scholarly journals Diagnostic accuracy of MALDI-TOF mass spectrometry for the direct identification of clinical pathogens from urine

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 266-273
Author(s):  
Min Tang ◽  
Jia Yang ◽  
Ying Li ◽  
Luhua Zhang ◽  
Ying Peng ◽  
...  

AbstractMatrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) has become one of the most popular methods for the rapid and cost-effective detection of clinical pathogenic microorganisms. This study aimed to evaluate and compare the diagnostic performance of MALDI-TOF MS with that of conventional approaches for the direct identification of pathogens from urine samples. A systematic review was conducted based on a literature search of relevant databases. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and area under the summary receiver operating characteristic (SROC) curve of the combined studies were estimated. Nine studies with a total of 3920 subjects were considered eligible and included in the meta-analysis. The pooled sensitivity was 0.85 (95% CI 0.79-0.90), and the pooled specificity was 0.93 (95% CI 0.82-0.97). The PLR and NLR were 11.51 (95% CI 4.53-29.26) and 0.16 (95% CI 0.11-0.24), respectively. The area under the SROC curve was 0.93 (95% CI 0.91-0.95). Sensitivity analysis showed that the results of this meta-analysis were stable. MALDI-TOF MS could directly identify microorganisms from urine samples with high sensitivity and specificity.

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S727-S727
Author(s):  
Ronan Hsieh ◽  
Rania Mekary ◽  
Raymund Li ◽  
Chi-Yang Lin ◽  
Tzu-Hua Weng ◽  
...  

Abstract Background Several studies showed inconsistent results on the efficiency measures of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) technology and patients’ clinical outcomes. A meta-analysis was conducted to determine the effectiveness of MALDI-TOF MS-based bacteriology in improving the accuracy of microbiology report and clinical outcomes. Methods PubMed and EMBASE databases were searched from database inception through May 1, 2018 for pre–post and parallel comparative studies that evaluated the use of MALDI-TOF MS for identification of microorganism from blood culture. Pooled effect estimates were derived using the random-effects model. Univariate meta-regression on trial-level covariates was used to assess heterogeneity sources. Funnel plot, Begg’s and Egger’s tests were used to assess publication bias. Results Thirteen studies with 3,534 patients were meta-analyzed. Compared with conventional methods, MALDI-TOF MS was associated with 34% reduction in mortality (RR = 0.66; 95% CI: 0.54; 0.81; I2 = 27.6%; 9 studies); 5.3-hour reduction in time-to-effective antibiotic therapy (95% CI: -6.4; -4.3; I2 = 98.0%), 24.5-hour reduction in time to identify bacteria (95% CI: −25.7; −23.3; I2 = 91.0%); 0.9-day reduction in hospital stay (95% CI: −1.4; −0.3; I2 = 56.6%), and US$4100 saving in direct hospitalization cost (95% CI: $−8,200; $−113; I2 = 66.1%). No significant heterogeneity sources were found (all P-interaction from meta-regression > 0.05) and no statistical evidence for publication bias was found (all P > 0.05). Conclusion Rapid pathogen identification by MALDI-TOF MS with or without antibiotic stewardship was associated with reduced mortality, improved outcomes of bloodstream infection, and may be cost-effective among patients with bloodstream infection. Nevertheless, a multicenter randomized controlled trial is needed to confirm findings of these pre–post comparison studies. Disclosures All authors: No reported disclosures.


2013 ◽  
Vol 24 (4) ◽  
pp. 191-194 ◽  
Author(s):  
Manal Tadros ◽  
Astrid Petrich

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) can be used to identify bacteria directly from positive blood and sterile fluid cultures. The authors evaluated a commercially available kit – the Sepsityper Kit (Bruker Daltonik, Germany) – and MALDI-TOF MS for the rapid identification of organisms from 80 flagged positive blood culture broths, of which 73 (91.2%) were blood culture specimens and seven (8.7%) were cerebrospinal fluid specimens, in comparison with conventional identification methods. Correct identification to the genus and species levels was obtained in 75 of 80 (93.8%) and 39 of 50 (78%) blood culture broths, respectively. Applying the blood culture analysis module, a newly developed software tool, improved the species identification of Gram-negative organisms from 94.7% to 100% and of Gram-positive organisms from 66.7% to 70%.MALDI-TOF MS is a promising tool for the direct identification of organisms cultured from sterile sites.


