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.

Occurrence of Non-Fermenting Gram-Negative Bacilli and Their In Vitro Susceptibility Pattern by Vitek 2 at a Tertiary Care Teaching Hospital – An Observational Study

2021 ◽  
Vol 8 (8) ◽  
pp. 429-434
Author(s):  
Atit Dineshchandra Shah ◽  
Urvashi Natubhai Limbachia ◽  
Bhavin K. Prajapati ◽  
Lata Patel ◽  
Dharati Tusharbhai Shah ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Multidrug Resistance ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Samples ◽  
Gram Negative ◽  
Vitek 2

BACKGROUND Non fermenting gram-negative bacilli (NFGNB) are a group of heterogenous, aerobic and non-sporing saprophytic bacteria, found as commensals in humans and other animals primarily causing opportunistic healthcare-associated infections. They are innately resistant to many antibiotics and are known to acquire resistance by various mechanisms. They pose a particular difficulty for the healthcare community because multidrug resistance is common and increasing among them and a number of strains have now been identified that exhibit pan drug resistance. This study was conducted to isolate and identify various non-fermenter gram negative bacilli (NFGNB), to study their antibiotic sensitivity pattern and their clinical significance from various clinical samples. METHODS A study was undertaken from March 2019 to February 2020 to isolate NFGNB from various clinical samples received for culture and sensitivity in the department of microbiology in a tertiary care hospital, Ahmedabad. Non lactose fermenting colonies on MacConkey agar plates were further processed by Vitek 2 to identify them and to study their antimicrobial susceptibility testing (AST). RESULTS A total of 2010 NFGNB were isolated from various clinical samples and their AST was evaluated by Vitek 2. Pseudomonas aeruginosa (52.7 %) and Acinetobacter baumannii (36.5 %) were the most common NFGNB isolated. Carbapenem resistance was 93 % for Acinetobacter species and 61 % for Pseudomonas species. CONCLUSIONS Accurate and rapid identification and antimicrobial susceptibility testing of NFGNB help in early initiation of appropriate antimicrobial therapy and proper management of patients thereby help in reducing emergence of MDR strains of NFGNB, mortality and overall hospital stay. KEYWORDS NFGNB – Non-Fermenting Gram-Negative Bacilli, Multidrug Resistance, Pan Drug Resistance, Carbapenem Resistance

scholarly journals Direct susceptibility testing by disk diffusion on positive BacT/ALERT blood cultures: A rapid and definite tool for antibiotic stewardship

2021 ◽  
Vol 7 (3) ◽  
pp. 179-185
Author(s):  
Sandhya Bhat K ◽  
V Lokeshwari
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antibiotic Stewardship ◽  
Susceptibility Testing ◽  
Tertiary Care ◽  
Blood Stream ◽  
Careful Consideration ◽  
Tertiary Care Centre ◽  
Gram Negative ◽  
Mortality And Morbidity ◽  
Gram Staining

Blood stream infections continue to be the major cause of mortality and morbidity and hence early availability of direct susceptibility reports can be lifesaving. This study aims to ascertain if direct susceptibility testing (DST) can be used as a diagnostic tool in bacteremic patients and to correlate the results of both DST and standard antimicrobial susceptibility reports (AST), thereby serving to benefit both the patients and also to reduce the irrational use of antibiotics. An experimental study was carried out after obtaining waiver of consent, in a tertiary care centre. A total of 37 patients were included in the study after careful consideration of the inclusion and exclusion criteria. Gram staining report, bacteriological profile, direct susceptibility report, antimicrobial susceptibility report of all the isolates were documented. Statistical analysis was done by using IBM SPSS software. Overall prevalence of sepsis was 40.5%. Gram negative bacteria were more commonly isolated (83.8) and Escherichia coli was the commonest isolate (51.4%). The antimicrobial resistance was observed maximum for amoxicillin/clavulanic acid (66.7%), ceftriaxone (60.6%), Cefotaxime (57.6%) and least for meropenem (9.1%), imipenem (6.1%). On comparison of DST with AST among 28 gram-negative Enterobacteriaceae isolates 15 minor errors (4.8%) and three major errors (0.97%) were recorded, with maximum errors being documented for piperacillin/tazobactam with five minor errors (17.9%) and one major error (3.6%). DST is an important tool for early institution of targeted therapy and should be considered as one of the step towards antibiotic stewardship intervention.

