scholarly journals 649. Clinical Implementation of a Rapid Susceptibility Testing Procedure, Directly From a Positive Blood Culture Using the Vitek®2 System on Gram Negative Rods

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S383-S383
Author(s):  
Charma Henry ◽  
Dustin Evans ◽  
Daniel Navas ◽  
Arleen Barker ◽  
Chonnapat Somyos ◽  
...  
Keyword(s):  
Blood Culture ◽  
Positive Blood Culture ◽  
Susceptibility Testing ◽  
Testing Procedure ◽  
Turnaround Time ◽  
National Average ◽  
Major Error ◽  
Clinical Implementation ◽  
Salmonella Spp ◽  
Gram Negative

Abstract Background The national average of identification and susceptibility for organisms isolated from positive blood culture to final susceptibility based on growth on solid media is 48 hours. The goal of this research was to prove that the Vitek®2 (bioMérieux, Inc.) system can provide an accurate and reliable susceptibility result directly from positive blood culture for Gram negative rods and reduce the turnaround time (TAT) from positive blood culture to the final susceptibility. Methods An FDA-modified validation procedure was performed on positive blood cultures directly from the bottle to the VITEK®2 System for susceptibility testing. The protocol tested and validated an aliquot of 50uL of blood directly from the positive bottle into 10 mL of saline (1:200). The solution was vortexed and 3mL were placed in the VITEK®2 test tube. This protocol was intended only for Gram negative rods using the AST-GN70, AST-GN81 & AST-GN801 cards. This protocol followed the CLSI M52 and M100 guidelines. Results 515 organisms from clinical blood culture samples from July 2018 to October 2019 were evaluated. Organisms included, but were not limited to: E. coli, K. pneumoniae, Enterobacter spp., and P. aeruginosa, Proteus spp., Salmonella spp., Acinetobacter spp., and S. maltophilia. There were 5,201 drug/bug combinations. AdventHealth Orlando achieved an essential agreement of 99.32% (n=5,166), minor error 0.74% (n=39) major error 0.02% (n=1) and very major error 0.49% (n=2). A 100% agreement was achieved on detection of ESBL, CRE, and MDR organisms. Conclusion Rapid direct blood culture protocol using the VITEK®2 System and the AST-GN cards is accurate, reliable and can be performed with less than 1 minute hands-on time. The protocol can be implemented in any laboratory at no additional costs or modification where the current VITEK®2 AST-GN panels are in use. This protocol was clinically implemented at AdventHealth Orlando on July 15, 2019. Compared with the national average of 72 hours, the TAT obtained during this study was 23 hours from positive blood culture to final susceptibility, a significant reduction of 25 hours. The authors encourage bioMérieux Inc. to evaluate and explore the opportunity to expand the use of the VITEK®2 system for this application with the appropriate clinical trial. Disclosures All Authors: No reported disclosures

scholarly journals Rapid and accurate direct antibiotic susceptibility testing of blood culture broths using MALDI Sepsityper combined with the BD Phoenix automated system

2014 ◽  
Vol 63 (12) ◽  
pp. 1590-1594 ◽  
Author(s):  
Briony Hazelton ◽  
Lee C. Thomas ◽  
Thomas Olma ◽  
Jen Kok ◽  
Matthew O’Sullivan ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Turnaround Time ◽  
Automated System ◽  
Antibiotic Susceptibility Testing ◽  
Gram Negative ◽  
Cell Pellet ◽  
Novel Method ◽  
Susceptibility Tests

Antibiotic susceptibility testing with the BD Phoenix system on bacterial cell pellets generated from blood culture broths using the Bruker MALDI Sepsityper kit was evaluated. Seventy-six Gram-negative isolates, including 12 with defined multi-resistant phenotypes, had antibiotic susceptibility testing (AST) performed by Phoenix on the cell pellet in parallel with conventional methods. In total, 1414/1444 (97.9 %) of susceptibility tests were concordant, with only 1 (0.07 %) very major error. This novel method has the potential to reduce the turnaround time for AST results by up to a day for Gram-negative bacteraemias.

scholarly journals Direct testing by VITEK® 2: A dependable method to reduce turnaround time in Gram-negative bloodstream infections

2018 ◽  
Vol 10 (03) ◽  
pp. 260-264
Author(s):  
Purabi Barman ◽  
Shimpi Chopra ◽  
Tarun Thukral
Keyword(s):  
Blood Culture ◽  
Conventional Method ◽  
Direct Method ◽  
Bloodstream Infections ◽  
Turnaround Time ◽  
Test Accuracy ◽  
Major Error ◽  
Gram Negative ◽  
Direct Testing ◽  
Microbiological Methods

ABSTRACT CONTEXT: Bloodstream infections pose a major health-care burden worldwide. Routine microbiological methods are time-consuming, thereby delaying appropriate treatment. AIMS: The aim of this study is to evaluate the method of direct testing of identification (ID) and antimicrobial susceptibility testing (AST) of positive blood culture bottles by VITEK®2. SETTINGS AND DESIGN: This was a prospective study at a tertiary level hospital. SUBJECTS AND METHODS: One hundred positive BACTEC blood culture bottles with monomicrobial Gram-negative organisms on microscopy were tested in parallel by direct ID/AST as well as conventional method. Results obtained by two methods were compared in terms of ID/AST and turnaround time (TAT). Results: Of the 100 isolates tested, only one was misidentified by the direct method and there was no unidentified isolate. The AST results demonstrated 99.74% categorical and 99.65% essential agreement. Of 1144 organism-antibiotic combinations, there were 0.44% major error, no very major error, or minor error observed. Conclusions: While conventional method is the gold standard, the direct ID/AST methods have demonstrated that it can be successfully utilized to decrease TAT to the final results by 18–24 h, without sacrificing test accuracy. This technique will help to tailor antimicrobial therapy, thereby reducing patient morbidity, mortality, and antibiotic resistance, as well.

