Real‐time PCR versus MALDI‐TOF MS and culture‐based techniques for diagnosis of bloodstream and pyogenic infections in humans and animals

Author(s):  
N.K. Abd El‐Aziz ◽  
A.A Gharib ◽  
E.A.A. Mohamed ◽  
A.H. Hussein
2010 ◽  
pp. NA-NA ◽  
Author(s):  
Steven R. Talbot ◽  
Heiko Russmann ◽  
Stefan Köhne ◽  
Bärbel Niederwöhrmeier ◽  
Gudrun Grote ◽  
...  

COVID ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 5-17
Author(s):  
Tingting Liu ◽  
Lin Kang ◽  
Yanwei Li ◽  
Jing Huang ◽  
Zishuo Guo ◽  
...  

Human coronaviruses (HCoVs) are associated with a range of respiratory symptoms. The discovery of severe acute respiratory syndrome (SARS)-CoV, Middle East respiratory syndrome, and SARS-CoV-2 pose a significant threat to human health. In this study, we developed a method (HCoV-MS) that combines multiplex PCR with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), to detect and differentiate seven HCoVs simultaneously. The HCoV-MS method had high specificity and sensitivity, with a 1–5 copies/reaction detection limit. To validate the HCoV-MS method, we tested 163 clinical samples, and the results showed good concordance with real-time PCR. Additionally, the detection sensitivity of HCoV-MS and real-time PCR was comparable. The HCoV-MS method is a sensitive assay, requiring only 1 μL of a sample. Moreover, it is a high-throughput method, allowing 384 samples to be processed simultaneously in 30 min. We propose that this method be used to complement real-time PCR for large-scale screening studies.


2021 ◽  
Author(s):  
Chanika Maenchantrarath ◽  
Pradchama Khumdee ◽  
Seksun Samosornsuk ◽  
Narissara Mungkornkaew ◽  
Worada Samosornsuk

Abstract Background C. albicans is the most important yeast that caused the infection in humans; the trend of resistance to fluconazole (FLC) was also increased, while the FLC susceptibility by conventional method takes time causing the treatment failure. To investigate FLC susceptibility to C. albicans using MALDI-TOF MS and Real-time PCR for CDR1, CDR2, MDR1 and ERG11, overall, 32 C. albicans strains included 4 reference strains (3 FLC susceptible (S) and 1 FLC resistant (R), 1 spontaneous mutant strain (FLC susceptible-dose dependent, SDD) and 27 clinical strains obtained from 2 Thai University Hospitals were performed FLC susceptibility testing by Sensititre YeastOne and broth microdilution method, FLC resistant expression mechanism by Real-time PCR and the major peak determination by MALDI-TOF MS.Results The change of CDR1 and CDR2 mRNA expression were only significantly observed in SDD and R strains. Using MALDI-TOF MS, the change of mass spectral intensity at range 3376-3382 m/z (major peak) was significantly related to FLC susceptibility as SDD (decreased at 4 µg/ml and increase at 8 µg/ml), S (all increased), and R (all slightly decreased or no change) after incubation for 6 h. All 27 clinical strains showed FLC MIC susceptible (MIC range 0.25-2 µg/ml), no change in CDR1 and CDR2 expression and S major peak type. The FLC resistance C. albicans with CDR1 and CDR2 expression may possibly effect the change of mass spectral intensity at range 3376-3382 m/z. Conclusions The MALDI-TOF MS may be used to simultaneously classify and predict FLC resistant C. albicans strains associated with CDR1 and CDR2 expression. Further studies are essential to clarify the methodology and improve the reliability of this assay for routine diagnosis.


2012 ◽  
Vol 328 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Melanie Pavlovic ◽  
Regina Konrad ◽  
Azuka N. Iwobi ◽  
Andreas Sing ◽  
Ulrich Busch ◽  
...  

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Jade Bokma ◽  
Laura Van Driessche ◽  
Piet Deprez ◽  
Freddy Haesebrouck ◽  
Marianne Vahl ◽  
...  

ABSTRACT Mycoplasma bovis is a leading cause of pneumonia in modern calf rearing. Fast identification is essential to ensure appropriate antimicrobial therapy. Therefore, the objective of this study was to develop a protocol to identify M. bovis from bronchoalveolar lavage fluid (BALf) with matrix-assisted laser desorption ionization–time of flight mass spectrometry MALDI-TOF MS and to determine the diagnostic accuracy in comparison with other techniques. BALf was obtained from 104 cattle, and the presence of M. bovis was determined in the following three ways: (i) rapid identification of M. bovis with MALDI-TOF MS (RIMM) (BALf was enriched and after 24, 48, and 72 h of incubation and was analyzed using MALDI-TOF MS), (ii) triplex real-time PCR for M. bovis, Mycoplasma bovirhinis, and Mycoplasma dispar, and (iii) 10-day incubation on selective-indicative agar. The diagnostic accuracy of the three tests was determined with Bayesian latent class modeling (BLCM). After 24 h of enrichment, M. bovis was identified with MALDI-TOF MS in 3 out of 104 BALf samples. After 48 and 72 h of enrichment, 32/104 and 38/100 samples, respectively, were M. bovis positive. Lipase-positive Mycoplasma-like colonies were seen in 28 of 104 samples. Real-time PCR resulted in 28/104 positive and 12/104 doubtful results for M. bovis. The BLCM showed a sensitivity (Se) and specificity (Sp) of 86.6% (95% credible interval [CI], 69.4% to 97.6%) and 86.4% (CI, 76.1 to 93.8) for RIMM. For real-time PCR, Se was 94.8% (CI, 89.9 to 97.9) and Sp was 88.9% (CI, 78.0 to 97.4). For selective-indicative agar, Se and Sp were 70.5% (CI, 52.1 to 87.1) and 93.9% (CI, 85.9 to 98.4), respectively. These results suggest that rapid identification of M. bovis with MALDI-TOF MS after an enrichment procedure is a promising test for routine diagnostics in veterinary laboratories.


