AEROBIC BLOOD CULTURES AND COMPARISON TO CLINICAL FINDINGS OF FREE-RANGING GREEN TURTLES (CHELONIA MYDAS) IN EAST CENTRAL FLORIDA.

Positive blood cultures have been identified in debilitated, stranded, and deceased green turtles (Chelonia mydas), suggestive of septicemia. Interpretation of these results is often difficult because multiple studies have previously identified bacteremia in clinically healthy reptiles. In this study, paired blood cultures and skin cultures obtained after aseptic preparation of the venipuncture site were collected from 50 immature free-ranging green turtles from Port Canaveral, Florida. Blood culture results were compared with health status (apparently healthy versus unhealthy, based on physical examination findings and appropriate body condition), date of collection, presence of external fibropapillomatosis, healed or unhealed injuries, and presence of barnacles. Weight, body condition score, body condition index, morphometric measures, volume of blood collected, and body temperature were compared between blood culture-positive and blood culture-negative turtles. Positive blood cultures were identified in 14% (7 of 50) of all turtles, including 15.6% (5 of 32) of apparently healthy turtles. Vibrio spp., Bacillus megaterium, Cellulomonas sp., and Staphylococcus pasteuri were isolated in blood culture from apparently healthy individuals. There was a significant association (P = 0.048) between positive skin cultures and positive blood cultures, but isolates obtained were consistently different between paired results. There was no significant association (P > 0.05) between blood culture results and health status, evidence of healed or unhealed injuries, external fibropapillomatosis, or presence of barnacles. Based on the results of this study, positive blood cultures suggestive of nonclinical bacteremia may be present in apparently healthy green turtles. The results of this study will aid the attending clinician in interpretation of blood culture results of apparently healthy or presumed septicemic captive and rehabilitating green turtles as part of the conservation and population recovery of this threatened species.

Evaluating the impact of rapid antimicrobial susceptibility testing for bloodstream infections: a review of actionability, antibiotic use and patient outcome metrics.

Antimicrobial susceptibility testing (AST) is a core function of the clinical microbiology laboratory and is critical to the management of patients with bloodstream infections (BSIs) to facilitate optimal antibiotic therapy selection. Recent technological advances have resulted in several rapid methods for determining susceptibility direct from positive blood culture that can provide turnaround times in under 8 h, which is considerably shorter than conventional culture-based methods. As diagnostic results do not directly produce a medical intervention, actionability is a primary determinant of the effect these technologies have on antibiotic use and ultimately patient outcomes. Randomized controlled trials and observational studies consistently show that rapid AST significantly reduces time to results and improves antimicrobial therapy for patients with BSI across various methods, patient populations and organisms. To date, the clinical impact of rapid AST has been demonstrated in some observational studies, but randomized controlled trials have not been sufficiently powered to validate many of these findings. This article reviews various metrics that have been described in the literature to measure the impact of rapid AST on actionability, antibiotic exposure and patient outcomes, as well as highlighting how implementation and workflow processes can affect these metrics.

Validation of short culture method for rapid bacterial identification of blood cultures via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

BACKGROUND: Development of rapid bacterial identification from blood cultures has been an area of intense study in diagnostic microbiology. Shortened turnaround time coupled with antimicrobial stewardship interventions have been shown to improve patient outcomes and decrease healthcare-associated costs. OBJECTIVES: We report the validation of a short incubation method for Gram-positive and Gram-negative bacterial identification utilizing MALDI-TOF MS without additional instrumentation, processing or cost compared with current practice. METHODS: Prospective, observational, single-centre study in a quaternary care academic hospital encompassing 376 blood cultures subjected to bacterial identification after short incubation periods of 3-4 and 6-8 h. RESULTS: There was 97.5% species-level identification agreement with tests undertaken after 3-4 h incubation with 83.6% isolates identified, and 99.7% species-level identification agreement after 6-8 h incubation with 96.7% isolates identified. CONCLUSIONS: The short incubation method provides a rapid MALDI-TOF MS bacterial identification method, reducing turnaround time by 10-18 h compared with standard practice without additional cost, processing or instrumentation.

