scholarly journals Antifungal Susceptibilities ofPaecilomyces Species

1998 ◽  
Vol 42 (7) ◽  
pp. 1601-1604 ◽  
Author(s):  
C. Aguilar ◽  
I. Pujol ◽  
J. Sala ◽  
J. Guarro

ABSTRACT The MICs and minimum fungicidal concentrations (MFCs) of amphotericin B, miconazole, itraconazole, ketoconazole, fluconazole, and flucytosine for 52 isolates of Paecilomyces species were evaluated by the broth microdilution method, largely based on the recommendations of the National Committee for Clinical Laboratory Standards (document M27-A). The fungal isolates tested included 16P. variotii, 11 P. lilacinus, 9 P. marquandii, 6 P. fumosoroseus, 4 P. javanicus, and 2 P. viridis isolates and 1 isolate of each of the following species: P. carneus, P. farinosus, P. fulvus, and P. niveus. The MFCs and the MICs at which 90% of isolates were inhibited (MIC90s) for the six antifungal agents were remarkably high; the MIC50s indicated that amphotericin B, miconazole, itraconazole, and ketoconazole had good activities, while fluconazole and flucytosine demonstrated poor efficacy. The ranges of the MICs were generally wider and lower than those of the MFCs. There were significant susceptibility differences among the species. All species with the exception of P. variotii were highly resistant to fluconazole and flucytosine; P. variotii was susceptible to flucytosine. Amphotericin B and the rest of the azoles showed good activity against P. variotii, while all the antifungal agents assayed showed low efficacy against P. lilacinus.

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.


2001 ◽  
Vol 9 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Jose A. Simoes ◽  
Alla A. Aroutcheva ◽  
Susan Shott ◽  
Sebastian Faro

Objective:To determine whether metronidazole has an adverse effect on the growth ofLactobacillus.Methods:Hydrogen peroxide- and bacteriocin-producing strains ofLactobacilluswere used as test strains. Concentrations of metronidazole used ranged from 128 to 7000 μg/ml. Susceptibility to metronidazole was conducted by the broth microdilution method recommended by the National Committee for Clinical Laboratory Standards.Results:Growth ofLactobacilluswas partially inhibited at concentrations between 1000 and 4000 μg/ml (p= 0.014). Concentrations ≥ 5000 μg/ml completely inhibited growth ofLactobacillus. Concentrations between 128 and 256 μg/ml stimulated growth ofLactobacillus(p= 0.025 and 0.005, respectively). Concentrations of metronidazole between 64 and 128 μg/ml or ≥ 512 μg/ml did not have an inhibitory or a stimulatory effect on the growth ofLactobacilluscompared to the control.Conclusions:High concentration of metronidazole, i.e. between 1000 and 4000 μg/ml, partially inhibited the growth ofLactobacillus. Concentrations ≥ 5000 μg/ml completely suppressed the growth ofLactobacillus. Concentrations between ≥ 128 and ≤ 256 μg/ml stimulated the growth ofLactobacillus. Further investigation to determine the ideal concentration of metronidazole is needed in order to use the antimicrobial agent effectively in the treatment of bacterial vaginosis.


2004 ◽  
Vol 70 (4) ◽  
pp. 2398-2403 ◽  
Author(s):  
Mokhlasur Rahman ◽  
Inger Kühn ◽  
Motiur Rahman ◽  
Barbro Olsson-Liljequist ◽  
Roland Möllby

ABSTRACT We describe the ScanMIC method, a colorimetric MIC method for susceptibility testing of gram-negative fermentative bacteria. The method is a slight modification of the National Committee for Clinical Laboratory Standards (NCCLS) recommended broth microdilution method that uses a redox indicator 2,3,5-triphenyltetrazolium chloride (TTC) to enhance the estimate of bacterial growth inhibition in a microplate and a flatbed scanner to capture the microplate image. In-house software was developed to transform the microplate image into numerical values based on the amount of bacterial growth and to generate the MICs automatically. The choice of indicator was based on its low toxicity and ease of reading by scanner. We compared the ScanMIC method to the NCCLS recommended broth microdilution method with 197 coliform strains against seven antibacterial agents. The interpretative categorical agreement was obtained in 92.4% of the assays, and the agreement for MIC differences (within ±1 log2 dilution) was obtained in 96% for ScanMIC versus broth microdilution and 97% for a two-step incubation colorimetric broth microdilution versus the broth microdilution method. The method was found to be labor-saving, not to require any initial investment, and to show reliable results. Thus, the ScanMIC method could be useful for epidemiological surveys that include susceptibility testing of bacteria.


