Diagnosis Of Bacteremia Research Articles

Clinical Characteristics, Management, and Outcomes of Bacteremia in Children with Cancer: A Retrospective Study

Abstract Background Bacteremia is a common infectious complication among pediatric oncology patients, yet management practices are not standardized. Antibiotic treatment courses as short as seven days are supported by literature and could improve patient quality of life and resource use. However, it is not known if short courses are associated with greater treatment failure in immunocompromised patients. Methods We conducted a retrospective study at St. Jude Children’s Research Hospital, including patients with a laboratory confirmed bloodstream bacterial infection between April 1, 2022, and March 31, 2023. Clinical characteristics such as age, gender, type of malignancy, phase of treatment, underlying chronic conditions, and clinical sites of infection were collected. Antibiotics used, duration of therapy, and route of administration were also gathered to examine clinical management. Clinical outcomes were measured by documenting ICU admission, oxygen, fluid and vasopressor requirements, date of hospital discharge, bacteremia recurrence, and mortality. Results 86 patients contributed 112 bacteremia episodes that met eligibility criteria. Severe neutropenia was present at onset in 68% of all episodes and 32% of patients did not have neutrophil recovery over 500 cells/ml during the episode. Gram-negative organisms accounted for 52% of isolated organisms, with the most common organisms isolated overall being Escherichia coli (19%), followed by Klebsiella pneumoniae (14%), and Viridans group streptococcus (14%). The median length of antibiotic treatment was 12 days. Treatment duration was not associated with oncologic diagnosis or Gram-negative versus Gram-positive infection. Conclusion Bacteremia occurs more frequently in patients who are neutropenic, especially those who are severely neutropenic with an absolute neutrophil count less than 500 cells/mL. Treatment duration is not associated with primary cancer diagnosis or type of bacteremia. In this single high resource setting, bloodstream infections resulted in significant morbidity, resource use, and a mortality rate of 8%, highlighting opportunities for investigation to improve clinical practices.

Simulation to optimize the laboratory diagnosis of bacteremia.

Optimization of laboratory pathways and resource availability has a direct impact on the clinical management of patients with bloodstream infection. This research offers an insight into the laboratory processing of blood cultures at a system level and allows clinical microbiology laboratories to explore the impact of changes to processes and resources.

Microbiological performance and adherence in blood culture protocols: The role of a second anaerobic bottle

BackgroundBacteremia represents high rates of morbidity and mortality, especially in developing countries, highlighting the need for a diagnostic method that allows prompt and appropriate patient treatment. This study compared microbiological performance and adherence of two blood culture protocols for the diagnosis of bacteremia. MethodsQuasi-experimental study conducted between June 2022 and February 2023. Two blood culture protocols were evaluated. Protocol 1 included two aerobic bottles and one anaerobic bottle. Protocol 2 included two aerobic and two anaerobic bottles. Protocols were analyzed in three phases: evaluation of protocol 1 (Phase 1); evaluation of protocol 1 plus educational activities for healthcare staff (Phase 2) and evaluation of protocol 2 (Phase 3). Results342 patients and 1155 blood culture bottles (732 aerobic and 423 anaerobic) were included. Positivity was 17.6 %, 22.8 % and 19.4 % in phases 1, 2 and 3, respectively. Among patients with bacteremia, 84.5 % had positive anaerobic bottles, with 9.9 % showing growth only in this bottle. The contamination rates were 1.9 %, 0.3 %, and 0.8 % for each phase, mainly in aerobic bottles. Median positivity time was 11 h for both bottes aerobic and anaerobic. Overall nursing adherence increased from 13.1 % in Phase 1, 25.9 % in Phase 2, and 28.1 % in Phase 3 (p = 0.009). ConclusionsThe findings indicate that adding a second anaerobic bottle does not enhance blood culture positivity. Rather than increasing bottle quantity, staff training might be a more effective approach to optimize results.

