Blood stream infection (BSI),a blood-borne disease caused by microorganisms such as bacteria,fungi,and viruses,can lead to bacteremia,sepsis,and infectious shock,posing a serious threat to human life and health.Identifying the pathogen is central to the precise treatment of BSI.Traditional blood culture is the gold standard for pathogen identification,while it has limitations in clinical practice due to the long time consumption,production of false negative results,etc.Nanopore sequencing,as a new generation of sequencing technology,can rapidly detect pathogens,drug resistance genes,and virulence genes for the optimization of clinical treatment.This paper reviews the current status of nanopore sequencing technology in the diagnosis of BSI.
Humans ; Nanopore Sequencing ; Sepsis/diagnosis* ; Bacteremia/microbiology* ; Bacteria ; Blood Culture/methods*

PURPOSE: Procalcitonin (PCT) is a current, frequently used marker for severe bacterial infection. The aim of this study was to assess the ability of PCT levels to differentiate bacteremic from nonbacteremic patients with fever. We assessed whether PCT level could be used to accurately rule out a diagnosis of bacteremia. MATERIALS AND METHODS: Serum samples and blood culture were obtained from patients with fever between August 2008 and April 2009. PCT was analyzed using a VIDAS(R) B.R.A.H.M.S PCT assay. We reviewed the final diagnosis and patient histories, including clinical presentation and antibiotic treatment. RESULTS: A total of 300 patients with fevers were enrolled in this study: 58 with bacteremia (positive blood culture) (group I); 137 with local infection (group II); 90 with other diseases (group III); and 15 with fevers of unknown origin (group IV). PCT levels were significantly higher in patients with bacteremia than in those with non-bacteremia (11.9 +/- 25.1 and 2.5 +/- 14.7 ng/mL, respectively, p < 0.001). The sensitivity and specificity were 74.2% and 70.1%, respectively, at a cut-off value of 0.5 ng/mL. A serum PCT level of < 0.4 ng/mL accurately rules out diagnosis of bacteremia. CONCLUSION: In febrile patients, elevated PCT may help predict bacteremia; furthermore, low PCT levels were helpful for ruling out bacteremia as a diagnosis. Therefore, PCT assessment could help physicians limit the number of prescriptions for antibiotics.
Bacteremia/blood/*diagnosis ; Biological Markers/blood ; C-Reactive Protein/analysis ; Calcitonin/*blood ; Early Diagnosis ; Female ; Fever/blood/*diagnosis/etiology ; Fever of Unknown Origin/blood/diagnosis/microbiology ; Humans ; Male ; Middle Aged ; Protein Precursors/*blood ; Sensitivity and Specificity ; Young Adult

INTRODUCTIONThe aim of this study was to externally validate the Cham score for the prediction of bacteraemia in emergency department (ED) patients with non-hospital acquired pneumonia.

MATERIALS AND METHODSThis is a secondary analysis of a dataset collected to identify independent predictors of bacteraemia in adult ED patients with non-hospital acquired pneumonia. The primary outcome of interest was the predictive performance (sensitivity, specificity, negative predictive value) of the score with respect to bacteraemia. Secondary outcomes included the performance of the score in patients not known to be intravenous (IV) drug users, the predictive performance of pneumonia severity index (PSI) class IV/V and PSI class IV/V or IV drug use as predictors and the clinical impact of score application on test ordering. Data analysis was by clinical performance and receiver operator characteristic curve analysis.

RESULTSA total of 200 patients were studied; 14 true positive blood cultures (7%, 95% CI, 4% to 11%). The Cham score had a sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 26.3% (95% CI, 20.3% to 33.4%) and negative predictive value (NPV) of 98% (87.0% to 99.9%). Area under the receiver operating characteristic (ROC) curve was 0.71 (95% CI, 0.56 to 0.86). Using PSI class IV/V or known IV drug use as predictors had sensitivity of 92.9% (95% CI, 64.2% to 99.6%), specificity of 51.1% (95% CI, 43.7% to 58.4%) and NPV of 99% (95% CI, 93.5% to 99.9%).

CONCLUSIONIn retrospective external validation, the Cham score performed better than in derivation with acceptable sensitivity and NPV. Simplified criteria (PSI class IV/V or known IV drug use), as yet not validated, had similar sensitivity and NPV but would avoid blood cultures in a higher proportion of patients.

Aged ; Aged, 80 and over ; Bacteremia ; blood ; diagnosis ; Bacteriological Techniques ; utilization ; Emergency Service, Hospital ; Female ; Hematologic Tests ; utilization ; Humans ; Male ; Middle Aged ; Pneumonia, Bacterial ; blood ; microbiology ; Retrospective Studies

This study was purposed to evaluate the diagnostic value of procalcitonin (PCT), C-reactive protein, interleukin-6 (IL-6), serum amyloid A (SAA) for bacteremia in patients with hematologic malignancy combined with febrile neutropenia. The total of 297 patients with hematologic malignancy combined with febrile neutropenia were analyzed retrospectively from 1253 patients admitted to West China hospital of Sichuan University from March 2011 to October 2012. They were divided into sepsis group (n = 95) and non-sepsis group (n = 202) according to blood culture. The results showed that the levels of PCT, CRP, IL-6 and SAA in sepsis group were higher than those in non-sepsis group, and there was statistically significant difference between these two groups (P < 0.05). The PCT had an AUC value of 0.974 (P < 0.05), and obviously higher than that of CRP (AUC = 0.681, P < 0.05), IL-6 (AUC = 0.661, P < 0.05) and SAA (AUC = 0.605, P < 0.05). When PCT had cut-off value of 1.06 ng/ml, sensitivity of 95.8%, specificity of 92.1%, and the Youden indicator of 0.879, the negative and positive predictive values were 97.8% and 85.0% respectively, the negative and positive likelihood ratios were 0.05 and 12.5 respectively, and all significantly higher than that of CRP, IL-6 and SAA. It is concluded that for patients with hematologic malignancy combined with febrile neutropenia and bacterial infection, the diagnostic value of serum PCT is superior to that of immune inflammatory factors (CRP, IL-6 and SAA), the PCT can predict the bacterium infection, provide laboratory evidence for rational antimicrobial drug usage and mortality reduction.
Adult ; Bacteremia ; diagnosis ; etiology ; C-Reactive Protein ; metabolism ; Calcitonin ; blood ; Calcitonin Gene-Related Peptide ; Febrile Neutropenia ; complications ; microbiology ; Female ; Hematologic Neoplasms ; complications ; microbiology ; Humans ; Interleukin-6 ; blood ; Male ; Middle Aged ; Protein Precursors ; blood ; Retrospective Studies ; Serum Amyloid A Protein ; metabolism

No abstract available.
Aged ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacteremia/blood/*diagnosis/microbiology ; C-Reactive Protein/analysis ; Cholecystitis/blood/cerebrospinal fluid/microbiology ; Electrophoresis, Gel, Pulsed-Field ; Enterococcus faecium/drug effects/isolation & purification/metabolism ; Humans ; Male ; Microbial Sensitivity Tests ; Microscopy, Electron, Scanning ; Ochrobactrum/drug effects/isolation & purification/*metabolism ; RNA, Ribosomal, 16S/analysis/genetics/metabolism ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization