scholarly journals Retrospective Evaluation of Colistin-Resistant Isolates in Automated System by Gradient Diffusion Method and Broth Microdilution Method

2019 ◽  
Vol 32 (1) ◽  
pp. 57-61
Author(s):  
Nazmiye Ulku Tuzemen ◽  
◽  
Kadir Efe ◽  
Halis Akalin ◽  
Cuneyt Ozakin ◽  
...  
Keyword(s):  
Automated System ◽  
Diffusion Method ◽  
Retrospective Evaluation ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Gradient Diffusion ◽  
Broth Microdilution Method

scholarly journals Categorizing susceptibility of clinical isolates of Candida auris to amphotericin B, caspofungin, and fluconazole utilizing the CLSI M44-A2 disk diffusion method

2021 ◽  
Author(s):  
Natalie S. Nunnally ◽  
Tajah Damm ◽  
Shawn R. Lockhart ◽  
Elizabeth L. Berkow
Keyword(s):  
Amphotericin B ◽  
Accurate Method ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Candida Auris ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method

We evaluated the CLSI M44ed3E disk diffusion method in comparison with the CLSI M27ed4 broth microdilution method for caspofungin and fluconazole and the Etest method for amphotericin B to categorize susceptibility of 347 clinical isolates of Candida auris. Utilizing the zone diameter cutoffs established here we observed the overall categorial agreement between the two methods. For caspofungin, concordant results were observed for 98% of isolates with <1% very major and 1% major errors. For fluconazole, concordant results were observed for 91% of isolates with 1% very major and 8% major errors. For amphotericin B, concordant results were observed for 74% of isolates with <1% very major errors and 25% major errors. The disk diffusion approach provides an accurate method for determining the susceptibility of C. auris for caspofungin and fluconazole, and for identification of at least 75% of amphotericin B-susceptible isolates.

scholarly journals Therapeutic Drug Monitoring of Tigecycline in 67 Infected Patients and a Population Pharmacokinetics/Microbiological Evaluation of A. baumannii Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Tianli Yang ◽  
Hekun Mei ◽  
Jin Wang ◽  
Yun Cai
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Population Pharmacokinetics ◽  
Drug Monitoring ◽  
Plasma Concentrations ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Therapeutic Drug ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

BackgroundThe widespread use of antibiotics has led to the emergence of multidrug-resistant (MDR) bacteria such as multidrug-resistant Acinetobacter baumannii (AB). Tigecycline (TGC), as the first glycylcycline antibiotic approved by FDA, is a broad-spectrum antibiotic which remains highly effective to treat AB infections.ObjectiveTo confirm the TGC treatment dosage and effectiveness to treat AB infections in the Chinese population by performing therapeutic drug monitoring (TDM).MethodsThis study was performed from October 2018 through March 2019 at the PLA General Hospital. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was validated and employed to determine the plasma concentrations of TGC in patients with infectious diseases. The minimum inhibitory concentration (MIC) of TGC to clinically isolated AB was determined by broth microdilution method, agar dilution method, and disk diffusion method. Moreover, a model of population pharmacokinetics/pharmacodynamics (PPK/PD) was constructed.ResultsA total of 186 plasma samples from 67 patients were detected by the validated HPLC-MS/MS method. The MIC values determined by the broth microdilution method were more sensitive and accurate than the other two methods. The microbial and clinical PK/PD breakpoints were reached when the maintenance dose of TGC was 100 mg.ConclusionOur study established a validated HPLC-MS/MS method to monitor the plasma concentrations of TGC. In view of the MIC range to AB isolates in our hospital and the PPK/PD modeling results, we recommend a relatively high dose of 100 mg q12h regimen to achieve the optimal clinical efficacy and antimicrobial response.

scholarly journals Antifungal Activity of Micafungin in Serum

2009 ◽  
Vol 53 (10) ◽  
pp. 4559-4562 ◽  
Author(s):  
Jun Ishikawa ◽  
Tetsuo Maeda ◽  
Itaru Matsumura ◽  
Masato Yasumi ◽  
Hidetoshi Ujiie ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
High Performance ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Serum Samples ◽  
Disk Diffusion Method ◽  
Serum Free ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Applied Dose

ABSTRACT We have evaluated the antifungal activity of micafungin in serum by using the disk diffusion method with serum-free and serum-added micafungin standard curves. Serum samples from micafungin-treated patients have been shown to exhibit adequate antifungal activity, which was in proportion to both the applied dose and the actual concentration of micafungin measured by high-performance liquid chromatography. The antifungal activity of micafungin in serum was also confirmed with the broth microdilution method.

scholarly journals Evaluation of Disk Diffusion Method for Determining Posaconazole Susceptibility of Filamentous Fungi: Comparison with CLSI Broth Microdilution Method

2006 ◽  
Vol 50 (3) ◽  
pp. 1108-1111 ◽  
Author(s):  
E. López-Oviedo ◽  
A. I. Aller ◽  
C. Martín ◽  
C. Castro ◽  
M. Ramirez ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Clinical Laboratory ◽  
Culture Media ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACT The disk diffusion method was evaluated for determining posaconazole susceptibility against 78 strains of molds using two culture media in comparison with the CLSI (Clinical Laboratory Standards Institute) broth microdilution method (M38-A). A significant correlation between disk diffusion and microdilution methods was observed with both culture media.

