scholarly journals A comparative study of the disc diffusion method with the broth microdilution and Etest methods for voriconazole susceptibility testing of Aspergillus spp.

2004 ◽  
Vol 53 (5) ◽  
pp. 739-742 ◽  
Author(s):  
M. C. Serrano
Keyword(s):  
Comparative Study ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Disc Diffusion Method

scholarly journals Russia-made Mueller–Hinton agar: compliance with contemporary requirements

2019 ◽  
Vol 9 (2) ◽  
pp. 409-416
Author(s):  
L. V. Domotenko ◽  
I. S. Kosilova ◽  
A. P. Shepelin
Keyword(s):  
Quality Control ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Nutrient Media ◽  
Mueller Hinton ◽  
Mueller Hinton Agar

At present, a rise of antimicrobial resistance requires that susceptibility of infectious agents to antimicrobial agents could be accurately evaluated as related errors may lead to selecting improper therapeutics provoking spread of drug resistance. Pathogen sensitivity to antimicrobial agents is commonly determined by a disc diffusion method. A quality of nutrient medium used in assays plays a crucial role influencing final results. In Russia, it turned out that regulatory documents such as the nationwide guidelines and clinical recommendations outlining methodology for antimicrobial susceptibility testing underlay availability in domestic market few nutrient media, including Mueller–Hinton Agar, AGV medium etc. exhibiting sometimes unsatisfactory quality. To harmonize such methodology with international requirements, theStateResearchCenterfor Applied Microbiology and Biotechnology has developed a technology and promoted manufacture of Russia-made Mueller–Hinton agar satisfying requirements of EUCAST documents, clinical guidelines, and ISO/TS 16782:2016. The main objective of this study was to compare quality of new agar product with five similar foreign media while examining 11 test strains by disc diffusion method. As a result, some of nutrient media available to the Russian market turned out to be off-standard: not all of them satisfy to the EUCAST requirements and clinical guidelines since diameter distribution for growth inhibition recommended by EUCAST for quality control does not fit into permissible range. Moreover, susceptibility of P. aeruginosa ATCC 27853 to aminoglycosides, fluoroquinolones, Meropenem, as well as S. aureus ATSS 25923 and E. faecalis ATCC 29212 to tigecycline was assessed with certain mistakes. The data obtained by us were analyzed in accordance to the new document ISO/TS 16782:2016 “Clinical laboratory testing — criterion for acceptable lots of dehydrated Mueller–Hinton agar and broth for antimicrobial susceptibility testing”, not approved yet In Russia. To determine potential reason for deviation of data from reference range, we measured concentration of bivalent metals in all nutrient media examined by atomic emission spectrometry with inductively coupled plasma. We determined new patterns affecting reliability of results on microbial antibiotic susceptibility. A need to check intralaboratory quality control of nutrient media was emphasized.  

scholarly journals Stenotrophomonas maltophilia endogenous endophthalmitis: clinical presentation, sensitivity spectrum and management

2009 ◽  
Vol 58 (6) ◽  
pp. 837-838 ◽  
Author(s):  
T. Das ◽  
H. S. Deshmukh ◽  
A. Mathai ◽  
Ashok Kumar Reddy
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Susceptibility Testing ◽  
Clinical Presentation ◽  
Diffusion Method ◽  
Endogenous Endophthalmitis ◽  
Antibiotic Susceptibility Testing ◽  
Disc Diffusion ◽  
Antibiotic Regimen ◽  
Nosocomial Pathogen ◽  
Disc Diffusion Method

Stenotrophomonas maltophilia is gaining importance as a community-acquired pathogen, after becoming firmly established as a nosocomial pathogen. Here we report a case of endogenous endophthalmitis due to S. maltophilia. Antibiotic-susceptibility testing of the isolate was performed by the Kirby–Bauer disc diffusion method. The organism was resistant to aminoglycosides, imipenem, ticarcillin and cotrimoxazole and was sensitive to ceftazidime and chloramphenicol. The patient was successfully treated with a sensitivity-based intravitreal antibiotic regimen.

scholarly journals Interpreting Susceptibility Testing of Carbapenem Against Pseudomonas aeruginosa

2016 ◽  
Vol 4 (1) ◽  
pp. 1-8
Author(s):  
Maite Micaelo ◽  
Florence Brossier ◽  
Nicolas Brechot ◽  
Charles Edouard Luyt ◽  
Qin Lu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Limited Data ◽  
Disc Diffusion Method ◽  
New Guidelines