1998 ◽  
Vol 36 (1) ◽  
pp. 198-202 ◽  
Author(s):  
Ana Espinel-Ingroff

The in vitro antifungal activity of a new triazole derivative, voriconazole, was compared with those of itraconazole and amphotericin B against 67 isolates of Aspergillus flavus,Aspergillus fumigatus, Bipolaris spp.,Fusarium oxysporum, Fusarium solani,Pseudallescheria boydii, Rhizopus arrhizus,Blastomyces dermatitidis, Histoplasma capsulatum, and Sporothrix schenckii. The in vitro activities of voriconazole were also compared with those of amphotericin B, fluconazole, and itraconazole against 189 isolates of emerging and common yeast pathogens of Blastoschizomyces capitatus, Candida (13 species), Cryptococcus neoformans, Hansenula anomala, Rhodotorula rubra, Saccharomyces cerevisiae, Sporobolomyces salmonicolor, and Trichosporon beigelii. MICs were determined according to a procedure under evaluation by the National Committee for Clinical Laboratory Standards (NCCLS) for broth microdilution testing of filamentous fungi and by the NCCLS M27-A broth microdilution method for yeasts. The in vitro activities of voriconazole were similar to or better than those of itraconazole and amphotericin B against Aspergillus spp.,Fusarium spp., and P. boydii as well as againstB. dermatitidis and H. capsulatum. The activities of voriconazole were also comparable to or better than those of amphotericin B, fluconazole, and itraconazole against most species of yeasts tested. Exceptions were certain isolates of R. rubra and S. salmonicolor. These results suggest that voriconazole has a wide spectrum of activity in vitro; its effectiveness in the treatment of human mycoses is under evaluation in clinical trials.


2001 ◽  
Vol 45 (11) ◽  
pp. 3065-3069 ◽  
Author(s):  
Mary E. Brandt ◽  
Michael A. Pfaller ◽  
Rana A. Hajjeh ◽  
Richard J. Hamill ◽  
Peter G. Pappas ◽  
...  

ABSTRACT The antifungal drug susceptibilities of two collections ofCryptococcus neoformans isolates obtained through active laboratory-based surveillance from 1992 to 1994 (368 isolates) and 1996 to 1998 (364 isolates) were determined. The MICs of fluconazole, itraconazole, and flucytosine were determined by the National Committee for Clinical Laboratory Standards broth microdilution method; amphotericin B MICs were determined by the E-test. Our results showed that the MIC ranges, the MICs at which 50% of isolates are inhibited (MIC50s), and the MIC90s of these four antifungal agents did not change from 1992 to 1998. In addition, very small numbers of isolates showed elevated MICs suggestive of in vitro resistance. The MICs of amphotericin B were elevated (≥2 μg/ml) for 2 isolates, and the MICs of flucytosine were elevated (≥32 μg/ml) for 14 isolates. Among the azoles, the fluconazole MIC was elevated (≥64 μg/ml) for 8 isolates and the itraconazole MIC (≥1 μg/ml) was elevated for 45 isolates. Analysis of 172 serial isolates from 71 patients showed little change in the fluconazole MIC over time. For isolates from 58 patients (82% of serial cases) there was either no change or a twofold change in the fluconazole MIC. In contrast, for isolates from seven patients (12% of serial cases) the increase in the MIC was at least fourfold. For isolates from another patient there was a 32-fold decrease in the fluconazole MIC over a 1-month period. We conclude that in vitro resistance to antifungal agents remains uncommon in C. neoformans and has not significantly changed with time during the past decade.


2000 ◽  
Vol 44 (5) ◽  
pp. 1242-1246 ◽  
Author(s):  
Angela M. Nilius ◽  
Patti M. Raney ◽  
Dena M. Hensey-Rudloff ◽  
Weibo Wang ◽  
Qun Li ◽  
...  