Retrospective evaluation of rapid genotypic ID and phenotypic AST systems on positive blood culture turnaround time and simulated potential impacts on bloodstream infection management.

BACKGROUND: Bloodstream infections are linked to heightened morbidity and mortality rates. The consequences of delayed antibiotic treatment can be detrimental. Effective management of bacteraemia hinges on rapid antimicrobial susceptibility testing. OBJECTIVES: This retrospective study examined the influence of the VITEK® REVEAL™ Rapid AST system on positive blood culture (PBC) management in a French tertiary hospital. MATERIALS AND METHODS: Between November 2021 and March 2022, 79 Gram-negative monomicrobial PBC cases underwent testing with both VITEK®REVEAL™ and VITEK®2 systems. RESULTS: The study found that VITEK®REVEAL™ yielded better results than the standard of care, significantly shortening the time to result (7.0 h compared to 9.6 h) as well as the turnaround time (15 h compared to 31.1 h) when applied for all isolates. CONCLUSIONS: This study implies that the use of VITEK®REVEAL™ enables swift adaptations of antibiotic treatment strategies. By considerably minimizing the turnaround time, healthcare professionals can promptly make necessary adjustments to therapeutic regimens. Notably, these findings underscore the potential of VITEK®REVEAL™ in expediting appropriate antibiotic interventions, even in less ideal conditions. Further studies in varied laboratory contexts are required to validate these encouraging outcomes.

Getting rapid diagnostic test data into the appropriate hands by leveraging pharmacy staff and a clinical surveillance platform: a case study from a US community hospital.

OBJECTIVES: To outline the procedural implementation and optimization of rapid diagnostic test (RDT) results for bloodstream infections (BSIs) and to evaluate the combination of RDTs with real-time antimicrobial stewardship team (AST) support plus clinical surveillance platform (CSP) software on time to appropriate therapy in BSIs at a single health system. METHODS: Blood culture reporting and communication were reported for four time periods: (i) a pre-BCID [BioFire® FilmArray® Blood Culture Identification (BCID) Panel] implementation period that consisted of literature review and blood culture notification procedure revision; (ii) a BCID implementation period that consisted of BCID implementation, real-time results notification via CSP, and creation of a treatment algorithm; (iii) a post-BCID implementation period; and (iv) a BCID2 implementation period. Time to appropriate therapy metrics was reported for the BCID2 time period. RESULTS: The mean time from BCID2 result to administration of effective antibiotics was 1.2 h (range 0-7.9 h) and time to optimal therapy was 7.6 h (range 0-113.8 h) during the BCID2 Panel implementation period. When comparing time to optimal antibiotic administration among patients growing ceftriaxone-resistant Enterobacterales, the BCID2 Panel group (mean 2.8 h) was significantly faster than the post-BCID Panel group (17.7 h; P = 0.0041). CONCLUSIONS: Challenges exist in communicating results to the appropriate personnel on the healthcare team who have the knowledge to act on these data and prescribe targeted therapy against the pathogen(s) identified. In this report, we outline the procedures for telephonic communication and CSP support that were implemented at our health system to distribute RDT data to individuals capable of assessing results, enabling timely optimization of antimicrobial therapy.

Comparison of Zybio Kit and saponin in-house method in rapid identification of bacteria from positive blood cultures by EXS2600 matrix-assisted laser desorption ionization time-of-flight mass spectrometry system.

