scholarly journals Determination of Disk Diffusion and MIC Quality Control Guidelines for Solithromycin, a Novel Fluoroketolide Antibacterial, against Neisseria gonorrhoeae

2015 ◽  
Vol 53 (12) ◽  
pp. 3888-3890 ◽  
Author(s):  
Stefan Riedel ◽  
James E. Ross ◽  
David J. Farrell ◽  
Robert K. Flamm ◽  
Ronald N. Jones
Keyword(s):  
Quality Control ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Control Strain ◽  
Content Type ◽  
Disk Diffusion Testing ◽  
Quality Control Study ◽  
Agar Dilution ◽  
Control Study

This solithromycin quality control study was performed to establish quality control (QC) ranges for theN. gonorrhoeaeATCC 49226 control strain for MIC agar dilution testing (AD) and zones by disk diffusion testing (DD). The following ranges were established: AD, 0.03 to 0.25 μg/ml, and DD, 33 to 43 mm. In January 2015, the CLSI Subcommittee on Antimicrobial Susceptibility Testing approved these ranges, which will be important when evaluating solithromycin against clinical isolates ofN. gonorrhoeae.

scholarly journals Determination of MIC Quality Control Ranges for the Novel Gyrase Inhibitor Zoliflodacin

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Alita A. Miller ◽  
Maria M. Traczewski ◽  
Michael D. Huband ◽  
Patricia A. Bradford ◽  
John P. Mueller
Keyword(s):  
Quality Control ◽  
Susceptibility Testing ◽  
The Novel ◽  
Tier 2 ◽  
Phase 3 ◽  
Content Type ◽  
Surveillance Studies ◽  
Agar Dilution

ABSTRACT This report describes the results of two different, multilaboratory quality control (QC) studies that were used to establish QC ranges for the novel gyrase inhibitor zoliflodacin against the ATCC strains recommended by the Clinical and Laboratory Standards Institute (CLSI). Following the completion of an eight-laboratory, CLSI document M23-defined tier 2 study, the agar dilution MIC QC range for zoliflodacin against the Neisseria gonorrhoeae QC strain ATCC 49226 was defined as 0.06 to 0.5 μg/ml and was approved by the CLSI Subcommittee on Antimicrobial Susceptibility Testing. This QC range will be used for in vitro susceptibility testing of zoliflodacin during phase 3 human clinical trials and surveillance studies, and eventually it will be implemented in clinical labs. In a separate study, broth microdilution MIC quality control ranges for zoliflodacin against additional QC strains were determined to be 0.12 to 0.5 μg/ml for Staphylococcus aureus ATCC 29213, 0.25 to 2 μg/ml for Enterococcus faecalis ATCC 29212, 1 to 4 μg/ml for Escherichia coli ATCC 25922, 0.12 to 0.5 μg/ml for Streptococcus pneumoniae ATCC 49619, and 0.12 to 1 μg/ml for Haemophilus influenzae ATCC 49247. These MIC QC ranges were also approved by CLSI for use in future in vitro susceptibility testing studies against organisms other than N. gonorrhoeae.

scholarly journals Determination of Disk Diffusion and MIC Quality Control Ranges for Nafithromycin (WCK 4873), a New Lactone-Ketolide

2017 ◽  
Vol 55 (10) ◽  
pp. 3021-3027 ◽  
Author(s):  
Meredith A. Hackel ◽  
James A. Karlowsky ◽  
Dana Dressel ◽  
Daniel F. Sahm
Keyword(s):  
Quality Control ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Tier 2 ◽  
Phase 3 ◽  
Content Type ◽  
Surveillance Studies ◽  
Testing Patient

