scholarly journals Multicenter Clinical Evaluation Of For Susceptibility Testing Of Enterobacterales

2021 ◽  
Author(s):  
Laurine S. Blanchard ◽  
Alex Van Belkum ◽  
Dominique Dechaume ◽  
Tom Armstrong ◽  
Christopher L. Emery ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Aminoglycoside Antibiotic ◽  
International Standards ◽  
Diffusion Method ◽  
Individual Species ◽  
Brand Name ◽  
Gradient Diffusion ◽  
The Us ◽  
Tract Infections ◽  
International Standards Organization

Plazomicin (PLZ), brand name ZEMDRI (Cipla Therapeutics), is a novel aminoglycoside antibiotic approved by the US Food and Drug Administration (FDA) for treatment of complicated urinary tract infections including pyelonephritis. ETEST® is a gradient diffusion method that represents an alternative to the more laborious broth micro-dilution (BMD) method for performing antimicrobial susceptibility testing (AST). A multi-center evaluation of the performance of the new ETEST® PLZ (bioMérieux) was conducted in comparison with BMD following FDA and International Standards Organization (ISO) recommendations using FDA-defined breakpoints. Clinical isolates of Enterobacterales (n=598) were included. Fifty-three isolates were resistant to PLZ according to BMD. Overall, the ETEST® PLZ demonstrated 99.0% Essential Agreement (EA), 92.8% Category Agreement (CA), 1.9% Very Major Errors (VME), 0% Major Errors (ME) and 7.0% minor Errors (mE) with both clinical and challenge isolates of Enterobacterales. The VME was found for a single Serratia marcescens strain. Individual species demonstrated EA rates ≥ 90%. In conclusion, we report that ETEST® PLZ represents an accurate tool for performing PLZ AST of Enterobacterales.

scholarly journals Multicenter Evaluation of the Etest Gradient Diffusion Method for Ceftolozane-Tazobactam Susceptibility Testing of Enterobacteriaceae and Pseudomonas aeruginosa

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Adam L. Bailey ◽  
Tom Armstrong ◽  
Hari-Prakash Dwivedi ◽  
Gerald A. Denys ◽  
Janet Hindler ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Beta Lactam ◽  
Content Type ◽  
Gradient Diffusion ◽  
Tract Infections ◽  
Abdominal Infections ◽  
Inhibitor Combination

ABSTRACT Ceftolozane-tazobactam (C/T) is a novel beta-lactam–beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration in 2014 for the treatment of complicated intra-abdominal infections (in combination with metronidazole) and complicated urinary tract infections. In this study, we evaluated the performance of the C/T Etest, a gradient diffusion method. C/T Etest was compared to broth microdilution (BMD) for 51 Enterobacteriaceae challenge isolates and 39 Pseudomonas aeruginosa challenge isolates at three clinical sites. Essential agreement (EA) between the methods ranged from 47 to 49/51 (92.2 to 96.1%) for the Enterobacteriaceae, and categorical agreement (CA) ranged from 49 to 51/51 (96.1 to 100.0%). EA and CA for P. aeruginosa were 100% at all sites. The C/T Etest was also compared to BMD for susceptibility testing on 966 clinical isolates (793 Enterobacteriaceae, including 167 Klebsiella pneumoniae and 159 Escherichia coli isolates, in addition to 173 P. aeruginosa isolates) collected at four clinical sites. EA between Etest and BMD was 96.9% for Enterobacteriaceae isolates and 98.8% for P. aeruginosa isolates. Within the Enterobacteriaceae, isolates from each species examined had >96% CA. For the clinical isolates, no very major errors were identified but two major errors were found (one for K. pneumoniae and one for Providencia rettgeri). By BMD, 47.0% of Enterobacteriaceae and 46.2% of P. aeruginosa challenge strains were nonsusceptible to C/T by CLSI breakpoint criteria; 8.2% of clinical Enterobacteriaceae isolates and 12.1% of clinical P. aeruginosa isolates were nonsusceptible to C/T by CLSI breakpoint criteria. In conclusion, Etest is accurate and reproducible for C/T susceptibility testing of Enterobacteriaceae and P. aeruginosa.

scholarly journals Multicenter Evaluation of the New Etest Gradient Diffusion Method for Piperacillin-Tazobactam Susceptibility Testing of Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii Complex

