scholarly journals Comparison of cation-adjusted Mueller-Hinton broth with Iso-Sensitest broth for the NCCLS broth microdilution method

2000 ◽  
Vol 46 (3) ◽  
pp. 369-376 ◽  
Author(s):  
L. M. Koeth
Keyword(s):  
Broth Microdilution ◽  
Microdilution Method ◽  
Mueller Hinton ◽  
Broth Microdilution Method ◽  
Mueller Hinton Broth

scholarly journals 656. Sulbactam-Durlobactam MIC Determination: Comparative Evaluation of the New ETEST® SUD to the CLSI 2021 Broth Microdilution Method

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S430-S430
Author(s):  
Veronique Sauvonnet ◽  
Elodie Escoffier ◽  
Christine Franceschi ◽  
Diane Halimi ◽  
Roland Martelin ◽  
...  
Keyword(s):  
Reference Method ◽  
Multidrug Resistant ◽  
Error Rates ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Mueller Hinton ◽  
Broth Microdilution Method ◽  
Lactam Antibiotic ◽  
Visible Growth ◽  
Resistant Strains

Abstract Background Species belonging to the Acinetobacter baumannii-calcoaceticus (ABC) complex, such as A. baumannii, A. pittii and A. nosocomialis, are a major cause of hospital acquired infections and outbreaks with increasing occurrence of multidrug-resistance. Sulbactam-durlobactam (SUD), a combination of one active β-lactam antibiotic (sulbactam) with a new β-lactamase inhibitor (durlobactam), is currently being tested in a phase 3 clinical trial by Entasis Therapeutics for the treatment of serious infections caused by ABC, including multidrug-resistant strains. At the same time, an ETEST® SUD (sulbactam-durlobactam - MIC range 0.004/4-64/4 µg/mL) has been developed and calibrated versus the broth microdilution reference method (BMD) as described by the Clinical and Laboratory Standards Institute (CLSI). This test is intended to determine the MIC of sulbactam-durlobactam for species of the ABC complex. The aim of this study was to perform a first comparative study of ETEST SUD with the CLSI BMD method on a panel of 263 isolates. Methods The panel consisted of 204 A. baumannii, 29 A. pittii, 30 A. nosocomialis, including 24 SUD-resistant strains, and one CLSI QC strain. BMD was performed using the 2021 CLSI guidelines. ETEST SUD was evaluated using the standard ETEST procedure for Acinetobacter spp. (inoculum 0.5 McFarland, Mueller Hinton medium, incubation at 35°C for 20-24h). For each method, the MIC was read at complete inhibition of visible growth. To determine category agreement (CA) and error rates, the sulbactam-durlobactam provisional breakpoint of 4 µg/mL was applied. Results The QC strain MICs were in the expected range with reproducible results. The essential MIC agreement [EA, ±1 dilution] was 97.7% without any tendency to over- or underestimate the MIC when compared to BMD. The CA was 98.5%. Two Very Major Errors, both within the EA, and two Major Errors, one within the EA, were observed. Conclusion In this study, the ETEST SUD was found to be equivalent to the CLSI reference method. MIC end points were easy to read. With a 15-dilution range and simplicity of use, ETEST SUD could represent a valuable tool for MIC determination and could be an alternative to BMD. For Research Use Only. The performance characteristics of this product have not been established yet. Disclosures All Authors: No reported disclosures

scholarly journals Activity of Daptomycin against Recent North American Isolates of Streptococcus pneumoniae

2003 ◽  
Vol 47 (9) ◽  
pp. 2974-2977 ◽  
Author(s):  
M. I. Restrepo ◽  
J. A. Velez ◽  
M. L. McElmeel ◽  
C. G. Whitney ◽  
J. H. Jorgensen
Keyword(s):  
Streptococcus Pneumoniae ◽  
North American ◽  
Broth Microdilution ◽  
Test Strips ◽  
Sheep Blood ◽  
Microdilution Method ◽  
Mueller Hinton ◽  
Broth Microdilution Method

ABSTRACT Daptomycin MICs at which 50% of isolates were inhibited (MIC50s) and MIC90s determined by the NCCLS broth microdilution method were both 0.25 μg/ml (range, 0.06 to 2 μg/ml) for 350 pneumococcal isolates. MICs determined by E test strips on commercially prepared Mueller-Hinton sheep blood agars with different calcium contents were 2 to 3 dilutions higher than those determined by strips that contained daptomycin plus calcium. Daptomycin zone diameters varied little on the same media.