ABSTRACTDisk diffusion and MIC quality control (QC) ranges were determined for nafithromycin, a new lactone-ketolide, following the completion of a nine-laboratory, Clinical and Laboratory Standards Institute (CLSI) document M23-defined tier 2 study. Five QC strains consistent with the spectrum of activity of nafithromycin were tested:Staphylococcus aureusATCC 25923 (disk only),S. aureusATCC 29213 (broth only),Enterococcus faecalisATCC 29212 (broth only),Streptococcus pneumoniaeATCC 49619 (disk and broth), andHaemophilus influenzaeATCC 49247 (disk and broth). Nafithromycin disk diffusion QC ranges were determined to be 25 to 31 mm forS. aureusATCC 25923, 25 to 31 mm forS. pneumoniaeATCC 49619, and 16 to 20 mm forH. influenzaeATCC 49247. Nafithromycin MIC QC ranges were determined to be 0.06 to 0.25 μg/ml forS. aureusATCC 29213, 0.016 to 0.12 μg/ml forE. faecalisATCC 29212, 0.008 to 0.03 μg/ml forS. pneumoniaeATCC 49619, and 2 to 8 μg/ml forH. influenzaeATCC 49247. All disk diffusion and MIC QC ranges established in this study were approved by the CLSI Subcommittee on Antimicrobial Susceptibility Testing at their June 2015 meeting and were initially reported in the 2017 M100S document. The QC ranges established in this study should be used for determining thein vitroactivity of nafithromycin in phase 2 and phase 3 human clinical trials and subsequently for testing patient isolates and isolates in phase 4 surveillance studies.

scholarly journals Impact of Variations in Test Method Parameters onIn VitroActivity of Surotomycin against Clostridium difficile and Surotomycin Quality Control Limits for Broth Microdilution and Agar Dilution Susceptibility Testing

2015 ◽  
Vol 54 (3) ◽  
pp. 749-753 ◽  
Author(s):  
Maria M. Traczewski ◽  
Jennifer Deane ◽  
Daniel Sahm ◽  
Steven D. Brown ◽  
Laurent Chesnel
Keyword(s):  
Quality Control ◽  
Clostridium Difficile ◽  
Calcium Concentration ◽  
Susceptibility Testing ◽  
Test Method ◽  
Test Parameter ◽  
Content Type ◽  
Parameter Variations ◽  
Agar Dilution ◽  
Control Limits

Test parameter variations were evaluated for their effects on surotomycin MICs. Calcium concentration was the only variable that influenced MICs; therefore, 50 μg/ml (standard for lipopeptide testing) is recommended. Quality control ranges forClostridium difficile(0.12 to 1 μg/ml) andEggerthella lenta(broth, 1 to 4 μg/ml; agar, 1 to 8 μg/ml) were approved by the Clinical and Laboratory Standards Institute based on these data.

scholarly journals In VitroActivity of Fosfomycin against a Collection of Clinical Pseudomonas aeruginosa Isolates from 16 Spanish Hospitals: Establishing the Validity of Standard Broth Microdilution as Susceptibility Testing Method

2013 ◽  
Vol 57 (11) ◽  
pp. 5701-5703 ◽  
Author(s):  
María Díez-Aguilar ◽  
María-Isabel Morosini ◽  
Rosa del Campo ◽  
María García-Castillo ◽  
Javier Zamora ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Content Type ◽  
Testing Method ◽  
Broth Microdilution Method ◽  
Agar Dilution

ABSTRACTThe broth microdilution method for fosfomycin andPseudomonas aeruginosawas assessed and compared with the approved agar dilution method in 206 genetically unrelatedP. aeruginosaclinical isolates. Essential agreement between the two methods was 84%, and categorical agreement was 89.3%. Additionally, Etest and disk diffusion assays were performed. Results validate broth microdilution as a reliable susceptibility testing method for fosfomycin againstP. aeruginosa. Conversely, unacceptable concordance was established between Etest and disk diffusion results with agar dilution results.

Results of a quality control study of different analytical methods for determination of PCDD/PCDF in egg samples

Chemosphere ◽  
1996 ◽  
Vol 32 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Rainer Malisch ◽  
Peter Schmid ◽  
Rolf Frommberger ◽  
Peter Fürst
Keyword(s):  
Quality Control ◽  
Analytical Methods ◽  
Quality Control Study ◽  
Control Study

scholarly journals Antimicrobial Susceptibilities of Commonly Encountered Bacterial Isolates to Fosfomycin Determined by Agar Dilution and Disk Diffusion Methods