2019 ◽  
Vol 58 (2) ◽  
Author(s):  
Sergio García-Fernández ◽  
Yohann Bala ◽  
Tom Armstrong ◽  
María García-Castillo ◽  
Carey-Ann D. Burnham ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Hospital Setting ◽  
Antimicrobial Susceptibility Testing ◽  
International Standards ◽  
Diffusion Method ◽  
Content Type ◽  
Gradient Diffusion

ABSTRACT Piperacillin-tazobactam (P/T) is a β-lactam–β-lactamase inhibitor combination frequently used in the hospital setting. Etest is a gradient diffusion method that represents an alternative to broth microdilution (BMD) for performing antimicrobial susceptibility testing. We conducted a multicenter evaluation of the performance of the new P/T Etest compared to that of BMD following U.S. Food and Drug Administration (FDA) and International Standards Organization (ISO) standard ISO 20776-2 criteria using Clinical and Laboratory Standards Institute (CLSI)-FDA and European Committee on Antimicrobial Susceptibility Testing (EUCAST) interpretive breakpoints, respectively. A total of 977 isolates (775 Enterobacterales isolates, 119 Pseudomonas aeruginosa isolates, and 83 Acinetobacter baumannii complex isolates) were tested. Overall essential agreement (EA) was 96.4% and 96.6% for Enterobacterales when FDA and ISO 20776-2 criteria, respectively, were followed. EA was 98.3% for P. aeruginosa and 91.6% for the A. baumannii complex when both the FDA and ISO criteria were followed. Applying CLSI-FDA breakpoints, categorical agreement (CA) reached 93.0%, 93.3%, and 89.2% for the Enterobacterales, P. aeruginosa, and the A. baumannii complex, respectively. Two very major errors (VMEs; 1.1%) were found among the Enterobacterales (for 2 Klebsiella pneumoniae isolates). No additional major errors (MEs) or VMEs were found. Applying EUCAST breakpoints, CA was 94.8% and 95.8% for Enterobacterales and P. aeruginosa, respectively (no breakpoints are currently available for the A. baumannii complex). No VMEs were observed among the Enterobacterales, but 2 (0.4%) MEs were found. Among the P. aeruginosa isolates, 2 (6.9%) VMEs and 3 (3.3%) MEs were observed. These errors resulted when P/T Etest MICs were 1 doubling dilution apart from the BMD MICs. In conclusion, the new P/T Etest represents an accurate tool for performing antimicrobial susceptibility testing of Enterobacterales, P. aeruginosa, and A. baumannii complex isolates with limited category errors.

Multicenter clinical evaluation of VITEK® 2 meropenem-vaborbactam for susceptibility testing of Enterobacterales and Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Hari P. Dwivedi ◽  
Simone Franklin ◽  
Sukantha Chandrasekaran ◽  
Omai Garner ◽  
Maria M. Traczewski ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Automated System ◽  
Individual Species ◽  
Method Performance ◽  
Overall Performance ◽  
Vitek 2 ◽  
Tract Infections ◽  
Alternate Solution ◽  
After Error

The carbapenem/beta-lactamase inhibitor (meropenem-vaborbactam; MEV) used to treat complicated urinary tract infections and pyelonephritis in adults was approved in 2017 by the U.S. Food and Drug Administration (FDA). We evaluated VITEK 2 MEV (bioMérieux, Durham, NC) compared to the reference broth microdilution (BMD) method. Of 449 Enterobacterales isolates analyzed per FDA/CLSI breakpoints, overall performance was 98.2% Essential Agreement (EA), 98.7% Category Agreement (CA), and 0% Very Major Errors (VME) or Major Errors (ME). For FDA intended for use 438 Enterobacterales isolates, performance was 98.2% EA, 98.6% CA, and 0% VME or ME. Evaluable EA was 81.0% but with only 42 on-scale evaluable results. Individual species demonstrated EA and CA rates ≥ 90% without any VME or ME. When evaluated using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, overall VITEK 2 MEV performance for Enterobacterales and Pseudomonas aeruginosa demonstrated 97.3% EA, 99.2% CA, 2.3% VME, and 0.6% ME (after error resolution: 97.3% EA, 99.4% CA, 2.2% VME, and 0.4% ME) compared to the reference BMD method. Performance for P. aeruginosa included 92.2% EA, 97.4% CA, 0% VME, and 3.0% ME (after error resolution: 92.2% EA, 98.7% CA, 0% VME, and 1.5% ME). Performance for Enterobacterales included 98.2% EA, 99.6% CA, 3.0% VME, and 0.2% ME. Evaluable EA was 80.6% but due to only 67 evaluable results. These findings support VITEK 2 MEV as an accurate automated system for MEV susceptibility testing of Enterobacterales and P. aeruginosa and could be an alternate solution to the manual labor intensive reference BMD method.

