Prospective observational pilot study of the T2Resistance panel in the T2Dx system for detection of resistance genes in bacterial bloodstream infections.

Early initiation of antimicrobial therapy targeting resistant bacterial pathogens causing sepsis and bloodstream infections (BSIs) is critical for a successful outcome. The T2Resistance Panel (T2R) detects the following resistance genes within organisms that commonly cause BSIs directly from patient blood samples: blaKPC, blaCTXM-14/15, blaNDM/bla/IMP/blaVIM, blaAmpC, blaOXA, vanA, vanB, and mecA/mecC. We conducted a prospective study in two major medical centers for the detection of circulating resistance genes by T2R in patients with BSIs. T2R reports were compared to antimicrobial susceptibility testing (AST), phenotypic identification, and standard molecular detection assays. Among 59 enrolled patients, 25 resistance genes were identified: blaKPC (n = 10), blaNDM/bla/IMP/blaVIM (n = 5), blaCTXM-14/15 (n = 4), blaAmpC (n = 2), and mecA/mecC (n = 4). Median time-to-positive-T2R in both hospitals was 4.4 hours [interquartile range (IQR): 3.65-4.97 hours] in comparison to that for positive blood cultures with final reporting of AST of 58.34 h (IQR: 45.51-111.2 hours; P < 0.0001). The sensitivity of T2R to detect the following genes in comparison to AST was 100% for blaCTXM-14/15, blaNDM/bla/IMP/blaVIM, blaAmpC, mecA/mecC and 87.5% for blaKPC. When monitored for the impact of significant antimicrobial changes, there were 32 events of discontinuation of unnecessary antibiotics and 17 events of escalation of antibiotics, including initiation of ceftazidime/avibactam in six patients in response to positive T2R results for blaKPC. In summary, T2R markers were highly sensitive for the detection of drug resistance genes in patients with bacterial BSIs, when compared with standard molecular resistance detection systems and phenotypic identification assays while significantly reducing by approximately 90% the time to detection of resistance compared to standard methodology and impacting clinical decisions for antimicrobial therapy. IMPORTANCE: This is the first reported study to our knowledge to identify key bacterial resistance genes directly from the bloodstream within 3 to 5 hours in patients with bloodstream infections and sepsis. The study further demonstrated a direct effect in modifying initial empirical antibacterial therapy in response to T2R signal to treat resistant bacteria causing bloodstream infections and sepsis.

Contaminant Organism Growth in Febrile Infants at Low Risk for Invasive Bacterial Infection.

In this multicenter, cross-sectional, secondary analysis of 4042 low-risk febrile infants, nearly 10% had a contaminated culture obtained during their evaluation (4.9% of blood cultures, 5.0% of urine cultures, and 1.8% of cerebrospinal fluid cultures). Our findings have important implications for improving sterile technique and reducing unnecessary cultures.

A multisite validation of a two hours antibiotic susceptibility flow cytometry assay directly from positive blood cultures.

BACKGROUND: Rapid antimicrobial susceptibility testing (AST) is urgently needed to provide safer treatment to counteract antimicrobial resistance. This is critical in septic patients, because resistance increases empiric therapy uncertainty and the risk of a poor outcome. We validate a novel 2h flow cytometry AST assay directly from positive blood cultures (PBC) by using a room temperature stable FASTgramneg and FASTgrampos kits (FASTinov® Porto, Portugal) in three sites: FASTinov (site-1), Hospital Ramon y Cajal, Madrid, Spain (site-2) and Centro Hospitalar S. João, Porto, Portugal (site-3). A total of 670 PBC were included: 333 spiked (site-1) and 337 clinical PBC (151 site-2 and 186 site-3): 367 gram-negative and 303 gram-positive. Manufacturer instructions were followed for sample preparation, panel inoculation, incubation (1h/37ºC) and flow cytometry analysis using CytoFlex (Site-1 and -2) or DxFlex (site-3) both instruments from Beckman-Coulter, USA. RESULTS: A proprietary software (bioFAST) was used to immediately generate a susceptibility report in less than 2 h. In parallel, samples were processed according to reference AST methods (disk diffusion and/or microdilution) and interpreted with EUCAST and CLSI criteria. Additionally, ten samples were spiked in all sites for inter-laboratory reproducibility. Sensitivity and specificity were >95% for all antimicrobials. Reproducibility was 96.8%/95.0% for FASTgramneg and 95.1%/95.1% for FASTgrampos regarding EUCAST/CLSI criteria, respectively. CONCLUSION: FASTinov® kits consistently provide ultra-rapid AST in 2h with high accuracy and reproducibility on both Gram-negative and Gram-positive bacteria. This technology creates a new paradigm in bacterial infection management and holds the potential to significantly impact septic patient outcomes and antimicrobial stewardship.

