scholarly journals Feasibility and potential significance of rapid in vitro qualitative phenotypic antimicrobial susceptibility testing of gram-negative bacilli with the ProMax system

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249203
Author(s):  
Jade Chen ◽  
Michael Tomasek ◽  
Amorina Cruz ◽  
Matthew L. Faron ◽  
Dakai Liu ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Pathogenic Bacteria ◽  
Susceptibility Testing ◽  
Klebsiella Oxytoca ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Clinical Samples ◽  
Automation System ◽  
Gram Negative

The emergence and evolution of antibiotic resistance has been accelerated due to the widespread use of antibiotics and a lack of timely diagnostic tests that guide therapeutic treatment with adequate sensitivity, specificity, and antimicrobial susceptibility testing (AST) accuracy. Automated AST instruments are extensively used in clinical microbiology labs and provide a streamlined workflow, simplifying susceptibility testing for pathogenic bacteria isolated from clinical samples. Although currently used commercial systems such as the Vitek2 and BD Phoenix can deliver results in substantially less time than conventional methods, their dependence on traditional AST inoculum concentrations and optical detection limit their speed somewhat. Herein, we describe the GeneFluidics ProMax lab automation system intended for a rapid 3.5-hour molecular AST from clinical isolates. The detection method described utilizes a higher starting inoculum concentration and automated molecular quantification of species-specific 16S rRNA through the use of an electrochemical sensor to assess microbiological responses to antibiotic exposure. A panel of clinical isolates consisting of species of gram-negative rods from the CDC AR bank and two hospitals, New York-Presbyterian Queens and Medical College of Wisconsin, were evaluated against ciprofloxacin, gentamicin, and meropenem in a series of reproducibility and clinical studies. The categorical agreement and reproducibility for Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella aerogenes, Klebsiella oxytoca, Klebsiella pneumoniae, and Pseudomonas aeruginosa were 100% and 100% for ciprofloxacin, 98.7% and 100% for gentamicin and 98.5% and 98.5% for meropenem, respectively.

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 Cefiderocol Antimicrobial Susceptibility Testing Considerations: the Achilles' Heel of the Trojan Horse?

2020 ◽  
Vol 59 (1) ◽  
pp. e00951-20 ◽  
Author(s):  
Patricia J. Simner ◽  
Robin Patel
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Disk Diffusion ◽  
Research Use ◽  
Gram Negative ◽  
Content Type ◽  
Mueller Hinton

ABSTRACTCefiderocol (formerly S-649266) is a novel siderophore-conjugated cephalosporin with activity against a broad array of multidrug-resistant (MDR), aerobic Gram-negative bacilli. The siderophore component binds iron and uses active iron transport for drug entry into the bacterial periplasmic space. The cephalosporin moiety is the active antimicrobial component, structurally resembling a hybrid between ceftazidime and cefepime. Like other β-lactam agents, the principal bactericidal activity of cefiderocol occurs via inhibition of bacterial cell wall synthesis by binding of penicillin-binding proteins (PBPs) and inhibiting peptidoglycan synthesis, leading to cell death. Iron concentrations need to be taken into consideration when in vitro antimicrobial susceptibility to cefiderocol is determined. Broth microdilution (BMD) and disk diffusion methods have been developed to determine in vitro activity of cefiderocol. For BMD, cation-adjusted Mueller-Hinton broth (CAMHB) requires iron depletion to provide MICs predictive of in vivo activity. A method to prepare iron-depleted CAMHB (ID-CAMHB) has been described by the Clinical and Laboratory Standards Institute (CLSI). For disk diffusion, standard Mueller-Hinton agar is recommended, presumably because iron is bound in the medium. Currently, clinical FDA and European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints and investigational (research-use-only) CLSI breakpoints exist for interpreting cefiderocol susceptibility results for certain Gram-negative bacilli. Cefiderocol does not have clinically relevant activity against Gram-positive or anaerobic organisms. FDA or EUCAST breakpoints should be applied to interpret results for Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii complex for patient care until the investigational status has been removed from CLSI breakpoints. Further clinical outcome data are required to assess the effectiveness of cefiderocol for treatment of other Acinetobacter species (non-baumannii complex) and Stenotrophomonas maltophilia at this time, and, as such, antimicrobial susceptibility testing of these organisms should be limited to research use in the scenario of limited treatment options.

scholarly journals Antimicrobial Susceptibilities of Clinical Isolates of HACEK Organisms

2013 ◽  
Vol 57 (4) ◽  
pp. 1989-1991 ◽  
Author(s):  
Bryan Coburn ◽  
Baldwin Toye ◽  
Prasad Rawte ◽  
Frances B. Jamieson ◽  
David J. Farrell ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Antimicrobial Susceptibilities

ABSTRACTThe “HACEK” organisms are a group of fastidious Gram-negative bacteria that cause a variety of infections, including infective endocarditis. Antimicrobial susceptibility testing is not universally available, and therapy for these infections is often empirical. We report the antimicrobial susceptibilities of 70 clinical HACEK isolates to 18 antimicrobials. All isolates were susceptible to ceftriaxone and levofloxacin, indicating that these agents remain appropriate empirical choices for the treatment of infections with this group of organisms.

scholarly journals Comparison of Accelerate PhenoTest™ BC Kit vs. MALDI-TOF MS/VITEK®2 System for the Rapid Identification and Antimicrobial Susceptibility Testing of Gram-negative Bacilli Causing Bloodstream Infections

