scholarly journals Comparison of an Automated System with Conventional Identification and Antimicrobial Susceptibility Testing

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Shalini Duggal ◽  
Rajni Gaind ◽  
Neha Tandon ◽  
Manorama Deb ◽  
Tulsi Das Chugh
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Automated System ◽  
Test Results ◽  
Automated Identification ◽  
Gram Positive ◽  
Accurate Identification ◽  
Gram Negative ◽  
Manual Methods ◽  
Better Than

The present study was designed to compare a fully automated identification/antibiotic susceptibility testing (AST) system BD Phoenix (BD) for its efficacy in rapid and accurate identification and AST with conventional manual methods and to determine if the errors reported in AST, such as the (very major errors) VME (false susceptibility), (major errors) ME (false resistance), and (minor errors) MiE (intermediate category interpretation) were within the range certified by FDA. Identification and antimicrobial susceptibility test results of eighty-five clinical isolates including both gram-positive and negative were compared on Phoenix considering the results obtained from conventional manual methods of identification and disc diffusion testing of antibiotics as standards for comparison. Phoenix performed favorably well. There was 100% concordance in identification for gram-negative isolates and 94.83% for gram-positive isolates. In seven cases, Phoenix proved better than conventional identification. For antibiotic results, categorical agreement was 98.02% for gram-positive and 95.7% for gram-negative isolates. VME was 0.33%, ME 0.66%, MiE 0.99% for gram-positive isolates and 1.23% VME, 1.23% ME, and 1.85% MiE for gram-negative isolates. Therefore, this automated system can be used as a tool to facilitate early identification and susceptibility pattern of aerobic bacteria in routine microbiology laboratories.

scholarly journals Comparison of Automated System Vitek-2 with Conventional Methods, for Identification and Antibiotic Sensitivity in Gram Positive Organisms.

JMS SKIMS ◽  
2019 ◽  
Vol 22 (2) ◽  
Author(s):  
Nayeem U din Wani ◽  
Nargis Bali ◽  
Lenah Bashir ◽  
Junaid Ahmad ◽  
Suhail Ahmad
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antibiotic Sensitivity ◽  
Blood Stream ◽  
Antimicrobial Susceptibility Testing ◽  
Automated System ◽  
Major Error ◽  
Gram Positive ◽  
Manual Methods ◽  
Vitek 2

Abstract Background: Prompt identification (ID) and antimicrobial susceptibility testing (AST) of organisms causing blood stream infections has a significant impact on the morbidity and mortality associated with these infections. The need to circumvent the slow turnaround time of conventional gold standard methods has paved way for the rapid automated systems. Aim: To Compare the results of Vitek-2 for the ID and AST of Gram positive isolates with conventional manual methods. Methodology: A total of 215 non-duplicate isolates of Gram positive bacteria recovered from blood samples were part of this prospective study carried out in the Department of Microbiology. Organisms were processed on the Vitek-2 system and by manual methods (ID/AST) for comparison. Descriptive statistics was used for the presentation and comparison of data and appropriate statistical charts were used to present the data. Observations: Concordant identification (ID) results of Vitek-2 were seen with all the isolates of S. aureus, S. epidermidis, S. pneumonia, E. faecalis and E. faecium. Discordant results of Vitek-2 were seen for S. hominis (5 isolates of the organism misidentified as S. epidermidis).  No minor, major or very major error with 100% categorical agreement (CA) was seen for penicillin, cefoxitin, oxacillin, linezolid, ciprofloxacin, tetracycline, co-trimoxazole, clindamycin and erythromycin for various organisms tested. Enterococci gave minor error of 4.5% with an overall CA of 95.5% for ampicillin and a major error of 2.8% with an overall CA of 97.2% for vancomycin. Conclusion: The organisms having slow metabolic rates and late lactose fermenters (S. hominis) are prone to errors by the Vitek-2 system; hence need to be reconfirmed with other possible method. Also AST results for critical antibiotics like vancomycin need to be verified manually before reporting.  Key words: Antimicrobial Susceptibility testing, Enterococci, Vitek-2

scholarly journals Microbial Profile of Various Catheter Tips among Hospitalized Patients

