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1.
Crit Care Explor ; 6(7): e1115, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38968174

ABSTRACT

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.


Subject(s)
Bacteremia , Blood Culture , Critical Illness , Intensive Care Units, Pediatric , Humans , Child, Preschool , Intensive Care Units, Pediatric/statistics & numerical data , Retrospective Studies , Child , Infant , Bacteremia/diagnosis , Bacteremia/microbiology , Bacteremia/blood , Male , Female , Adolescent , Time Factors , Infant, Newborn , Young Adult
2.
Diagn Microbiol Infect Dis ; 110(1): 116384, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39002446

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Bacteremia , Blood Culture , Time-to-Treatment , Blood Culture/methods , Blood Culture/statistics & numerical data , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteremia/microbiology , Time-to-Treatment/statistics & numerical data , Anti-Bacterial Agents/administration & dosage , Drug Prescriptions/statistics & numerical data , Retrospective Studies , Humans , Male , Female , Young Adult , Adult , Middle Aged , Aged , Aged, 80 and over
3.
Diagn Microbiol Infect Dis ; 110(1): 116436, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39003931

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Blood Culture , Microbial Sensitivity Tests , Microbial Sensitivity Tests/methods , Humans , Blood Culture/methods , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/isolation & purification , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/isolation & purification , Bacteria/drug effects , Bacteria/isolation & purification , Bacteria/classification , Bacteremia/microbiology , Time Factors
4.
Diagn Microbiol Infect Dis ; 110(1): 116412, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39018932

ABSTRACT

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.


Subject(s)
Bacteremia , Blood Culture , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Workflow , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Humans , Blood Culture/methods , Retrospective Studies , Bacteremia/diagnosis , Bacteremia/microbiology , Bacteria/isolation & purification , Bacteria/classification , Octoxynol , Sepsis/diagnosis , Sepsis/microbiology
5.
J Antimicrob Chemother ; 79(8): 2053-2061, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38958258

ABSTRACT

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.


Subject(s)
Bacteremia , Gram-Negative Bacterial Infections , Humans , Bacteremia/epidemiology , Bacteremia/microbiology , Bacteremia/mortality , Retrospective Studies , Male , Female , Middle Aged , Aged , Ontario/epidemiology , Gram-Negative Bacterial Infections/epidemiology , Gram-Negative Bacterial Infections/mortality , Gram-Negative Bacterial Infections/microbiology , Risk Factors , Gram-Negative Bacteria/isolation & purification , Adult , Blood Culture , Cross Infection/epidemiology , Cross Infection/microbiology , Cross Infection/mortality , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Clinical Relevance
6.
Curr Microbiol ; 81(8): 261, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38981918

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Blood Culture , Gram-Negative Bacteria , Microbial Sensitivity Tests , Microbial Sensitivity Tests/methods , Humans , Blood Culture/methods , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Bacteremia/microbiology , Time Factors , Gram-Negative Bacterial Infections/microbiology
7.
BMC Pediatr ; 24(1): 438, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38982359

ABSTRACT

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.


Subject(s)
Algorithms , Blood Culture , Humans , Blood Culture/methods , Child , Child, Preschool , Body Weight , Infant , Male , Female , Infant, Newborn , Bacteremia/diagnosis , Bacteremia/microbiology
8.
Diagn Microbiol Infect Dis ; 110(1): 116424, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38996775

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Bacteremia , Molecular Diagnostic Techniques , Humans , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacteremia/microbiology , Male , Middle Aged , Female , Aged , Anti-Bacterial Agents/therapeutic use , Molecular Diagnostic Techniques/methods , Intensive Care Units , Critical Care/methods , Early Diagnosis , Multiplex Polymerase Chain Reaction/methods , Blood Culture/methods , Retrospective Studies , Critical Illness , Length of Stay
9.
Diagn Microbiol Infect Dis ; 110(1): 116406, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39002449

ABSTRACT

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.


Subject(s)
Candida , Candidemia , Humans , Candidemia/diagnosis , Candidemia/microbiology , Candida/isolation & purification , Candida/classification , Sensitivity and Specificity , Blood Culture/methods
10.
BMC Infect Dis ; 24(1): 699, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39009969

ABSTRACT

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.


Subject(s)
Bacteremia , Blood Culture , Osteomyelitis , Humans , Male , Aged, 80 and over , Bacteremia/microbiology , Bacteremia/diagnosis , Bacteremia/drug therapy , Osteomyelitis/microbiology , Osteomyelitis/diagnosis , Osteomyelitis/drug therapy , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , RNA, Ribosomal, 16S/genetics , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/drug therapy , Gram-Negative Bacterial Infections/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics
11.
Acta Clin Belg ; 79(3): 168-173, 2024 Jun.
Article in English | MEDLINE | ID: mdl-39007879

ABSTRACT

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.


