A new molecular method for rapid etiological diagnosis of sepsis with improved performance

2021 ◽  
Author(s):  
Shamanta Grosso ◽  
Lucia Pagani ◽  
Nilla Tosoni ◽  
Massimo Crapis ◽  
Enrico Turrini ◽  
...  
Keyword(s):  
Clinical Diagnosis ◽  
Real Time Pcr ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Molecular Method ◽  
Blood Samples ◽  
Etiological Diagnosis ◽  
Pcr Technology ◽  
Improved Performance ◽  
Pathogen Dna

The value of blood cultures for confirming the clinical diagnosis of sepsis is suboptimal. There is growing interest in the potential of real-time PCR technology by detection of minute amounts of pathogen DNA in patient blood samples with results available within 4–6 h. Adopting a two-step approach, we evaluated the compliance of two versions of the MicrobScan assay on a total of 748 patients with suspected bloodstream infections. The results obtained with a second version of the MicrobScan assay are characterized by increased specificity (from 95.1 to 98.2%) and sensitivity (from 76.7 to 85.1), increased throughput and the possibility of simultaneously testing different kinds of samples collected from the potential sites of infection and utilizing different syndromic panels.

scholarly journals 1341. Blood Volume Collected for Blood Cultures in Infants with Suspected Neonatal Sepsis in the NICU

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S682-S682
Author(s):  
Maria S Rueda Altez ◽  
Lamia Soghier ◽  
Joseph M Campos ◽  
James Bost ◽  
Jiaxiang Gai ◽  
...  
Keyword(s):  
Bloodstream Infection ◽  
Blood Volume ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Categorical Variables ◽  
Continuous Variables ◽  
Volume Calculation ◽  
Culture Negative ◽  
Time Of Collection ◽  
Rule Out

Abstract Background Blood cultures have high sensitivity to detect bacteremia in septic neonates when >=1 ml of blood is collected. Neonatologists often cite low confidence in microbiologic sampling as rationale for continuing antibiotics without a focus of infection despite negative blood cultures, resulting in prolonged antimicrobial therapy. We aim to describe the blood culture sample volumes in NICU patients, to identify factors associated with sample volumes < 1ml, and to compare the sample volumes of patients treated for culture-negative sepsis with those with bloodstream infections and those treated for a ≤72-hour sepsis rule-out Methods Data from this observational cohort study were collected retrospectively and prospectively from NICU patients with blood cultures obtained from September 2018 to February 2019. Clinical data were collected through chart review. All inoculated culture bottles were weighed for volume calculation. We determined the association of age, weight, sample source, and time of collection with volume < 1mL. Continuous variables were analyzed using Wilcoxon-Mann-Whitney, and categorical variables using chi-squared test. For aim 3, the volumes of the groups were compared using analysis of variance. Results A total of 310 blood cultures were identified, corresponding to 159 patients. Of these, 49 (16%) were positive. Among the negative blood cultures, 86% were collected in patients who subsequently received antibiotics (Figure 1). Median inoculated volume was 0.6 ml (IQR: 0.1-2.4). Weight and age at time of culture collection, source of sample, and time of collection were not significantly associated with the inoculation of < 1ml of blood. Median volume of blood was 0.6ml (0.3-0.6) for sepsis rule-out, 0.6ml (0.2-0.6) for bloodstream infection, and 0.6ml (0.6-1.4) for culture-negative sepsis. No difference was found among the three groups (p=0.54) Figure 1. Classification of blood cultures identified during study period Conclusion The blood volume collected for cultures in the NICU is lower than recommended. Clinical and environmental characteristics are not significantly associated with the inoculated volume. The volume of blood sampled does not differ in patients with culture-negative sepsis, bloodstream infection and sepsis rule-out, and should not be a justification for longer duration of antibiotic therapy Disclosures All Authors: No reported disclosures

Evaluation of standardized automated rapid antimicrobial susceptibility testing of Enterobacterales-containing blood cultures: a proof-of-principle study

2020 ◽  
Vol 75 (11) ◽  
pp. 3218-3229
Author(s):  
Stefano Mancini ◽  
Elias Bodendoerfer ◽  
Natalia Kolensnik-Goldmann ◽  
Sebastian Herren ◽  
Kim Röthlin ◽  
...  
Keyword(s):  
Standard Method ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Inhibition Zone ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Disc Diffusion ◽  
Inhibition Zones ◽  
Reading System

Abstract Background Rapid antimicrobial susceptibility testing (RAST) of bacteria causing bloodstream infections is critical for implementation of appropriate antibiotic regimens. Objectives We have established a procedure to prepare standardized bacterial inocula for Enterobacterales-containing clinical blood cultures and assessed antimicrobial susceptibility testing (AST) data generated with the WASPLabTM automated reading system. Methods A total of 258 blood cultures containing Enterobacterales were examined. Bacteria were enumerated by flow cytometry using the UF-4000 system and adjusted to an inoculum of 106 cfu/mL. Disc diffusion plates were automatically streaked, incubated for 6, 8 and 18 h and imaged using the fully automated WASPLabTM system. Growth inhibition zones were compared with those obtained with inocula prepared from primary subcultures following the EUCAST standard method. Due to time-dependent variations of the inhibition zone diameters, early AST readings were interpreted using time-adjusted tentative breakpoints and areas of technical uncertainty. Results and conclusions Inhibition zones obtained after 18 h incubation using an inoculum of 106 cfu/mL prepared directly from blood cultures were highly concordant with those of the EUCAST standard method based on primary subcultures, with categorical agreement (CA) of 95.8%. After 6 and 8 h incubation, 89.5% and 93.0% of the isolates produced interpretable results, respectively, with CA of >98.5% and very low numbers of clinical categorization errors for both the 6 h and 8 h readings. Overall, with the standardized and automated RAST method, consistent AST data from blood cultures containing Enterobacterales can be generated after 6–8 h of incubation and subsequently confirmed by standard reading of the same plate after 18 h.