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 2144. Performance of 2019 CLSI Ciprofloxacin Breakpoint Antimicrobial Susceptibility Testing Algorithms for Enterobacteriaceae and Pseudomonas aeruginosa Directly from Positive Blood Culture on the Accelerate Pheno™ System

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S726-S727
Author(s):  
Alena Shamsheyeva ◽  
Niels Oppermann ◽  
Aimee Taku ◽  
Anyangatia Ndobegang ◽  
Dulini Gamage ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Blood Culture ◽  
Positive Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Outcome Data ◽  
Antimicrobial Susceptibility Testing ◽  
Bacterial Cells ◽  
Major Error ◽  
New Research

Abstract Background The Clinical and Laboratory Standards Institute (CLSI) updated fluoroquinolone breakpoints in 2019 in response to evolving resistance and new outcome data. The performance of updated antimicrobial susceptibility testing (AST) algorithms for ciprofloxacin with the 2019 breakpoints for Enterobacteriaceae and Pseudomonas aeruginosa was evaluated using the Accelerate Pheno™ system with contrived positive blood culture samples compared with broth microdilution (BMD). Methods A total of 294 clinical isolates (100 P. aeruginosa, 82 Klebsiella spp., 56 E. coli, 24 Citrobacter spp., 14 Enterobacter spp., 15 Proteus spp., and 3 S. marcescens) were tested with ciprofloxacin. Aliquots of BD BACTEC™ Standard Aerobic media containing healthy donor blood were seeded with 10–100 bacterial cells and incubated until positivity. Aliquots of the positive blood cultures were run using the Accelerate PhenoTest™ BC kit on the Accelerate Pheno™ system according to the manufacturer instructions for use. Results were obtained using an updated ciprofloxacin algorithm and compared with CLSI standard reference BMD. Only samples with valid results with both the Accelerate Pheno™ system and reference BMD were included in analysis. Essential agreement (EA), categorical agreement (CA), very major error (VME), major error (ME) and minor error (mE) rates were calculated using 2019 CLSI breakpoints. Results EA and CA for all antimicrobial/organism combinations were >94%. There were 2 MEs (1 K. pneumoniae, 1 C. freundii) and no VMEs. Conclusion Results with the new research use only (RUO) algorithms are very good and meet FDA acceptance criteria for AST performance. These data will be submitted to the FDA for clearance, once FDA recognizes the CLSI breakpoints. Disclosures All authors: No reported disclosures.

scholarly journals Evaluation of the Performance of Direct Susceptibility Test by VITEK-2 from Positively Flagged Blood Culture Broth for Gram-Negative Bacilli

2021 ◽  
Author(s):  
Kavipriya D. ◽  
Suman Susan Prakash ◽  
Sarumathi Dhandapani ◽  
Deepashree Rajshekar ◽  
Apurba Sankar Sastry
Keyword(s):  
Blood Culture ◽  
Susceptibility Testing ◽  
Blood Stream Infection ◽  
Tertiary Care ◽  
Reference Method ◽  
Culture Broth ◽  
Timely Initiation ◽  
Gram Negative ◽  
Mortality And Morbidity ◽  
Vitek 2

Abstract Background Timely initiation of antimicrobial therapy in patients with blood stream infection is absolutely necessary to reduce mortality and morbidity. Most clinical microbiology laboratories use conventional methods for identification and antimicrobial susceptibility testing (AST) that involve biochemical methods for identification followed by AST by disk diffusion. The aim of the current study is to assess the various errors associated with direct susceptibility testing done from blood culture broth using automated AST system-Vitek-2 compact compared with the reference method of AST done from bacterial colonies. Materials and Methods The study was conducted in a tertiary care public sector 2,200-bedded hospital in South India for a period of 6 months. The study involved positively flagged blood culture bottles that yielded single morphotype of Gram-negative organism by Gram stain. A total of 120 bacterial isolates were collected that consisted of consecutively obtained first 60 isolates of Enterobacteriaceae family (30 Escherichia coli and 30 Klebsiella pneumoniae) and consecutively obtained first 60 nonfermenters (30 Pseudomonas aeruginosa and 30 Acinetobacter baumannii). Vitek-2 AST was done from these 120 blood culture broth, following the protocol by Biomerieux, and results were obtained. Then, Vitek-2 was done from colonies (reference method) using appropriate panel for Enterobacteriaceae and nonfermenters, and results were obtained. Both the results were compared. Results Nonfermenters showed a better categorical agreement of 97.6%, as compared to Enterobacteriaceae, which showed 97%. Among Enterobacteriaceae, both E. coli and K. pneumoniae showed categorical agreement of 97% each. Conclusion The procedure of AST directly from blood culture broth represents a simple and effective technique that can reduce the turnaround time by 24 hours, which in turn benefits the clinician in appropriate utilization of antimicrobials for better patient care.

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