RESUMO
OBJECTIVES: The risk factors and outcomes associated with persistent bacteraemia in Gram-negative bloodstream infection (GN-BSI) are not well described. We conducted a follow-on analysis of a retrospective population-wide cohort to characterize persistent bacteraemia in patients with GN-BSI. METHODS: We included all hospitalized patients >18 years old with GN-BSI between April 2017 and December 2021 in Ontario who received follow-up blood culture (FUBC) 2-5 days after the index positive blood culture. Persistent bacteraemia was defined as having a positive FUBC with the same Gram-negative organism as the index blood culture. We identified variables independently associated with persistent bacteraemia in a multivariable logistic regression model. We evaluated whether persistent bacteraemia was associated with increased odds of 30- and 90-day all-cause mortality using multivariable logistic regression models adjusted for potential confounders. RESULTS: In this study, 8807 patients were included; 600 (6.8%) had persistent bacteraemia. Having a permanent catheter, antimicrobial resistance, nosocomial infection, ICU admission, respiratory or skin and soft tissue source of infection, and infection by a non-fermenter or non-Enterobacterales/anaerobic organism were associated with increased odds of having persistent bacteraemia. The 30-day mortality was 17.2% versus 9.6% in those with and without persistent bacteraemia (aOR 1.65, 95% CI 1.29-2.11), while 90-day mortality was 25.5% versus 16.9%, respectively (aOR 1.53, 95% CI 1.24-1.89). Prevalence and odds of developing persistent bacteraemia varied widely depending on causative organism. CONCLUSIONS: Persistent bacteraemia is uncommon in GN-BSI but is associated with poorer outcomes. A validated risk stratification tool may be useful to identify patients with persistent bacteraemia.
Assuntos
Bacteriemia , Infecções por Bactérias Gram-Negativas , Humanos , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Ontário/epidemiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/mortalidade , Infecções por Bactérias Gram-Negativas/microbiologia , Fatores de Risco , Bactérias Gram-Negativas/isolamento & purificação , Adulto , Hemocultura , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Relevância ClínicaRESUMO
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.
Assuntos
Bacteriemia , Hemocultura , Osteomielite , Humanos , Masculino , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Osteomielite/microbiologia , Osteomielite/diagnóstico , Osteomielite/tratamento farmacológico , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , RNA Ribossômico 16S/genética , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/diagnóstico , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/genéticaRESUMO
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.
Assuntos
Antibacterianos , Hemocultura , Bactérias Gram-Negativas , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Microbiana/métodos , Humanos , Hemocultura/métodos , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bacteriemia/microbiologia , Fatores de Tempo , Infecções por Bactérias Gram-Negativas/microbiologiaRESUMO
The purpose of this study was to assess changes in time to optimal therapy (TTOT) for bacteremia due to select organisms after implementation of the BioFire® FilmArray® blood culture identification panels at two community teaching hospitals. TTOT (days) was similar in Pre-BCID compared to BCID1 and BCID2 [(2.48 vs. 2.65, p=0.10); (2.48 vs. 2.37, p=0.27)]. There were no significant differences in time to effective antimicrobial therapy between groups. However, there were significantly more therapy changes and appropriate carbapenem use within 24 hours of the Gram stain result for gram-negative organisms in the BCID2 arm compared to the Pre-BCID arm. Additionally, a significant reduction in the duration of vancomycin for gram-positive organisms was noted in the BCID2 arm compared to the Pre-BCID arm. These findings suggest that the incorporation of the BCID2 panel resulted in changes in prescribing practices, leading to more appropriate antimicrobial utilization in a subset of patients.
Assuntos
Antibacterianos , Bacteriemia , Hemocultura , Tempo para o Tratamento , Hemocultura/métodos , Hemocultura/estatística & dados numéricos , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Tempo para o Tratamento/estatística & dados numéricos , Antibacterianos/administração & dosagem , Prescrições de Medicamentos/estatística & dados numéricos , Estudos Retrospectivos , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou maisRESUMO
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.