We evaluated the performance of Zybio EXS2600 matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) (Zybio Inc., Chongqing, China) for the identification of bacteria from positive blood culture (BC) bottles using Blood Culture Positive Sample Pretreatment Kit (Zybio Inc., Chongqing, China) in comparison to an in-house saponin method. Following a positive signal by the BACTEC™ FX system, confirmation of identification was achieved using subcultured growing biomass used for MALDI-TOF MS analysis. A total of 94 positive BC bottles with 97 bacterial isolates were analyzed. The overall identification rates at the genus and species levels for the saponin method were 89.7% (87/97) and 74.2% (72/97), respectively. With the Zybio Kit, 88.7% (86/97) and 80.4% (78/97) of microorganisms were correctly identified to the genus and species levels, respectively. The saponin method identified 65.3% (32/49) of Gram-positive bacteria at the species level, whereas the Zybio Kit achieved a higher species-level identification rate of 79.6% (39/49) (p = 0.1153). The saponin method with additional on-plate formic acid extraction showed a significantly higher overall identification rate in comparison to the saponin method without that step for both genus (87.6% [85/97] vs. 70.1% [68/97], p = 0.0029) and species level (70.1% [68/97] vs. 46.4% [45/97], p = 0.0008). Identification rates of Gram-negative bacteria showed a higher identification rate, however, not statistically significant with additional Zybio Kit protocol step on both genus (85.4% [41/48] vs. 81.3% [39/48], p = 0.5858) and species level (77.1% [37/48] vs. 75% [36/48], p = 0.8120). Zybio Kit could offer an advantage in species-level identification, particularly for Gram-positive bacteria. The inclusion of on-plate formic acid extraction in the saponin method notably enhanced identification at both genus and species levels for Gram-positive bacteria. The extended protocol provided by the Zybio Kit could potentially offer an advantage in the identification of Gram-negative bacteria at both genus and species levels. Enhancements to the Zybio EXS2600 MALDI-TOF instrument software database are necessary.

[Blood culture utilization and its indications in emergency departments; time for change?] / Inzet van bloedkweken en hun indicatie op SEH's.

OBJECTIVE: To gain insight into the blood culture (BC) utilization in emergency departments (EDs) and to identify differences in the indications for BC collection. DESIGN: Retrospective study METHOD: Data were collected in 11 EDs for 2018, 2019, and 2020. Indications for blood culture collection were identified in from the hospital protocols. Participants indicated which indications are used in their ED. RESULTS: In 2019, ten EDs collected BC from 19% to 30% of all patients for internal medicine and geriatrics. Both the used indications and the cutoff values varied. For fever, >38.0°C, >38.3°C, or >38.5°C were used, and for hypothermia <36.0°C or <35.0°C. CONCLUSION: There is a variation in the percentage of collected BC in the EDs. Additionally, the used indications and the cutoff values differed. A national discussion on criteria is needed to reduce this variation. Meanwhile, structured benchmarking can make BC collection more appropriate.

Integrating omics techniques and culture-independent systems may improve the detection of persistent candidemia: data from an observational study.

INTRODUCTION: Blood cultures have low sensitivity for candidemia. Sensitivity can be improved by the culture-independent system T2 Magnetic Resonance (T2). SeptiCyte RAPID is a host response assay quantifying the risk of infection-related inflammation through a scoring system (SeptiScore). We investigate the performance of SeptiScore in detecting persistent candidemia as defined by conventional cultures and T2. METHODS: This is a prospective multicentre observational study on patients with candidemia. Blood cultures and blood samples for assessment by T2 and SeptiCyte were collected for 4 consecutive days after the index culture. The performance of SeptiScore was explored to predict persistent candidemia as defined by (1) positive follow-up blood culture (2) either positive follow-up blood culture or T2 sample. RESULTS: 10 patients were enrolled including 34 blood collections assessed with the 3 methods. Overall, 4/34 (12%) follow-up blood cultures and 6/34 (18%) T2 samples were positive. A mixed model showed significantly higher SeptiScores associated with persistent candidemia when this was defined as either a positive follow-up blood culture or T2 sample (0.82, 95%CI 0.06 to 1.58) but not when this was defined as a positive follow-up blood culture only (-0.57, 95%CI -1.28 to 0.14). ROC curve for detection of persistent candidemia by SeptiScore at day 1 follow-up showed an AUC of 0.85 (95%CI 0.52-1.00) when candidemia was defined by positive follow-up blood culture, and an AUC of 1.00 (95%CI 1.00-1.00) when candidemia was defined according to both methods. CONCLUSION: Integrating transcriptome profiling with culture-independent systems and conventional cultures may increase our ability to diagnose persistent candidemia.