Evaluating the Clinical Impact of Species-Level Identification in Coagulase-Negative Staphylococci Positive Blood Cultures

Background: Coagulase-negative staphylococci (CoNS) are often considered contaminants when isolated from blood cultures. While criteria exist to distinguish true bacteremia from contamination (Table 1), clinical judgement is often necessary. Clinical microbiology laboratories have traditionally identified CoNS to the species level only if present in multiple cultures. There have been concerns that blood cultures positive for rare or less familiar CoNS species might be misinterpreted as true bacteremia. Tufts Medical Center (TMC) clinical microbiology laboratory started reporting all CoNS to the species level in January 2023. We studied the impact of species-level identification of CoNS on clinically relevant outcomes following this change. Methods: The study evaluated inpatients at TMC aged ≥ 18 years with CoNS isolated from blood cultures between July 2022 and June 2023. The primary outcome was the difference in anti-staphylococcal antibiotic utilization between the pre- and post-intervention groups. Secondary outcomes included differences in true bacteremia diagnosis, length of hospital stay, and mortality between the two groups. We also compared the performance of Souvenir’s criteria with clinical judgement at distinguishing contamination from true bacteremia. A total of 100 patients were included in the pre- and post-intervention groups to detect an estimated effect size of 15% with a power of 81%. Results: Most patients were male, White, and English speaking (Table 2). No differences were found between the two groups in terms of infectious disease consultation frequency, blood culture collection department, or the presence of central venous catheters (Table 2). Staphylococcus epidermidis was the predominant CoNS in the post-intervention group. Blood cultures were repeated before and after starting antibiotics in 24% and 74% (pre-intervention) and 18% and 84% (post-intervention) of cases, respectively. Anti-staphylococcus antibiotic use was the same in both groups (82%). The median antibiotic therapy duration was 4.5 days pre- vs 3 days post-intervention (p =0.39). There were no differences in hospital length of stay or mortality between the two groups (Table 3). The clinical diagnosis of true bacteremia was established in 28% of cases in the pre- vs 25% in the post-intervention group (p= 0.63). Compared to clinical judgement, Souvenir’s true bacteremia criteria demonstrated a sensitivity of 80.3%, negative PV of 91.9%, and positive PV of 55.2%. Conclusions: Species-level identification of CoNS positive blood cultures did not impact antibiotic utilization, diagnosis of true bacteremia, length of hospital stay, or mortality. Further studies with larger cohorts and prospective designs are needed to validate these findings and assess the long-term implications in patients.

Epidemiology, microbiology, and diagnosis of infection in diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome: A multicenter retrospective observational study

AimsWe investigated the characteristics of infection and the utility of inflammatory markers in diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS). MethodsA multicenter, retrospective observational study in 21 acute-care hospitals was conducted in Japan. This study included adult hospitalized patients with DKA and HHS. We analyzed the diagnostic accuracy of markers including C-reactive protein (CRP) and procalcitonin (PCT) for bacteremia. Multiple regression models were created for estimating bacteremia risk factors. ResultsA total of 771 patients, including 545 patients with DKA and 226 patients with HHS, were analyzed. The mean age was 58.2 (SD, 19.3) years. Of these, 70 tested positive for blood culture. The mortality rates of those with and without bacteremia were 14 % and 3.3 % (P-value < 0.001). The area under the curve (AUC) of CRP and PCT for diagnosis of bacteremia was 0.85 (95 %CI, 0.81–0.89) and 0.76 (95 %CI, 0.60–0.92), respectively. Logistic regression models identified older age, altered level of consciousness, hypotension, and higher CRP as risk factors for bacteremia. ConclusionsThe mortality rate was higher in patients with bacteremia than patients without it. CRP, rather than PCT, may be valid for diagnosing bacteremia in hyperglycemic emergencies.Trial Registration: This study is registered in the UMIN clinical trial registration system (UMIN000025393, Registered December 23, 2016)

ICP-MS based detection method combined with Au NP and Ag NP labeling for bacteremia diagnosis

Bacteremia, as a serious infectious disease, has an increasing incidence and a high mortality rate. Early diagnosis and early treatment are crucial for improving the cure rate. In this work, we proposed an inductively coupled plasma mass spectrometry (ICP-MS)-based detection method combined with gold nanoparticle (Au NP) and silver nanoparticle (Ag NP) labeling for the simultaneous detection of Salmonella and Escherichia coli (E. coli O157:H7) in human blood samples. Salmonella and E. coli O157:H7 were captured by magnetic beads coupled with anti-8G3 and anti-7C2, and then specifically labeled by Au NP-anti-5H12 and Ag NP-anti-8B1 respectively, which were used as signal probes for ICP-MS detection. Under the optimal experimental conditions, the limits of detection of 164 CFU mL−1 for Salmonella, 220 CFU mL−1for E. coli O157:H7 and the linear ranges of 400–80,000 CFU mL−1Salmonella, 400–60,000 CFU mL−1 E. coli O157:H7 were obtained. The proposed method can realize the simultaneous detection of two types of pathogenic bacteria in human whole blood in 3.5 h, showing great potential for the rapid diagnosis of bacteremia in clinic.