2018 ◽  
Vol 5 ◽  
pp. 32-38
Author(s):  
Pushpa Man Shrestha ◽  
Nisha Thapa ◽  
Navraj Dahal ◽  
Nabaraj Adhikari ◽  
Upendra Thapa Shrestha
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Descriptive Analysis ◽  
Multidrug Resistant ◽  
Antimicrobial Susceptibility Testing ◽  
Resistance Pattern ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Klebsiella Spp

Objectives: This study aimed to identify the microbiological profile of various catheter tips, and multidrug resistance pattern of extended spectrum β-lactamase (ESBL) producing E. coli and Klebsiella spp. isolates. Methods: A descriptive analysis of 263 catheter tip specimens processed for culture and antimicrobial susceptibility testing was carried out in B&B Hospital, Lalitpur. Five different types of catheter tips were analyzed for microbiological growth and antimicrobial susceptibility testing. Results: Among catheter tips, the highest percentage of microbial growth was observed in tracheostomy tip. Monomicrobial growth was recorded in 82.9% catheter tips and polymicrobial growth was observed in 17.1% tip samples. Of 180 isolates, gram negative rods (76.6%) followed by yeast (19.4%) and gram-positive cocci (3.9%) were isolated. Gram negative Acinetobacter spp. (25%) and Pseudomonas spp. (23.3%) and gram-positive Enterococcus spp. (2.2%) were the most frequently isolated bacteria. However, carbapenam was the most effective antibiotic for both groups. Conclusion: Of the total isolates tested, 61.4% were found to be multidrug resistant (MDR). Among gram negative rods, 22.2% E. coli and 27.3% Klebsiella spp. were confirmed as ESBL producer. It is recommended to apply standard protocol during insertion and removal of catheter which may help in managing nosocomial infection associated with catheters.

scholarly journals Breast Abscesses Caused by Anaerobic Microorganisms: Clinical and Microbiological Characteristics

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 341 ◽  
Author(s):  
Fernando Cobo ◽  
Vicente Guillot ◽  
José María Navarro-Marí
Keyword(s):  
Clavulanic Acid ◽  
High Resistance ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Local Data ◽  
Gram Positive ◽  
Gram Negative ◽  
Amoxicillin Clavulanic Acid ◽  
Resistance Rates

The objectives of this study were to report the antimicrobial susceptibility of 35 clinically significant anaerobic bacteria isolated from breast abscesses between March 2017 and February 2020 in a tertiary hospital in Granada (Spain) and to describe key clinical features of the patients. Species identification was performed mainly by MALDI-TOF MS. Antimicrobial susceptibility tests were carried out against benzylpenicillin, amoxicillin–clavulanic acid, imipenem, moxifloxacin, clindamycin, metronidazole, and piperacillin–tazobactam using the gradient diffusion technique and European Committee on Antimicrobial Susceptibility Testing EUCAST breakpoints (except for moxifloxacin). The most frequent anaerobes were Finegoldia magna (31.4%; n = 11), Actinomyces spp. (17.1%; n = 6), Propionibacterium spp. (17.1%; n = 6), and Prevotella spp. (14.2%; n = 5). Imipenem, amoxicillin–clavulanic acid, and piperacillin–tazobactam were universally active against all genera tested. High overall resistance rates to clindamycin were observed, especially for Gram-positive anaerobic cocci (56.2%) and Gram-positive anaerobic bacilli (38.4%). High resistance rates to metronidazole were also observed for Gram-positive (76.9%) and Gram-negative anaerobic bacilli (50%). High resistance rates to moxifloxacin were found for Gram-negative anaerobic bacilli (50%) and Gram-positive anaerobic cocci (31.2%). No breast abscess cases of Bacteroides spp. were detected. Routine antimicrobial susceptibility testing for anaerobes in breast abscesses may contribute to allow empirical therapies to be selected in accordance with local data on resistant strains.

scholarly journals Rapid antimicrobial susceptibility testing on positive blood cultures through an innovative light scattering technology: performances and turnaround time evaluation

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lidvine Boland ◽  
Corentin Streel ◽  
Hélène De Wolf ◽  
Hector Rodriguez ◽  
Alexia Verroken
Keyword(s):  
Light Scattering ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Turnaround Time ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Cocci