An improved protocol for bacteria identification by MALDI-TOF MS directly from positive blood cultures.

FASTinov® developed a rapid antimicrobial susceptibility test that includes the purification of a bacterial suspension directly from positive blood cultures (BC). In order to streamline laboratory workflow, the use of the bacterial suspension obtained through FASTinov® sample prep was tested for identification (ID) by matrix absorption laser deionization-time of flight mass spectrometry (MALDI-TOF MS) (Bruker) in 364 positive BC, and its accuracy assessed comparing with the MALDI-TOF MS ID of the next-day subcultured colonies. FASTinov sample prep was highly reliable for rapid ID directly from BC with proportion of agreement of 94.9% for Gram-positive and 96.3% for Gram-negative bacteria.

Rate and predictors of blood culture positivity after antibiotic administration: a prospective single-center study.

PURPOSE: Blood culture obtainment prior to antibiotic administration, in patients with suspected infection, is considered the best practice in international guidelines. However, there is little data regarding the effect of a single dose of antibiotics on blood culture sterilization. METHODS: We conducted a prospective study, enrolling consecutive patients with suspected infection, hospitalized in an internal medicine ward between December 2019 and January 2023. Included patients had a positive blood culture prior to antibiotic administration and a set of blood cultures taken within 24 h after a single dose of antibiotics. The rate of patients with pathogen isolation after antibiotic administration was assessed. Logistic regression was performed to examine factors associated with blood culture positivity. RESULTS: A total of 155 patients were recruited for the study of which 131 (50.8% female 77.5 ± 13.4 years) met the inclusion criteria. The overall rate of patients with a positive blood culture after a single dose of antibiotics was 42.0% (55/131 patients). Increasing time between antibiotic administration and post-antibiotic culture was an independent predictor for blood culture sterilization (odds ratio 0.89 [95% confidence interval, 0.83-0.97; p = 0.006] for every 60 min). Blood culture volume was an independent predictor for blood culture positivity in a sensitivity analysis which included 82 patients (OR = 1.26 [95% CI 1.03-1.57] for every 1 ml increase; p = 0.024). CONCLUSION: Blood culture positivity is reduced by antimicrobial therapy but remains high after a single dose of antibiotics. If cultures are not obtained prior to antibiotic administration, they should be obtained as soon as possible afterwards.

Deficits in blood culture collection in the emergency department if sepsis is suspected: results of a retrospective cohort study.

PURPOSE: Blood cultures (BCs) are key for pathogen detection in septic patients. We investigated the extent to which sampling was performed and what factors were associated with the absence of general or inadequate BC sampling. METHODS: We conducted a retrospective cohort study of hospitalized patients with sepsis admitted to one of three EDs in 2018. Primary outcome was the extent of general BC collection of at least 1 set. Secondary outcome was the extent of adequate BC sampling, defined as ≥ 2 sets before antibiotic therapy (AT). Multivariable logistic regression analysis was performed to identify factors associated with deficits in both outcomes. RESULTS: 1143 patients were analyzed. BCs were collected from 946 patients. Single BCs were taken from 520 patients, ≥ 2 sets from 426 patients. Overall, ≥ 2 BCs were taken from 349 patients before AT. BC sampling before AT occurred significantly more frequently when ≥ 2 BC sets were taken rather than a single one (81.9%, versus 68.4%, p < 0.001) and this also led to the highest pathogen detection rate in our cohort (65.6%). A body temperature of ≥ 38 °C was the a supporting factor for general and adequate BC collection in all three EDs. Retrospective analysis of 533 patients showed that the qSOFA score had no influence on general or adequate BC collection. CONCLUSION: Data on everyday clinical practice in the pre-analytical phase of microbiological diagnostics shows considerable deficits and indicates the need for more implementation of best practice. The variations identified in BC sampling between EDs should be further investigated.

Risk factors for positive follow-up blood cultures in Gram-negative bacteremia among immunocompromised patients with neutropenia.

