scholarly journals Beyond Blood Culture and Gram Stain Analysis: A Review of Molecular Techniques for the Early Detection of Bacteremia in Surgical Patients

2016 ◽  
Vol 17 (3) ◽  
pp. 294-302 ◽  
Author(s):  
Michelle H. Scerbo ◽  
Heidi B. Kaplan ◽  
Anahita Dua ◽  
Douglas B. Litwin ◽  
Catherine G. Ambrose ◽  
...  
Keyword(s):  
Blood Culture ◽  
Early Detection ◽  
Molecular Techniques ◽  
Surgical Patients ◽  
Gram Stain ◽  
Stain Analysis

scholarly journals Rationale for Early Detection of EWSR1 Translocation-Associated Sarcoma Biomarkers in Liquid Biopsy

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 824
Author(s):  
Felix I. L. Clanchy
Keyword(s):  
Early Detection ◽  
Liquid Biopsy ◽  
Residual Disease ◽  
Surgical Excision ◽  
Molecular Techniques ◽  
Rt Pcr ◽  
Liquid Biopsies ◽  
Societal Burden ◽  
Recent Developments ◽  
Mesenchymal Tumours

Sarcomas are mesenchymal tumours that often arise and develop as a result of chromosomal translocations, and for several forms of sarcoma the EWSR1 gene is a frequent translocation partner. Sarcomas are a rare form of malignancy, which arguably have a proportionally greater societal burden that their prevalence would suggest, as they are more common in young people, with survivors prone to lifelong disability. For most forms of sarcoma, histological diagnosis is confirmed by molecular techniques such as FISH or RT-PCR. Surveillance after surgical excision, or ablation by radiation or chemotherapy, has remained relatively unchanged for decades, but recent developments in molecular biology have accelerated the progress towards routine analysis of liquid biopsies of peripheral blood. The potential to detect evidence of residual disease or metastasis in the blood has been demonstrated by several groups but remains unrealized as a routine diagnostic for relapse during remission, for disease monitoring during treatment, and for the detection of occult, residual disease at the end of therapy. An update is provided on research relevant to the improvement of the early detection of relapse in sarcomas with EWSR1-associated translocations, in the contexts of biology, diagnosis, and liquid biopsy.

Comparison of the accuracy of some laboratory parameters with blood culture for early detection of neonatal sepsis at Zagazig university children hospital.

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Basma Talaat Gad Elmahdy ◽  
Atef Mohammed Mohammed khalil ◽  
Doaa Metwaly AbdElmonem ◽  
Ali Abd Elhameed Abdo
Keyword(s):  
Blood Culture ◽  
Early Detection ◽  
Neonatal Sepsis ◽  
Laboratory Parameters

scholarly journals Evaluation of MRSASelect™Chromogenic Medium for the Early Detection of Methicillin-ResistantStaphylococcus aureusfrom Blood Cultures

2013 ◽  
Vol 24 (4) ◽  
pp. e113-e116 ◽  
Author(s):  
Kanchana Manickam ◽  
Andrew Walkty ◽  
Philippe RS Lagacé-Wiens ◽  
Heather Adam ◽  
Barbara Swan ◽  
...  
Keyword(s):  
Early Detection ◽  
Antimicrobial Therapy ◽  
Predictive Value ◽  
Turnaround Time ◽  
Blood Cultures ◽  
Gram Stain ◽  
Chromogenic Medium ◽  
Gram Positive ◽  
Microbiological Methods ◽  
Gram Positive Cocci