Abstract Background A bacteremia diagnosis with speeded-up identification and antimicrobial susceptibility testing (AST) is mandatory to adjust empirical broad-spectrum antibiotherapy and avoid the emergence of multi-resistant bacteria. Alfred 60AST (Alifax, Polverara, PD, Italy) is an innovative automated system based on light scattering measurements allowing direct AST from positive blood cultures with rapid results. In this study we aimed to evaluate the system’s performances and turnaround time (TAT) compared to routine AST. Methods The study was conducted during 2 non-consecutive 3-month periods at the microbiology laboratory of the Cliniques universitaires Saint-Luc. All blood cultures detected positive in the 0 AM–10 AM time frame with a pure Gram-positive cocci or Gram-negative bacilli stain were included for Alfred 60AST testing. Two customized EUCAST antibiotic panels were set up composed of 1) a “Gram-negative” panel including cefuroxime, ceftazidime Enterobacteriaceae, piperacillin-tazobactam Enterobacteriaceae, ciprofloxacine, and ceftazidime Pseudomonas 2) a “Gram-positive” panel including cefoxitin Staphylococcus aureus, cefoxitin coagulase-negative (CNS) Staphylococci and ampicillin Enterococci. Categorical agreement (CA), very major errors (VME), major errors (ME), minor errors (mE) and TAT to Alfred 60AST results were calculated in comparison with AST results obtained from direct testing on positive blood cultures with the Phoenix system (Becton Dickinson, Franklin Lakes, NJ, USA). Results Five hundred seventy and one hundred nine antibiotics were evaluated on respectively 166 Gram-negative bacilli and 109 Gram-positive cocci included in the studied population. During the first study period regarding Gram-negative strains a CA of 89.5% was obtained with a high rate of VME (19 and 15.4% respectively) for cefuroxime and piperacillin-tazobactam Enterobacteriaceae. Considering this, Alifax reviewed these antibiotics’ formulations improving Gram-negative bacilli total CA to 92.2% with no VME during the second study period. For Gram-positive cocci, total CA was 88.1% with 2.3% VME, 13.8% ME (mainly cefoxitin CNS) and 12% mE rates both study periods combined. Median TAT to AST results was 5 h with Alfred versus 12 h34 with Phoenix. Conclusion The Alfred 60AST system shows correct yet improvable microbiological performances and a major TAT reduction compared to direct automated AST testing. Clinical studies measuring the impact of the approach on antibiotic management of patients with bacteremia are recommended.

scholarly journals Identification and antimicrobial susceptibility testing of Gram-positive and Gram-negative bacteria from positive blood cultures using the Accelerate Pheno™ system

2019 ◽  
Vol 39 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Måns Ullberg ◽  
Volkan Özenci
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Antimicrobial Susceptibility Testing ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Hands On

Abstract Rapid identification and antimicrobial susceptibility testing remain a crucial step for early efficient therapy of bloodstream infections. Traditional methods require turnaround times of at least 2 days, while rapid procedures are often associated with extended hands-on time. The Accelerate Pheno™ System provides microbial identification results within 90 min and susceptibility data in approximately 7 h directly from positive blood cultures with only few minutes of hands-on time. The aim of this study was, therefore, to evaluate the performance of the Accelerate Pheno™ System in identification and antimicrobial susceptibility testing of both Gram-positive and Gram-negative bacteria directly from clinical blood culture samples. We analyzed 108 and 67 blood culture bottles using the Accelerate PhenoTest™ BC kit with software version v1.0 and the FDA-cleared version v1.2, respectively. Reliable identification was achieved for Enterobacteriaceae, staphylococci, and enterococci, with 76/80 (95%), 42/46 (91%), and 10/11 (91%) correct identifications. Limitations were observed in the identification of streptococci, including Streptococcus pneumoniae and Streptococcus pyogenes, and coagulase-negative staphylococci. Antimicrobial susceptibility results for Enterobacteriaceae, for amikacin, ertapenem, ciprofloxacin, gentamicin, meropenem, and piperacillin-tazobactam ranged between 86 and 100% categorical agreement. Using v1.2, results for ceftazidime showed 100% concordance with the reference method. For staphylococci, the overall performance reached 92% using v1.2. Qualitative tests for detection of methicillin or macrolide-lincosamide-streptogramin B (MLSB) resistance caused major and very major errors for isolates. Overall, the present data show that the Accelerate Pheno™ system can, in combination with Gram stain, be used as a rapid complementation to standard microbial diagnosis of bloodstream infections.

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