The rate of blood culture contamination and common organisms isolated in Malaysian public hospitals.

INTRODUCTION: Blood culture contamination remains a dilemma issue in the diagnosis of bloodstream infection. However, to date, there is no national data on blood culture contamination and the common organism isolated in Malaysia. This is a pioneer multi-centre study involving public hospitals with medical microbiologists in Malaysia to determine the blood culture contamination rate and the common organism isolated. MATERIALS AND METHODS: This retrospective cross-sectional study involved record review of all blood culture results over 9 months period from 1st January 2018 until 30th September 2018 in 27 government hospitals in Malaysia. For each positive culture result, the type of isolated organism was classified to represent true bacteraemia or contamination. RESULTS: We analysed 448,109 blood culture records from the participating hospitals. The blood culture positivity rate was 12.5% (57395 of 448109) and 25.0% (14367 of 57395) of the positive blood culture represents contamination. The national blood culture contamination rate in Malaysia was 3.2%. The contamination rate in the adult population was significantly higher than the paediatric population (3.6% vs. 2.6%; p<0.001). The blood contamination rate by institution ranged from 1.5% to 6.8%. The most frequently isolated microorganisms in the contaminated cultures were coagulase-negative staphylococci (71.0%). CONCLUSION: Blood culture contamination is a major issue that warrants priority in recognition, and interventions should be implemented to reduce the blood contamination rate in Malaysia.

[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.

Blood culture bottles meet the operating room: enhancing the diagnostic accuracy of infectious spondylitis through open microsurgical biopsy and intraoperative inoculation.

PURPOSE: Infectious spondylitis is caused by hematogenous seeding or adjacent soft tissue infection. No study has provided evidence that incubating biopsy specimens in blood culture bottles could enhance detection rates, nor has any study compared this method with conventional culture techniques. We aimed to assess the diagnostic yield of open microsurgical biopsies for infectious spondylitis and the efficacy of various culture media in the presence and absence of pre-biopsy antibiotic therapy. METHODS: This retrospective study, which was conducted at a university-affiliated teaching hospital in Korea, enrolled 165 adult patients with suspected infectious spondylitis between February 2014 and September 2020. The diagnostic yield of open biopsy was compared among three culture media, namely, blood culture bottles, swab culture using transport media, and tissue culture using plain tubes, while considering preoperative antibiotic exposure. RESULTS: Causative bacteria were identified in 84.2% of all cases. Blood culture bottles had the highest positivity rate (83.5%), followed by swab cultures (64.4%) and tissue cultures (44.9%). The differences in positivity rates were significant (P < 0.001). Preoperative antibiotic therapy reduced detection rates across all media, particularly in tissue cultures. CONCLUSIONS: We established the high diagnostic yield of open microsurgical biopsy using blood culture bottles, suggesting that pre-biopsy antibiotic therapy significantly affects bacterial detection, thereby underscoring the importance of culture medium selection in the diagnosis of infectious spondylitis.

Evaluation of EUCAST rapid antimicrobial susceptibility test directly from positive blood culture for Pseudomonas aeruginosa.

In this study, we evaluated the performance of the EUCAST RAST method on a collection of 154 clinical strains of P. aeruginosa, including strains resistant to ceftazidime and carbapenems. While the test is convenient for routine laboratories, we observed significant rates of VME (ranging from 0.0 to 15.0%) and ME (ranging from 1.3 to 16.3%) after 6 h, particularly for key antibiotics such as ceftazidime, piperacillin/tazobactam, and meropenem. Extending the incubation time to 8 h may improve results (CA ranging from 87.2 to 99%), but caution is required in interpretation due to persistence of VME (ranging from 0.0 to 15.6%) and ME (ranging from 0.0 to 11.7%).