Assuntos
Hemocultura , Hemocultura/métodos , Hemocultura/instrumentação , Humanos , Fatores de Tempo , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bactérias/isolamento & purificaçãoRESUMO
Delayed time to antimicrobial susceptibility results can impact patients' outcomes. Our study evaluated the impact of susceptibility turnaround time (TAT) and inadequate empiric antibacterial therapy (IET) in patients with bloodstream infections (BSI) caused by Enterobacterales (ENT) species on in-hospital mortality and length of stay (LOS). This retrospective, multicenter investigation which included 29,570 blood ENT-positive admissions across 161 US healthcare facilities evaluated the association between antimicrobial susceptibility testing (AST) TAT, carbapenem susceptibility, and empiric therapy on post-BSI in-hospital mortality and LOS following an ENT BSI event in adult patients. After adjusting for outcomes covariates, post-BSI in-hospital mortality was significantly higher for patients in the IET vs adequate empiric therapy (AET) group [odds ratio (OR): 1.61 (95% CI: 1.32, 1.98); P < 0.0001], and when AST TAT was >63 h [OR:1.48 (95% CI: 1.16, 1.90); P = 0.0017]. Patients with carbapenem non-susceptible (carb-NS) ENT BSI had significantly higher LOS (16.6 days, 95% CI: 15.6, 17.8) compared to carbapenem susceptible (carb-S, 12.2 days, 95% CI: 11.8, 12.6), (P < 0.0001). Extended AST TAT was significantly associated with longer LOS for TAT of 57-65 h and >65 h (P = 0.005 and P< 0.0001, respectively) compared to TAT ≤42 h (reference). Inadequate empiric therapy (IET), carb-NS, and delayed AST TAT are significantly associated with adverse hospital outcomes in ENT BSI. Workflows that accelerate AST TAT for ENT BSIs and facilitate timely and adequate therapy may reduce post-BSI in-hospital mortality rate and LOS.IMPORTANCEFor patients diagnosed with bloodstream infections (BSI) caused by Enterobacterales (ENT), delayed time to antimicrobial susceptibility (AST) results can significantly impact in-hospital mortality and hospital length of stay. However, this relationship between time elapsed from blood culture collection to AST results has only been assessed, to date, in a limited number of publications. Our study focuses on this important gap using retrospective data from 29,570 blood ENT-positive admissions across 161 healthcare facilities in the US as we believe that a thorough understanding of the dynamic between AST turnaround time, adequacy of empiric therapy, post-BSI event mortality, and hospital length of stay will help guide effective clinical management and optimize outcomes of patients with ENT infections.
Assuntos
Antibacterianos , Bacteriemia , Hemocultura , Infecções por Enterobacteriaceae , Mortalidade Hospitalar , Tempo de Internação , Humanos , Tempo de Internação/estatística & dados numéricos , Estudos Retrospectivos , Masculino , Feminino , Infecções por Enterobacteriaceae/mortalidade , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Pessoa de Meia-Idade , Bacteriemia/mortalidade , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Idoso , Testes de Sensibilidade Microbiana , Carbapenêmicos/uso terapêutico , Carbapenêmicos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Adulto , Idoso de 80 Anos ou maisRESUMO
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.
Assuntos
Antibacterianos , Bacteriemia , Técnicas de Diagnóstico Molecular , Humanos , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Masculino , Pessoa de Meia-Idade , Feminino , Idoso , Antibacterianos/uso terapêutico , Técnicas de Diagnóstico Molecular/métodos , Unidades de Terapia Intensiva , Cuidados Críticos/métodos , Diagnóstico Precoce , Reação em Cadeia da Polimerase Multiplex/métodos , Hemocultura/métodos , Estudos Retrospectivos , Estado Terminal , Tempo de InternaçãoRESUMO
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.
Assuntos
Candida , Candidemia , Humanos , Candidemia/diagnóstico , Candidemia/microbiologia , Candida/isolamento & purificação , Candida/classificação , Sensibilidade e Especificidade , Hemocultura/métodosRESUMO
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.
Assuntos
Antibacterianos , Hemocultura , Testes de Sensibilidade Microbiana , Testes de Sensibilidade Microbiana/métodos , Humanos , Hemocultura/métodos , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/isolamento & purificação , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/classificação , Bacteriemia/microbiologia , Fatores de TempoRESUMO
Rapid and reliable identification of the causal organism in bloodstream infections and sepsis is crucial for both individual patient care and public health. We have implemented a rapid in-house identification protocol (with 10 % Triton) using MALDI-TOF MS for identifying the causative organism in positive blood cultures without prior culture. Our objective was to retrospectively analyze data collected over a four-year period while implementing this rapid in-house identification protocol and to develop a guide for evaluating and reporting the obtained results. Overall, our method utilizing MALDI-TOF MS for rapid in-house identification, demonstrated comparable results to other commercially available and in-house methods reported in the literature. Over the past four years, direct identification has facilitated the distinction between clinically relevant positive blood cultures and irrelevant ones, guiding rapid focus control and appropriate antibiotic treatment. The established guide can serve as a valuable tool in reporting positive blood cultures and associated antibiotic treatments.