INTRODUCTION: Gram-negative bacillary bloodstream infection (GN-BSI) is a frequent clinical challenge among immunocompromised hosts and is associated with a high mortality. The utility of follow-up blood cultures (FUBCs) for GN-BSI in this population, particularly in the setting of neutropenia, is poorly defined. METHODS: We conducted a single-center, retrospective cohort study between the period of July 2018 and April 2022 to investigate the utility of FUBCs and delineate risk factors for positive cultures among neutropenic patients with monomicrobial GN-BSI. Univariate logistic regression was performed to assess risk factors associated with positive FUBCs. RESULTS: Of 206 patients, 98% had FUBCs performed, and 9% were positive. Risk factors for positive FUBCs included multidrug-resistant GN infection (OR 3.26; 95% confidence interval [CI] 1.22-8.72) and vascular catheter source (OR 4.82; CI 1.76-13.17). Among patients lacking these risk factors, the prevalence of positive FUBCs was low (2.8%) and the negative predictive value was 92%. Those with positive and negative FUBCs had similar rates of all-cause mortality (16.7% vs. 16.6%; p = .942) and microbiologic relapse (11.1% vs. 6.0%; p = .401) within 90-days of treatment completion. However, positive FUBCs were associated with prolonged hospitalization and longer duration of antimicrobial therapy. CONCLUSION: Positive FUBCs were infrequent in neutropenic patients with GN-BSI, and their occurrence did not significantly impact mortality or microbiologic relapse. Risk factors for positive FUBCs included multidrug resistant Gram-negative infection and vascular catheter source. Prospective studies will be necessary to elucidate the benefits and risks of FUBCs when managing GN-BSI in patients with underlying immune compromise.

Bile Culture May Guide Antibiotic Stewardship in Acute Bacterial Cholangitis.

BACKGROUND: Bile cultures are often sent with blood cultures in patients with acute bacterial cholangitis. AIMS: To assess the yield of blood and bile cultures in patients with cholangitis and the clinical utility of bile cultures in guiding therapy. METHODS: All patients diagnosed with cholangitis, based on the Tokyo 2013/2018 guidelines were recruited retrospectively over ten years. The clinical and investigation details were recorded. The results of bile and blood cultures including antibiotic sensitivity patterns were noted. The concordance of microorganisms grown in blood and bile cultures and their sensitivity pattern were assessed. RESULTS: A total of 1063 patients with cholangitis were included. Their mean age was 52.7 ± 14 years and 65.4% were males. Blood cultures were positive in 372 (35%) patients. Bile culture was performed in 384 patients with 84.4% being positive, which was significantly higher than the yield of blood culture (p < 0.001). Polymicrobial growth was more in bile (59.3%) than in blood cultures (13.5%, p < 0.001). E.coli, Klebsiella, Enterococcus and Pseudomonas were the four most common organisms isolated from both blood and bile. Extended spectrum betalactamase producing organisms were isolated in 57.7% and 58.8% of positive blood and bile cultures, respectively. Among 127 patients with both blood and bile cultures positive, complete or partial concordance of organisms was noted in about 90%. CONCLUSION: Bile and blood cultures have a similar microbial profile in most patients with cholangitis. As bile cultures have a significantly higher yield than blood cultures, they could effectively guide antimicrobial therapy, especially in those with negative blood cultures.

Pediatric blood cultures-turning up the volume: a before and after intervention study.

The major determinant of blood culture (BC) diagnostic performance is blood volume, and pediatric sample volumes are frequently low. We aimed to assess BC volumes in our institution, design an intervention to increase volumes, and assess its impact. All pediatric BCs submitted over a 7-month period to the microbiology laboratory in a university hospital (including emergency department, pediatric ward, and neonatal unit) were included. A pre-intervention period assessed current practice. A multi-faceted intervention (education, guideline introduction, active feedback strategies) was collaboratively designed by all stakeholders. Impact was assessed in a post-intervention period. The main outcome measures included the percentage of samples adequately filled using three measures of sample adequacy (1) manufacturer-recommended minimum validated volume-> 0.5 ml, (2) manufacturer-recommended optimal minimum volume-> 1.0 ml, (3) newly introduced age-specific recommendations. Three hundred ninety-eight pre-intervention and 388 post-intervention samples were included. Initial volumes were low but increased significantly post-intervention (median 0.77 ml vs. 1.52 ml), with multivariable regression analysis estimating volumes increased 89% post-intervention. There were significant increases in all measures of volume adequacy, including an increase in age-appropriate filling (20.4-53.1%), with less improvement in those aged > 3 years. Overall, 68.4% of pathogens were from adequately filled cultures, while 76% of contaminants were from inadequately filled cultures. A pathogen was detected in a higher proportion of adequately filled than inadequately filled cultures (9.4% vs. 2.2%, p < 0.001).  Conclusion: Blood volume impacts BC sensitivity, with lower volumes yielding fewer pathogens and more contaminants. Focused intervention can significantly improve volumes to improve diagnostic performance. What is Known: • Blood volume is the major determinant of blood culture positivity, and yet pediatric blood culture volumes are frequently low, resulting in missed pathogens and increased contamination. What is New: • Adequately filled (for age) blood cultures have a pathogen detection rate three times higher than inadequately filled blood cultures. • This interventional study shows that collaboratively designed multi-modal interventions including focus on accurate volume measurement can lead to significant increases in blood volumes and improve blood culture diagnostic performance.

