Reevaluation of the cefepime minimal inhibitory concentrations and disk diffusion test zone diameter relationship for a worldwide collection of Enterobacteriaceae enriched for extended-spectrum β-lactamase–producing organisms

2005 ◽  
Vol 52 (2) ◽  
pp. 95-99 ◽  
Author(s):  
Sudha Pottumarthy ◽  
Lalitagauri M. Deshpande ◽  
Helio S. Sader ◽  
Ronald N. Jones
Keyword(s):  
Disk Diffusion ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Minimal Inhibitory Concentrations ◽  
Zone Diameter ◽  
Extended Spectrum ◽  
Test Zone

scholarly journals Evaluation of Mannitol Salt Agar for Detection of Oxacillin Resistance in Staphylococcus aureus by Disk Diffusion and Agar Screening

1998 ◽  
Vol 36 (8) ◽  
pp. 2254-2257 ◽  
Author(s):  
Günter Kampf ◽  
Christoph Lecke ◽  
Ann-Katrin Cimbal ◽  
Klaus Weist ◽  
Henning Rüden
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Mannitol Salt Agar ◽  
Disk Diffusion Test ◽  
Zone Diameter ◽  
Oxacillin Resistance

Mannitol salt agar was evaluated for detection of oxacillin resistance in 136 Staphylococcus aureus isolates. AllmecA-positive isolates (n = 54) were correctly categorized as oxacillin resistant by the disk diffusion test (1-μg disk; zone diameter, <16 mm); the specificity was 97.6%. Agar screening (2 μg of oxacillin per ml) revealed a sensitivity of 98.1% and a specificity of 95.1%.

scholarly journals MIC Quality Control Guidelines and Disk Diffusion Test Optimization for CEM-101, a Novel Fluoroketolide

2009 ◽  
Vol 48 (4) ◽  
pp. 1470-1473 ◽  
Author(s):  
R. N. Jones ◽  
J. E. Ross ◽  
P. R. Rhomberg ◽  
Keyword(s):  
Quality Control ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Test Optimization

scholarly journals A Novel Extended-Spectrum TEM-Type β-Lactamase (TEM-52) Associated with Decreased Susceptibility to Moxalactam inKlebsiella pneumoniae

1998 ◽  
Vol 42 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Claire Poyart ◽  
Pierre Mugnier ◽  
Gilles Quesne ◽  
Patrick Berche ◽  
Patrick Trieu-Cuot
Keyword(s):  
Sequence Analysis ◽  
Amino Acid Substitutions ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Mobilizable Plasmid ◽  
Allelic Replacement ◽  
Extended Spectrum ◽  
Amoxicillin Clavulanate ◽  
Previously Treated ◽  
Element Sequence

ABSTRACT Klebsiella pneumoniae NEM865 was isolated from the culture of a stool sample from a patient previously treated with ceftazidime (CAZ). Analysis of this strain by the disk diffusion test revealed synergies between amoxicillin-clavulanate (AMX-CA) and CAZ, AMX-CA and cefotaxime (CTX), AMX-CA and aztreonam (ATM), and more surprisingly, AMX-CA and moxalactam (MOX). Clavulanic acid (CA) decreased the MICs of CAZ, CTX, and MOX, which suggested that NEM865 produced a novel extended-spectrum β-lactamase. Genetic, restriction endonuclease, and Southern blot analyses revealed that the resistance phenotype was due to the presence in NEM865 of a 13.5-kb mobilizable plasmid, designated pNEC865, harboring a Tn3-like element. Sequence analysis revealed that the blaT gene of pNEC865 differed from bla TEM-1 by three mutations leading to the following amino acid substitutions: Glu104→Lys, Met182→Thr, and Gly238→Ser (Ambler numbering). The association of these three mutations has thus far never been described, and theblaT gene carried by pNEC865 was therefore designatedbla TEM-52. The enzymatic parameters of TEM-52 and TEM-3 were found to be very similar except for those for MOX, for which the affinity of TEM-52 (Ki , 0.16 μM) was 10-fold higher than that of TEM-3 (Ki , 1.9 μM). Allelic replacement analysis revealed that the combination of Lys104, Thr182, and Ser238 was responsible for the increase in the MICs of MOX for the TEM-52 producers.