Gram-negative bacteremia, the risk factors, and outcome in children

We aimed to determine the epidemiology and resistance patterns of Gram-negative bacteria, the risk factors and outcome of bloodstream infection (BSI). In all, 412 episodes in children who were hospitalized with the diagnosis of bacteremia were analyzed. The most common microorganisms were Klebsiella spp. (43.9%), Escherichia coli (13.5 %) and Acinetobacter spp. (10.6 %). Among isolates, 41.2 % were multidrug-resistant, 13.5 % were extensively drug-resistant and 0.4 % were pan-drug-resistant. Carbapenem resistance was revealed in 27.6 % of isolates. Carbapenem and colistin resistance increased over the years. The most common risk factors were the presence of a central-venous catheter and pediatric intensive care unit admission. Clinical response and infection-related mortality were significantly different in cases infected with carbapenem-resistant gram-negative (CRGN) vs carbapenem-susceptible gram-negative bacteria. The increase in multi-resistant Klebsiella spp. seems to be the biggest obstacles in fight against nosocomial infections. The increasing number of CRGN infections over the years affects both the clinical response and mortality rate of BSI.

Impact of infective versus sterile transvenous lead removal on 30-day outcomes in cardiac implantable electronic devices.

Transvenous lead removal (TLR) is associated with increased mortality and morbidity. This study sought to evaluate the impact of TLR on in-hospital mortality and outcomes in patients with and without CIED infection. From January 1, 2017, to December 31, 2020, we utilized the nationally representative, all-payer, Nationwide Readmissions Database to assess patients who underwent TLR. We categorized TLR as indicated for infection, if the patient had a diagnosis of bacteremia, sepsis, or endocarditis during the initial admission. Conversely, if none of these conditions were present, TLR was considered sterile. The impact of infective vs sterile indications of TLR on mortality and major adverse events was studied. Out of the total 25,144 patients who underwent TLR, 14,030 (55.8%) received TLR based on sterile indications, while 11,114 (44.2%) received TLR due to device infection, with 40.5% having systemic infection and 59.5% having isolated pocket infection. TLR due to infective indications was associated with a significant in-hospital mortality (5.59% vs 1.13%; OR = 5.16; 95% CI 4.33-6.16; p < 0.001). Moreover, when compared with sterile indications, TLR performed due to device infection was associated with a considerable risk of thromboembolic events including pulmonary embolism and stroke (OR = 3.80; 95% CI 3.23-4.47, p < 0.001). However, there was no significant difference in the conversion to open heart surgery (1.72% vs. 1.47%, p < 0.111), and infection was not an independent predictor of cardiac (OR = 1.12; 95% CI 0.97-1.29) or vascular complications (OR = 1.12; 95% CI 0.73-1.72) between the two groups. Higher in-hospital mortality and rates of thromboembolic events associated with TLR resulting from infective indications may warrant further pursuing this diagnosis in patients.

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.

Universal Digital High-Resolution Melt Analysis for the Diagnosis of Bacteremia

Fast and accurate diagnosis of bloodstream infection is necessary to inform treatment decisions for septic patients, who face hourly increases in mortality risk. Blood culture remains the gold standard test but typically requires approximately 15 hours to detect the presence of a pathogen. We, therefore, assessed the potential for universal digital high-resolution melt (U-dHRM) analysis to accomplish faster broad-based bacterial detection, load quantification, and species-level identification directly from whole blood. Analytical validation studies demonstrated strong agreement between U-dHRM load measurement and quantitative blood culture, indicating that U-dHRM detection is highly specific to intact organisms. In a pilot clinical study of 17 whole blood samples from pediatric patients undergoing simultaneous blood culture testing, U-dHRM achieved 100% concordance when compared with blood culture and 88% concordance when compared with clinical adjudication. Moreover, U-dHRM identified the causative pathogen to the species level in all cases where the organism was represented in the melt curve database. These results were achieved with a 1-mL sample input and sample-to-answer time of 6 hours. Overall, this pilot study suggests that U-dHRM may be a promising method to address the challenges of quickly and accurately diagnosing a bloodstream infection.

