scholarly journals Investigation of in vitro susceptibility of non-albicans Candida species to fluconazole, itraconazole, voriconazole by reference broth microdilution method: Application of new species-specific clinical breakpoints and epidemiological cutoff values

Author(s):  
Gülşen Hazırolan
2010 ◽  
Vol 54 (No. 12) ◽  
pp. 583-588 ◽  
Author(s):  
M. Ruzauskas ◽  
R. Siugzdiniene ◽  
V. Spakauskas ◽  
J. Povilonis ◽  
V. Seputiene ◽  
...  

The aim of this study was to test and analyse the antimicrobial susceptibility of <I>Enterococcus</I> isolates from Lithuanian poultry farms. Investigations were carried out during the years 2008–2009. The sampling sites, located all over the country, included eight poultry farms of large capacity. All samples were collected from broilers. <I>Enterococcus</I> spp. were isolated from intestines immediately after slaughtering. A total of 160 samples were collected, 20 samples from each farm. The MICs (Minimum Inhibitory Concentrations) of eleven antimicrobial agents were determined for each of the isolates using the broth microdilution method with specific microtitre plate panels (Trek Diagnostic Systems, Inc.). Susceptibility according to clinical breakpoints of chloramphenicol, linezolid, erythromycin, penicillin, quinupristin/dalfopristin, tetracycline, vancomycin, ciprofloxacin and nitrofurantoin was evaluated. One hundred and forty seven samples (92%) from a total of 160 tested samples were positive for <I>Enterococcus</I> spp., however, only 74 strains were selected as non-duplicate isolates. The most predominant species were identified as <I>E. faecium</I> (38%), <I>E. faecalis</I> (17.5%), <I>E. gallinarum</I> (12%) and <I>E. casseliflavus</I> (12%). The most frequent resistance properties were resistances to tetracycline (75.6%), erythromycin (56.8%) and ciprofloxacin (41.9%). No strains resistant to vancomycin and linezolid were found. High percentages of susceptibility to chloramphenicol (82.4%) and penicillin (71.6%) were also observed. A high MIC of tigecycline (≥ 1 mg/l) to 12.2% of enterococci was determined during this study. 44.6% of tested strains had a high MIC (≥ 64 mg/l) to tylosin. There was no significant correlation found between resistances of different species to different antimicrobial agents <I>in vitro</I>.


2013 ◽  
Vol 58 (2) ◽  
pp. 916-922 ◽  
Author(s):  
M. A. Pfaller ◽  
A. Espinel-Ingroff ◽  
B. Bustamante ◽  
E. Canton ◽  
D. J. Diekema ◽  
...  

ABSTRACTSince epidemiological cutoff values (ECVs) using CLSI MICs from multiple laboratories are not available forCandidaspp. and the echinocandins, we established ECVs for anidulafungin and micafungin on the basis of wild-type (WT) MIC distributions (for organisms in a species-drug combination with no detectable acquired resistance mechanisms) for 8,210Candida albicans, 3,102C. glabrata, 3,976C. parapsilosis, 2,042C. tropicalis, 617C. krusei, 258C. lusitaniae, 234C. guilliermondii, and 131C. dubliniensisisolates. CLSI broth microdilution MIC data gathered from 15 different laboratories in Canada, Europe, Mexico, Peru, and the United States were aggregated to statistically define ECVs. ECVs encompassing 97.5% of the statistically modeled population for anidulafungin and micafungin were, respectively, 0.12 and 0.03 μg/ml forC. albicans, 0.12 and 0.03 μg/ml forC. glabrata, 8 and 4 μg/ml forC. parapsilosis, 0.12 and 0.06 μg/ml forC. tropicalis, 0.25 and 0.25 μg/ml forC. krusei, 1 and 0.5 μg/ml forC. lusitaniae, 8 and 2 μg/ml forC. guilliermondii, and 0.12 and 0.12 μg/ml forC. dubliniensis. Previously reported single and multicenter ECVs defined in the present study were quite similar or within 1 2-fold dilution of each other. For a collection of 230 WT isolates (nofksmutations) and 51 isolates withfksmutations, the species-specific ECVs for anidulafungin and micafungin correctly classified 47 (92.2%) and 51 (100%) of thefksmutants, respectively, as non-WT strains. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin and micafungin due tofksmutations.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Fahriye Eksi ◽  
Efgan Dogan Gayyurhan ◽  
Iclal Balci

This study was performed to determine the distribution ofCandidaspecies isolated from the blood cultures of the patients hospitalized in our hospital and to investigate their antifungal susceptibility.Candidastrains were identified at species level by using classical methods and API ID 32C (bioMerieux, France) identification kits. The susceptibility of the strains to amphotericin B, fluconazole, voriconazole, and caspofungin was evaluated by using the reference broth microdilution method in document M27-A3 of the Clinical and Laboratory Standards Institute. Of the 111Candidastrains isolated, 47.7% were identified asC. albicansand 52.3% as non-albicansCandidastrains. The MIC ranges were 0.03–1 μg/mL for amphotericin B, 0.125–≥64 μg/mL for fluconazole, 0.03–16 μg/mL for voriconazole, and 0.015–0.25 μg/mL for caspofungin. AllCandidastrains were susceptible to amphotericin B and caspofungin. 10.8% isolates were resistant to fluconazole and 8.1% isolates were dose-dependent susceptible. While 0.9% isolate was resistant to voriconazole, 0.9% isolate was dose-dependent susceptible. In our study,C. albicansandC. parapsilosiswere the most frequently encountered agents of candidemia and it was detected that voriconazole with a low resistance rate might also be used with confidence in the treatment of infections occurring with these agents, primarily besides amphotericin B and caspofungin.


Author(s):  
Crystiane Rodrigues Araújo ◽  
Karla Carvalho Miranda ◽  
Orionalda de Fatima Lisboa Fernandes ◽  
Ailton José Soares ◽  
Maria do Rosário Rodrigues Silva

The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.


2006 ◽  
Vol 50 (12) ◽  
pp. 4027-4029 ◽  
Author(s):  
Lucio Vera-Cabrera ◽  
Barbara A. Brown-Elliott ◽  
Richard J. Wallace ◽  
Jorge Ocampo-Candiani ◽  
Oliverio Welsh ◽  
...  

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.


2000 ◽  
Vol 44 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Francesco Barchiesi ◽  
Daniela Arzeni ◽  
Annette W. Fothergill ◽  
Luigi Falconi Di Francesco ◽  
Francesca Caselli ◽  
...  

ABSTRACT A broth microdilution method performed in accordance with the National Committee for Clinical Laboratory Standards guidelines was used to compare the in vitro activity of the new antifungal triazole SCH 56592 (SCH) to that of fluconazole (FLC), itraconazole (ITC), and ketoconazole (KETO) against 257 clinical yeast isolates. They included 220 isolates belonging to 12 different species of Candida, 15 isolates each of Cryptococcus neoformans andSaccharomyces cerevisiae, and seven isolates ofRhodotorula rubra. The MICs of SCH at which 50% (MIC50) and 90% (MIC90) of the isolates were inhibited were 0.06 and 2.0 μg/ml, respectively. In general, SCH was considerably more active than FLC (MIC50 and MIC90 of 1.0 and 64 μg/ml, respectively) and slightly more active than either ITC (MIC50 and MIC90 of 0.25 and 2.0 μg/ml, respectively) and KETO (MIC50 and MIC90 of 0.125 and 4.0 μg/ml, respectively). Our in vitro data suggest that SCH has significant potential for clinical development.


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