Every Crisis Is an Opportunity: Advancing Blood Culture Stewardship During a Blood Culture Bottle Shortage.

The current manufacturing disruption of BACTEC blood culture bottles has drawn attention to diagnostic stewardship around blood culture utilization. In this perspective, we offer strategies for implementing blood culture stewardship using a graded approach based on a hospital's blood culture bottle supply. These strategies should inform plans to mitigate the impact of the shortage on patient care and reinforce fundamental principles of blood culture stewardship.

Validity of reducing blood culture incubation time for the BD BACTEC FX blood culture system considering microbiological and clinical aspects.

INTRODUCTION: A blood culture (BC) test is vital for diagnosing bacteremia in clinical practice. Although incubation time varies among automated BC systems, 4-5 days is deemed to be sufficient time for the BD BACTEC FX blood culture system. This study compared the clinical and microbiological characteristics of true-positive BC samples on day 5 with those within 4 days to reduce missed true bacteremia cases. METHODS: We conducted a retrospective study of blood cultures from hospitalized patients between April 2020 and April 2023 at a tertiary care hospital in Japan. RESULTS: In total, 12,342 BC sets were collected from 6,567 patients. Gram-positive bacilli other than Bacillus spp. and Corynebacterium spp., non-albicans Candida, and yeasts other than Candida spp. were detected more frequently in BC-positive patients on day 5 than in those within 4 days. The gastrointestinal tract was the portal of entry more frequently on day 5 than within 4 days (25 % vs. 4 %, p = 0.006). CONCLUSION: A 4-day incubation period is sufficient for the BD BACTEC FX blood culture system under routine conditions. However, a 5-day incubation period may be warranted when low pathogenicity is suspected or the gastrointestinal tract is suspected as the portal of entry.

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

Background: Bacteremia 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. Methods: Quasi-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). Results: 342 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). Conclusions: The 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.

Routine Infectious Diseases Consultations on a Pediatric Cardiac Unit to Improve Positive Blood Culture Management.

Bacteremia can be life-threatening, and highly medicalized patients, such as those with complex congenital heart disease, are at high risk. Infectious diseases (ID) consultation is associated with improved outcomes in bacteremia. We noted an opportunity for improvement in management of positive blood cultures in our cardiac care unit (CCU). We completed a quality improvement project that included a single plan-do-study-act cycle consisting of a policy of routine ID consultation for all positive blood cultures events in the CCU. Our outcome measure of interest was percentage of appropriately managed blood culture events, the process measure was percentage of blood culture events for which the ID service was formally consulted, and the balancing measure was number of individual patients for whom the ID service was formally consulted. Appropriate antimicrobial management was determined via chart review by an ID physician. Data were analyzed via run chart and simple statistics. Following the intervention, the rate of appropriately managed positive blood culture events increased from a baseline of 86% to 98%, and the rate of ID consultation for these events increased from 75% to 98%. A shift was noted in run charts for both the outcome and process measures. There was an increase in patients for whom the ID service was consulted throughout the entire study period. We successfully implemented mandatory ID consultations in a CCU to increase proportion of appropriately managed blood cultures. While this intervention cannot be universally applied, others may find it useful in selected scenarios.

Prudent Use of Blood Cultures for Hospitalized Patients With Cirrhosis.

Background No reliable risk stratification method is available to guide the extent of infectious work-up among hospitalized patients with cirrhosis. Therefore, we aimed to create a risk stratification method for obtaining blood cultures from hospitalized patients with cirrhosis. Methods This was a retrospective cohort study using the Healthcare Cost and Utilization Project - National Readmission Database 2019. Adult patients who were not immunocompromised comprised the final cohort. The primary outcome was the incidence of bacteremia among hospitalized patients with cirrhosis. Secondary outcomes included length of hospital stay, inpatient mortality, and 30-day readmission rate among cirrhosis patients with and without bacteremia. After propensity score matching, the χ2 test was used to assess the primary outcome and inpatient mortality. The Wilcoxon signed-rank test was used to compare the length of hospital stay. Readmission rates were compared via survival analysis. Concomitant bacterial infection, cirrhosis causes, and complications were assessed as potential risk factors for bacteremia using binomial regression. Results The risk ratio (RR) of bacteremia was 1.66 (95% confidence interval (CI): 1.55-1.78) among patients with cirrhosis compared to those without cirrhosis. A concomitant bacterial infection was found to have a strong association with bacteremia in patients with cirrhosis (RR: 3.3, 95% CI: 3.03-3.59). Among cirrhosis patients without concomitant bacterial infection, the incidence of bacteremia was 0.76% (<1%). Among the causes of cirrhosis, primary sclerosing cholangitis was found to have a strong association with bacteremia (RR: 3.88, 95% CI: 2.3-6.04, P < 0.001). Patients with cirrhosis who had bacteremia were hospitalized three days longer than those without bacteremia. There was no difference in inpatient mortality or 30-day readmission rates between cirrhotic patients with and without bacteremia. Conclusion This study suggests that, in the absence of another concomitant bacterial infection and primary sclerosing cholangitis, we can avoid unnecessary blood cultures among immunocompetent patients with cirrhosis. However, given some inherent limitations associated with the database (such as the unavailability of vitals or laboratory values), additional studies are needed to validate its findings.