Assuntos
Bacteriemia , Hemocultura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fluxo de Trabalho , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , Hemocultura/métodos , Estudos Retrospectivos , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bactérias/isolamento & purificação , Bactérias/classificação , Octoxinol , Sepse/diagnóstico , Sepse/microbiologiaRESUMO
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.
Assuntos
Algoritmos , Hemocultura , Humanos , Hemocultura/métodos , Criança , Pré-Escolar , Peso Corporal , Lactente , Masculino , Feminino , Recém-Nascido , Bacteriemia/diagnóstico , Bacteriemia/microbiologiaRESUMO
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.
Assuntos
Bacteriemia , Hemocultura , Estado Terminal , Unidades de Terapia Intensiva Pediátrica , Humanos , Pré-Escolar , Unidades de Terapia Intensiva Pediátrica/estatística & dados numéricos , Estudos Retrospectivos , Criança , Lactente , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Bacteriemia/sangue , Masculino , Feminino , Adolescente , Fatores de Tempo , Recém-Nascido , Adulto JovemRESUMO
INTRODUCTION: This study explored the efficacy of repeat blood cultures in bacteremic acute myeloid leukemia (AML) patients following allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: This was a retrospective study of AML patients who experienced febrile neutropenia (FN) and bacteremia following HSCT at the Taussig Cancer Center from January 1, 2019, to December 31, 2022. The primary endpoint was the rate of positive repeat blood cultures following initial positive blood culture. RESULTS: Fifty patients were included in the study. There were 50 occurrences of FN with positive initial blood cultures that were diagnosed following HSCT. Fifty initial sets of blood cultures and 96 sets of repeat blood cultures were drawn between the 50 occurrences of FN. Twelve of 96 (12.5%) repeat blood culture sets were positive for a pathogen, which occurred over nine of 50 (18.0%) episodes of FN. Three of 96 (3.2%) repeat blood culture sets grew a pathogen that differed from the pathogen that grew in the preceding positive blood culture. CONCLUSION: Among bacteremic AML patients in the post-HSCT period, the yield of repeat blood cultures for detecting previously detected and new pathogens was low.
Assuntos
Bacteriemia , Hemocultura , Neutropenia Febril , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Transplante Homólogo , Humanos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Bacteriemia/etiologia , Leucemia Mieloide Aguda/complicações , Leucemia Mieloide Aguda/terapia , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Neutropenia Febril/microbiologia , Neutropenia Febril/sangue , Adulto , Transplante Homólogo/efeitos adversos , Idoso , Adulto JovemRESUMO
We report discovery of a new bacterial genus and species of the family Pasteurellaceae by using phylogenetic and metabolic analysis. The bacterium, Emayella augustorita, was isolated from blood cultures of a patient in France diagnosed with an adenocarcinoma of the intestines and who was treated with a biliary prosthesis placement.