Performance of T2Bacteria in relationship to blood cultures - a retrospective comparative study.

PURPOSE: Blood culture (BC) is the gold standard for diagnosing blood stream infections (BSI) but is limited by long turnaround times (TAT) and low detection rate. The T2 Magnetic Resonance method (T2MR) offers a rapid, culture-independent alternative. The objective of this study was to compare the performance of the T2Bacteria assay to BCs in a real-world setting. METHODS: Retrospective comparative study consisting of T2Bacteria samples and BCs sampled within 72 h from the T2Bacteria sample. The primary outcome was detections by BC and T2Bacteria, respectively. The secondary outcome was difference in TAT. RESULTS: In total, 640 episodes were included, consisting of 640 T2Bacteria samples and 2,117 BCs. A median of three BCs was collected for each T2Bacteria sample. Overall positivity was 101 (15.8%) by either method. In 29 (28.7%) episodes, both T2Bacteria and BC were concordantly positive. In discordant episodes, 46/101 (45.5%) episodes were T2Bacteria positive/BC negative and 26/101 (25.7%) were T2Bacteria negative/BC positive (McNemar χ2, p < 0,05). In T2Bacteria positive/BC negative episodes, eight had growth of the same microorganism in a non-BC culture. Median (IQR) TAT for BC was 35 h and 30 min (25 h 50 min - 45 h 24 min), compared to 21 h and 3 min (17 h 6 min - 27 h 30 m) for T2Bacteria (p < 0.001), with longer delays for samplings occurring outside work hours. CONCLUSIONS: The study highlights a high discordance between T2Bacteria and BC and suggests complementary roles of the methods in BSI diagnostics. Furthermore, it is crucial to improve TAT by reducing preanalytical delays.

Procalcitonin for safe reduction of unnecessary blood cultures in the emergency department: Development and validation of a prediction model.

OBJECTIVES: Blood cultures (BCs) are commonly ordered in emergency departments (EDs), while a minority yields a relevant pathogen. Diagnostic stewardship is needed to safely reduce unnecessary BCs. We aimed to develop and validate a bacteremia prediction model for ED patients, with specific focus on the benefit of incorporating procalcitonin. METHODS: We included adult patients with suspected bacteremia from a Dutch ED for a one-year period. We defined 23 candidate predictors for a "full model", of which nine were used for an automatable "basic model". Variations of both models with C-reactive protein and procalcitonin were constructed using LASSO regression, with bootstrapping for internal validation. External validation was done in an independent cohort of patients with confirmed infection from 71 Spanish EDs. We assessed discriminative performance using the C-statistic and calibration with calibration curves. Clinical usefulness was evaluated by sensitivity, specificity, saved BCs, and Net Benefit. RESULTS: Among 2111 patients in the derivation cohort (mean age 63 years, 46% male), 273 (13%) had bacteremia, versus 896 (20%) in the external cohort (n = 4436). Adding procalcitonin substantially improved performance for all models. The basic model with procalcitonin showed most promise, with a C-statistic of 0.87 (0.86-0.88) upon external validation. At a 5% risk threshold, it showed a sensitivity of 99% and could have saved 29% of BCs while only missing 10 out of 896 (1.1%) bacteremia patients. CONCLUSIONS: Procalcitonin-based bacteremia prediction models can safely reduce unnecessary BCs at the ED. Further validation is needed across a broader range of healthcare settings.

Recovery of pathogens with implementation of a weight-based algorithm for pediatric blood cultures: an observational intervention study.