[Molecular diagnosis of bacteriaemia: benefits of using the FilmArray® BCID2 sepsis panel in a third level hospital]. / Diagnóstico molecular de bacteriemias: beneficios del empleo del panel de sepsis BCID2 de Filmarray® en un hospital de tercer nivel.

INTRODUCTION: Delay in initiating appropriate antimicrobial therapy prolongs hospitalization, increases in-hospital mortality, and raises economic costs. Currently, the identification and susceptibility testing of bacteria in positive blood cultures require a considerable amount of time. The objective of this study was to assess the impact of the BCID2 FilmArray® (FA) panel on the timing of appropriate antimicrobial therapy and potential antimicrobial costs. METHODS: This is a retrospective observational study focused on positive blood cultures in hospitalized patients. FA processing was conducted concurrently with routine sample processing. Changes in antibiotic treatments based on FA results were evaluated, and the reduction in antimicrobial therapy duration and associated cost savings were calculated. RESULTS: Eighty-seven bacteremia episodes were analysed. In 42 (48%) of them antimicrobial therapy was de-escalated to narrower spectrum agents, while in 7 (8%) therapy was escalated to broader spectrum antimicrobials. Additionally, in 8 (9%) antimicrobials were switched without changing spectrum and in 30 (34%) no changes were made based on FA results. Antimicrobial changes were made 2.3 days faster than with routine sample processing resulting in calculated potential savings of US$ 7408. CONCLUSION: The implementation of FA facilitated a faster administration of appropriate antimicrobial therapy, leading to a reduction in the duration of broadspectrum empirical antimicrobial therapy and subsequent economic savings.

Introducción: Los retrasos en el tratamiento antimicrobiano adecuado de las bacteriemias prolongan la estadía hospitalaria, aumentan la mortalidad e incrementan los costos. Aún hoy en día se requiere un tiempo considerable para obtener la identificación y antibiograma de los microorganismos en los hemocultivos positivos. El objetivo fue evaluar el impacto de la implementación del panel BCID2 de FilmArray® (FA) sobre el tiempo de inicio de tratamientos antimicrobianos adecuados y sobre los costos potenciales de los mismos. Métodos: Estudio observacional retrospectivo de los hemocultivos positivos de pacientes hospitalizados, procesados por FA y por metodología tradicional. Se evaluaron los cambios de antimicrobianos en base a los resultados del FA. Se calcularon los días de reducción de tratamiento antimicrobiano y el ahorro potencial en el uso de los mismos, teniendo en cuenta también los costos del FA. Resultados: Se analizaron 87 episodios de bacteriemia. En 42 (48.3%) de ellos se desescaló el tratamiento a antimicrobianos de menor espectro, en 7 (8%) se escaló a antimicrobianos de mayor espectro, en 8 (9.2%) se cambió el antimicrobiano sin variar el espectro y en 30 (34.5%) no se realizaron cambios con los resultados del FA. Los cambios de antimicrobianos se realizaron en promedio 2.3 días más rápido que con los métodos convencionales. Se calculó un ahorro potencial de US$ 7408. Conclusión: La implementación del panel BCID2 de FilmArray® permitió adecuar los tratamientos antimicrobianos más rápidamente acortando la duración de los tratamientos empíricos de amplio espectro, lo cual resultó costo-efectivo.

Evaluation of Direct Antimicrobial Susceptibility Testing of Gram-Negative Bacilli and Staphylococcus aureus from Positive Pediatric Blood Culture Bottles Using BD Phoenix M50.