INTRODUCTION:Staphylococcus aureusbacteremia is associated with considerable morbidity and mortality. In theory, reducing the turnaround time in reporting of methicillin-resistantS aureus(MRSA) among patients with bactermia could assist with the rapid optimization of antimicrobial therapy.OBJECTIVE: To evaluate the sensitivity and specificity of MRSASelect(Bio-Rad Laboratories, USA), a chromogenic medium, in the early detection of MRSA from blood cultures growing Gram-positive cocci in clusters, and to confirm that routine use of this medium would, in fact, reduce turnaround time for MRSA identification.METHODS: The present study was conducted at three microbiology laboratories in Manitoba. Between April 2010 and May 2011, positive blood cultures with Gram-positive cocci in clusters visualized on Gram stain were subcultured to both MRSASelectand routine media. MRSA isolates were identified using conventional microbiological methods from routine media and using growth with the typical colony morphology (pink colony) on MRSASelectmedium.RESULTS: A total of 490 blood cultures demonstrating Gram-positive cocci in clusters on Gram stain were evaluated.S aureuswas recovered from 274 blood cultures, with 51S aureusisolates (51 of 274 [18.6%]) identified as MRSA. MRSASelectmedium had a sensitivity of 98%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 99.8% for the recovery and identification of MRSA directly from positive blood culture bottles. In addition, use of MRSASelectmedium was found to improve turnaround time in the detection of MRSA by almost 24 h relative to conventional methods.DISCUSSION: These data support the utility of MRSASelectmedium for the rapid identification of MRSA from positive blood cultures. Further clinical studies are warranted to determine whether the improvement in turnaround time will result in a measurable reduction in suboptimal antimicrobial therapy and/or improvement in patient outcome.

scholarly journals Classical Microbiological Diagnostics of Bacteremia: Are the Negative Results Really Negative? What is the Laboratory Result Telling Us About the “Gold Standard”?

2020 ◽  
Vol 8 (3) ◽  
pp. 346
Author(s):  
Tomasz Źródłowski ◽  
Joanna Sobońska ◽  
Dominika Salamon ◽  
Isabel M. McFarlane ◽  
Mirosław Ziętkiewicz ◽  
...  
Keyword(s):  
Blood Culture ◽  
Healthy Volunteers ◽  
Culture Method ◽  
Blood Cultures ◽  
Gram Stain ◽  
Blood Samples ◽  
Negative Results ◽  
Gram Staining ◽  
Study Results

Standard blood cultures require at least 24–120 h to be reported as preliminary positive. The objective of this study was to compare the reliability of Gram staining and fluorescent in-situ hybridization (FISH) for detecting bacteria in otherwise negative blood culture bottles. Ninety-six sets were taken from patients with a diagnosis of sepsis. Six incomplete blood culture sets and eight blood cultures sets demonstrating positive growth were excluded. We performed Gram stain and FISH on 82 sets taken from post-operative septic patients: 82 negative aerobic blood cultures, 82 anaerobic blood cultures, and 82 blood samples, as well as 57 blood samples taken from healthy volunteers. From the eighty-two blood sets analyzed from the septic patients, Gram stain visualized bacteria in 62.2% of blood samples, 35.4% of the negative aerobic bottles, and in 31.7% of the negative anaerobic bottles. Utilizing FISH, we detected bacteria in 75.6%, 56.1%, and 64.6% respectively. Among the blood samples from healthy volunteers, FISH detected bacteria in 64.9%, while Gram stain detected bacteria in only 38.6%. The time needed to obtain the study results using Gram stain was 1 h, for FISH 4 h, and for the culture method, considering the duration of growth, 5 days. Gram stain and FISH allow quick detection of bacteria in the blood taken directly from a patient. Finding phagocytosed bacteria, which were also detected among healthy individuals, confirms the hypothesis that blood microbiome exists.

scholarly journals Early detection of extended-spectrum β-lactamase from blood culture positive for an Enterobacteriaceae using βLACTA test

2015 ◽  
Vol 8 ◽  
pp. 1-3 ◽  
Author(s):  
Guy Prod'hom ◽  
Christian Durussel ◽  
Dominique Blanc ◽  
Antony Croxatto ◽  
Gilbert Greub
Keyword(s):  
Blood Culture ◽  
Early Detection ◽  
Extended Spectrum ◽  
Culture Positive

scholarly journals Automated Interpretation of Blood Culture Gram Stains by Use of a Deep Convolutional Neural Network

2017 ◽  
Vol 56 (3) ◽  
Author(s):  
Kenneth P. Smith ◽  
Anthony D. Kang ◽  
James E. Kirby
Keyword(s):  
Neural Network ◽  
Blood Culture ◽  
Convolutional Neural Network ◽  
Clinical Laboratory ◽  
Clinical Microbiology Laboratory ◽  
Proof Of Concept ◽  
Gram Stain ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Cocci