BACKGROUND: Recovering pathogenic bacteria and yeast from pediatric blood cultures and reliably distinguishing between pathogens and contaminants are likely to be improved by increasing the volume of blood submitted to microbiology laboratories for culturing beyond the low volumes that have historically have been used. The primary aim of this study was to assess whether the pathogen recovery rate would increase after implementation of a weight-based algorithm for determining the intended volume of blood submitted for culturing. Secondary aims were to: 1) evaluate the effects of the algorithm implementation on the blood culture contamination rate; 2) determine whether pathogens might be found more often than contaminants in several as opposed to single bottles when more than one bottle is submitted; and 3) describe the microbiological findings for pathogens and contaminants in blood cultures by applying a clinical validation of true blood culture positivity. METHODS: A pre-post comparison of positivity and contamination rates after increasing the theoretical blood volume and number of blood culture bottles was performed, on the basis of a clinical validation of blood culture findings as pathogens vs contaminants. RESULTS: We examined 5327 blood cultures, including 186 with growth (123 true positives and 63 contaminated). The rate of true positive blood cultures significantly increased from 1.6% (42/2553) pre to 2.9% (81/2774, p = .002) post intervention. The rate of contaminated blood cultures did not change significantly during the study period (1.4% [35/2553] pre vs 1.0% [28/2774], p = .222) post intervention), but the proportion of contaminated cultures among all positive cultures decreased from 45% (35/77) pre to 26% (28/109, p = .005) post intervention. A microorganism that grew in a single bottle was considered a contaminant in 35% (8/23) of cases, whereas a microorganism that grew in at least two bottles was considered a contaminant in 2% (1/49, p < .001) of cases. According to common classification criteria relying primarily on the identity of the microorganism, 14% (17/123) of the recovered pathogens would otherwise have been classified as contaminants. CONCLUSION: Implementation of a weight-based algorithm to determine the volume and number of blood cultures in pediatric patients is associated with an increase in the pathogen recovery rate.

Ruthenibacterium lactatiformans isolated from a human blood culture: a first report.

BACKGROUND: Ruthenibacterium lactatiformans, a Gram-stain-negative, rod-shaped, obligate anaerobic bacterium of the Oscillospiraceae family, has not been previously reported in human infections. This study reports the first case of bacteraemia and potential vertebral osteomyelitis caused by Ruthenibacterium lactatiformans. CASE PRESENTATION: An 82-year-old man with a history of diabetes, chronic renal failure, and prior spinal surgery for spondylolisthesis and spinal stenosis presented with fever and lower back pain. Magnetic resonance imaging revealed multiple vertebral osteomyelitis lesions. Initial blood cultures identified methicillin-resistant Staphylococcus aureus (MRSA), which prompted vancomycin treatment. However, repeated blood cultures not only confirmed persistent MRSA, but also detected Gram-negative bacilli (GNB). Despite surgical removal of the spinal hardware and antimicrobial therapy, the patient's osteomyelitis worsened, necessitating transfer for further management. Subsequent analysis using 16S rRNA gene sequencing identified the GNB as Ruthenibacterium lactatiformans. CONCLUSIONS: This is the first documented instance of human infection with Ruthenibacterium lactatiformans, signifying its pathogenic potential in vertebral osteomyelitis. The involvement of anaerobic bacteria and the possibility of polymicrobial infections complicate the diagnosis and treatment of vertebral osteomyelitis. This report underscores the need for caution when identifying the causative organism and selecting an appropriate treatment.

Rapid Antimicrobial Susceptibility Testing Using the MicroScan System: Performance Evaluation of a 4-Hour Bacterial Cultivation From Positive Blood Cultures.

