scholarly journals Direct-on-Target Microdroplet Growth Assay for Detection of Bacterial Resistance in Positive Blood Cultures

2021 ◽  
Vol Volume 14 ◽  
pp. 4611-4617
Author(s):  
Hao Tang ◽  
Rongrong Li ◽  
Huaming Xu ◽  
Guoping Lu ◽  
Zhen Liu ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Blood Cultures ◽  
Growth Assay

scholarly journals Rapid Direct Susceptibility Testing from Positive Blood Cultures by the Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry-Based Direct-on-Target Microdroplet Growth Assay

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Evgeny A. Idelevich ◽  
Luise M. Storck ◽  
Katrin Sparbier ◽  
Oliver Drews ◽  
Markus Kostrzewa ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Laser Desorption ◽  
Blood Cultures ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Identification Score ◽  
Growth Assay ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

ABSTRACTThe recently developed direct-on-target microdroplet growth assay (DOT-MGA) allows rapid universal antimicrobial susceptibility testing (AST) using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS). Here, we investigated a direct application of this method on positive blood cultures (BCs) for the acceleration of sepsis diagnostics. Blood samples spiked with meropenem-nonsusceptible and meropenem-susceptibleEnterobacteralesisolates were inoculated into Bactec Plus Aerobic/F bottles and incubated in the Bactec automated system. Positive-BC broth was processed using four different methods, filtration/dilution, dilution, lysis/centrifugation, and differential centrifugation. For both dilution-based methods, AST was performed from 1:100, 1:1,000, and 1:10,000 dilutions of positive-BC broth in cation-adjusted Mueller-Hinton broth (CA-MHB). For both centrifugation-based methods, a 0.5 McFarland standard turbidity suspension was prepared from a bacterial pellet and adjusted to a final inoculum of 5 × 105CFU/ml in CA-MHB. Six-microliter microdroplets with or without meropenem at the breakpoint concentration were spotted in triplicate onto a MALDI-TOF MS target, followed by incubation in a humidity chamber for 3 or 4 h and subsequent broth removal. Spectra were evaluated by MALDI Biotyper software. The test was considered valid if the growth control without antibiotic achieved an identification score of ≥1.7. For samples with meropenem, successful identification (score, ≥1.7) was interpreted as a nonsusceptible result, whereas failed identification (score, <1.7) defined susceptibility. The best test performance was achieved with the lysis/centrifugation method after a 4-h incubation. At this time point, 96.3% validity, 91.7% sensitivity, and 100% specificity were reached. This study demonstrated the feasibility and accuracy of a rapid DOT-MGA from positive BCs. Parallel to susceptibility determination, this method provides simultaneous species identification.

Effect of Calcium on the Growth and Differentiation of Cultured Rat Esophageal Epithelial Cells

1982 ◽  
Vol 40 ◽  
pp. 132-133
Author(s):  
W.T. Gunning ◽  
M.R. Marino ◽  
M.S. Babcock ◽  
G.D. Stoner
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Replication Rate ◽  
Enzymatic Dissociation ◽  
Growth Assay ◽  
Epidermal Growth ◽  
Fetal Bovine ◽  
Esophageal Epithelial Cells ◽  
Cellular Replication

The role of calcium in modulating cellular replication and differentiation has been described for various cell types. In the present study, the effects of Ca++ on the growth and differentiation of cultured rat esophageal epithelial cells was investigated.Epithelial cells were isolated from esophagi taken from 8 week-old male CDF rats by the enzymatic dissociation method of Kaighn. The cells were cultured in PFMR-4 medium supplemented with 0.25 mg/ml dialyzed fetal bovine serum, 5 ng/ml epidermal growth factor, 10-6 M hydrocortisone 10-6 M phosphoethanolamine, 10-6 M ethanolamine, 5 pg/ml insulin, 5 ng/ml transferrin, 10 ng/ml cholera toxin and 50 ng/ml garamycin at 36.5°C in a humidified atmosphere of 3% CO2 in air. At weekly intervals, the cells were subcultured with a solution containing 1% polyvinylpyrrolidone, 0.01% EGTA, and 0.05% trypsin. After various passages, the replication rate of the cells in PFMR-4 medium containing from 10-6 M to 10-3 M Ca++ was determined using a clonal growth assay.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

ED Blood Cultures May Not Help in Pneumonia

2010 ◽  
Vol 3 (2) ◽  
pp. 14
Author(s):  
BRUCE JANCIN
Keyword(s):  
Blood Cultures

A Case of Catabacter hongkongensis and Alistipes indistinctus Isolated from Blood Cultures of a Patient with Acute Appendicitis

2019 ◽  
Vol 9 (3) ◽  
pp. 177
Author(s):  
Jiyun Ryu ◽  
Youngjin Kim ◽  
Jaejoon Lee ◽  
Sun Young Cho ◽  
Tae Sung Park ◽  
...  
Keyword(s):  
Acute Appendicitis ◽  
Blood Cultures
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