2019 ◽  
Author(s):  
William Stokes ◽  
Lorraine Campbell ◽  
Johann Pitout ◽  
John Conly ◽  
Deirdre Church ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Bloodstream Infections ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Samples ◽  
Gram Negative ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Conventional Methods ◽  
Tof Ms

Abstract Introduction: Our laboratory uses MALDI-TOF MS (MALDI) and the VITEK®2 system (DV2) directly from positive blood cultures (BC) for organism identification (ID) and antimicrobial susceptibility testing (AST). Our objective was to compare direct MALDI/DV2 to a commercial BC ID/AST platform, the Accelerate Pheno™ system, in the ID/AST of clinical and seeded BC positive for Gram-negative bacilli (GNB). Methods: BC positive for GNB were collected over a three month period and tested using AXDX, direct MALDI/DV2, and compared to conventional methods. A subset of sterile BC were seeded with multi-drug resistant GNB. Discrepancies in very major errors (VME) and major errors (ME) were confirmed with broth microdilution. Results: A total of 29 clinical samples and 35 seeded samples were analyzed. Direct MALDI had a higher ID failure rate (31.0%) compared to AXDX (3.4%) [p<0.001]. Time to ID/AST was 1.5/6.9 hours, 5.8/16.5 hours and 21.6/33.0 hours for AXDX, direct MALDI/DV2 and conventional methods, respectively (p<0.001). For clinical samples, AXDX and DV2 had essential agreement (EA)/categorical agreement (CA) >96%. For seeded samples, AXDX had EA, CA, VME, ME and mE of 93.2%, 89.0%, 2.2%, 0%, and 9.2%, respectively. AXDX had a large number of non-reports (6.1%), stemming from meropenem testing. DV2 had EA, CA, VME, ME and mE of 97.5%, 94.7%, 1.3%, 0%, and 4.4%, respectively. Conclusions: AXDX had fewer ID failures and more rapid ID/AST results. Direct MALDI/DV2 and AXDX both had high agreement for clinical samples but direct MALDI/DV2 had higher agreement when challenged with MDR GNB.

scholarly journals In Vitro Activity of OPT-80 Tested against Clinical Isolates of Toxin-Producing Clostridium difficile

2008 ◽  
Vol 52 (11) ◽  
pp. 4163-4165 ◽  
Author(s):  
James A. Karlowsky ◽  
Nancy M. Laing ◽  
George G. Zhanel
Keyword(s):  
Clostridium Difficile ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Agar Dilution

ABSTRACT Agar dilution antimicrobial susceptibility testing (CLSI, M11-A7, 2007) performed for 208 toxin-producing clinical isolates of Clostridium difficile resulted in OPT-80 MICs ranging from 0.06 to 1 μg/ml, with 90% of the isolates inhibited by a concentration of 0.5 μg/ml. The in vitro activity of OPT-80 was independent of the susceptibilities of isolates to nine other antimicrobial agents.

scholarly journals Analysis of Potential β-Lactam Surrogates To Predict In Vitro Susceptibility and Resistance to Ceftaroline for Clinical Isolates of Enterobacteriaceae

2018 ◽  
Vol 56 (4) ◽  
pp. e01892-17
Author(s):  
Meredith A. Hackel ◽  
Joseph P. Iaconis ◽  
James A. Karlowsky ◽  
Daniel F. Sahm
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
The United States ◽  
Antimicrobial Susceptibility Testing ◽  
Clinical Isolates ◽  
Content Type ◽  
United States Food ◽  
States Food ◽  
Susceptibility And Resistance

ABSTRACT Ceftaroline fosamil was approved by the United States Food and Drug Administration in 2010 and by the European Medicines Agency in 2012. As of April 2017, only one commercial antimicrobial susceptibility testing device offered a Gram-negative panel that included ceftaroline. This circumstance is unfortunate, as many clinical microbiology laboratories rely solely on commercial devices to generate in vitro antimicrobial susceptibility testing results for common bacterial pathogens. In lieu of device-based testing of clinical isolates of Enterobacteriaceae, laboratories wishing to test ceftaroline must either opt for disk diffusion testing or use a gradient strip; however, both alternatives interrupt laboratory workflow and require additional labor and expense. Identification of a reliable surrogate β-lactam to predict in vitro susceptibility to ceftaroline may offer another interim solution as laboratories await availability of ceftaroline for testing on their commercial devices. We tested six β-lactams (aztreonam, ceftazidime, ceftriaxone, cefotaxime, cefoxitin, and cefpodoxime) as potential surrogates for ceftaroline against a collection of 543 clinical isolates of Enterobacteriaceae selected to approximate the distribution of ceftaroline MICs observed in AWARE global surveillance studies conducted in 2013. All six potential surrogates generated very major error rates of 16.3% to 56.6%, far exceeding the accepted limit of 1.5% set by the Clinical and Laboratory Standards Institute (CLSI) and the United States Food and Drug Administration (FDA) Center for Devices and Radiological Health. Failure to identify a reliable surrogate to predict in vitro susceptibility and resistance to ceftaroline for clinical isolates of Enterobacteriaceae underscores the need for expedited addition of newer antimicrobial agents to commercial antimicrobial susceptibility testing devices.

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