2021 ◽  
Vol 20 ◽  
pp. 153303382110119
Author(s):  
Wen-Ting Zhang ◽  
Guo-Xun Zhang ◽  
Shuai-Shuai Gao

Background: Leukemia is a common malignant disease in the human blood system. Many researchers have proposed circulating microRNAs as biomarkers for the diagnosis of leukemia. We conducted a meta-analysis to evaluate the diagnostic accuracy of circulating miRNAs in the diagnosis of leukemia. Methods: A comprehensive literature search (updated to October 13, 2020) in PubMed, EMBASE, Web of Science, Cochrane Library, Wanfang database and China National Knowledge Infrastructure (CNKI) was performed to identify eligible studies. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) for diagnosing leukemia were pooled for both overall and subgroup analysis. The meta-regression and subgroup analysis were performed to explore heterogeneity and Deeks’ funnel plot was used to assess publication bias. Results: 49 studies from 22 publications with a total of 3,489 leukemia patients and 2,756 healthy controls were included in this meta-analysis. The overall sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the curve were 0.83, 0.92, 10.8, 0.18, 59 and 0.94, respectively. Subgroup analysis shows that the microRNA clusters of plasma type could carry out a better diagnostic accuracy of leukemia patients. In addition, publication bias was not found. Conclusions: Circulating microRNAs can be used as a promising noninvasive biomarker in the early diagnosis of leukemia.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bo Zhang ◽  
Bingjie Zhang ◽  
Zhulin Zhou ◽  
Yutong Guo ◽  
Dan Wang

AbstractObjectiveGlycosylated hemoglobin (HbA1c) has obvious clinical value in the diagnosis of diabetes, but the conclusions on the diagnostic value of diabetic retinopathy (DR) are not consistent. This study aims to comprehensively evaluate the accuracy of glycosylated hemoglobin in the diagnosis of diabetic retinopathy through the meta-analysis of diagnostic tests.MethodsCochrane Library, Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), China Wanfang Database, Chinese Biomedical Literature Database (CBM) were searched until November, 2020. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to assess the quality of the included studies. The pooled sensitivity, specificity, positive likelihood ratio (+LR), negative likelihood ratio (-LR), diagnostic odds ratio (DOR) and areas under the receiver operating characteristic (ROC) curve were calculated by Stata 15.0 software.ResultsAfter screening, 18 high-quality papers were included. The results of meta-analysis showed that the combined DOR = 18.19 (95% CI: 10.99–30.11), the sensitivity= 0.81 (95% CI): 0.75 ~ 0.87), specificity = 0.81 (95%CI: 0.72 ~ 0.87), +LR = 4.2 (95%CI: 2.95 ~ 6.00), −LR = 0.23 (95%CI: 0.17 ~ 0.31), and the area under the Summary ROC curve was 0.88 (95%CI:  0.85 ~ 0.90).ConclusionThe overall accuracy of HbA1cC forin diagnosing diabetic retinopathy is good. As it is more stable than blood sugar and is not affected by meals, it may be a suitable indicator for diabetic retinopathy.


2021 ◽  
Vol 9 (1) ◽  
pp. 142
Author(s):  
Jang-Jih Lu ◽  
Hsiu-Jung Lo ◽  
Chih-Hua Lee ◽  
Mei-Jun Chen ◽  
Chih-Chao Lin ◽  
...  

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid and accurate method to identify microorganisms in clinical laboratories. This study isolates yeast-like microorganisms in the oral washes that are collected from non-bedridden nursing home residents, using CHROMagar Candida plates, and identifies them using Bruker MALDI-TOF MS. The ribosomal DNA sequences of the isolates are then examined. Three hundred and twenty yeast isolates are isolated from the oral washes. Candida species form the majority (78.1%), followed by Trichosporon/Cutaneotrichosporon species (8.8%). Bruker MALDI-TOF MS gives a high-level confidence, with a log(score) value of ≥1.8, and identifies 96.9% of the isolates. There are six inconclusive results (1.9%), and those sequences are verified as rare clinical species, including Candida ethanolica, Cutaneotrichosporon jirovecii, Exophiala dermatitidis, and Fereydounia khargensis. Almost all of the isolates have a regular color on the CHROMagar Candida plates. If the colonies are grouped by color on the plates, a specific dominant yeast species is present in each color group, except for purple or orange isolates. In conclusion, MALDI-TOF MS is verified as a fast, accurate and practical method to analyze oral yeasts in elderly subjects.


2021 ◽  
Vol 56 (4) ◽  
pp. 1-12
Author(s):  
Łukasz Hildebrant ◽  
Urszula Wendt

Introduction: MALDI TOF MS method is increasingly used in routine microbiological diagnostics to identify clinical strains. The result of the identification test is based on the measurement of the mass, charge and flight time of the protein ions. This makes it possible to monitor and supervise the method using a numerical score developed with statistical techniques. Aim: The study aimed to determine the stability and correctness of the mass spectrometry method. Materials and methods: To evaluate the characteristics of the method, microbial identification tests were performed using reference strains. All tests were performed as part of the MALDI TOF MS internal quality control system. Results: All reference strains (100%) were correctly identified to the species level, although the score values were not always within the reliability criteria of the results established by the producer. It was found that the mean values of the score were from 2.000 – 2.299 (49.2%) and 2.300 – 3.000 (50.0%). The coefficient of variation for control tests performed in the consecutive years ranged from 5.18 – 6.56%, which evidence of the high stability of the method. For individual species, reproducibility precision over the 8 years ranged from 2.89% (n = 13) for Enterococcus faecalis ATCC 51299 to 7.02% (n = 28) for Klebsiella pneumoniae ATCC 700603, which proves the high precision of measurements. Conclusions: The mass spectrometry method is characterized by very high stability and correctness. The intra-laboratory quality control system using reference strains is a useful tool for monitoring and supervising the method and laboratory personnel competency performing identification tests during routine microbiological work.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Na Sun ◽  
Jinhua Zhao ◽  
Wenli Qiao ◽  
Taisong Wang