Bloodstream infections (BSIs) are life-threatening infections for which a timely initiation of appropriate antimicrobial therapy is critical. Antibiotic susceptibility testing (AST) directly performed on positive blood culture broths can help initiate targeted antibiotic therapy sooner than the standard AST performed on colonies isolated on solid media after overnight incubation. Faster antimicrobial susceptibility testing (AST) results can improve clinical outcomes, and reduce broad-spectrum antimicrobial consumption and healthcare-associated costs in sepsis. In this study, we evaluated the accuracy of a direct AST inoculation method on the BD Phoenix M50 system using serum separator tubes to harvest bacteria from positive pediatric blood culture bottles. Direct AST was performed on 132 monomicrobial pediatric blood culture bottles that were positive for Enterobacterales (65; 49.2%), Staphylococcus aureus (46; 34.8%), and non-fermenting Gram-negative bacilli (21; 16%). Overall, the categorical and essential agreements between the direct method and standard method were 99.6% and 99.8%, respectively. Very major, major, and minor error rates were 0.1%, 0.09%, and 0.20% respectively. Direct AST performed on pediatric blood culture bottles using BD Phoenix M50 can quickly provide accurate susceptibility information to guide antimicrobial therapy in patients with BSI.

Is It Useful to Repeat Blood Cultures in Endocarditis Patients? A Critical Appraisal.

BACKGROUND: Previous guidelines for endocarditis have suggested repeating blood cultures until they become negative, with limited evidence. METHODS: Literature reviews were conducted (1) on the incidence of persistent bacteremia and association with outcome and (2) on timing of valve culture negativization to examine the claim for prolongation of antibiotic therapy starting from negative blood cultures. RESULTS: Persistent bacteremia and fever may be present in the first 3 days of endocarditis, despite treatment, and are more common in Staphylococcus (especially MRSA) and Enterococcus species. Persistent bacteremia (48-72 h), persistent infection (day 7), and new onset septic shock are related and predict in-hospital mortality. It is, however, persistent infection at day 7 and septic shock that primarily determine the infectious course of endocarditis, and not persistent bacteremia. Valve cultures at surgery become negative in most cases (>85-90%) after 14-21 days of antibiotic therapy, with no calculated benefit for prolonging therapy after 21 days. CONCLUSIONS: Persistent infection at 7 days after appropriate antibiotic therapy is a better key event for prognosis then positive or negative blood cultures at 48-72 h. Therapy prolongation from the day of negative blood cultures is not reasonable. There is no need to survey blood cultures in endocarditis patients after starting therapy.

Risk factors of bloodstream infection in erythroderma from atopic dermatitis, psoriasis, and drug reactions: a retrospective observational cohort study.

Background: Atopic dermatitis (AD), psoriasis, and drug reactions associated with erythroderma are frequently complicated by infections. However, bloodstream infection (BSI) have received less research attention. Objectives: This study aimed to investigate the clinical characteristics and risk factors associated with BSI in patients with erythroderma. Methods: A retrospective analysis was conducted on 141 erythroderma cases. Eleven cases were identified as having BSI. Clinical records of both BSI and non-BSI groups were reviewed and compared. Results: BSI was diagnosed in 7.80% (11/141) of erythroderma cases, with a breakdown of 7.14% in AD, 2.00% in psoriasis, and 17.14% in drug reactions. Notably, all positive skin cultures (7/7) showed bacterial isolates concordant with blood cultures. Univariate logistic regression analysis revealed several significant associations with BSI, including temperature (≤36.0 or ≥38.5 °C; odds ratio (OR) = 28.06; p < 0.001), chilling (OR = 22.10; p < 0.001), kidney disease (OR = 14.64; p < 0.001), etiology of drug reactions (OR = 4.18; p = 0.03), albumin (ALB) (OR = 0.86; p < 0.01), C-reaction protein (CRP) (OR = 1.01; p = 0.02), interleukin 6 (IL-6) (OR = 1.02; p = 0.02), and procalcitonin (PCT) (OR = 1.07; p = 0.03). Receiver operating characteristic (ROC) curves demonstrated significant associations with ALB (p < 0.001; the area under curve (AUC) = 0.80), PCT (p = 0.009; AUC = 0.74), and CRP (p = 0.02; AUC = 0.71). Conclusions: Increased awareness of BSI risk is essential in erythroderma management. Patients with specific risk factors, such as abnormal body temperature (≤36.0 or ≥38.5 °C), chilling sensations, kidney disease, a history of drug reactions, elevated CRP (≥32 mg/L), elevated PCT (≥1.00 ng/ml), and low albumin (≤31.0 g/L), require close monitoring for BSI development.

Evaluation of Quantamatrix dRASTTM system for rapid antimicrobial susceptibility testing of bacterial isolates from positive blood cultures, in comparison with commercial Micronaut broth microdilution system.