An alternative disk diffusion test in broth and macrodilution method for colistin susceptibility in Enterobacteriales

2019 ◽  
Vol 167 ◽  
pp. 105765
Author(s):  
López-Jácome Luis Esaú ◽  
Rengel-Garcia Christian Rodolfo ◽  
Hernández-Durán Melissa ◽  
Colín-Castro Claudia Adriana ◽  
García-Contreras Rodolfo ◽  
...  
Keyword(s):  
Disk Diffusion ◽  
Diffusion Test ◽  
Disk Diffusion Test

scholarly journals Ceftaroline resistance in Staphylococcus pseudintermedius gene mecA carriers

2018 ◽  
Vol 38 (12) ◽  
pp. 2233-2236
Author(s):  
Carolina B. Scherer ◽  
Larissa S. Botoni ◽  
Antônio U. Carvalho ◽  
Kelly M. Keller ◽  
Adriane P. Costa-Val
Keyword(s):  
Methicillin Resistance ◽  
Meca Gene ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Staphylococcus Pseudintermedius ◽  
Ceftaroline Fosamil ◽  
Disk Diffusion Test ◽  
Methicillin Resistant ◽  
Resistant Strains ◽  
Current Report

ABSTRACT: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) being a constant concern, ceftaroline fosamil has been recently approved as a new cephalosporin, active against MRSA, for use in humans; only rare cases of resistance have been reported till date. There is no report of resistance to ceftaroline in Staphylococcus pseudintermedius, which is the main bacterium causing dermatitis and otitis in dogs. To evaluate staphylococcal resistance to ceftaroline, 35 isolates of methicillin-resistant S. pseudintermedius (MRSP), carrying the mecA gene, from 26 dogs with folliculitis and nine dogs with external otitis, underwent disk diffusion test with cefoxitin, oxacillin, and ceftaroline. Tests with cefoxitin and oxacillin showed > 90% sensitivity in methicillin resistance detection. In the disk diffusion test, 97.14% (34/35) were resistant to cefoxitin, 94.29% (33/35) to oxacillin, and 31.43% (11/35) to ceftaroline. Of the ceftaroline-resistant strains, 27.27% (3/11) were obtained from the ears of dogs while the rest (8/11) were from the skin. The current report is the first description of MRSP resistance to ceftaroline.

scholarly journals Ceftazidime-avibactam and Meropenem Double Disk Diffusion Test for Identifying Carbapanem-Resistant Enterobacteriaceae and Distinguishing Between Serine and Metallo-β-Lactamase Producing Organisms

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S375-S375
Author(s):  
Lynn-Yao Lin ◽  
Ian Critchley ◽  
David Melnick
Keyword(s):  
Enterobacter Cloacae ◽  
Disk Diffusion ◽  
Screening Methods ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Carbapenem Resistant ◽  
The Us ◽  
Susceptible Control ◽  
Carbapenem Resistant Enterobacteriaceae ◽  
Selection Of

Abstract Background Early detection of carbapenem-resistant Enterobacteriaceae(CRE) is crucial for selection of effective treatment. While KPC is the most prevalent carbapenemase in the US, phenotypic screening methods, such as the carbapenemase inactivation method (CIM) and CarbaNP, cannot easily distinguish between serine and metallo-β-lactamases (MBL). The aim of this study was to evaluate a simple double disk diffusion (DD) test to confirm carbapenem (meropenem) resistance (MER disk) and that resistance was due to a serine carbapenemase as indicated by susceptibility to ceftazidime-avibactam (CAZ-AVI disk). MBL-producing organisms are likely to be resistant to both MER and CAZ-AVI. Methods In total, 83 clinical isolates of Enterobacteriaceae were selected for the validation: 54 Klebsiella pneumoniae (KP), 16 Enterobacter cloacae (ECL) and 13 Escherichia coli (EC). All isolates were screened for specific β-lactamase genes (Checkpoints, Wageningen, Netherlands) and included KPC, OXA, IMP, VIM, NDM as well as strains with KPC and alterations on OmpK35 and OmpK36. Isolates were tested for susceptibility to MER and CAZ-AVI by disk diffusion and broth microdilution (BMD) per CLSI guidelines. Results were analyzed to evaluate suitability of the DD test to distinguish between serine and MBL-producing organisms. Results Overall correlation between disk and BMD was 97–100% for CAZ-AVI and 94–100% for MER. Among the 50 CRE that were susceptible to CAZ-AVI were strains positive for KPC, or OXA, or in combination with ESBLs. Among the 16 isolates that were resistant to both CAZ-AVI and MER were strains that produced MBLs such as IMP, VIM and NDM and included strains with alteration in OmpK35 and OmpK36. Among the 17 carbapenem-susceptible control strains all were susceptible to both agents and were positive for AmpC or ESBLs. Conclusion The CAZ-AVI and MER DD test was successful in confirming CRE phenotype and in distinguishing between serine carbapenemase-producing and MBL-producing organisms. The test will be useful in screening patients in future trials to evaluate the efficacy of CAZ-AVI in global CRE studies where MBL’s are more prevalent in other geographic regions. Both disks are commercially available and can be performed in most clinical laboratories. Disclosures L. Y. Lin, Allergan plc: Employee, Salary; I. Critchley, Allergan plc: Employee, Salary; D. Melnick, Allergan plc: Employee, Salary

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