scholarly journals Evaluation of the Revised Ceftaroline Disk Diffusion Breakpoints When Testing a Challenge Collection of Methicillin-ResistantStaphylococcus aureusIsolates

2018 ◽  
Vol 56 (12) ◽  
Author(s):  
Helio S. Sader ◽  
Paul R. Rhomberg ◽  
Timothy B. Doyle ◽  
Robert K. Flamm ◽  
Rodrigo E. Mendes
Keyword(s):  
Error Rates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Wild Type ◽  
Disk Diffusion Method ◽  
Content Type ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Mueller Hinton Agar

ABSTRACTWe assessed ceftaroline disk diffusion breakpoints forStaphylococcus aureuswhen applying revised Clinical and Laboratory Standards Institute (CLSI) ceftaroline MIC breakpoints. Disk-MIC correlation was evaluated by testing a challenge collection (n= 158) of methicillin-resistantS. aureus(MRSA) isolates composed of 106 randomly selected isolates plus 52 isolates with decreased susceptibility to ceftaroline (MIC, 1 to 16 μg/ml). Disk diffusion was performed with 30-μg disks and Mueller-Hinton agar from 2 manufacturers each. Revised CLSI susceptible (S)/susceptible dose-dependent (SDD)/resistant (R) MIC breakpoints of ≤1/2 to 4/≥8 μg/ml were applied. The disk breakpoints that provided the lowest error rates were CLSI S/R breakpoints of ≥25 mm/≤19 mm, with no very major (VM) or major (Ma) errors and with minor (Mi) error rates of 0.0% for ≥2 doubling dilutions above the I or SDD (≥I + 2), 22.1% for I or SDD plus or minus 1 doubling dilution (I ± 1), and 2.3% for ≤2 doubling dilutions below the I or SDD ≤I − 2 (overall Mi error rate, 16.5%). No mutation in the penicillin-binding protein 2a (PBP2a) was observed in 5 of 15 isolates with a ceftaroline MIC of 2 μg/ml; 3 of 11 isolates with a ceftaroline MIC of 1 μg/ml exhibited mutations in the penicillin-binding domain (PBD; 1 isolate) or in the non-PBD (2 isolates). All isolates except 1, with a ceftaroline MIC of ≥4 μg/ml, showed ≥1 mutation in the PBD and/or non-PBD. In summary, results from the disk diffusion method showed a good correlation with those from the reference broth microdilution method. Our results also showed that the ceftaroline MIC distribution of isolates with no mutations in the PBP2a goes up to 4 μg/ml, and reference broth microdilution and disk diffusion methods do not properly separate wild-type from non-wild-type isolates.

scholarly journals Antifungal resistance modulation of Aspergillus fumigatus isolates from brooder pneumonia affected birds by Eucalyptus globulus extracts

2020 ◽  
pp. 145-155
Keyword(s):  
Antifungal Activity ◽  
Aspergillus Fumigatus ◽  
Eucalyptus Globulus ◽  
Ethanol Extract ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Diffusion Test ◽  
Base Pairs ◽  
Microdilution Method ◽  
Broth Microdilution Method

Brooder pneumonia is a common respiratory problem during brooding period of poultry. It is most frequently caused by Aspergillus fumigatus. Use of azole drugs for treatment and prophylaxis results in resistance. The aim of this study was to determine whether the phytochemicals of Eucalyptus globulus are modulating resistance in Aspergillus fumigatus. Lung samples n = 50 of dead broiler chicks were collected from different farms of Lahore. Out of 50 lung samples 28 % (14) were considered positive for Aspergillus fumigatus after observing their macroscopic, microscopic characteristics and by performing PCR by amplifying ITS1-ITS4 gene (597 base pairs) and RodA gene (313 base pairs). Kirby-Bauer disc diffusion test was performed 14 isolates (100 %) were resistant towards both Fluconazole and Ketoconazole whereas 11 (78.57 %) were resistant towards Itraconazole. Eucalyptus globulus leaves were collected, and these were identified. Three solvent extracts were prepared. Maximum yield was of ethanolic extract. Antifungal activity was evaluated by agar well diffusion method. Highest antifungal activity was shown by Eucalyptus globulus Ethanol followed by chloroform and hexane extract showed no activity against any isolate then minimum inhibitory concentration of plant extracts that previously showed antifungal activity against isolates were evaluated by broth microdilution method. Modulation effect was checked by combining antifungal drug one by one with subinhibitory concentration of plant extract evaluated previously by broth microdilution method. 5 isolates were subjected into this experiment which are all sensitive towards Eucalyptus globulus ethanol and chloroform extracts tested previously in agar well diffusion test and MIC values were also evaluated. It was concluded that when Itraconazole was combined with E. globulus Ethanol extract then resistance was modified. Data of modulation was analyzed by One-way ANOVA and it reported P value of <0.05. It was synergistic inhibitory effect when Itraconazole was combined with Eucalyptus globulus Ethanol extract.

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.

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