scholarly journals 644. Comparative Evaluation of ETEST® ERV bioMérieux with the CLSI Broth Microdilution Method for Eravacycline MIC Determination

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S297-S297
Author(s):  
Veronique Sauvonnet ◽  
Corey Fyfe ◽  
Diane Halimi ◽  
Roland Martelin ◽  
Gilles Zambardi
Keyword(s):  
Agar Plate ◽  
Reference Method ◽  
Multidrug Resistant ◽  
Bacterial Suspension ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Mueller Hinton ◽  
Broth Microdilution Method ◽  
Mueller Hinton Agar ◽  
Abdominal Infections

Abstract Background Eravacycline (XERAVA™) is a novel, FDA and EMA-approved fully-synthetic fluorocycline antibiotic developed by Tetraphase Pharmaceuticals Inc. for the treatment of complicated intra-abdominal infections (cIAI) including those caused by multidrug-resistant (MDR) pathogens that have been highlighted as urgent public health threats by the US CDC and the WHO. The new ETEST ERV strip (MIC range 0.002 – 32 µg/mL) has been developed by bioMérieux and calibrated vs. the broth microdilution reference method (BMD) as described by the Clinical and Laboratory Standards Institute (CLSI) to determine the minimal inhibitory concentration (MIC) of eravacycline against Enterobacterales and Enterococci. The aim of the study was to compare ETEST ERV to the CLSI BMD method on a panel of 166 strains comprising 131 Enterobacterales and 35 Enterococci. Methods Quality control was performed with the CLSI QC strains E.coli ATCC 25922 and E.faecalis ATCC 29212. The ETEST ERV strip was applied on a Mueller–Hinton agar plate previously seeded with a 0.5 McF bacterial suspension. After incubation for 16–20H at 35°C, the reading was performed using the bacteriostatic mode i.e.,80% of growth. The FDA-approved breakpoints were applied (S≤0.5µg/mL for Enterobacterales and S ≤0.064 µg/mL for Enterococci). Results The MIC essential agreement was 99.4% at ±1 dilution for the whole panel and the category agreement was 96.4% with 4.8% Major Errors (1 E. coli, 2 K. pneumoniae, 1 K.aerogenes, 1 C. koseri, 1 E. faecalis), all at ±1 dilution around the single breakpoint. No Very Major Error (VME) was observed. Conclusion In this study, the new ETEST ERV strip has been found to be substantially equivalent to the CLI reference method. MIC end-points appear easier to read in comparison to the reference method. With a 15-dilution MIC range and simplicity of use, ETEST ERV could represent a valuable tool for MIC determination and an alternative to the BMD reference method. ETEST ERV will undergo clinical studies to seek IVD FDA clearance and CE marking. For Research Use Only. The performance characteristics of this product have not yet been established. Disclosures All authors: No reported disclosures.

scholarly journals In Vitro Activity of the Siderophore Cephalosporin, Cefiderocol, against Carbapenem-Nonsusceptible and Multidrug-Resistant Isolates of Gram-Negative Bacilli Collected Worldwide in 2014 to 2016

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Meredith A. Hackel ◽  
Masakatsu Tsuji ◽  
Yoshinori Yamano ◽  
Roger Echols ◽  
James A. Karlowsky ◽  
...  
Keyword(s):  
Burkholderia Cepacia ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Content Type ◽  
Microdilution Method ◽  
Mueller Hinton ◽  
Broth Microdilution Method ◽  
Mueller Hinton Broth