The Clinical Utility of Automated Immature Granulocyte Measurement in the Early Diagnosis of Bacteremia.

Background Early diagnosis and prompt management are crucial for bacteremia and sepsis, as they have the potential to lead to septic shock and fatal outcomes. Bacteremia induces the recruitment of immature granulocytes (IGs) into the circulation, which indicates active bone marrow response. The goal of our present study is to determine the effectiveness of automated IG measurement as an alternate indicator for infection and also its clinical utility in predicting positive blood culture (BC) results. Methods We conducted a retrospective study including 100 BC-positive patients for whom complete blood count (CBC) and BC were done at the same time. Multiple hematological parameters including total white blood cell count (TWC), absolute neutrophil count (ANC), absolute lymphocyte count (ALC), IG count (IGC), and IG percentage (IG%) were obtained from the automated hematology analyzer, and IGC/TWC (IG ratio), IGC/ANC (immature-to-total neutrophil ratio), and ANC/ALC (neutrophil-to-lymphocyte ratio) were calculated using the primary data and compared with 100 uninfected normal individuals. Results The mean value of IG% and IGC between culture-positive and culture-negative groups were statistically significant (p-value < 0.05), suggesting that they are potential markers for bacteremia, and also the IG% was significantly higher in patients with positive BCs. Conclusion IG measurement is an easily accessible, cost-effective potential marker for screening bacteremia. Therefore, IGC and IG% could be incorporated as a part of the CBC report.

Role of cell-free DNA levels in the diagnosis and prognosis of sepsis and bacteremia: A systematic review and meta-analysis.

Sepsis remains a major cause of mortality in intensive care units (ICUs). Prompt diagnosis and effective management are imperative for better outcomes. In this systematic review and meta-analysis, we explore the potential of circulating cell-free DNA (cfDNA), as a promising tool for early sepsis detection and prognosis assessment, aiming to address limitations associated with traditional diagnostic methods. Following PRISMA guidelines, we collected relevant literature from thirteen databases. Studies were included if they analyzed quantitative diagnostic or prognostic cfDNA levels in humans in case of sepsis. We collected data on basic study characteristics, baseline patient demographics (e.g. age and sex), and cfDNA levels across different stages of sepsis. Pooled SMD with 95%-CI was calculated, and Comprehensive Meta-Analysis (CMA) software facilitated meta-analysis. Receiver operating characteristic (ROC) curves were generated to assess cfDNA's combined sensitivity and specificity in diagnostics and prognostics. We included a final of 44 studies, of which, only 32 with 2950 participants were included in the meta-analysis. cfDNA levels were higher in septic patients compared to healthy controls (SMD = 3.303; 95%-CI [2.461-4.145], p<0.01). Furthermore, cfDNA levels were higher in non-survivors than survivors (SMD = 1.554; 95%-CI [0.905-2.202], p<0.01). Prognostic studies demonstrated a pooled sensitivity and specificity of 0.78, while diagnostic studies showed a sensitivity of 0.81 and a specificity of 0.87. These findings show that cfDNA levels are significantly higher in sepsis patients compared to control groups and non-survivors in comparison to survivors among both adult and pediatric populations.

Combination of machine learning algorithms with natural language processing may increase the probability of bacteremia detection in the emergency department: A retrospective, big-data analysis of 94,482 patients.

