Cefoperazone disk diffusion susceptibility test: confirmation of the tentative interpretive criteria, Pseudomonas aeruginosa cross-resistance, and determination of quality control performance limits.

1982 ◽  
Vol 15 (5) ◽  
pp. 777-786 ◽  
Author(s):  
R N Jones ◽  
T L Gavan ◽  
A L Barry ◽  
C Thornsberry ◽  
D L Gibbs
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quality Control ◽  
Susceptibility Test ◽  
Disk Diffusion ◽  
Cross Resistance ◽  
Control Performance ◽  
Performance Limits

scholarly journals In Vitro Antimicrobial Activity of a New Cephalosporin, Ceftaroline, and Determination of Quality Control Ranges for MIC Testing

2008 ◽  
Vol 53 (3) ◽  
pp. 1271-1274 ◽  
Author(s):  
Steven D. Brown ◽  
Maria M. Traczewski
Keyword(s):  
Antimicrobial Activity ◽  
Quality Control ◽  
Disk Diffusion ◽  
Bacterial Isolates ◽  
In Vitro Antimicrobial Activity ◽  
Reference Strains ◽  
Phenotypic Groups

ABSTRACT The spectrum of activity of ceftaroline was evaluated against 1,247 bacterial isolates representing 44 different species or phenotypic groups. For the majority of species, the activity of ceftaroline was comparable or superior to that of ceftriaxone. MIC and/or disk diffusion quality control ranges of ceftaroline were determined for five standard ATCC reference strains.

scholarly journals Role of efflux pump inhibitor in decreasing antibiotic cross-resistance of Pseudomonas aeruginosa in a burn hospital in Iran

2016 ◽  
Vol 10 (06) ◽  
pp. 600-604 ◽  
Author(s):  
Mahshid Talebi-Taher ◽  
َAli Majidpour ◽  
Abbas Gholami ◽  
Samira Rasouli-Kouhi ◽  
Maryam Adabi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Cross Resistance ◽  
Beta Lactams ◽  
Efflux Pump Inhibitor ◽  
Efflux Pump Inhibitors

Introduction: Multidrug resistance in Pseudomonas aeruginosa may be due to efflux pump overexpression. This study phenotypically examined the role of efflux pump inhibitors in decreasing antibiotic cross-resistance between beta-lactams, fluoroquinolones, and aminoglycosides in P. aeruginosa isolates from burn patients in Iran. Methodology: A total of 91 phenotypically and genotypically confirmed P. aeruginosa samples were studied. Multidrug cross-resistance was determined using the disk diffusion method and minimum inhibitory concentration (MIC) test. The contribution of efflux pumps was determined by investigating MIC reduction assay to markers of beta-lactams, fluoroquinolones, and aminoglycosides in the absence and presence of an efflux pump inhibitor. All the isolates were also tested by polymerase chain reaction for the presence of mexA, mexC, and mexE efflux genes. Results: Of the isolates, 81 (89%) and 83 (91.2%) were multidrug resistant according to the disk diffusion and MIC method, respectively. Cross-resistance was observed in 67 (73.6%) and 68 (74.7%) of isolates according to the disk diffusion and MIC method, respectively. In the presence of the efflux pump inhibitor, twofold or higher MIC reduction to imipenem, cefepime, ciprofloxacin, and gentamicin was observed in 59, 65, 55, and 60 isolates, respectively. Except for two isolates that were negative for mexC, all isolates were positive for mexA, mexC, and mexE genes simultaneously. Conclusion: Efflux pumps could cause different levels of resistance based on their expression in clinical isolates. Early detection of different efflux pumps in P. aeruginosa could allow the use of other antibiotics and efflux pump inhibitors in combination with antibiotic therapy.

scholarly journals Determination of Disk Diffusion and MIC Quality Control Guidelines for High-Dose Cefepime-Tazobactam (WCK 4282), a Novel Antibacterial Combination Consisting of a β-Lactamase Inhibitor and a Fourth-Generation Cephalosporin