Assuntos
Hemocultura , Infecções por Pasteurellaceae , Pasteurellaceae , Filogenia , Sepse , Humanos , Pasteurellaceae/isolamento & purificação , Pasteurellaceae/genética , Pasteurellaceae/classificação , Infecções por Pasteurellaceae/microbiologia , Infecções por Pasteurellaceae/diagnóstico , Sepse/microbiologia , Sepse/diagnóstico , RNA Ribossômico 16S/genética , Masculino , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , França , IdosoRESUMO
Many methods are being tried for rapid and accurate identification of sepsis-causing microorganisms. We analyzed the performance of three different preparation methods [MBT Sepsityper IVD Kit (Bruker Daltonics GmbH, Germany), sodium dodecyl sulfate (SDS) lysis, and differential centrifugation with protein extraction (Centrifugation +PE)] and compared in standard and Sepsityper modules of the Bruker Biotyper MALDI-TOF MS for direct identification of bacteria from 240 positive blood culture bottles of BACTEC FX (Becton Dickinson, USA). By using the standard module, correct identification at species level (score ≥2) was done in 46.7% of the samples with SDS lysis, 44.2% with centrifugation +PE, and 25.4% with the Sepsityper kit. These ratios at the genus level (score range 1.70-1.99) were 34.6%, 31.3%, and 32.5%, respectively. With SDS lysis (195), more bacteria were identified correctly than centrifugation +PE (181) and the Sepsityper kit (139). A statistically significant difference was found between SDS and the Sepsityper kit and Centrifugation +PE and the Sepsityper kit (P < 0.001, both). By using the Sepsityper module, correct identification at species level (score ≥1.8) was determined in 74.2% of the samples with SDS lysis and centrifugation +PE each and 55% with the Sepsityper kit. These ratios at the genus level (score range 1.60-1.79) were 16.3%, 10%, and 19.2%, respectively. SDS lysis (217) had significantly higher identification rates than centrifugation +PE (202) and the Sepsityper kit (178) (P = 0.028 and P < 0.001). A statistically significant difference was also observed between centrifugation +PE and the Sepsityper kit (P < 0.001). Best performance was obtained with SDS lysis among the methods. Although better performance was achieved by using Sepsityper software module, risk of misidentification should not be ignored. IMPORTANCE: Sepsis is a life-threatening condition, and rapid and accurate identification of the causative microorganisms from blood cultures is crucial for timely and effective treatment. Although there are many studies on direct identification from blood cultures with MALDI-TOF MS, further standardization is still needed. In our study, we analyzed the performance of three different preparation methods and compared by using two analysis modules of the Bruker Biotyper MALDI-TOF MS for direct identification of bacteria from numerous positive blood culture bottles. The literature reports a limited number of studies that compare different preparation methods for direct blood culture identification, processing a large number of blood samples concurrently and evaluating the same samples as in our study. Moreover, although SDS is used very frequently in medical laboratories, there are few studies on direct identification from blood culture bottles. In our study, the highest correct identification rate was observed with the SDS method.
Assuntos
Bactérias , Hemocultura , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Humanos , Hemocultura/métodos , Bactérias/isolamento & purificação , Bactérias/classificação , Sepse/diagnóstico , Sepse/microbiologia , Técnicas Bacteriológicas/métodos , Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Centrifugação/métodosRESUMO
PURPOSE: To evaluate the performance of a rapid multiplex microarray-based method (Unyvero BCU system, BCU) to identify microorganisms and detect antimicrobial resistance directly from positive blood culture (BC) bottles with polymicrobial growth, and to assess relevance of information provided for timely guidance of polymicrobial bloodstream infection treatment. METHODS: Accuracy, time-to-actionable results and potential impact of BCU on antimicrobial treatment were compared with those of standard of care during a prospective study for the sample analysis (November 2017-November 2018) and a retrospective study for the clinical data analysis and the time-to-result analysis. The study was complemented with an experimental study, based on spiked blood cultures to assess the ability of the method to detect antimicrobial resistance genes. RESULTS: Sixty-five clinical polymicrobial BC samples (163 total microorganisms) and 30 simulated polymicrobial BC samples (60 strains) were included. BCU reported 84.6% samples as polymicrobial, correctly identified all the bacteria of the mix for 72.3% samples (47/65) and detected bacteria that were missed by the conventional culture for 13.8% samples. All identifications and antimicrobial resistances were accurately detected for 61.5% (40/65) samples. Limitations concerned the detection of anaerobes, enterococci and enterobacterial susceptibility to third generation cephalosporins. BCU results would have guided antimicrobial treatment for 50.8% of the cases (33/65) in a timely and relevant manner, had no impact for 27.7% (18/65) and been misleading for 18.5% (12/65). CONCLUSIONS: Despite some limitations, the Unyvero BCU system is a rapid and reliable method for polymicrobial BC sample analysis.
Assuntos
Bacteriemia , Bactérias , Hemocultura , Coinfecção , Reação em Cadeia da Polimerase Multiplex , Humanos , Bacteriemia/tratamento farmacológico , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Coinfecção/tratamento farmacológico , Coinfecção/microbiologia , Estudos Retrospectivos , Estudos Prospectivos , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/classificação , Reação em Cadeia da Polimerase Multiplex/métodos , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Farmacorresistência Bacteriana , Masculino , Feminino , Pessoa de Meia-Idade , IdosoRESUMO
To have an impact on the mortality of bloodstream infections, microbiological diagnostics of blood cultures (BC) should provide first results within 12 h. Here, we show how a decentralized BC incubation connected to the central BC incubators via a browser-based application significantly reduces turnaround times.