Prompt diagnosis of bacteremia in the emergency department (ED) is of utmost importance. Nevertheless, the average time to first clinical laboratory finding range from 1 to 3 days. Alongside a myriad of scoring systems for occult bacteremia prediction, efforts for applying artificial intelligence (AI) in this realm are still preliminary. In the current study we combined an AI algorithm with a Natural Language Processing (NLP) algorithm that would potentially increase the yield extracted from clinical ED data. This study involved adult patients who visited our emergency department and at least one blood culture was taken to rule out bacteremia. Using both tabular and free text data, we built an ensemble model that leverages XGBoost for structured data, and logistic regression (LR) on a word-analysis technique called bag-of-words (BOW) Term Frequency-Inverse Document Frequency (TF-IDF), for textual data. All algorithms were designed in order to predict the risk for bacteremia with ED patients whose blood cultures were sent to the laboratory. The study cohort comprised 94,482 individuals, of whom 52% were males. The prevalence of bacteremia in the entire cohort was 9.7%. The model trained on the tabular data yielded an area under the curve (AUC) of 73.7% for XGBoost, while the LR that was trained on the free text achieved an AUC of 71.3%. After checking a range of weights, the best combination was for 55% weight on the XGBoost prediction and 45% weight on the LR prediction. The final model prediction yielded an AUC of 75.6%. Harnessing artificial intelligence to the task of bacteremia surveillance in the ED settings by a combination of both free text and tabular data analysis improved predictive performance compared to using tabular data alone. We recommend that future AI applications based on our findings should be assimilated into the clinical routines of ED physicians.

Impact of quality improving interventions on blood culture contamination rate- A prospective observational study

Background: Blood cultures (BC) is the gold standard for diagnosis of bacteremia but false positive blood cultures due to specimen contamination can lead to increased usage of unnecessary antibiotics and have negative impact on antimicrobial stewardship program. Overgrowth of contaminants can also obscure growth of genuine pathogens and hamper accurate diagnosis. The aim of this study is to evaluate effectiveness of Quality improving (QI) interventions to reduce the blood culture contamination rate Material and Methods: Prospective observational study, conducted at a public sector hospital, for a total duration of 6 months. A taskforce developed and implemented QI interventions to reduce blood culture contamination, and evaluated effectiveness of these interventions by comparing contamination rates prior to and after implementation of the intervention. Results: The post-intervention average contamination rate was significantly lower with the mean contamination rate of 4.7 ± 1.5% as compared to baseline BC contamination rate which was 10.6 ± 1.8% (p=0.013) Conclusion: Quality improving (QI) interventions significantly reduced the blood culture contamination rate. Keywords: Quality improvement, Interventions, Blood culture, Contamination.

Host response signature trends in persistent bacteraemia and metastatic infection due to Staphylococcus aureus and Gram-negative bacilli: a prospective multicentre observational study

Background A prompt diagnosis of bacteraemia and sepsis is essential. Markers to predict the risk of persistent bacteraemia and metastatic infection are lacking. SeptiCyte RAPID is a host response assay stratifying patients according to the risk of infectious vs sterile inflammation through a scoring system (SeptiScore). In this study we explore the association between SeptiScore and persistent bacteraemia as well as metastatic and persistent infection in the context of a proven bacteraemia episode. Methods This is a prospective multicentre observational 14-month study on patients with proven bacteraemia caused by Staphylococcus aureus or Gram-negative bacilli. Samples for assessment by SeptiCyte were collected with paired blood cultures for 4 consecutive days after the index blood culture. Results We included 86 patients in the study, 40 with S. aureus and 46 with Gram-negative bacilli bacteraemia. SeptiScores over the follow-up were higher in patients with Gram-negative compared to S. aureus bacteraemia (median 6.4, IQR 5.5–7.4 vs 5.6 IQR 5.1–6.2, p = 0.002). Higher SeptiScores were found to be associated with positive blood cultures at follow-up (AUC = 0.86, 95%CI 0.68–1.00) and with a diagnosis of metastatic infection at day 1 and 2 of follow-up (AUC = 0.79, 95%CI 0.57–1.00 and AUC = 0.82, 95%CI 0.63–1.00 respectively) in the context of Gram-negative bacteraemia while no association between SeptiScore and the outcomes of interest was observed in S. aureus bacteraemia. Mixed models confirmed the association of SeptiScore with positive blood cultures at follow-up (p = 0.04) and metastatic infection (p = 0.03) in the context of Gram-negative bacteraemia but not S. aureus bacteraemia after adjusting for confounders. Conclusions SeptiScores differ in the follow-up of S. aureus and Gram-negative bacteraemia. In the setting of Gram-negative bacteraemia SeptiScore demonstrated a good negative predictive value for the outcomes of interest and might help rule out the persistence of infection defined as metastatic spread, lack of source control or persistent bacteraemia.