2017 ◽  
Vol 55 (5) ◽  
pp. 1437-1445 ◽  
Author(s):  
Maya Beganovic ◽  
Michael Costello ◽  
Sarah M. Wieczorkiewicz

ABSTRACT Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) decreases the time to organism identification and improves clinical and financial outcomes. The purpose of this study was to evaluate the impact of MALDI-TOF MS alone versus MALDI-TOF MS combined with real-time, pharmacist-driven, antimicrobial stewardship (AMS) intervention on patient outcomes. This single-center, pre-post, quasiexperimental study evaluated hospitalized patients with positive blood cultures identified via MALDI-TOF MS combined with prospective AMS intervention compared to a control cohort with MALDI-TOF MS identification without AMS intervention. AMS intervention included: real-time MALDI-TOF MS pharmacist notification and prospective AMS provider feedback. The primary outcome was the time to optimal therapy (TTOT). A total of 252 blood cultures, 126 in each group, were included in the final analysis. MALDI-TOF MS plus AMS intervention significantly reduced the overall TTOT (75.17 versus 43.06 h; P < 0.001), the Gram-positive contaminant TTOT (48.21 versus 11.75 h; P < 0.001), the Gram-negative infection (GNI) TTOT (71.83 versus 35.98 h; P < 0.001), and the overall hospital length of stay (LOS; 15.03 versus 9.02 days; P = 0.021). The TTOT for Gram-positive infection (GPI) was improved (64.04 versus 41.61 h; P = 0.082). For GPI, the hospital LOS (14.64 versus 10.31 days; P = 0.002) and length of antimicrobial therapy 24.30 versus 18.97 days; P = 0.018) were reduced. For GNI, the time to microbiologic clearance (51.13 versus 34.51 h; P < 0.001), the hospital LOS (15.40 versus 7.90 days; P = 0.027), and the intensive care unit LOS (5.55 versus 1.19 days; P = 0.035) were reduced. To achieve optimal outcomes, rapid identification with MALDI-TOF MS combined with real-time AMS intervention is more impactful than MALDI-TOF MS alone.


2009 ◽  
Author(s):  
Takato O. Yoshida ◽  
Eiji Kohno ◽  
Marc Dodeller ◽  
Takashi Sakurai ◽  
Seiji Yamamoto ◽  
...  
Keyword(s):  

2013 ◽  
Vol 59 (11) ◽  
pp. 1649-1656 ◽  
Author(s):  
Wilhelm Schneiderhan ◽  
Alexander Grundt ◽  
Stefan Wörner ◽  
Peter Findeisen ◽  
Michael Neumaier

BACKGROUND Because sepsis has a high mortality rate, rapid microbiological diagnosis is required to enable efficient therapy. The effectiveness of MALDI-TOF mass spectrometry (MALDI-TOF MS) analysis in reducing turnaround times (TATs) for blood culture (BC) pathogen identification when available in a 24-h hospital setting has not been determined. METHODS On the basis of data from a total number of 912 positive BCs collected within 140 consecutive days and work flow analyses of laboratory diagnostics, we evaluated different models to assess the TATs for batch-wise and for immediate response (real-time) MALDI-TOF MS pathogen identification of positive BC results during the night shifts. The results were compared to TATs from routine BC processing and biochemical identification performed during regular working hours. RESULTS Continuous BC incubation together with batch-wise MALDI-TOF MS analysis enabled significant reductions of up to 58.7 h in the mean TATs for the reporting of the bacterial species. The TAT of batch-wise MALDI-TOF MS analysis was inferior by a mean of 4.9 h when compared to the model of the immediate work flow under ideal conditions with no constraints in staff availability. CONCLUSIONS Together with continuous cultivation of BC, the 24-h availability of MALDI-TOF MS can reduce the TAT for microbial pathogen identification within a routine clinical laboratory setting. Batch-wise testing of positive BC loses a few hours compared to real-time identification but is still far superior to classical BC processing. Larger prospective studies are required to evaluate the contribution of rapid around-the-clock pathogen identification to medical decision-making for septicemic patients.


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