Evaluation of the Cobas-Bact system for direct and rapid identification and antimicrobial susceptibility testing of gram-negative rods from positive blood culture broths.

1989 ◽  
Vol 27 (1) ◽  
pp. 102-105 ◽  
Author(s):  
W Kamm ◽  
A Wenger ◽  
J Bille
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Rapid Identification ◽  
Antimicrobial Susceptibility Testing ◽  
Gram Negative

scholarly journals Evaluation of the Accelerate PhenoTM system for rapid identification and antimicrobial susceptibility testing of positive blood culture bottles inoculated with primary sterile specimens from patients with suspected severe infections

2021 ◽  
Author(s):  
V Chapot ◽  
L Effenberg ◽  
J Dohmen-Ruetten ◽  
J Buer ◽  
J Kehrmann
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Rapid Identification ◽  
Antimicrobial Susceptibility Testing ◽  
Pathogen Identification ◽  
Severe Infections ◽  
Conventional Methods ◽  
Blood Specimens

The Accelerate PhenoTM system (APS, Accelerate Diagnostics) is approved for the rapid identification and phenotypic antimicrobial susceptibility testing (AST) of microorganisms grown from positive blood cultures inoculated with blood from septic patients. We evaluated the performance for identification and AST from positive blood culture bottles inoculated with primary sterile non-blood specimens from patients with suspected severe infections. One hundred positive blood culture bottles with primary sterile specimens (63 cerebrospinal fluids, 16 ascites, 7 pleural fluids, 4 vitreous fluids, 5 joint aspirates and 5 other aspirates) from 100 patients were included. Pathogen identification was in agreement with conventional methods for 72 of 100 cultures (72%) and for 81 of 112 (72%) pathogens when considering all pathogens, for 72 of 92 (78%) cultures and 81 of 104 (78%) pathogens when considering on-panel pathogens only. Eight of 31 isolates (26%) not identified by APS were pathogens not included in the APS panel. APS and conventional methods accordingly identified all pathogens from two of nine polymicrobial cultures (22%). APS generated antimicrobial resistance results for 57 pathogens of 57 cultures. The overall category agreement between APS and culture based AST was 91.2%, the rates for minor errors 6.9%, major 1.7% and very major errors 0.2%. APS may accelerate pathogen identification and phenotypic AST from positive blood culture bottles inoculated with primary sterile specimens from patients with serious infections, especially for hospitals without on-site microbiology laboratory. However, the inclusion of non-blood specimens with a high likelihood of polymicrobial infections may result in an inferior performance.

Rapid Identification and Antimicrobial Susceptibility of Gram Negative Bacteria Detected in Positive Blood Culture Bottles

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Nevine Nabil Kassem ◽  
Hala Mahmoud Hafez ◽  
Dalia H Abdelhamid ◽  
Ola Ali Mahmoud
Keyword(s):  
Blood Culture ◽  
Causative Agent ◽  
Positive Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Rapid Identification ◽  
Gram Negative ◽  
Antimicrobial Susceptibility Profile ◽  
Direct Primary