Healthcare associated infections caused by non-fermenting Gram negative rods (NFGNR): six years of experience of a tertiary hospital

2013 ◽  
Vol 7 (2) ◽  
pp. 06-12
Author(s):  
Zahidul Hasan ◽  
Md. Kamrul Islam ◽  
Arifa Hossain
Keyword(s):  
Blood Stream Infection ◽  
Tertiary Care ◽  
Blood Stream ◽  
Tertiary Hospital ◽  
Healthcare Associated Infections ◽  
Care Hospital ◽  
Gram Negative ◽  
Acinetobacter Spp ◽  
Tract Infections ◽  
Healthcare Associated

Recently non-fermenting Gram negative rods (NFGNR) are playing an important role in healthcare associated infections. This observational study in a tertiary care hospital of Dhaka city conducted during 01August 2007 to 30 June 2013 found that 34.8% isolated organisms from patients with healthcare associated infections were NFGNR. Majority (74.3 %) of these infections were occurring inside critical care areas. Pseudomonas and Acinetobacter together constituted 79.6% of the total NFGNR whereas Burkholderia cephacia complex (15.4%), Stenotrophomonas (4.3%) and Chryseobacterium species (0.7%) combined constituted remaining 20.4%. Out of total NFGNRs, Pseudomonas was responsible for highest number of catheter associated urinary tract infections (55.6%), ventilator associated pneumonia (46.3%), respiratory tract infection (65.8%) and surgical site infection (70.6%). Blood stream infection was predominantly caused by Burkholderia cephacia complex (33.5%) and Acinetobacter spp. (39.5%). Other than colistin most of the organisms were resistant to antibiotics commonly recommended for NFGNR.DOI: http://dx.doi.org/10.3329/bjmm.v7i2.19326 Bangladesh J Med Microbiol 2013; 07(02): 6-12

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 Applicability and performance of EUCAST’s rapid antimicrobial susceptibility testing (RAST) on primarily sterile body fluids in blood culture bottles in laboratory routine with total lab automation

2021 ◽  
Author(s):  
Jasmin Kaur Jasuja ◽  
Stefan Zimmermann ◽  
Irene Burckhardt
Keyword(s):  
Blood Culture ◽  
Susceptibility Testing ◽  
Reference Method ◽  
Body Fluids ◽  
E Coli ◽  
Mueller Hinton ◽  
Mueller Hinton Agar ◽  
And Performance ◽  
Sterile Body Fluids ◽  
Better Than

AbstractOptimisation of microbiological diagnostics in primarily sterile body fluids is required. Our objective was to apply EUCAST’s RAST on primarily sterile body fluids in blood culture bottles with total lab automation (TLA) and to compare results to our reference method Vitek2 in order to report susceptibility results earlier. Positive blood culture bottles (BACTEC™ Aerobic/Anaerobic/PEDS) inoculated with primarily sterile body fluids were semi-automatically subcultured onto Columbia 5% SB agar, chocolate agar, MacConkey agar, Schaedler/KV agar and Mueller-Hinton agar. On latter, cefoxitin, ampicillin, vancomycin, piperacillin/tazobactam, meropenem and ciprofloxacin were added. After 6 h, subcultures and RAST were imaged and MALDI-TOF MS was performed. Zone sizes were digitally measured and interpreted following RAST breakpoints for blood cultures. MIC values were determined using Vitek2 panels. During a 1-year period, 197 Staphylococcus aureus, 91 Enterococcus spp., 38 Escherichia coli, 11 Klebsiella pneumoniae and 8 Pseudomonas aeruginosa were found. Categorical agreement between RAST and MIC was 96.5%. Comparison showed no very major errors, 2/7 (28.6%) and 1/7 (14.3%) of major errors for P. aeruginosa and meropenem and ciprofloxacin, 1/9 (11.1%) for K. pneumoniae and ciprofloxacin, 4/69 (7.0%) and 3/43 (5.8%) for Enterococcus spp. and vancomycin and ampicillin, respectively. Minor errors for P. aeruginosa and meropenem (1/8; 12.8%) and for E. coli and ciprofloxacin (2/29; 6.5%) were found. 30/550 RAST measurements were within area of technical uncertainty. RAST is applicable and performs well for primarily sterile body fluids in blood culture bottles, partially better than blood-based RAST. Official EUCAST evaluation is needed.

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