A reliable and above all, rapid antimicrobial susceptibility test (AST) is required for the diganostics of blood stream infections (BSI). In this study, resistance testing using DxM MicroScan WalkAway (MicroScan) from a 4-h subculture is compared with the standard overnight culture (18-24 h). Randomly selected positive blood cultures (PBC, n = 102) with gram-negative bacteria were included in the study. PBC were sub-cultured onto appropriate agar plates and AST by MicroScan was performed after 4 h of incubation and repeated after incubation for 18-24 h as standard. In a total of 1909 drug-strain pairs, the 4-h subculture approach showed a very high essential agreement (EA) (98.6%) and categorical agreement (CA) (97.1%) compared with the standard. The incidence of minor error (mE), major error (ME), very major error (VME), and adjusted very major error (aVME) was 1.1%, 0.4%, 12.9%, and 5.3%, respectively. In summary, the use of 4-h subcultures for resistance testing with the MicroScan offers a very reliable and easy to realize time saving when testing positive blood cultures with gram-negative bacteria.

Time to Positive Blood Cultures Among Critically Ill Children Admitted to the PICU.

OBJECTIVES: Our study aimed to assess the time to positivity (TTP) of clinically significant blood cultures in critically ill children admitted to the PICU. DESIGN: Retrospective review of positive blood cultures in patients admitted or transferred to the PICU. SETTING: Large tertiary-care medical center with over 90 PICU beds. PATIENTS: Patients 0-20 years old with bacteremia admitted or transferred to the PICU. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the TTP, defined as time from blood culture draw to initial Gram stain result. Secondary endpoints included percentage of cultures reported by elapsed time, as well as the impact of pathogen and host immune status on TTP. Host immune status was classified as previously healthy, standard risk, or immunocompromised. Linear regression for TTP was performed to account for age, blood volume, and Gram stain. Among 164 episodes of clinically significant bacteremia, the median TTP was 13.3 hours (interquartile range, 10.7-16.8 hr). Enterobacterales, Staphylococcus aureus, Streptococcus agalactiae, and Streptococcus pneumoniae were most commonly identified. By 12, 24, 36, and 48 hours, 37%, 89%, 95%, and 97% of positive cultures had resulted positive, respectively. Median TTP stratified by host immune status was 13.2 hours for previously healthy patients, 14.0 hours for those considered standard risk, and 10.6 hours for immunocompromised patients (p = 0.001). Median TTP was found to be independent of blood volume. No difference was seen in TTP for Gram-negative vs. Gram-positive organisms (12.2 vs. 13.9 hr; p = 0.2). CONCLUSIONS: Among critically ill children, 95% of clinically significant blood cultures had an initial positive result within 36 hours, regardless of host immune status. Need for antimicrobial therapy should be frequently reassessed and implementation of a shorter duration of empiric antibiotics should be considered in patients with low suspicion for infection.

Early detection of bacteremia pathogens with rapid molecular diagnostic tests and evaluation of effect on intensive care patient management.

INTRODUCTION: The BioFire FilmArray Blood Culture Identification panel (BCID2), a rapid molecular blood culture identification test based on multiplex nested polymerase chain reaction. The aim of this study was to evaluate clinical outcomes between the period before (pre-BCID2 group) and after (post-BCID2 group) the introduction of the BCID2 panel into our routine practice. METHODS: The primary endpoint was time to optimal antibiotherapy, and the secondary endpoints were duration of hospital and intensive care unit stay, 7-day, 14-day and 28-day mortality rates after bacteremia. RESULTS: The median time from empirical antibiotherapy to optimal antimicrobial therapy was 4560 (IQR;3060-7140) minutes in the pre-BCID2 group and 1715 (IQR;1362- 2776.25) minutes (in the post-BCID2 group (p<0.05). CONCLUSION: Adding the BCID2 panel may improve antibiotic management in critically ill bacteremia patients.

Clinical evaluation of the T2Candida assay for the rapid diagnosis of candidemia.

We evaluated the clinical performance of the T2Candida assay. The overall agreement of the T2Candida assay results with the blood culture results was 95.3 % (121/127). The T2Candida assay detected three Candida albicans/tropicalis-positive specimens and one Candida krusei/glabrata-positive specimen; however, it did not detect two Candida glabrata specimens.