Antimicrobial susceptibility testing (AST) from blood culture (BC) may take several days, limiting the eventual impact on antimicrobial stewardship. Hence, rapid AST systems represent a valuable support in shorting the time-to-response. In this work, the Quantamatrix dRASTTM system (dRAST) was evaluated for rapid AST on 100 monomicrobial BCs (50 Gram-negatives and 50 Gram-positives), including several isolates with clinically relevant resistance mechanisms. AST results were provided in 6-hours, on average. Compared to Micronaut (Merlin) system based on broth microdilution, dRAST exhibited an overall categorical agreement of 92.5 %, essential agreement of 89.0 %, and mean bias of 15.9 %. Category overestimation (potentially leading to unnecessary high-dosage treatment or to exclude active agents) and category underestimation (potentially leading to underdosing or using ineffective agents) were observed in 4.3 % and 3.1 % of cases, respectively. Even though several issues were reported, results confirmed the potential contribution of dRAST to shorten the BCs clinical microbiology workflow and management.

Impact of Catheter-Drawn Blood Cultures on Patient Management: A Multicenter, Retrospective Cohort Study.

Background: Nosocomial bloodstream infections associated with intravascular catheters pose significant financial burden, morbidity, and mortality. There is much debate about whether or not blood cultures should be drawn through central venous catheters, and while guidelines advocate for catheter-drawn cultures when catheter infection is suspected, there is variable practice in this regard. Methods: We performed a retrospective cohort study assessing episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures in tertiary care hospitals in the United States and Spain. Results: We identified 143 episodes in 122 patients meeting inclusion criteria. Thirty percent of such episodes revealed growth of potential pathogens such as Staphylococcus aureus. Overall, 21% of follow-up percutaneously-drawn blood cultures obtained within 48 hours revealed growth of the same microbe after an episode of positive catheter-drawn blood cultures with negative concomitant percutaneously-drawn cultures (33% when potential pathogens were isolated; 16% when common skin contaminants were isolated). Patients with cultures growing pathogenic organisms were more likely to receive targeted antimicrobial therapy and have their catheters removed sooner. Conclusions: Many episodes of positive catheter-drawn blood cultures with concomitant negative percutaneously-drawn cultures lead to growth from percutaneously-drawn follow-up blood cultures. Thus, such initial discordant results should not be disregarded. Our findings advocate for a nuanced approach to blood culture interpretation, emphasizing the value of catheter-drawn blood cultures in clinical decision making and management.

Comparison of time-to-detection of Mindray TDR and BacT/ALERT®3D blood culture systems using simulated blood cultures.

PURPOSE: Blood culture (BC) is the standard for diagnosing bloodstream infections. Available blood culture (BC) systems have been developed to shorten the time to detection (TTD) of positive BCs. This study aimed to evaluate the performance of the Mindray TDR automatic BC system by comparing it with the BacT/ALERT®3D system. METHODS: Sixteen reference strains and 14 clinical isolates were used. Serial dilutions were prepared from all bacterial and yeast colonies with a final concentration of 100 CFU/ml and 10 CFU/ml. The prepared solutions were simultaneously inoculated into the bottles of both systems and placed in blood culture devices. RESULTS: Three hundred and fifty-two (176 BacT/ALERT®3D and 176 Mindray TDR-X060) blood culture bottles were evaluated, 336 aerobic and 16 anaerobic. At both 10 CFU/ml and 100 CFU/ml dilution, there was no significant difference between the two systems in terms of mean detection times for all isolates (p = 0.965, p = 0.245). When evaluated according to the type of organism, the detection time of gram-positive bacteria at 10 CFU/ml dilution was significantly shorter in the BacT/ALERT system (p = 0.019), whereas detection time for yeasts was significantly shorter with the Mindray system (p = 0.047). The number of anaerobic bacteria was too small to draw statistical conclusions, but we observed a trend of shorter detection times in the Mindray TDR-X060 system. CONCLUSION: Two systems with similar operating principles showed different concentrations-dependent performances in terms of positivity detection times depending on the type of microorganism. Mindray TDR-X060 system has been found to be safe to use at high concentrations with this at lower concentrations further comparative studies are needed on the newly introduced Mindray system.

European society of clinical microbiology and infectious diseases guidelines for antimicrobial stewardship in emergency departments (endorsed by European association of hospital pharmacists).