Early diagnosis of candidemia with explainable machine learning on automatically extracted laboratory and microbiological data: results of the AUTO-CAND project

Background Candidemia is associated with a heavy burden of morbidity and mortality in hospitalized patients. The availability of blood culture results could require up to 48–72 h after blood draw; thus, early treatment decisions are made in the absence of a definite diagnosis. Methods In this retrospective study, we assessed the performance of different supervised machine learning algorithms for the early differential diagnosis of candidemia and bacteremia in adult patients on a large dataset automatically extracted within the AUTO-CAND project. Results Overall, 12,483 episodes of candidemia (1275; 10%) or bacteremia (11,208; 90%) were included in the analysis. A random forest classifier achieved the best diagnostic performance for candidemia, with sensitivity 0.98 and specificity 0.65 on the training set (true skill statistic [TSS] = 0.63) and sensitivity 0.74 and specificity 0.57 on the test set (TSS = 0.31). Then, the random classifier was trained in the subgroup of patients with available serum β-D-glucan (BDG) and procalcitonin (PCT) values by exploiting the feature ranking learned in the entire dataset. Although no statistically significant differences were observed from the performance measures obtained by employing BDG and PCT alone, the performance measures of the classifier that included the features selected in the entire dataset, plus BDG and PCT, were the highest in most cases. Conclusions Random forest classifiers trained on large datasets of automatically extracted data have the potential to improve current diagnostic algorithms for candidemia. However, further development through implementation of automatically extracted clinical features may be necessary to achieve crucial improvements.

2270. Dealing with an old foe –Assessment of Knowledge, Attitude, and Practices: A survey on management of Staphylococcus aureus bacteraemia among Indian Physicians

Abstract Background Staphylococcus aureus bacteraemia (SAB) is associated with high morbidity, mortality, and healthcare costs. Effective management of SAB significantly improves outcome. There is significant gap in the guidelines and clinical practice. This survey was conducted with aim to assess opinions and practice patterns in management of SAB among Indian clinicians. Methods We conducted a cross-sectional respondent-driven survey, using a 45-item, anonymous, voluntary, multiple-choice google form questionnaire among clinicians in India, after obtaining ethical approval from the institute. We distributed survey via social media, WhatsApp, and E-mail. Survey responses were analysed using SPSS, Version 25.0. Results The total of 125 practicing clinicians responded to this survey. Questions where systematically divided into treatment of choice for MSSA, MRSA, additional investigations, persistent bacteraemia, and adjunctive anti-toxin therapy. Around 57% of the respondents have 1-10 episodes of SAB every month. For suspected SAB, most respondents (74%) preferred vancomycin as empiric therapy. If MSSA was identified, 66.7% initiated on Anti staphylococcal penicillin, while in MRSA vancomycin was selected by majority (80%) (Figure 1 &amp; 2). Most clinicians (74%) perceived 1st generation cephalosporins non-inferior to ASPs. Infectious diseases referral for SAB was undertaken in only in about 56% of the cases, with 25% respondents citing non-availability of ID specialist in the institute. Repeat blood cultures and echocardiography was performed by most respondents. Lack of consensus was apparent in diagnosis and management of persistent bacteraemia and oral switch of therapy (Figure 1 &amp; 2).Most respondents managed SAB with at least 14 days of parenteral antibiotics in several scenarios. But, in patients with complicated SAB there was significant practice variation (Figure 3). Figure - 1 Drug of choice in MSSA, MRSA and management of persistent bacteraemia according to the respondents Figure 2 Persistent bacteraemia definition according to the respondents along with the additional tests performed Conclusion There were some areas of consensus, but this survey highlights considerable practice variation among clinicians. Although the value of ID consultation in SAB management has been established by multiple studies, this survey demonstrates that there remains ample opportunity to further define best practices and optimize management of this complex disease. Disclosures All Authors: No reported disclosures

C-reactive protein and the neutrophil-to-lymphocyte ratio on admission predicting bacteraemia with COVID-19