scholarly journals Phenotypic detection of Carbapenamase among Klebsiella pneumoniae isolated from clinical samples using modified Hodged test

2020 ◽  
Vol 13 (3) ◽  
pp. 135-140
Author(s):  
HauwaYakubu ◽  
Mahmud Yerima Iliyasu ◽  
Asma’u Salisu ◽  
Abdulmumin Ibrahim Sulaiman ◽  
Fatima Tahir ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Susceptibility Testing ◽  
University Teaching ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Beta Lactam ◽  
Beta Lactamases ◽  
Beta Lactam Antibiotics ◽  
Microbiological Techniques ◽  
Tract Infections

Carbapenemases are microbial enzymes that confer resistance to virtually all available beta-lactam antibiotics and the most frequent carbapenemases are the Klebsiella pneumoniae Carbapenamase (KPC). Detection of carbapenemases is a significant infection control strategy as the enzymes are often associated with extensive antimicrobial resistance, therapeutic failures and mortality associated with infectious diseases. A total of 400 clinical samples were collected from different groups of patients in Abubakar Tafawa Balewa University Teaching Hospital, Bauchi, Nigeria and 118 K. pneumoniae were isolated using standard microbiological techniques. The isolates were subjected to antibiotic susceptibility testing by Kirby-Bauer disc diffusion method, then screened for Carbapenamase production using modified Hodge test. The results indicated that the isolates were resistant to Ampicillin (61.9%), Ceftriaxone (50.8%) and Ceftazidime (50.8%), then Ciprofloxacin (54.2%), but predominantly sensitive to Imipenem (66.9%), Eterpenem (60.2%) and Meropenem (65.3%). It was found that 38 (32.2%) of the isolates phenotypically shows the presence of Carbapenamase, with highest frequency of (40.7%) among patients, mainly adult females with cases of Urinary Tract Infections (UTIs) and the least from wound (11.8%).This study revealed that the isolates produced other beta-lactamases than KPC or variants of Carbapenamase that cannot be detected by modified Hodge test, thus shows low resistance to carbapenems. Therefore further studies is needed to genotypically confirm the presence of KPC in these isolates.

scholarly journals Detection of biofilm formation by Escherichia coli with its antibiogram profile

2018 ◽  
Vol 5 (9) ◽  
pp. 3771
Author(s):  
Gaurab Risal ◽  
Aayush Shrestha ◽  
Saroj Kunwar ◽  
Gajal Paudel ◽  
Rameshwor Dhital ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Biofilm Formation ◽  
Technical College ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
E Coli ◽  
Mueller Hinton ◽  
Mueller Hinton Agar ◽  
Tract Infections ◽  
Descriptive Method

Background: In urinary tract infections, an important role is played by bacterial biofilms which are responsible for persistence infections together with the antimicrobial resistance. Higher resistance can be seen in biofilm forming uropathogens in comparison with free-floating bacteria. So, the present study was performed with a goal to find the prevalence of biofilm formation and also the antimicrobial resistant pattern of uropathogens.Methods: A descriptive method was conducted at Modern Technical College, Sanepa, Lalitpur in samples isolated from UTI suspected patients. The overall duration of this study was approximately 3 months. Total of 50 isolated E. coli was tested for biofilm formation and antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion method on Mueller Hinton agar as per CLSI guidelines.Results: From the 50 isolates of E. coli, 32 were biofilm producers (3 strong and 29 moderate) and 18 were weak/non-biofilm producers. Among the biofilm producers, cefotaxime was more resistant in 20 of the isolates followed by ceftriaxone in 16 and amoxyclav in 13, whereas amikacin was least resistant in 2 of the isolates.Conclusions: Among the isolated E. coli, biofilm-forming isolates showed higher antimicrobial resistance as compared to the non-biofilm producer. Thus, uropathogen should be routinely screened for biofilm formation. 

scholarly journals Multicenter Clinical Evaluation of Etest Meropenem-Vaborbactam (bioMérieux) for Susceptibility Testing of Enterobacterales (Enterobacteriaceae) and Pseudomonas aeruginosa