ABSTRACTMicroscopic interpretation of stained smears is one of the most operator-dependent and time-intensive activities in the clinical microbiology laboratory. Here, we investigated application of an automated image acquisition and convolutional neural network (CNN)-based approach for automated Gram stain classification. Using an automated microscopy platform, uncoverslipped slides were scanned with a 40× dry objective, generating images of sufficient resolution for interpretation. We collected 25,488 images from positive blood culture Gram stains prepared during routine clinical workup. These images were used to generate 100,213 crops containing Gram-positive cocci in clusters, Gram-positive cocci in chains/pairs, Gram-negative rods, or background (no cells). These categories were targeted for proof-of-concept development as they are associated with the majority of bloodstream infections. Our CNN model achieved a classification accuracy of 94.9% on a test set of image crops. Receiver operating characteristic (ROC) curve analysis indicated a robust ability to differentiate between categories with an area under the curve of >0.98 for each. After training and validation, we applied the classification algorithm to new images collected from 189 whole slides without human intervention. Sensitivity and specificity were 98.4% and 75.0% for Gram-positive cocci in chains and pairs, 93.2% and 97.2% for Gram-positive cocci in clusters, and 96.3% and 98.1% for Gram-negative rods. Taken together, our data support a proof of concept for a fully automated classification methodology for blood-culture Gram stains. Importantly, the algorithm was highly adept at identifying image crops with organisms and could be used to present prescreened, classified crops to technologists to accelerate smear review. This concept could potentially be extended to all Gram stain interpretive activities in the clinical laboratory.

scholarly journals Evaluation of broad-range 16S rRNA PCR for the diagnosis of bloodstream infections: two years of experience

2014 ◽  
Vol 8 (10) ◽  
pp. 1252-1258 ◽  
Author(s):  
Reem Mostafa Hassan ◽  
Mervat G El Enany ◽  
Hussien H Rizk
Keyword(s):  
Blood Culture ◽  
16S Rrna ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Bloodstream Infections ◽  
Molecular Techniques ◽  
Molecular Technique ◽  
High Negative Predictive Value ◽  
Patient Groups ◽  
Low Sensitivity

Introduction: Diagnosis of bloodstream infections using bacteriological cultures suffers from low sensitivity and reporting delay. Advanced molecular techniques introduced in many laboratories provide rapid results and may show improvements in patient outcomes. This study aimed to evaluate the usefulness of a molecular technique, broad-range 16S rRNA PCR followed by sequencing for the diagnosis of bloodstream infections, compared to blood culture in different patient groups. Methodology: Conventional PCR was performed, using broad-range 16S rRNA primers, on blood cultures collected from different patients with suspected bloodstream infections; results were compared with those of blood culture. Results: Though blood culture is regarded as the gold standard, PCR evaluation showed sensitivity of 86.25%, specificity of 91.25%, positive predictive value of 76.67%, negative predictive value of 95.22%, and accuracy of 88.8%. Conclusions: Molecular assays seem not to be sufficient to replace microbial cultures in the diagnosis of bloodstream infections, but they can offer a rapid, good negative test to rule out infection due to their high negative predictive value.

scholarly journals How Can the Microbiologist Help in Diagnosing Neonatal Sepsis?

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Michela Paolucci ◽  
Maria Paola Landini ◽  
Vittorio Sambri
Keyword(s):  
Blood Culture ◽  
Neonatal Sepsis ◽  
Gold Standard ◽  
Early Onset ◽  
Late Onset ◽  
Molecular Techniques ◽  
Diagnosis And Treatment ◽  
Diagnosis And Management ◽  
Sepsis Diagnosis ◽  
Expected Outcomes

Neonatal sepsis can be classified into two subtypes depending upon whether the onset of symptoms is before 72 hours of life (early-onset neonatal sepsis—EONS) or later (late-onset neonatal sepsis—LONS). These definitions have contributed greatly to diagnosis and treatment by identifying which microorganisms are likely to be responsible for sepsis during these periods and the expected outcomes of infection. This paper focuses on the tools that microbiologist can offer to diagnose and eventually prevent neonatal sepsis. Here, we discuss the advantages and limitation of the blood culture, the actual gold standard for sepsis diagnosis. In addition, we examine the utility of molecular techniques in the diagnosis and management of neonatal sepsis.

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