Subject(s)
Blood Culture , Blood Culture/methods , Blood Culture/instrumentation , Humans , Time Factors , Bacteremia/diagnosis , Bacteremia/microbiology , Bacteria/isolation & purification
12.
Microbiol Spectr ; 12(8): e0040224, 2024 Aug 06.
Article in English | MEDLINE | ID: mdl-38953323

ABSTRACT

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.


Subject(s)
Anti-Bacterial Agents , Bacteremia , Blood Culture , Enterobacteriaceae Infections , Hospital Mortality , Length of Stay , Humans , Length of Stay/statistics & numerical data , Retrospective Studies , Male , Female , Enterobacteriaceae Infections/mortality , Enterobacteriaceae Infections/drug therapy , Enterobacteriaceae Infections/microbiology , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Middle Aged , Bacteremia/mortality , Bacteremia/drug therapy , Bacteremia/microbiology , Aged , Microbial Sensitivity Tests , Carbapenems/therapeutic use , Carbapenems/pharmacology , Enterobacteriaceae/drug effects , Adult , Aged, 80 and over
13.
Transpl Infect Dis ; 26(4): e14345, 2024 Aug.
Article in English | MEDLINE | ID: mdl-39012614

ABSTRACT

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.


Subject(s)
Bacteremia , Blood Culture , Febrile Neutropenia , Hematopoietic Stem Cell Transplantation , Leukemia, Myeloid, Acute , Transplantation, Homologous , Humans , Hematopoietic Stem Cell Transplantation/adverse effects , Bacteremia/microbiology , Bacteremia/diagnosis , Bacteremia/etiology , Leukemia, Myeloid, Acute/complications , Leukemia, Myeloid, Acute/therapy , Retrospective Studies , Male , Female , Middle Aged , Febrile Neutropenia/microbiology , Febrile Neutropenia/blood , Adult , Transplantation, Homologous/adverse effects , Aged , Young Adult
15.
Emerg Infect Dis ; 30(8): 1719-1721, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38907366

ABSTRACT

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.


Subject(s)
Blood Culture , Pasteurellaceae Infections , Pasteurellaceae , Phylogeny , Sepsis , Humans , Pasteurellaceae/isolation & purification , Pasteurellaceae/genetics , Pasteurellaceae/classification , Pasteurellaceae Infections/microbiology , Pasteurellaceae Infections/diagnosis , Sepsis/microbiology , Sepsis/diagnosis , RNA, Ribosomal, 16S/genetics , Male , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Bacteremia/microbiology , Bacteremia/diagnosis , France , Aged
16.
Eur J Clin Microbiol Infect Dis ; 43(8): 1545-1557, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38834891

ABSTRACT

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.


Subject(s)
Bacteremia , Bacteria , Blood Culture , Coinfection , Multiplex Polymerase Chain Reaction , Humans , Bacteremia/drug therapy , Bacteremia/microbiology , Bacteremia/diagnosis , Coinfection/drug therapy , Coinfection/microbiology , Retrospective Studies , Prospective Studies , Bacteria/drug effects , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/classification , Multiplex Polymerase Chain Reaction/methods , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Microbial Sensitivity Tests , Drug Resistance, Bacterial , Male , Female , Middle Aged , Aged
17.
J Microbiol Methods ; 223: 106973, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38880388

ABSTRACT

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.


Subject(s)
Blood Culture , Blood Culture/methods , Humans , Microbiological Techniques/methods , Bacteremia/microbiology , Bacteremia/diagnosis , Time Factors
18.
Microbiol Spectr ; 12(8): e0063824, 2024 Aug 06.
Article in English | MEDLINE | ID: mdl-38940589

ABSTRACT

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.


Subject(s)
Bacteria , Blood Culture , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Humans , Blood Culture/methods , Bacteria/isolation & purification , Bacteria/classification , Sepsis/diagnosis , Sepsis/microbiology , Bacteriological Techniques/methods , Bacteremia/diagnosis , Bacteremia/microbiology , Centrifugation/methods
19.
J Microbiol Immunol Infect ; 57(4): 580-593, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38942661

ABSTRACT

BACKGROUND: The increasing prevalence of drug-resistant pathogens leads to delays in adequate antimicrobial treatment in intensive care units (ICU). The real-world influence of the BioFire FilmArray Blood Culture Identification 2 (BCID2) panel on pathogen identification, diagnostic concordance with conventional culture methods, and antimicrobial stewardship in the ICU remains unexplored. METHODS: This retrospective observational study, conducted from July 2021 to August 2023, involved adult ICU patients with positive blood cultures who underwent BCID2 testing. The concordance between BCID2 and conventional culture results was examined, and its impact on antimicrobial stewardship was assessed through a comprehensive retrospective review of patient records by intensivists. RESULTS: A total of 129 blood specimens from 113 patients were analysed. Among these patients, a high proportion of drug-resistant strains were noted, including carbapenem-resistant Klebsiella pneumoniae (CRKP) (57.1%), carbapenem-resistant Acinetobacter calcoaceticus-baumannii complex (100%), methicillin-resistant Staphylococcus aureus (MRSA) (70%), and vancomycin-resistant Enterococcus faecium (VRE) (100%). The time from blood culture collection to obtaining BCID2 results was significantly shorter than conventional culture (46.2 h vs. 86.9 h, p < 0.001). BCID2 demonstrated 100% concordance in genotype-phenotype correlation in antimicrobial resistance (AMR) for CRKP, carbapenem-resistant Escherichia coli, MRSA, and VRE. A total of 40.5% of patients received inadequate empirical antimicrobial treatment. The antimicrobial regimen was adjusted or confirmed in 55.4% of patients following the BCID2 results. CONCLUSIONS: In the context of a high burden of drug-resistant pathogens, BCID2 demonstrated rapid pathogen and AMR detection, with a noticeable impact on antimicrobial stewardship in BSI in the ICU.