Assuntos
Hemocultura , Hemocultura/métodos , Humanos , Técnicas Microbiológicas/métodos , Bacteriemia/microbiologia , Bacteriemia/diagnóstico , Fatores de TempoRESUMO
Introduction: The diagnosis of tuberculosis (TB) disease and TB infection (TBI) remains a challenge, and there is a need for non-invasive and blood-based methods to differentiate TB from conditions mimicking TB (CMTB), TBI, and healthy controls (HC). We aimed to determine whether combination of cytokines and established biomarkers could discriminate between 1) TB and CMTB 2) TB and TBI 3) TBI and HC. Methods: We used hemoglobin, total white blood cell count, neutrophils, monocytes, C-reactive protein, and ten Meso Scale Discovery analyzed cytokines (interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon (IFN)-É£, and tumor necrosis factor (TNF)-α) in TruCulture whole blood tubes stimulated by lipopolysaccharides (LPS), zymosan (ZYM), anti-CD3/28 (CD3), and unstimulated (Null) to develop three index tests able to differentiate TB from CMTB and TBI, and TBI from HC. Results: In 52 persons with CMTB (n=9), TB (n=23), TBI (n=10), and HC (n=10), a combination of cytokines (LPS-IFN-É£, ZYM-IFN-É£, ZYM-TNF-α, ZYM-IL-1ß, LPS-IL-4, and ZYM-IL-6) and neutrophil count could differentiate TB from CMTB with a sensitivity of 52.2% (95% CI: 30.9%-73.4%) and a specificity of 100 % (66.4%-100%). Null- IFN-É£, Null-IL-8, CD3-IL-6, CD3-IL-8, CD3-IL-13, and ZYM IL-1b discriminated TB from TBI with a sensitivity of 73.9% (56.5% - 91.3%) and a specificity of 100% (69.2-100). Cytokines and established biomarkers failed to differentiate TBI from HC with ≥ 98% specificity. Discussion: Selected cytokines may serve as blood-based add-on tests to detect TB in a low-endemic setting, although these results need to be validated.
Assuntos
Biomarcadores , Hemocultura , Citocinas , Tuberculose , Humanos , Citocinas/sangue , Masculino , Feminino , Adulto , Biomarcadores/sangue , Tuberculose/diagnóstico , Tuberculose/imunologia , Tuberculose/sangue , Pessoa de Meia-Idade , Diagnóstico Diferencial , Adulto Jovem , Idoso , Mycobacterium tuberculosis/imunologia , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Early and appropriate antibiotic treatment improves the clinical outcome of patients with sepsis. There is an urgent need for rapid identification (ID) and antimicrobial susceptibility testing (AST) of bacteria that cause bloodstream infection (BSI). Rapid ID and AST can be achieved by short-term incubation on solid medium of positive blood cultures using MALDI-TOF mass spectrometry (MS) and the BD M50 system. The purpose of this study is to evaluate the performance of rapid method compared to traditional method. METHODS: A total of 124 mono-microbial samples were collected. Positive blood culture samples were short-term incubated on blood agar plates and chocolate agar plates for 5 â¼ 7 h, and the rapid ID and AST were achieved through Zybio EXS2000 MS and BD M50 System, respectively. RESULTS: Compared with the traditional 24 h culture for ID, this rapid method can shorten the cultivation time to 5 â¼ 7 h. Accurate organism ID was achieved in 90.6% of Gram-positive bacteria (GP), 98.5% of Gram-negative bacteria (GN), and 100% of fungi. The AST resulted in the 98.5% essential agreement (EA) and 97.1% category agreements (CA) in NMIC-413, 99.4% EA and 98.9% CA in PMIC-92, 100% both EA and CA in SMIC-2. Besides, this method can be used for 67.2% (264/393) of culture bottles during routine work. The mean turn-around time (TAT) for obtaining final results by conventional method is approximately 72.6 ± 10.5 h, which is nearly 24 h longer than the rapid method. CONCLUSIONS: The newly described method is expected to provide faster and reliable ID and AST results, making it an important tool for rapid management of blood cultures (BCs). In addition, this rapid method can be used to process most positive blood cultures, enabling patients to receive rapid and effective treatment.