scholarly journals Scanning Electron Microscope: A New Potential Tool to Replace Gram Staining for Microbe Identification in Blood Cultures

2021 ◽  
Vol 9 (6) ◽  
pp. 1170
Author(s):  
Gabriel Haddad ◽  
Sara Bellali ◽  
Tatsuki Takakura ◽  
Anthony Fontanini ◽  
Yusuke Ominami ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Blood Culture ◽  
Scanning Electron Microscope ◽  
Sample Preparation ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Preliminary Identification ◽  
Gram Staining ◽  
Micro Organisms ◽  
Scanning Electron

Blood culture is currently the most commonly used method for diagnosing sepsis and bloodstream infections. However, the long turn-around-time to achieve microbe identification remains a major concern for clinical microbiology laboratories. Gram staining for preliminary identification remains the gold standard. We developed a new rapid strategy using a tabletop scanning electron microscope (SEM) and compared its performance with Gram staining for the detection of micro-organisms and preliminary identification directly from blood cultures. We first optimised the sample preparation for twelve samples simultaneously, saving time on imaging. In this work, SEM proved its ability to identify bacteria and yeasts in morphotypes up to the genus level in some cases. We blindly tested 1075 blood cultures and compared our results to the Gram staining preliminary identification, with MALDI-TOF/MS as a reference. This method presents major advantages such as a fast microbe identification, within an hour of the blood culture being detected positive, low preparation costs, and data traceability. This SEM identification strategy can be developed into an automated assay from the sample preparation, micrograph acquisition, and identification process. This strategy could revolutionise urgent microbiological diagnosis of infectious diseases.

scholarly journals 53. Incidence of Bloodstream Infections and Outcomes in Patients with Severe COVID-19 Pneumonia

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S156-S157
Author(s):  
Aikaterini Papamanoli ◽  
Jeanwoo Yoo ◽  
Azad Mojahedi ◽  
Robin Jacob ◽  
Prabhjot Grewal ◽  
...  
Keyword(s):  
Length Of Stay ◽  
Medical Records ◽  
Bloodstream Infections ◽  
Blood Stream ◽  
Blood Cultures ◽  
High Flow ◽  
University Hospital ◽  
Skin Microbiota ◽  
Prolonged Recovery ◽  
The Impact

Abstract Background Coronavirus disease 19 (COVID-19) leading to acute respiratory distress syndrome is associated with need for intensive care (IC), mechanical ventilation (MV), and prolonged recovery. These patients are thus predisposed to blood stream infections which can worsen outcomes. This risk may be aggravated by adjunctive therapies. Methods We reviewed the medical records of all adults admitted to Stony Brook University Hospital, NY, from March 1 to April 15, 2020 with severe COVID-19 pneumonia (requiring high-flow O2). Patients who received MV or died within 24h were excluded. Patients were followed until death or hospital discharge. We reviewed positive blood cultures (PBC) for pathogenic microorganisms, and calculated the incidence of bacteremia, rates of infective endocarditis (IE), and impact on mortality. Microbes isolated only once and belonging to groups defined as commensal skin microbiota were labelled as contaminants. We also examined the impact of adjunctive therapies with immunosuppressive potential (steroids and tocilizumab), on bacteremia. Results A total of 469 patients with severe COVID-19 pneumonia were included (Table 1). Of these, 199 (42.4%) required IC and 172 (36.7%) MV. Median length of stay was 13 days (8–22) and 94 (20.0%) had PBC. Of these, 43 were considered true pathogens (bacteremia), with predominance of E. faecalis and S. epidermidis, and 51 were considered contaminants (Table 2). The incidence of bacteremia (43/469, 9.2%) was 5.1 per 1000 patient-days (95%CI 3.8–6.4). An echocardiogram was performed in 21 patients, 1 had an aortic valve vegetation (IE) by methicillin sensitive S. aureus. Bacteremia rates were nonsignificantly higher with steroids (5.9 vs 3.7 per 1000 patient-days; P=0.057). Use of tocilizumab was not associated with bacteremia (5.8 vs 4.8 per 1000 patient-days; P=0.28). Mortality was nonsignificantly higher in patients with (15/43, 34.9%) vs. without (108/426, 25.4%) bacteremia (P=0.20). Length of stay was the strongest predictor of bacteremia, with risk increasing by 7% (95%CI 6%-9%, P< 0.001) per additional day. Cohort Characteristics of Patients with Severe COVID-19 Pneumonia on High-Flow O2 (N= 469) All Microorganisms Isolated from Blood Cultures Conclusion The incidence of bacteremia was relatively low and IE was uncommon in this study of severe COVID-19 patients. Risk of bacteremia increased with longer hospital stay and with steroids use, but not with tocilizumab. Disclosures All Authors: No reported disclosures

Qualitative versus quantitative blood cultures in the diagnosis of catheter-related bloodstream infections in children with malignancy

2005 ◽  
Vol 45 (7) ◽  
pp. 939-944 ◽  
Author(s):  
Ioannis Germanakis ◽  
Athanasia Christidou ◽  
Emmanouil Galanakis ◽  
Iraklis Kyriakakis ◽  
Yiannis Tselentis ◽  
...  
Keyword(s):  
Bloodstream Infections ◽  
Blood Cultures
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