ABSTRACT The in vitro activity of the investigational siderophore cephalosporin, cefiderocol (formerly S-649266), was determined against a 2014–2016, 52-country, worldwide collection of clinical isolates of carbapenem-nonsusceptible Enterobacteriaceae (n = 1,022), multidrug-resistant (MDR) Acinetobacter baumannii (n = 368), MDR Pseudomonas aeruginosa (n = 262), Stenotrophomonas maltophilia (n = 217), and Burkholderia cepacia (n = 4) using the Clinical and Laboratory Standards Institute (CLSI) standard broth microdilution method. Iron-depleted cation-adjusted Mueller-Hinton broth (ID-CAMHB), prepared according to a recently approved (2017), but not yet published, CLSI protocol, was used to test cefiderocol; all other antimicrobial agents were tested using CAMHB. The concentration of cefiderocol inhibiting 90% (MIC90) of isolates of carbapenem-nonsusceptible Enterobacteriaceae was 4 μg/ml; cefiderocol MICs ranged from 0.004 to 32 μg/ml, and 97.0% (991/1,022) of isolates demonstrated cefiderocol MICs of ≤4 μg/ml. The MIC90s for cefiderocol for MDR A. baumannii, MDR P. aeruginosa, and S. maltophilia were 8, 1, and 0.25 μg/ml, respectively, with 89.7% (330/368), 99.2% (260/262), and 100% (217/217) of isolates demonstrating cefiderocol MICs of ≤4 μg/ml. Cefiderocol MICs for B. cepacia ranged from 0.004 to 8 μg/ml. We conclude that cefiderocol demonstrated potent in vitro activity against a 2014–2016, worldwide collection of clinical isolates of carbapenem-nonsusceptible Enterobacteriaceae, MDR A. baumannii, MDR P. aeruginosa, S. maltophilia, and B. cepacia isolates as 96.2% of all (1,801/1,873) isolates tested had cefiderocol MICs of ≤4 μg/ml.

scholarly journals In Vitro Activities of Daptomycin against 2,789 Clinical Isolates from 11 North American Medical Centers

2001 ◽  
Vol 45 (6) ◽  
pp. 1919-1922 ◽  
Author(s):  
Arthur L. Barry ◽  
Peter C. Fuchs ◽  
Steven D. Brown
Keyword(s):  
Clinical Isolates ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Medical Centers ◽  
Mueller Hinton ◽  
Calcium Cations ◽  
Important Exception ◽  
Mueller Hinton Broth

ABSTRACT The in vitro activity of daptomycin is affected by the concentration of calcium cations in the test medium. Mueller-Hinton broth is currently adjusted to contain 10 to 12.5 mg of magnesium per liter and 20 to 25 mg of calcium per liter, but for testing of daptomycin, greater concentrations of calcium (50 mg/liter) are recommended to better resemble the normal concentration of ionized calcium in human serum. Two levels of calcium were used for broth microdilution tests of 2,789 recent clinical isolates of gram-positive bacterial pathogens. MICs of daptomycin were two- to fourfold lower when the broth contained additional calcium. For most species, however, the percentages of strains that were inhibited by 2.0 μg of daptomycin per ml were essentially identical with the two broth media. Enterococci were the important exception; i.e., 92% were inhibited when tested in calcium-supplemented broth but only 35% were inhibited by 2.0 μg/ml without the additional calcium. This type of information should be considered when selecting criteria for defining in vitro susceptibility to daptomycin.

Antimicrobial Essential Oil Combinations to Combat Foot Odour

Planta Medica ◽  
2018 ◽  
Vol 84 (09/10) ◽  
pp. 662-673 ◽  
Author(s):  
Ané Orchard ◽  
Alvaro Viljoen ◽  
Sandy van Vuuren
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Antimicrobial Efficacy ◽  
Juniperus Virginiana ◽  
Broth Microdilution ◽  
Synergistic Interactions ◽  
Microdilution Method ◽  
Broth Microdilution Method

AbstractFoot odour (bromodosis) is an embarrassing and perplexing condition mostly caused by bacteria of the Brevibacterium species. Essential oils are a credible option as an affordable treatment of odour and contribute towards antimicrobial efficacy. Therefore, this study sets out to investigate the antimicrobial activity of essential oil combinations against odour-causing bacteria. The broth microdilution method was used to investigate the antimicrobial activity of 119 essential oil combinations, and the fractional inhibitory index was calculated to determine the interactive profile. Combinations that resulted in synergy in 1 : 1 ratios were further evaluated in different concentrations, and isobolograms were plotted to determine the influence of the ratio on overall activity. Numerous combinations could be identified as having synergistic interactions against the Brevibacterium spp. and no antagonism was observed. The combination of Juniperus virginiana (juniper) and Styrax benzoin (benzoin) demonstrated synergy against all three Brevibacterium spp. tested and J. virginiana was the essential oil responsible for the majority of the synergistic interactions. The results reported here confirm the promising potential of the majority of these oils and selected combinations in treating and controlling bromodosis.

scholarly journals Standartization of broth microdilution method for Mycobacterium tuberculosis

