

Objective: To evaluate the correlation between Brucella spp. blood culture, which is accepted as the gold standard in the diagnosis of brucellosis, and the Brucella coombs gel test (BCGT), a new and rapid test developed in our country. Material and method: Brucellosis is suspected in 100 patients from various clinics of our hospital microbiology laboratories, simultaneous blood culture results (Bactrim / allet 3D bioMerieux, France) and serum standard tube agglutination test (STA Seromed, Turkey), Brucella Coombs gel test (BCGT, Islab, Turkey) It was evaluated retrospectively. Results: Serology and blood culture growth were negative in 82/100 of the patients. STA/ BCGT results were consistent in 18/100, and ≥ 1/320 was positive. Brucella Melitensis was isolated from blood cultures of seven patients and concurrently taken BCGT was positive (100%). There are 11 patients with positive serology with culture-negative. Conclusion: Although blood culture is accepted as gold standard, it is not always possible to catch blood culture positivity. Serology tests, especially BCGT, should be preferred routinely because it gives early results, is cheap and safe.

Evaluation of Optimal Blood Culture Incubation Time to Maximize Clinically Relevant Results from a Contemporary Blood Culture Instrument and Media System

Timely diagnosis of microorganisms in blood cultures is necessary to optimize therapy. Although blood culture media and systems have evolved for decades, the standard interval for incubation prior to discard as negative has remained five days. Here, we evaluated the optimal incubation time for the BACT/ALERT VIRTUO blood culture detection system (bioMérieux) using FA Plus (aerobic) and FN Plus (anaerobic) resin culture bottles in routine clinical use. Following IRB approval, a retrospective review evaluated the outcomes of 158,710 bottles collected between November 2018 and October 2019. The number of positive blood bottles was 13,592 (8.6%); 99% of positive aerobic and anaerobic bottles flagged positive by 91.5 h and 108 h, respectively. The mean (median) time-to-positivity for Staphylococcus aureus was 18.4 h (15.6 h), Escherichia coli 12.3 h (9.5 h), Pseudomonas aeruginosa 22.2 h (15.9 h), and Candida spp. 48.9 h (42.9 h). Only 175 bottles (0.1% of all bottles) flagged positive after four days of incubation; 89 (51%) of these bottles grew Cutibacterium (Propionibacterium) species. Chart review of blood cultures positive after four days (96 h) rarely had clinical impact, and sometimes had a negative impact on patientcare. Finally, a seeded study of the HACEK group, historically associated with delayed blood culture positivity, demonstrated no benefit to extended incubation beyond four days. Collectively, these findings demonstrated that a four-day incubation time was sufficient for the VIRTUO system and media. Implementation of the four-day incubation time could enhance clinically relevant results by reducing recovery of contaminants and finalizing blood cultures one day earlier.