Objectives: Carbapenems are among the most powerful anti pseudomonal agents. Since meropenem and doripenem were marketed, there are limited data regarding drug susceptibility testing by routine methods (disc diffusion and Etest) for them. The aim of our study was to compare in vitro activity of the imipenem, meropenem and doripenem against Pseudomonas aeruginosa. Methods: Three hundred and eleven P. aeruginosa strains isolated from respiratory specimens in 170 patients who developed ventilator-associated pneumonia in two intensive care units were collected over a period of 31 months. The susceptibility of all of these isolates to imipenem, meropenem and doripenem were determined by Etest and disc diffusion method. Results: Considering either all of the isolates or only the first isolates recovered per patient (311 and 170 respectively) the susceptibility rate for doripenem was higher than that for meropenem and imipenem. When MICs determined by Etest were converted into interpretative categories (S, I, R) using French (CA-SFM) guidelines, agreement was poor, especially for meropenem and doripenem. The percent of agreement with the disc diffusion method were 90.6% and 89.7% for imipenem, 80.5% and 82.6% for meropenem and 80.5% and 73.3% for doripenem, for the first isolates and all of the isolates, respectively. Errors were mostly minor errors, and the rate of errors was as high as 17.7% and 16.1% for meropenem and 17.7% and 25.7% for doripenem for the first isolates and all of the isolates, respectively Conclusion: The accuracy of disc diffusion using CA-SFM guidelines appears unsatisfactory for all the three carbapenems justifying the adaptation of new guidelines for P. aeruginosa and carbapenems

The role of the bla KPC gene in antimicrobial resistance of Klebsiella pneumoniae

2019 ◽  
Author(s):  
Atossa Ghasemnejad ◽  
Monir Doudi ◽  
Nour Amirmozafari
Keyword(s):  
Klebsiella Pneumoniae ◽  
Antimicrobial Susceptibility ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Disc Diffusion Method ◽  
Biochemical Tests ◽  
Microdilution Method ◽  
Broth Microdilution Method

Background and Objectives: Klebsiella pneumoniae isolates that produce K. pneumoniae carbapenemase (KPC) have be- come a grave concern for the treatment of infections. KPC-producing strains are not only able to hydrolyze carbapenems but are also resistant to a variety of β-lactam and non-β-lactam antibiotics. The present study evaluated the prevalence of bla in K. pneumoniae infections and determined the antimicrobial susceptibility of the isolates. Materials and Methods: The K. pneumoniae isolates were identified by biochemical tests and confirmed by genotyping. The modified Hodge test (MHT) was performed to detect carbapenemases, and antimicrobial susceptibility was determined for all isolates by the disc diffusion method. Also, for MHT-positive isolates, supposed to carbapenemases isolates, broth microdilution method was used to measure the minimum inhibitory concentrations (MICs) of meropenem and colistin. Results: The bla KPC genotypic evaluation revealed that only 5 of 96 isolates carried bla genes. Antimicrobial pattern showed that isolates carrying bla were resistant to cefepime, ticarcillin/tazobactam, and aztreonam discs. Also, results of broth microdilution method showed that KPC-producing K. pneumoniae was resistant to meropenem and colistin, according to the CLSI and EUCAST. Conclusion: In this study nearly half the isolates showed carbapenemase activity as shown by MHT results, but only few of them were carrying bla . Thus bla gene is not the main cause of resistance spread to carbapenems in Isfahan, Iran.

scholarly journals Detection of Methicillin ResistantStaphylococcus aureusand Determination of Minimum Inhibitory Concentration of Vancomycin forStaphylococcus aureusIsolated from Pus/Wound Swab Samples of the Patients Attending a Tertiary Care Hospital in Kathmandu, Nepal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Raghabendra Adhikari ◽  
Narayan Dutt Pant ◽  
Sanjeev Neupane ◽  
Mukesh Neupane ◽  
Roshan Bhattarai ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Meca Gene ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
Disc Diffusion Method ◽  
Inducible Clindamycin Resistance ◽  
Microdilution Method ◽  
Broth Microdilution Method

The present study was conducted to evaluate the performance of cefoxitin disc diffusion method and oxacillin broth microdilution method for detection of methicillin resistantS. aureus(MRSA), taking presence of mecA gene as reference. In addition, inducible clindamycin resistance and beta-lactamase production were studied and minimum inhibitory concentration (MIC) of vancomycin forS. aureusisolates was determined. A total of 711 nonrepeated pus/wound swab samples from different anatomic locations were included in the study. TheStaphylococcus aureuswas identified on the basis of colony morphology, Gram’s stain, and biochemical tests. A total of 110 (15.47%)S. aureusisolates were recovered, of which 39 (35.50%) isolates were identified as MRSA by cefoxitin disc diffusion method. By oxacillin broth microdilution method, 31.82% of theStaphylococcus aureusisolates were found to be MRSA. However, mecA gene was present in only 29.1% of the isolates. Further, beta-lactamase production was observed in 71.82% of the isolates, while inducible clindamycin resistance was found in 10% ofS. aureusisolates. The MIC value of vancomycin forS. aureusranged from 0.016 μg/mL to 1 μg/mL. On the basis of the absolute sensitivity (100%), both phenotypic methods could be employed for routine diagnosis of MRSA in clinical microbiology laboratory; however cefoxitin disc diffusion could be preferred over MIC method considering time and labour factor.

Sign in / Sign up

Export Citation Format

Share Document