SCOPE: This European Society of Clinical Microbiology and Infectious Diseases guideline provides evidence-based recommendations to support a selection of appropriate antibiotic use practices for patients seen in the emergency department (ED) and guidance for their implementation. The topics addressed in this guideline are (a) Do biomarkers or rapid pathogen tests improve antibiotic prescribing and/or clinical outcomes? (b) Does taking blood cultures in common infectious syndromes improve antibiotic prescribing and/or clinical outcomes? (c) Does watchful waiting without antibacterial therapy or with delayed antibiotic prescribing reduce antibiotic prescribing without worsening clinical outcomes in patients with specific infectious syndromes? (d) Do structured culture follow-up programs in patients discharged from the ED with cultures pending improve antibiotic prescribing? METHODS: An expert panel was convened by European Society of Clinical Microbiology and Infectious Diseases and the guideline chair. The panel selected in consensus the four most relevant antimicrobial stewardship topics according to pre-defined relevance criteria. For each main question for the four topics, a systematic review was performed, including randomized controlled trials and observational studies. Both clinical outcomes and stewardship process outcomes related to antibiotic use were deemed relevant. The literature searches were conducted between May 2021 and March 2022. In April 2022, the panel members were formally asked to suggest additional studies that were not identified in the initial searches. Data were summarized in a meta-analysis if possible or otherwise summarized narratively. The certainty of the evidence was classified according to the Grading of Recommendations Assessment, Development and Evaluation criteria. The guideline panel reviewed the evidence per topic critically appraising the evidence and formulated recommendations through a consensus-based process. The strength of the recommendations was classified as strong or weak. To substantiate the implementation process, implementation trials or observational studies describing facilitators/barriers for implementation were identified from the same searches and were summarized narratively. RECOMMENDATIONS: The recommendations on the use of biomarkers and rapid pathogen diagnostic tests focus on the initiation of antibiotics in patients admitted through the ED. Their effect on the discontinuation or de-escalation of antibiotics during hospital stay was not reported, neither was their effect on hospital infection prevention and control practices. The recommendations on watchful waiting (i.e. withholding antibiotics with some form of follow-up) focus on specific infectious syndromes for which the primary care literature was also included. The recommendations on blood cultures focus on the indication in three common infectious syndromes in the ED explicitly excluding patients with sepsis or septic shock. Most recommendations are based on very low and low certainty of evidence, leading to weak recommendations or, when no evidence was available, to best practice statements. Implementation of these recommendations needs to be adapted to the specific settings and circumstances of the ED. The scarcity of high-quality studies in the area of antimicrobial stewardship in the ED highlights the need for future research in this field.

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.

Performance of ePlex® blood culture identification panels in clinical isolates and characterization of antimicrobial stewardship opportunities.

We assessed the performance of GenMark's ePlex® Blood Culture Identification (BCID) Panels for overall agreement of organism identification and resistance mechanism detection with standard microbiologic methods. This study included patients with a positive blood culture from May 2020 to January 2021. The primary outcomes were to assess concordance of ePlex® organism identification with standard identification methods and concordance of ePlex® genotypic resistance mechanism detection with standard phenotypic susceptibility testing. Secondary outcomes included panel specific performance and characterization of antimicrobial stewardship opportunities. The overall identification concordance rate in 1276 positive blood cultures was 98.1%. The overall concordance for the presence of resistance markers was 98.2% and concordance for the absence of resistance markers was 100%. A majority of ePlex® results (69.5%) represented opportunities for potential antimicrobial stewardship intervention. High concordance rates between the ePlex® BCID panels and standard identification and susceptibility methods enable utilization of results to guide rapid antimicrobial optimization.

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.

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.

Accelerated microbial identification "directly" from positive blood cultures using MALDI-TOF MS: Local clinical laboratory challenges.

Rapid identification of microbial pathogens "directly" from positive blood cultures (PBCs) is critical for prompt initiation of empirical antibiotic therapy and clinical outcomes. Towards higher microbial identification rates, we modified a published initial serum separator tubes-based MALDI-TOF-MS protocol, for blood culture specimens received at a non-hospital based standalone diagnostic laboratory, Bangalore, India: (a) "Initial" protocol #1: From 28 PBCs, identification= 39% (Gram-negative= 43%: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa; Gram-positive: 36%: Enterococcus faecalis, Staphylococcus aureus, Staphylococcus haemolyticus); mis-identification= 14%; non-identification= 47%. (b) "Modified" protocol #2: Quality controls (ATCC colonies spiked in negative blood cultures) From 7 analysis, identification= 100% (Escherichia coli, Klebsiella pneumonia, Klebsiella oxytoca, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus); From 7 PBCs, identification= 57%; mis-identification= 14%; non-identification= 29%. Microbial preparations of highest quality and quantity for proteomic analysis and separate spectra matching reference databases for colonies and PBCs are needed for best clinical utility.