Epidemiological patterns of candidaemia: A comprehensive analysis over a decade.

BACKGROUND: The prevalence of fungal bloodstream infections (BSI), especially candidaemia, has been increasing globally during the last decades. Fungal diagnosis is still challenging due to the slow growth of fungal microorganisms and need for special expertise. Fungal polymicrobial infections further complicate the diagnosis and extend the time required. Epidemiological data are vital to generate effective empirical treatment strategies. OBJECTIVES: The overall aim of this project is to describe the epidemiology of monomicrobial candidaemia and polymicrobial BSI, both with mixed fungaemia and with mixed Candida/bacterial BSIs. METHODS: We conducted a single-centre retrospective epidemiological study that encompasses 950,161 blood cultures during the years 2010 to 2020. The epidemiology of monomicrobial and polymicrobial candidaemia episodes were investigated from the electronic records. RESULTS: We found that 1334 candidaemia episodes were identified belonging to 1144 individual patients during 2010 to 2020. Candida albicans was the most prevalent species detected in candidaemia patients, representing 57.7% of these episodes. Nakaseomyces (Candida) glabrata and Candida parapsilosis complex showed an increasing trend compared to previous studies, whereas Candida albicans demonstrated a decrease. 19.8% of these episodes were polymicrobial and 17% presented with mixed Candida/bacterial BSIs while 2.8% were mixed fungaemia. C. albicans and N. glabrata were the most common combination (51.4%) in mixed fungaemia episodes. Enterococcus and Lactobacillus spp. were the most common bacteria isolated in mixed Candida/bacterial BSIs. CONCLUSIONS: Polymicrobial growth with candidaemia is common, mostly being mixed Candida/bacterial BSIs. C. albicans was detected in more than half of all the candidaemia patients however showed a decreasing trend in time, whereas an increase is noteworthy in C. parapsilosis complex and N. glabrata.

Evaluation of an automated rapid phenotypic antimicrobial susceptibility testing (ASTar, Q-linea AB) applied directly on blood cultures bottles positive for Gram-negative pathogens.

We evaluated the performance of a new rapid phenotypic antimicrobial susceptibility test (ASTar; Q-linea AB) on Gram-negative bacilli, directly from positive blood cultures bottles. MIC values obtained by the routine reference method (Microscan, Beckman Coulter) were compared to the ones provided by the tested method (ASTar). ASTar demonstrated an overall essential agreement of 98% and a category agreement of 96.1%. The overall rate of major errors and very major errors was 2.5% and 3.3%, respectively. ASTar can represent a rapid, simple, and reliable method to speed up information about antimicrobial susceptibility of Gram-negative pathogens from positive blood culture bottles.

Bacteremia caused by Veillonella parvula: Two case reports and a review of the literature.

Veillonella parvula is a non-motile Gram-negative coccus that forms part of the normal microbiota in several body sites and which has been rarely isolated as cause of infections in human population, particularly in bacteremias. Here we give the overview of characteristics of genus Veillonella and the summary of its role in infections, particularly in bacteremia. We additionally report two patients with bacteremia due to V. parvula. Two sets of blood cultures of each patient yielded a pure culture of an anaerobic microorganism identified as V. parvula by MALDI-TOF MS, and confirmed by 16S rRNA gene sequencing. The two patients were male and one of them had risk factors for anaerobic bacteremia. The isolates were susceptible to most antibiotics and the outcome was successful in both patients. Bacteremia due to V. parvula is still rare. MALDI-TOF MS appear to be an excellent tool for the correct identification of these species.