Abstract Background Blood stream infection (BSI) is one of the most serious situations in infectious disease .Accurate and timely identification of the causative agent and determination of its antimicrobial susceptibility profile are essential for guiding targeted and effective antimicrobial treatment. Current methods involve culturing of blood in a liquid medium and subsequently subculturing of signal positive bottles on solid media in order to obtain isolated colonies that can be further used in identification and susceptibility testing of the isolates. The standard method requires additional 48-72hours following the appearance of a positive signal in order to provide a reliable patient report. On the other hand, rapid identification of the causative agent and determination of its susceptibility profile by direct inoculation of the biochemical test media with the blood-broth mixtures from signal positive bottles and performing primary susceptibility testing might help reducing the time needed for provision of results compared to the standard isolated-colony based method and hence would help the rapid initiation of effective and targeted antimicrobial therapy and reduce the bacteremia-related morbidity and mortality. Objective The aim of the present study was to determine the accuracy and precision of the non-standard methods (direct identification and susceptibility testing using the blood/broth mixture) by comparing its results to those of the standard isolate-based identification and susceptibility testing methods. Material and method The study included 52 signal blood culture bottles yielding gram negative isolates. Bottles were selected amongst blood culture bottles submitted to the Main Microbiology laboratory, Ain Shams University hospital, for culture and antimicrobial susceptibility testing during the period between May 2018 and October 2018. a portion of the blood-broth mixture was aspirated from positive blood culture bottles, after being well mixed, and was subcultured onto agar media for the isolation of the causative agent and subsequently determination of its antimicrobial susceptibility profile was performed. Another part of the aspirated blood-broth mixture was diluted with sterile saline, its turbidity was adjusted against a 0.5McFarland standard and was used to inoculate directly the biochemical test media panel used for the identification of gram negative organisms as well as to perform direct (primary) antimicrobial susceptibility. Results The present study revealed there was 100% categorical agreement between the results of the direct biochemical inoculation method and those of the standard isolate-based inoculation method regarding the identification of the causative agent. The results of the direct biochemical identification method were also consistent giving rise to a 100% withinrun precision categorical agreement and a 100% between-run precision categorical agreement. The overall categorical agreement between the results of the standard isolate-based AST method and the results of the direct (primary susceptibility) AST method was 96.3% for the signal blood culture media. The major error rate was 0.5% whereas the minor error rate was 3.3% . Consistent results were also obtained for the AST done directly from the signal blood culture bottles since the between-run and within-run precision categorical agreement were 96.3% and 98.6%, respectively. Conclusion the overall performance of the AST done directly from positive blood culture bottles fulfilled the acceptable performance criteria specified in the Cumitech 31A so the direct method can be used for the earlier determination of AST and identification of Gram negative bacteria and thus to reduce the time for early initiation of appropriate antibiotic

scholarly journals Evaluation of the Accelerate Pheno System for Fast Identification and Antimicrobial Susceptibility Testing from Positive Blood Cultures in Bloodstream Infections Caused by Gram-Negative Pathogens

2017 ◽  
Vol 55 (7) ◽  
pp. 2116-2126 ◽  
Author(s):  
Matthias Marschal ◽  
Johanna Bachmaier ◽  
Ingo Autenrieth ◽  
Philipp Oberhettinger ◽  
Matthias Willmann ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Test System ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Diagnostic Tools ◽  
Gram Negative ◽  
Content Type

ABSTRACT Bloodstream infections (BSI) are an important cause of morbidity and mortality. Increasing rates of antimicrobial-resistant pathogens limit treatment options, prompting an empirical use of broad-range antibiotics. Fast and reliable diagnostic tools are needed to provide adequate therapy in a timely manner and to enable a de-escalation of treatment. The Accelerate Pheno system (Accelerate Diagnostics, USA) is a fully automated test system that performs both identification and antimicrobial susceptibility testing (AST) directly from positive blood cultures within approximately 7 h. In total, 115 episodes of BSI with Gram-negative bacteria were included in our study and compared to conventional culture-based methods. The Accelerate Pheno system correctly identified 88.7% (102 of 115) of all BSI episodes and 97.1% (102 of 105) of isolates that are covered by the system's identification panel. The Accelerate Pheno system generated an AST result for 91.3% (95 of 104) samples in which the Accelerate Pheno system identified a Gram-negative pathogen. The overall category agreement between the Accelerate Pheno system and culture-based AST was 96.4%, the rates for minor discrepancies 1.4%, major discrepancies 2.3%, and very major discrepancies 1.0%. Of note, ceftriaxone, piperacillin-tazobactam, and carbapenem resistance was correctly detected in blood culture specimens with extended-spectrum beta-lactamase-producing Escherichia coli ( n = 7) and multidrug-resistant Pseudomonas aeruginosa ( n = 3) strains. The utilization of the Accelerate Pheno system reduced the time to result for identification by 27.49 h ( P < 0.0001) and for AST by 40.39 h ( P < 0.0001) compared to culture-based methods in our laboratory setting. In conclusion, the Accelerate Pheno system provided fast, reliable results while significantly improving turnaround time in blood culture diagnostics of Gram-negative BSI.

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