2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Sophonie Jean ◽  
Sheri Garrett ◽  
Claire Anglade ◽  
Laurence Bridon ◽  
Leanne Davies ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Reference Method ◽  
Individual Species ◽  
Beta Lactamase ◽  
Content Type ◽  
European Committee ◽  
Tract Infections ◽  
Inhibitor Combination ◽  
Lactamase Inhibitor

ABSTRACT Meropenem-vaborbactam (MEV) is a novel carbapenem–beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration (FDA) for treatment of complicated urinary tract infections, including pyelonephritis, in adults. In this study, we evaluated the performance of Etest MEV (bioMérieux, Marcy l’Etoile, France) compared to that of broth microdilution for 629 Enterobacterales and 163 Pseudomonas aeruginosa isolates. According to CLSI/FDA breakpoints, 13 Enterobacterales isolates (12 clinical and 1 challenge) were resistant to MEV. Overall, Etest MEV demonstrated 92.4% essential agreement (EA), 99.2% category agreement (CA), 0% very major errors (VME), 0% major errors (ME), and 0.8% minor errors (mE) with clinical and challenge isolates of Enterobacterales. Individual species demonstrated EA rates of ≥80%, with the exception of Proteus mirabilis, for which clinical and challenge isolates demonstrated 34.3% EA, 97.1% CA, 0% ME, and 2.9% mE, precluding the use of Etest MEV with this species. Excluding P. mirabilis, MEV Etest MEV demonstrated 95.8% EA, 99.3% CA, 0% VME, 0% ME, and 0.7% mE with Enterobacterales isolates. When evaluated using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, Etest MEV performance with clinical (16 MEV resistant) and challenge (12 MEV resistant) isolates of Enterobacterales (excluding P. mirabilis) and P. aeruginosa demonstrated an unacceptably high VME rate of 7.1% despite 95.2% EA, 99.2% CA, and 0.5% ME compared to the reference method. In conclusion, we report that Etest MEV is accurate and reproducible for MEV susceptibility testing for P. aeruginosa and Enterobacterales, with the exception of P. mirabilis, using CLSI/FDA breakpoints. Etest MEV should not be used with P. mirabilis due to unacceptable analytical performance.

Accuracy of gradient diffusion method for susceptibility testing of dalbavancin and comparators

2021 ◽  
pp. 1-5
Author(s):  
A. G. Leroy ◽  
V. Lavigne-Quilichini ◽  
P. Le Turnier ◽  
B. Loufti ◽  
E. Le Breton ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Diffusion Method ◽  
Gradient Diffusion

Mecillinam: Old Molecule, New Option

2018 ◽  
Vol 13 (03) ◽  
pp. 229-233
Author(s):  
Mevliye Yetik ◽  
Fulya Bayındır Bilman
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
First Line ◽  
Disk Diffusion Method ◽  
In Vitro Susceptibility ◽  
E Coli ◽  
Tract Infections

Background Mecillinam is a β-lactam antibiotic that is increasingly being used for the treatment of uncomplicated urinary tract infections. Nevertheless, the international guidelines still recommend nitrofurantoin, fosfomycin trometamol, and pivmecillinam as first-line agents in the treatment of such infections. Aim The objective of this study was to determine the in vitro efficacy of mecillinam against Escherichia coli and Klebsiella pneumoniae strains isolated from children with urinary tract infections. Materials Methods We investigated E. coli and K. pneumoniae isolates, obtained within the period from January 2016 to October 2017, from urine samples of patients aged 0 to 16 years. Antibiotics susceptibility testing was conducted through the disk diffusion method based on the guidelines provided by EUCAST (European Committee on Antimicrobial Susceptibility Testing). Extended-spectrum β-lactamase (ESBL)-positivity was detected by the double-disk synergy test. Isolates with mecillinam inhibition-zone diameter breakpoints lower than < 15 mm were considered to be resistant according to EUCAST criteria. Results A total of 450 isolates were assessed in the study, 135 of which were ESBL-producing E.coli, 230 were non-ESBL-producing E. coli, 35 were ESBL-producing K. pneumoniae, and 50 were non-ESBL-producing K. pneumoniae isolates. Mecillinam susceptibility was observed in most of the non-ESBL-producing and ESBL-producing E. coli isolates (230/230, 100% and 115/135, 85.1%, respectively). The rates of susceptibility of the non-ESBL-producing and ESBL-producing K. pneumoniae isolates were 37/50 (74%) and 24/35 (68.6%), respectively. Conclusion The in vitro susceptibility results obtained support the usage of mecillinam as a first-line agent. The high susceptibility of non-ESBL-producing E. coli and K. pneumoniae isolates established in vitro brings the hope that this antibiotic could soon be used in clinical practice in Turkey.