ABSTRACT A-192411.29 is a novel antifungal agent derived from the structural template of the natural product echinocandin. The in vitro activity of A-192411.29 against common pathogenic yeasts was assessed by National Committee for Clinical Laboratory Standards method M27-A. It demonstrated broad-spectrum, fungicidal activity and was active against the most clinically relevant yeasts, such as Candida albicans, Candida tropicalis, and Candida glabrata, as well as less commonly encounteredCandida species; in general, its potency on a weight basis was comparable to that of amphotericin B. It maintained potent in vitro activity against Candida strains with reduced susceptibilities to fluconazole and amphotericin B. The in vitro activity of A-192411.29 against Cryptococcus neoformans was comparable to its activity against Candida spp. However, A-192411.29 did not demonstrate complete growth inhibition ofAspergillus fumigatus by the broth microdilution method used. A-192411.29 possesses an antifungal profile comparable to or better than those of fluconazole and amphotericin B against pathogenic yeasts, including strains resistant to fluconazole or amphotericin B, suggesting that it may be a therapeutically useful new antifungal drug.


1998 ◽  
Vol 36 (9) ◽  
pp. 2609-2612 ◽  
Author(s):  
M. A. Pfaller ◽  
S. Arikan ◽  
M. Lozano-Chiu ◽  
Y.-S. Chen ◽  
S. Coffman ◽  
...  

A method using a commercially prepared colorimetric microdilution panel (ASTY; Kyokuto Pharmaceutical Industrial Co., Ltd.) was compared in four different laboratories with the National Committee for Clinical Laboratory Standards (NCCLS) reference microdilution method by testing 802 clinical isolates of Candida spp. (C. albicans, C. glabrata, C. tropicalis,C. parapsilosis, C. krusei, C. lusitaniae, C. guilliermondii, C. lipolytica, C. rugosa, and C. zeylanoides) against amphotericin B, 5-fluorocytosine (5FC), fluconazole, and itraconazole. Reference MIC endpoints were established after 48 h of incubation, and ASTY endpoints were established after 24 and 48 h of incubation. ASTY endpoints were determined to be the time at which the color of the first well changed from red (indicating growth) to purple (indicating growth inhibition) or blue (indicating no growth). Excellent agreement (within 2 dilutions) between the reference and colorimetric MICs was observed. Overall agreement was 93% at 24 h and 96% at 48 h. Agreement ranged from 90% with itraconazole and 5FC to 96% with amphotericin B at 24 h and from 92% with itraconazole to 99% with amphotericin B and 5FC at 48 h. The ASTY colorimetric microdilution panel method appears to be comparable to the NCCLS reference method for testing the susceptibilities of Candida spp. to a variety of antifungal agents.


1999 ◽  
Vol 37 (3) ◽  
pp. 591-595 ◽  
Author(s):  
A. Espinel-Ingroff ◽  
M. Pfaller ◽  
S. A. Messer ◽  
C. C. Knapp ◽  
S. Killian ◽  
...  

National Committee for Clinical Laboratory Standards (NCCLS) standard guidelines are available for the antifungal susceptibility testing of common Candida spp. and Cryptococcus neoformans, but NCCLS methods may not be the most efficient and convenient procedures for use in the clinical laboratory. MICs of amphotericin B, fluconazole, flucytosine, itraconazole, and ketoconazole were determined by the commercially prepared Sensititre YeastOne Colorimetric Antifungal Panel and by the NCCLS M27-A broth microdilution method for 1,176 clinical isolates of yeasts and yeast-like organisms, including Blastoschizomyces capitatus, Cryptococcus spp., 14 common and emerging species of Candida, Hansenula anomala,Rhodotorula spp., Saccharomyces cerevisiae,Sporobolomyces salmonicolor, and Trichosporon beigelii. Colorimetric MICs of amphotericin B corresponded to the first blue well (no growth), and MICs of the other agents corresponded to the first purple or blue well. Three comparisons of MIC pairs by the two methods were evaluated to obtain percentages of agreement: 24- and 48-h MICs and 24-h colorimetric versus 48-h reference MICs. The best performance of the YeastOne panel was with 24-h MICs (92 to 100%) with the azoles and flucytosine for all the species tested, with the exception of C. albicans (87 to 90%). For amphotericin B, the best agreement between the methods was with 48-h MIC pairs (92 to 99%) for most of the species tested. The exception was for isolates ofC. neoformans (76%). These data suggest the potential value of the YeastOne panel for use in the clinical laboratory.


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.


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