[Infections and fever]. / Infektion und Fieber.

Fever can be due to infectious or noninfectious causes and results from the body's natural response to exogenous or endogenous pyrogens. Laboratory tests including complete blood count, differential blood count, C­reactive protein, erythrocyte sedimentation rate and procalcitonin do not have sufficient sensitivity and specificity to definitively detect or rule out an infectious (bacterial, viral, parasitic) cause of fever. Blood cultures should be carried out when bacteremic or septic illnesses are suspected. Fever is not always present in infections and can be absent, especially in older and immunocompromised patients. If fever is suspected, core temperatures should be taken, e.g., rectally, orally or invasively. Depending on the clinical situation, infectious causes must be excluded as the most likely cause of an acutely occurring fever. The investigation of long-standing fever (fever of unknown origin, FUO) can be complex and some infectious diseases should first be ruled out, whereby a syndromic classification often helps to clarify the cause of the fever.

Reporting of Antimicrobial Resistance from Blood Cultures, an Antibacterial Resistance Leadership Group Survey Summary: Resistance Marker Reporting Practices from Positive Blood Cultures.

BACKGROUND: We assessed how laboratories use and handle reporting of results of rapid diagnostics performed on positive blood culture broths, with a focus on antimicrobial resistance (AMR) markers. METHODS: A survey assembled by the Antibacterial Resistance Leadership Group Diagnostics Committee was circulated from December 2020 to May 2021. The survey was sent to local hospitals, shared on the ClinMicroNet and Division C listservs, and included in a College of American Pathologists proficiency testing survey. RESULTS: Ninety-six laboratories of various sizes across the United States (95%) and outside of the United States (5%) participated. Of the laboratories that had at least 1 rapid diagnostic in place (94%), significant heterogeneity in methods used and reporting practices was found across community (52%) and academic (40%) laboratories serving hospitals of various sizes. Respondents had implemented 1 to 6 different panels/platforms for a total of 31 permutations. Methods of reporting rapid organism identification and AMR results varied from listing all targets as "detected"/"not detected" (16-22%) without interpretive guidance, to interpreting results (23-42%), or providing therapeutic guidance comments to patient-facing healthcare teams (3-17%). CONCLUSIONS: Current approaches to reporting molecular AMR test results from positive blood culture vary significantly across clinical laboratories. Providing interpretative comments with therapeutic guidance alongside results reported may assist clinicians who are not well-versed in genetic mechanisms of AMR. However, this is currently not being done in all clinical laboratories. Standardized strategies for AMR gene result reporting are needed.

An assessment of the downstream implications of blood culture collection and transit.

The implications of the variables within the pre-analytical phase of blood culture processing are poorly understood. This study aims to explore the effect of transit times (TT) and culture volume, on time to microbiological diagnosis and patient outcomes. Blood cultures received between 1st March and 31st July 2020/21 were identified. TT, time in incubator (TII), and for positive samples, request to positivity times (RPT) were calculated. Demographic details were recorded for all samples, and culture volume, length of stay (LoS), and 30-day mortality for patients with positive samples. Statistical analysis examined how culture volume and TT effected culture positivity and outcome; in the context of the 4-h national TT target. Totally, 14,375 blood culture bottles were received from 7367 patients; 988 (13.4%) were positive for organisms. There was no significant difference between TT of negative and positive samples. The RPT was significantly lower for samples with TT < 4 h (p < 0.001). Culture bottle volume did not affect RPT (p = 0.482) or TII (p = 0.367). A prolonged TT was associated with a longer length-of-stay in those with a bacteraemia with a significant organism (p = 0.001). We found shorter blood culture transportation time was associated with a significantly faster time of positive culture reporting, while optimal blood culture volume did not make a significant impact. Delays in reporting for significant organisms correspond to a prolonged LoS. Laboratory centralisation makes achieving the 4-h target a logistical challenge; however, this data suggests such targets have significant microbiological and clinical impacts.

Evaluation of the Reveal® rapid AST system to assess the susceptibility of Pseudomonas aeruginosa from blood cultures.