scholarly journals Determination of Susceptibility to Fosfomycin and Tigecycline of Enterobacteriaceae, ParticularlyEscherichia coliIsolates, Producing Extended-Spectrum β-Lactamases from Multiple Regional Canadian Hospitals

2013 ◽  
Vol 24 (3) ◽  
pp. e80-e82 ◽  
Author(s):  
Carlee Beuk ◽  
Christian Hill ◽  
Sue Whitehead ◽  
Edith Blondel-Hill ◽  
Ken Wagner ◽  
...  
Keyword(s):  
British Columbia ◽  
Susceptibility Testing ◽  
Test Method ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Health Region ◽  
Extended Spectrum ◽  
Tract Infections

BACKGROUND: The worldwide spread of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, particularlyEscherichia coli,has significantly limited therapeutic options, especially for urinary tract infections. Although limited in their indications, fosfomycin and tigecycline are potential agents to treat infections due to ESBL-producing organisms. Although not routinely performed, susceptibility testing to both is necessary to ensure there is not an increase in resistance.METHODS: A total of 160 isolates of ESBL-producingE coliwere isolated from patients at multiple regional hospitals in the Interior Health Region of British Columbia from June 2009 to January 2012. Isolates were obtained from various body fluids and sites including urine (78.2%), wounds, blood, gall bladder drain and respiratory specimens. All isolates were tested using the E-test method (Etest, bioMérieux, France) for tigecycline and Kirby Bauer disk diffusion method for fosfomycin using European Committee of Antimicrobial Susceptibility Testing breakpoints for tigecycline and Clinical and Laboratory Standards Institute zone sizes for fosfomycin.RESULTS: All 160 isolates were found to be susceptible to tigecycline, while five isolates (3.1%) were resistant to fosfomycin (four resistant, one intermediate).CONCLUSION: Although resistance to these antibiotics has previously been reported, the present study confirmed that isolates of ESBL-producingE colifrom the Interior Health Region of British Columbia remain highly susceptible to both tigecycline and fosfomycin.

scholarly journals Comparative Analysis of Gradient Diffusion and Disk Diffusion with Agar Dilution for Susceptibility Testing of Elizabethkingia anophelis

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 450
Author(s):  
Chien-Tung Chiu ◽  
Chung-Hsu Lai ◽  
Yi-Han Huang ◽  
Chih-Hui Yang ◽  
Jiun-Nong Lin
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Gradient Diffusion ◽  
Minimum Requirements ◽  
Agar Dilution

Elizabethkingia anophelis has recently emerged as a cause of life-threatening infections. This study compared the results of antimicrobial susceptibility testing (AST) conducted for E. anophelis through different methods. E. anophelis isolates collected between January 2005 and June 2019 were examined for their susceptibility to 14 antimicrobial agents by using disk diffusion, gradient diffusion (Etest; (bioMérieux S.A., Marcy l’Etoile, France), and agar dilution methods. The agar dilution method was the reference assay. According to the agar dilution method, the isolates exhibited the highest susceptibility to minocycline (100%), doxycycline (97.6%), rifampin (95.2%), and levofloxacin (78.6%). A very major error rate of >1.5% was observed for nine antibiotics tested using the disk diffusion method. The overall categorical agreement rate between the disk diffusion and agar dilution methods was 74.8%, and ceftazidime, minocycline, levofloxacin, and rifampin met the minimum requirements for discrepancy and agreement rates. The Etest method tended to produce lower log2 minimum inhibitory concentrations for the antibiotics, except for trimethoprim–sulfamethoxazole and rifampin; the method resulted in very major errors for nine antibiotics. The overall essential and categorical agreement rates between the Etest and agar dilution methods were 67.3% and 76.1%, respectively. The Etest method demonstrated acceptable discrepancy and agreement rates for ceftazidime, minocycline, doxycycline, levofloxacin, and rifampin. AST results obtained through the disk diffusion and Etest methods for multiple antibiotics differed significantly from those obtained using the agar dilution method. These two assays should not be a routine alternative for AST for E. anophelis.

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