2000 ◽  
Vol 95 (1) ◽  
pp. 127-129 ◽  
Author(s):  
Clarice Queico Fujimura Leite ◽  
Ana Laura Remédio Zeni Beretta ◽  
Ivone Shizuko Anno ◽  
Maria Alice da Silva Telles
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

scholarly journals In Vitro Activities of the Novel Oxazolidinones DA-7867 and DA-7157 against Rapidly and Slowly Growing Mycobacteria

2006 ◽  
Vol 50 (12) ◽  
pp. 4027-4029 ◽  
Author(s):  
Lucio Vera-Cabrera ◽  
Barbara A. Brown-Elliott ◽  
Richard J. Wallace ◽  
Jorge Ocampo-Candiani ◽  
Oliverio Welsh ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Clinical Isolates ◽  
Nontuberculous Mycobacterium ◽  
The Novel ◽  
Broth Microdilution ◽  
Reference Species ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Aerobic Actinomycetes

ABSTRACT DA-7867 and DA-7157 are oxazolidinones active against pathogenic aerobic actinomycetes including Nocardia spp. and Mycobacterium tuberculosis. However, the activity of these drugs against nontuberculous mycobacterium (NTM) species is not known. In this work, we compared the susceptibilities of 122 clinical isolates and 29 reference species of both rapidly growing and slowly growing mycobacteria to linezolid, DA-7867, and DA-7157 by the broth microdilution method. The MICs for 50 and 90% of the strains tested (MIC50s and MIC90s, respectively) of DA-7867 and DA-7157 were lower than those of linezolid. In all of the cases, a MIC90 of <8 μg/ml was observed for all of the species tested in both groups of NTM. For M. kansasii and M. marinum isolates, the MIC90s of both DA-7867 and DA-7157 were less than 0.5 μg/ml. These results demonstrate the potential of these compounds to treat NTM infections.

Susceptibility of Filamentous Fungi to Voriconazole in Malaysia Tested by Sensititre YeastOne and CLSI Microdilution Methods

2021 ◽  
Author(s):  
Xue Ting Tan ◽  
Stephanie Jane Ginsapu ◽  
Fairuz binti Amran ◽  
Salina binti Mohamed Sukur ◽  
Surianti binti Shukor
Keyword(s):  
Filamentous Fungi ◽  
Susceptibility Testing ◽  
Rhizopus Oryzae ◽  
Antifungal Susceptibility ◽  
Sporothrix Schenckii ◽  
Rank Test ◽  
Broth Microdilution ◽  
Syncephalastrum Racemosum ◽  
Microdilution Method ◽  
Broth Microdilution Method

Abstract Background: Voriconazole is a trizaole antifungal to treat fungal infection. In this study, the susceptibility pattern of voriconazole against filamentous fungi was studied using Sensititre® YeastOne and Clinical & Laboratory Standards Institute (CLSI) M38 broth microdilution method. Methods: The suspected cultures of Aspergillus niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, A. calidoutus, A. creber, A. ochraceopetaliformis, A. tamarii, Fusarium solani, F. longipes, F. falciferus, F. keratoplasticum, Rhizopus oryzae, R. delemar, R. arrhizus, Mucor sp., Poitrasia circinans, Syncephalastrum racemosum and Sporothrix schenckii were received from hospitals. Their identification had been confirmed in our lab and susceptibility tests were performed using Sensititre® YeastOne and CLSI M38 broth microdilution method. The significant differences between two methods were calculated using Wilcoxon Sign Rank test.Results: Mean of the minimum inhibitory concentrations (MIC) for Aspergillus spp. and Fusarium were within 0.25 μg/mL-2.00 μg/mL by two methods except A. calidoutus, F. solani and F. keratoplasticum. Moreover, mean of MIC for S. schenkii were around 3.00 μg/mL by two methods. In contrast, mean of MIC for Rhizopus spp., Mucor sp., P. circinans and S. racemosum were ≥6.00 μg/mL by two methods. Generally, the MIC obtained by Sensititre YeastOne was one two-fold increase or decrease compared with the results obtained by CLSI method. The overall agreement between Sensititre YeastOne and CLSI methods to test susceptibility testing of voricaonazole was more than 70% except A. sydowii. The significant differences between two methods were significant when tested on A. niger, A. flavus, A. fumigatus, A. versicolor, A. sydowii, F. solani and S. schenkii. Conclusions: In conclusion, Sensititre YeastOne method appears to be an alternative procedure for antifungal susceptibility testing for some Malaysian moulds.

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