Objective.We conducted a meta-analysis to evaluate the predictive value of interim18F-FDG PET/CT in patients with DLBCL treated with R-CHOP chemotherapy.Methods.We searched for articles published in PubMed, ScienceDirect, Wiley, Scopus, and Ovid database from inception to March 2014. Articles related to interim PET/CT in patients with DLBCL treated with R-CHOP chemotherapy were selected. PFS with or without OS was chosen as the endpoint to evaluate the prognostic significance of interim PET/CT.Results.Six studies with a total of 605 cases were included. The sensitivity of interim PET/CT ranged from 21.2% to 89.7%, and the pooled sensitivity was 52.4%. The specificity of interim PET/CT ranged from 37.4% to 90.7%, and the pooled specificity was 67.8%. The pooled positive likelihood ratio and negative likelihood ratio were 1.780 and 0.706, respectively. The explained AUC was 0.6978 and theQ*was 0.6519.Conclusions.The sensitivity and specificity of interim PET/CT in predicting the outcome of DLBCL patients treated with R-CHOP chemotherapy were not satisfactory (52.4% and 67.8%, resp.). To improve this, some more work should be done to unify the response criteria and some more research to assess the prognostic value of interim PET/CT with semiquantitative analysis.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Dong-Lan Tang ◽  
Xiao Chen ◽  
Chang-Guo Zhu ◽  
Zhong-wei Li ◽  
Yong Xia ◽  
...  

Abstract Background The present meta-analysis examined the diagnostic accuracy of T2 Candida for candidiasis. Methods The literature databases, such as PubMed, Embase, DVIO, Cochrane library, Web of Science, and CNKI, were searched on T2 Candida detection. Results A total of 8 articles, comprising of 2717 research subjects, were included in the study. The pooled sensitivity and specificity were 0.91 (95% confidence interval (CI): 0.88–0.94) and 0.94 95% CI: 0.93–0.95), respectively. The pooled positive likelihood ratio and negative likelihood ratio was 10.16 (95% CI: 2.75–37.50) and 0.08 (95% CI: 0.02–0.35), respectively. The combined diagnostic odds ratio is 133.65 95% CI: 17.21–1037.73), and the AUC of SROC is 0.9702 [(SE = 0.0235), Q* = 0.9201(SE = 0.0381)]. Conclusions The current evidence supported that T2 Candida has high accuracy and sensitivity and is of major clinical significance in the diagnosis of Candida infection.


2021 ◽  
Author(s):  
Ahmad Shahir Sadr ◽  
zahra abdollahpour ◽  
Atousa Aliahmadi ◽  
Changiz Eslahchi ◽  
Mina Nekouei ◽  
...  

Abstract The hydrogen/deuterium exchange (HDX) is a reliable method to survey the dynamic behavior of proteins and epitope mapping. Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) is a quantifying tool to assay for HDX in the protein of interest. We combined HDX-MALDI-TOF MS and molecular docking/MD simulation to identify accessible amino acids and analyze their contribution in the structural changes of profilin1 (PFN1). The molecular docking/MD simulations are computational tools for enabling the analysis of the type of amino acids that may be involved via HDX identified under the lowest binding energy condition. Glycine to Valine amino acid (G117V) substitution mutation is linked to amyotrophic lateral sclerosis (ALS). This mutation is found to be in the actin-binding site of PFN1 and prevents the dimerization/polymerization of actin and invokes a pathologic toxicity that leads to ALS. In this study, we sought to understand the PFN1 protein dynamic behavior using purified wild type and mutant PFN1 proteins. The data obtained from HDX-MALDI-TOF MS for PFN1WT and PFN1G117V at various time intervals, from seconds to hours, revealed multiple peaks corresponding to molecular weights from monomers to multimers. PFN1/Benzaldehyde complexes identified 20 accessible amino acids to HDX that participate in the docking simulation in the surface of WT and mutant PFN1. Consistent results from HDX-MALDI-TOF MS and docking simulation predict candidate amino acid(s) involved in the dimerization/polymerization of PFNG117V. This information may shed critical light on the structural and conformational changes with details of amino acid epitopes for mutant PFN1s’ dimerization, oligomerization, and aggregation.


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