This study was set up to assess the performance of the Reveal® rapid AST system to determine the drug susceptibility of Pseudomonas aeruginosa strains directly from blood cultures. Two hundred fully sequenced clinical P. aeruginosa strains were selected for the evaluation, of which 26.5% (n = 53) produced transferable ß-lactamases, and 2.0 to 33.0% had susceptibility levels close to the EUCAST 2021 breakpoints of 11 commonly used antipseudomonal antibiotics. The Reveal® AST system was run with a commercial MIC microplate designed for fast-growing Gram-negative bacilli (Microscan Neg MDR MIC 1), and was compared to the manually operated GN6F MIC microdilution panel from Thermo Fisher, as a comparator method. The Reveal® AST system provided MIC results for the 11 antipseudomonal antibiotics tested within a mean time to result of 6 h 22 min. By comparison with the GN6F panel, the overall rates of categorical agreement (CA), very major errors (VME), major errors (ME), and minor errors (mE for meropenem only) were 96.1%, 1.6%, 4.2%, and 0.6%, respectively. The Specific Reveal® AST system appears to be a reliable and fast technology to determine the susceptibility of P. aeruginosa to antibiotics, including those with resistance levels near categorical breakpoints, directly from blood cultures.

Machine learning pipeline for blood culture outcome prediction using Sysmex XN-2000 blood sample results in Western Australia.

BACKGROUND: Bloodstream infections (BSIs) are a significant burden on the global population and represent a key area of focus in the hospital environment. Blood culture (BC) testing is the standard diagnostic test utilised to confirm the presence of a BSI. However, current BC testing practices result in low positive yields and overuse of the diagnostic test. Diagnostic stewardship research regarding BC testing is increasing, and becoming more important to reduce unnecessary resource expenditure and antimicrobial use, especially as antimicrobial resistance continues to rise. This study aims to establish a machine learning (ML) pipeline for BC outcome prediction using data obtained from routinely analysed blood samples, including complete blood count (CBC), white blood cell differential (DIFF), and cell population data (CPD) produced by Sysmex XN-2000 analysers. METHODS: ML models were trained using retrospective data produced between 2018 and 2019, from patients at Sir Charles Gairdner hospital, Nedlands, Western Australia, and processed at Pathwest Laboratory Medicine, Nedlands. Trained ML models were evaluated using stratified 10-fold cross validation. RESULTS: Two ML models, an XGBoost model using CBC/DIFF/CPD features with boruta feature selection (BFS) , and a random forest model trained using CBC/DIFF features with BFS were selected for further validation after obtaining AUC scores of [Formula: see text] and [Formula: see text] respectively using stratified 10-fold cross validation. The XGBoost model obtained an AUC score of 0.76 on a internal validation set. The random forest model obtained AUC scores of 0.82 and 0.76 on internal and external validation datasets respectively. CONCLUSIONS: We have demonstrated the utility of using an ML pipeline combined with CBC/DIFF, and CBC/DIFF/CPD feature spaces for BC outcome prediction. This builds on the growing body of research in the area of BC outcome prediction, and provides opportunity for further research.

The effect of follow-up blood cultures on mortality and antibiotic use in gram-negative bloodstream infections.

BACKGROUND: Gram-negative bloodstream infections (GN-BSIs) are a significant clinical challenge. The utility of follow-up blood cultures (FUBCs) in GN-BSIs and their impact on mortality and antibiotic consumption are areas of debate. This study aimed to evaluate the effect of FUBCs on mortality and antibiotic consumption in patients with GN-BSIs. METHODS: This single-center, retrospective study was conducted in aged > 18 years of patients with GN-BSIs. FUBC was defined as a blood culture performed 2-7 days after the first blood culture. Patients were grouped as FUBC and no FUBC and compared. A 1:1 match analysis was performed between the groups according to the SOFA score. The matched subgroup was compared for mortality risk factors with logistic regression models. The two groups were compared for the duration of effective antibiotic therapy and total antibiotic consumption (days of therapy per 1000 patient days (DOT/1000 PD)). RESULTS: FUBC was performed in 564 (69.4%) of 812 patients. Persistent, positive and negative FUBC rates were 7.9%, 14%, and 78%, respectively. The frequency of persistent GN-BSI in patients with appropriate antibiotic therapy was 3.9%. SOFA score (OR:1.33; 95% CI, 1.23-1.44), Charlson comorbidity index score (OR:1.18; 95% CI, 1.08-1.28), hospital-acquired infections (OR:1.93; 95% CI, 1.08-3.46) and carbapenem-resistant GN-BSI (OR: 2.92; 95% CI, 1.72-4.96) were independent risk factors for mortality. No relationship was found between FUBC and mortality (p > 0.05). Duration of effective antibiotic therapy (10(4-16) vs. 15(9-20), p < 0.001) and DOT/1000 PD (1609 (1000-2178) vs. 2000 (1294-2769), p < 0.001) were longer in the FUBC group. CONCLUSION: Routine FUBC should not be recommended because of the low prevalence of persistent infections in patients under appropriate antibiotic therapy and FUBC increases antibiotic consumption.