Subject(s)
Anti-Bacterial Agents , Antimicrobial Stewardship , Blood Culture , Intensive Care Units , Humans , Retrospective Studies , Male , Female , Middle Aged , Aged , Blood Culture/methods , Anti-Bacterial Agents/therapeutic use , Anti-Bacterial Agents/pharmacology , Bacteremia/drug therapy , Bacteremia/microbiology , Bacteremia/diagnosis , Microbial Sensitivity Tests , Drug Resistance, Bacterial , Adult , Aged, 80 and over , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/isolation & purification , Bacteria/drug effects , Bacteria/isolation & purification , Bacteria/classification , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Sepsis/drug therapy , Sepsis/microbiology , Sepsis/diagnosis
20.
Front Cell Infect Microbiol ; 14: 1358801, 2024.
Article in English | MEDLINE | ID: mdl-38895732

ABSTRACT

Background: Rapid and accurate diagnosis of the causative agents is essential for clinical management of bloodstream infections (BSIs) that might induce sepsis/septic shock. A considerable number of suspected sepsis patients initially enter the health-care system through an emergency department (ED), hence it is vital to establish an early strategy to recognize sepsis and initiate prompt care in ED. This study aimed to evaluate the diagnostic performance and clinical value of droplet digital PCR (ddPCR) assay in suspected sepsis patients in the ED. Methods: This was a prospective single-centered observational study including patients admitted to the ED from 25 October 2022 to 3 June 2023 with suspected BSIs screened by Modified Shapiro Score (MSS) score. The comparison between ddPCR and blood culture (BC) was performed to evaluate the diagnostic performance of ddPCR for BSIs. Meanwhile, correlative analysis between ddPCR and the inflammatory and prognostic-related biomarkers were conducted to explore the relevance. Further, the health economic evaluation of the ddPCR was analyzed. Results: 258 samples from 228 patients, with BC and ddPCR performed simultaneously, were included in this study. We found that ddPCR results were positive in 48.13% (103 of 214) of episodes, with identification of 132 pathogens. In contrast, BC only detected 18 positives, 88.89% of which were identified by ddPCR. When considering culture-proven BSIs, ddPCR shows an overall sensitivity of 88.89% and specificity of 55.61%, the optimal diagnostic power for quantifying BSI through ddPCR is achieved with a copy cutoff of 155.5. We further found that ddPCR exhibited a high accuracy especially in liver abscess patients. Among all the identified virus by ddPCR, EBV has a substantially higher positive rate with a link to immunosuppression. Moreover, the copies of pathogens in ddPCR were positively correlated with various markers of inflammation, coagulation, immunity as well as prognosis. With high sensitivity and specificity, ddPCR facilitates precision antimicrobial stewardship and reduces health care costs. Conclusions: The multiplexed ddPCR delivers precise and quantitative load data on the causal pathogen, offers the ability to monitor the patient's condition and may serve as early warning of sepsis in time-urgent clinical situations as ED. Importance: Early detection and effective administration of antibiotics are essential to improve clinical outcomes for those with life-threatening infection in the emergency department. ddPCR, an emerging tool for rapid and sensitive pathogen identification used as a precise bedside test, has developed to address the current challenges of BSI diagnosis and precise treatment. It characterizes sensitivity, specificity, reproducibility, and absolute quantifications without a standard curve. ddPCR can detect causative pathogens and related resistance genes in patients with suspected BSIs within a span of three hours. In addition, it can identify polymicrobial BSIs and dynamically monitor changes in pathogenic microorganisms in the blood and can be used to evaluate antibiotic efficacy and survival prognosis. Moreover, the copies of pathogens in ddPCR were positively correlated with various markers of inflammation, coagulation, immunity. With high sensitivity and specificity, ddPCR facilitates precision antimicrobial stewardship and reduces health care costs.


Subject(s)
Early Diagnosis , Emergency Service, Hospital , Polymerase Chain Reaction , Sepsis , Humans , Prospective Studies , Sepsis/diagnosis , Sepsis/microbiology , Male , Female , Middle Aged , Aged , Polymerase Chain Reaction/methods , Sensitivity and Specificity , Biomarkers/blood , Blood Culture/methods , Adult
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