Background Bacteraemia can co-occur with COVID-19. The present study aimed to determine the cut-off value for C-reactive protein (CRP) and the neutrophil-to-lymphocyte ratio (NLR) for predicting bacteraemia in patients with COVID-19. Methods Patients admitted to Tokyo Metropolitan Tama Medical Centre for COVID-19 treatment between 1 April 2020 and 30 October 2022 were included. Patients transferred from other hospitals and those whose CRP and/or neutrophil count was not measured at admission were excluded. Community-acquired bacteraemia was diagnosed if true bacteraemia was diagnosed in patients via a blood culture performed within 72 h of admission. The cut-off value for CRP and the NLR for community-acquired bacteraemia were determined using receiver operating characteristic analysis. Results Among 2989 patients hospitalized for COVID-19 treatment, 19 received the diagnosis of community-acquired bacteraemia, for which CRP ≥ 6.3 was determined to be the cut-off value. The sensitivity and specificity of the cut-off was 89.5% and 73.3%, respectively. The NLR cut-off value was ≥ 7.7, which had a sensitivity and specificity of 84.2% and 84.0%, respectively. Conclusions Considering the possibility of the co-occurrence of bacteraemia with COVID-19, a blood culture should be performed when CRP is ≥ 6.3 or the NLR is ≥ 7.7.

Oxidant and antioxidant balance in children with bacteremia.

There is a crucial balance between oxidant and antioxidant defense mechanisms. We aimed to evaluate the role of the balance of these systems in children with bloodstream infection. We analyzed prospectively oxidant and antioxidant stress parameters from serum samples of children with BSI besides demographic and clinical data of children. Serum levels of the total antioxidant status (TAS), total oxidant status (TOS), albumin, plasma thiol, disulphide, catalase (CAT), myeloperoxidase (MPO), ischemia-modified albumin (IMA) levels, ferroxidase and arylesterase (ARES) activity were evaluated in both patients and healthy controls. A total of 113 children were evaluated, 50 of them had bacteremia and the remaining 63 were healthy subjects. The median TOS values were 18.5 µmol H<inf>2</inf>O<inf>2</inf>/L and 13.1 µmol H<inf>2</inf>O<inf>2</inf>/L in patient and control groups, respectively with a statistically significant difference between groups. The mean serum IMA levels were 0.8±0.1 absorbance unit (ABSU) in patients and 0.5±0.09 ABSU in control, the difference between groups was statistically significant. The native thiol, total thiol levels and the disulphide levels were significantly lower in the patient group as compared with the control group. The myeloperoxidase level was 136 U/L in patients and 107 in controls with a statistically significant difference between groups. TOS, IMA, MPO, and particularly plasma thiols seem good candidates for accurate diagnosis of bacteremia in children.

Changing culture: An intervention to improve blood culture quality in the emergency department.

Blood cultures (BCs) remain a key investigation in ED patients at risk of bacteraemia. The aim of this study was to assess the effect of a multi-modal, nursing-led intervention to improve the quality of BCs in the ED, in terms of single culture, underfilling and contamination rates. The present study was conducted in the ED of a large urban tertiary referral hospital. The study included four phases: pre-intervention, intervention, post-intervention and sustainability periods. A multi-modal intervention to improve BC quality consisting small group education, posters, brief educational videos, social media presence, quality feedback, small group/individual mentoring and availability of BC collection kits was designed and delivered by two senior ED nurses over 7 weeks. Study data comprised rates of single, underfilled and contaminated cultures in each of three 18-week periods: pre-intervention (baseline), post-intervention and sustainability. Over the study period 4908 BC sets were collected during 2347 episodes of care in the ED. Single culture sets reduced from 56.2% in the pre-intervention period to 22.8% post-intervention (P < 0.01) and 18.8% in the sustainability period (P < 0.01). Underfilled bottle rates were also significantly reduced (aerobic 52.8% pre-intervention to 19.2% post-intervention, 18.8% sustainability, anaerobic 46.8% pre-intervention to 23.3% post-intervention, 23.8% sustainability). Skin contaminants were grown from 3.7% of BC sets in the pre-intervention period, improving to 1.5% in the post-intervention period (P < 0.001) and 2.1% in the sustainability period (P = 0.03). Total volume of blood cultured was significantly associated with diagnosis of bacteraemia. Significant improvements in BC quality are possible with nursing-based interventions in the ED.