Adherence to use of blood cultures according to current national guidelines and their impact in patients with community acquired pneumonia: A retrospective cohort.

BACKGROUND: Community acquired pneumonia (CAP) is the most frequent cause of mortality secondary to infectious etiologies. Recommendations about the use of blood cultures in the diagnosis and treatment of CAP has been a contentious topic of debate and ever-changing recommendations. METHODS: A cohort study was conducted in a community teaching hospital. All the patients that were admitted with a diagnosis of CAP, between January and December of 2019 were included. Sociodemographic and clinical characteristics were obtained. Blood cultures results were obtained, and it was evaluated if they were done in compliance with current recommendations by the Infectious Disease Society of America (IDSA). RESULTS: 721 patients were included in the study. Median age was 68 years and 50% of the patients were male (n = 293). Patients presented from home (84%) and the most common comorbidities were hypertension and diabetes (68% and 31%). 96 patients had positive blood culture and 34% (n = 247) of all the blood cultures were adequately ordered. 80 patients died or went to hospice and the median length of hospital stay in our cohort was 7 days. The multivariate model showed that mortality was associated with positive blood cultures (OR = 3.1 95%CI 1.63-5.87) and appropriateness of blood cultures (OR = 2.96 95% CI 1.2-5.7). CONCLUSION: Adequate use of blood cultures in patients with CAP might have some association with the outcomes of this disease. However, a prospective study evaluating the utility of this test following current IDSA recommendations is needed to understand their impact in mortality and morbidity.

Overcultured? Blood cultures on discharged ED patients were ordered more frequently after the SEP-1 bundle initiation.

INTRODUCTION: In 2015, the Severe Sepsis and Early Septic Shock Management Bundle (SEP-1) tied hospital reimbursement to performance on a series of time sensitive indicators, including ordering blood cultures on patients with severe sepsis or septic shock. This metric could have broadly shaped ordering practices in the Emergency Department (ED), including for patients who did not have severe sepsis or septic shock. In this study, we sought to evaluate whether the frequency of blood culture orders on adult patients discharged from the ED changed after the SEP-1 metric, whether the rates of positivity for pathogens or contaminants changed after the SEP-1 metric, and whether similar changes were seen in orders for other laboratory tests. METHODS: This was a retrospective evaluation of blood culture orders from discharged adult ED patients from a suburban academic hospital between January 1, 2012 and June 30, 2019. We compared the number of blood cultures per discharged adult patient before and after the SEP-1 metric. We categorized each culture that grew an organism as a pathogen or a contaminant, and we compared rates of pathogen and contaminant growth before and after SEP-1. We compared rates of orders of blood cultures and lactates as labs related to SEP-1 with rates of orders of D-dimers, lipases, human chorionic gonadotropins (HCGs), and brain natriuretic peptides (BNPs) as labs unrelated to SEP-1 before and after the implementation of the SEP-1 metric. RESULTS: There were 144,343 adult patients discharged from the ED during the study period. A total of 6754 blood cultures were drawn from 3827 of those patient visits. The rate increased from 43.1 cultures per 1000 discharged patients before the SEP-1 metric to 75.9 blood cultures per 1000 discharged patients, an increase of 76.2% (p < 0.001). The cultures had a decreased rate of positivity (from 3.93% before SEP-1 to 3.03% after SEP-1, p = 0.044) and an unchanged rate of blood cultures resulting in a contaminant (2.49% to 1.85%, p = 0.071). Overall, orders of the labs unrelated to SEP-1 increased by an average of 16.8% after the SEP-1 metric and orders of the labs related to SEP-1 increased by an average of 81.0%. CONCLUSION: After the SEP-1 bundle, blood cultures were ordered more frequently on discharged ED patients. These cultures had a lower rate of positivity for pathogens and an unchanged rate of growth of contaminants. This increase was not matched by a similar increase in other labs. Taken together, these findings suggest that the SEP-1 metric had the unintended consequence of increasing orders of blood cultures on patients healthy enough to be discharged from the ED.