2011 ◽  
Vol 55 (9) ◽  
pp. 4295-4301 ◽  
Author(s):  
Ching-Lan Lu ◽  
Chia-Ying Liu ◽  
Yu-Tsung Huang ◽  
Chun-Hsing Liao ◽  
Lee-Jene Teng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Enterococcus Faecalis ◽  
Susceptibility Testing ◽  
Inhibition Zone ◽  
Common Species ◽  
Disk Diffusion ◽  
Content Type ◽  
Zone Diameter ◽  
Agar Dilution

ABSTRACTWe studied the antimicrobial activity of fosfomycin against 960 strains of commonly encountered bacteria associated with urinary tract infection using standard agar dilution and disk diffusion methods. Species studied included 3 common species ofEnterobacteriaceae,Pseudomonas aeruginosa,Acinetobacter baumannii, andStenotrophomonas maltophilia; methicillin-susceptible and -resistantStaphylococcus aureus; and vancomycin-susceptible and resistantEnterococcus faecalisandE. faecium. MICs and inhibition zone diameters were interpreted in accordance with both the currently recommended Clinical and Laboratory Standards Institute (CLSI) criteria for urinary tract isolates ofEscherichia coliandEnterococcus faecalisand the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria forEnterobacteriaceae. Tentative zone diameter interpretive criteria were developed for species not currently published by CLSI or EUCAST.Escherichia coliwas uniformly susceptible to fosfomycin, as were most strains ofKlebsiella pneumoniaeandEnterobacter cloacae. A. baumanniiwas resistant to fosfomycin, while the prevalence of resistance inP. aeruginosaandS. maltophiliawas greatly affected by the choice of MIC breakpoint. New tentative zone diameter criteria forK. pneumoniae,E. cloacae,S. aureus, andE. faeciumwere able to be set, providing some interim laboratory guidance for disk diffusion until further breakpoint evaluations are undertaken by CLSI and EUCAST.

scholarly journals Analysis of MIC and Disk Diffusion Testing Variables for Gepotidacin and Comparator Agents against Select Bacterial Pathogens

2017 ◽  
Vol 55 (6) ◽  
pp. 1767-1777 ◽  
Author(s):  
L. M. Koeth ◽  
J. M. DiFranco-Fisher ◽  
N. E. Scangarella-Oman ◽  
L. A. Miller
Keyword(s):  
Antibacterial Agent ◽  
Lung Surfactant ◽  
Atmospheric Condition ◽  
Disk Diffusion ◽  
Inoculum Concentration ◽  
Content Type ◽  
Disk Diffusion Testing ◽  
Calcium Magnesium ◽  
Agar Dilution

ABSTRACTThis study was conducted to determine the effect of testing parameters on thein vitroactivity of gepotidacin, a new triazaacenaphthylene antibacterial agent for the treatment of conventional and biothreat pathogens. CLSI methods, and variations of those methods, were used to test 10Staphylococcus aureus, 10Streptococcus pneumoniae, 10Haemophilus influenzae, and 5Escherichia coliisolates by MIC and 30S. aureus, 15S. pneumoniae, and 15S. pyogenesisolates by disk diffusion (DD) methods. Levofloxacin and linezolid were tested as comparator agents for MIC and DD methods, respectively. Broth microdilution (BMD), macrodilution (MD), and agar dilution (AD) methods were compared. Variations in media, temperature, incubation time, CO2level, and inoculum concentration were tested by all methods, and variations in pH, calcium, magnesium, zinc, potassium, thymidine, and polysorbate 80 levels were tested by BMD and DD. The addition of albumin, serum, and lung surfactant was studied by BMD. The variables that impacted the results the most were high inoculum and pH 5.5 (no growth ofH. influenzaeandS. pneumoniaeby BMD). Gepotidacin AD MIC levels were increased and disk zone diameters were decreased for all species in 10% CO2incubation. The following variables had a minimal effect on gepotidacin results: pH, agar method, atmospheric condition, temperature, and addition of serum and albumin for broth methods. There were also some slight differences in gepotidacin disk results between disk manufacturers and some agar types and also with potassium and thymidine forS. pneumoniae. For all other variations, gepotidacin MIC and disk results were considered comparable to reference results.

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