2017 ◽  
Vol 55 (10) ◽  
pp. 3130-3134 ◽  
Author(s):  
Stefan Riedel ◽  
Michael D. Huband ◽  
Helio S. Sader ◽  
Robert K. Flamm ◽  
Ronald N. Jones
Keyword(s):  
Quality Control ◽  
Generation Cephalosporin ◽  
Test Methods ◽  
Disk Diffusion ◽  
Fourth Generation ◽  
High Dose ◽  
Gram Negative ◽  
Lactamase Inhibitor

ABSTRACTHigh-dose cefepime-tazobactam (1:1; WCK 4282), a novel antibacterial combination consisting of the β-lactamase inhibitor tazobactam and a fourth-generation cephalosporin, is under clinical development for the treatment of serious Gram-negative infections. A quality control (QC) study was performed to establish disk diffusion and MIC ranges for cefepime-tazobactam for multiple QC reference strains. The cefepime-tazobactam QC ranges for a fixed tazobactam MIC of 8 μg/ml and disk diffusion (30/20-μg disk) test methods were approved by the CLSI Subcommittee on Antimicrobial Susceptibility Testing in January 2015 and January 2016. These QC ranges will be important for accuratein vitroactivity evaluations of cefepime-tazobactam when tested against clinical Gram-negative bacteria during clinical studies and routine patient care.

scholarly journals Performance Evaluation of the Gradient Diffusion Strip Method and Disk Diffusion Method for Ceftazidime–Avibactam Against Enterobacterales and Pseudomonas aeruginosa: A Dual-Center Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjia Zhang ◽  
Gang Li ◽  
Ge Zhang ◽  
Wei Kang ◽  
Simeng Duan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Major Error ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Strip Method ◽  
Gradient Diffusion

Objectives: Ceftazidime–avibactam is a novel synthetic beta-lactam + beta-lactamase inhibitor combination. We evaluated the performance of the gradient diffusion strip method and the disk diffusion method for the determination of ceftazidime–avibactam against Enterobacterales and Pseudomonas aeruginosa.Methods: Antimicrobial susceptibility testing of 302 clinical Enterobacterales and Pseudomonas aeruginosa isolates from two centers were conducted by broth microdilution (BMD), gradient diffusion strip method, and disk diffusion method for ceftazidime–avibactam. Using BMD as a gold standard, essential agreement (EA), categorical agreement (CA), major error (ME), and very major error (VME) were determined according to CLSI guidelines. CA and EA rate > 90%, ME rate < 3%, and VME rate < 1.5% were considered as acceptable criteria. Polymerase chain reaction and Sanger sequencing were performed to determine the carbapenem resistance genes of all 302 isolates.Results: A total of 302 strains were enrolled, among which 182 strains were from center 1 and 120 strains were from center 2. A percentage of 18.21% (55/302) of the enrolled isolates were resistant to ceftazidime–avibactam. The CA rates of the gradient diffusion strip method for Enterobacterales and P. aeruginosa were 100% and 98.65% (73/74), respectively, and the EA rates were 97.37% (222/228) and 98.65% (73/74), respectively. The CA rates of the disk diffusion method for Enterobacterales and P. aeruginosa were 100% and 95.95% (71/74), respectively. No VMEs were found by using the gradient diffusion strip method, while the ME rate was 0.40% (1/247). No MEs were found by using the disk diffusion method, but the VME rate was 5.45% (3/55). Therefore, all the parameters of the gradient diffusion strip method were in line with acceptable criteria. For 31 blaKPC, 33 blaNDM, 7 blaIMP, and 2 blaVIM positive isolates, both CA and EA rates were 100%; no MEs or VMEs were detected by either method. For 15 carbapenemase-non-producing resistant isolates, the CA and EA rates of the gradient diffusion strips method were 100%. Whereas the CA rate of the disk diffusion method was 80.00% (12/15), the VME rate was 20.00% (3/15).Conclusion: The gradient diffusion strip method can meet the needs of clinical microbiological laboratories for testing the susceptibility of ceftazidime–avibactam drugs. However, the VME rate > 1.5% (5.45%) by the disk diffusion method. By comparison, the performance of the gradient diffusion strip method was better than that of the disk diffusion method.

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.

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