scholarly journals In Vitro Susceptibility of Isolates of Aspergillus fumigatus and Sporothrix schenckii to Amphotericin B

1972 ◽  
Vol 2 (5) ◽  
pp. 402-404 ◽  
Author(s):  
J. W. Brandsberg ◽  
M. E. French
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Sporothrix Schenckii ◽  
In Vitro Susceptibility

scholarly journals Molecular Studies Reveal Frequent Misidentification of Aspergillus fumigatus by Morphotyping

2006 ◽  
Vol 5 (10) ◽  
pp. 1705-1712 ◽  
Author(s):  
S. Arunmozhi Balajee ◽  
David Nickle ◽  
Janos Varga ◽  
Kieren A. Marr
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Distinct Species ◽  
Enzyme Polymorphism ◽  
Antifungal Drugs ◽  
Clinical Isolates ◽  
Polymorphism Analysis ◽  
In Vitro Susceptibility ◽  
Epidemiological Surveys

ABSTRACT Aspergillus fumigatus has been understood to be the most common cause of invasive aspergillosis (IA) in all epidemiological surveys. However, recent studies have uncovered a large degree of genetic heterogeneity between isolates morphologically identified as A. fumigatus, leading to the description of a new species, Aspergillus lentulus. Here, we examined the genetic diversity of clinical isolates identified as A. fumigatus using restriction enzyme polymorphism analysis and sequence-based identification. Analysis of 50 clinical isolates from geographically diverse locations recorded the presence of at least three distinct species: A. lentulus, Aspergillus udagawae, and A. fumigatus. In vitro, A. lentulus isolates demonstrated decreased susceptibility to antifungal drugs currently used for IA, including amphotericin B, voriconazole, and caspofungin; A. udagawae isolates demonstrated decreased in vitro susceptibility to amphotericin B. Results of the present study demonstrate that current phenotypic methods to identify fungi do not differentiate between genetically distinct species in the A. fumigatus group. Differential antifungal susceptibilities of these species may account for some of the reported poor outcomes of therapy in clinical studies.

In vitro susceptibility of isolates ofSporothrix schenckiito amphotericin B, itraconazole, and terbinafine: comparison of yeast and mycelial forms

2006 ◽  
Vol 52 (9) ◽  
pp. 843-847 ◽  
Author(s):  
Lidiane Meire Kohler ◽  
Betânia Maria Soares ◽  
Daniel de Assis Santos ◽  
Maria Elisabete Da Silva Barros ◽  
Júnia Soares Hamdan
Keyword(s):  
Amphotericin B ◽  
Clinical Laboratory ◽  
Sporothrix Schenckii ◽  
Clinical Findings ◽  
In Vitro Tests ◽  
Mycelial Form ◽  
In Vitro Susceptibility ◽  
Significant Difference ◽  
Different Levels

Forty-three clinical isolates of Sporothrix schenckii derived from humans and animals were evaluated in vitro for their susceptibility to amphotericin B, itraconazole, and terbinafine. MICs were determined by the method of micro dilution in liquid media, using protocols M27-A2 for the yeast form and M38-A for the mycelial form, both standardized by the Clinical Laboratory Standards Institute. In general, higher MICs were found for the mycelial form (intervals of up to two dilutions). In the case of amphotericin B, a significant difference in activity was observed, with higher values (p < 0.05) found for the mycelial form. MICs for itraconazole and terbinafine were similar for both yeast and mycelial forms but slightly higher for mycelia. Although data presented here indicate different levels of susceptibility when both growth forms were compared, indicating an intrinsic difference between them, it is still difficult to draw a consensus as to which form correlates better with clinical findings. More studies are necessary to determine the criteria for in vitro tests that will lead to efficient therapeutic choices.Key words: Sporothrix schenckii, susceptibility testing, antifungal drug.

A comparative study of the broth micro- and macro-dilution techniques for the determination of the in vitro susceptibility ofAspergillus fumigatus

1996 ◽  
Vol 42 (9) ◽  
pp. 960-964 ◽  
Author(s):  
Elias K. Manavathu ◽  
George J. Alangaden ◽  
Stephen A. Lerner
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Medical Center ◽  
Acquired Resistance ◽  
Inoculum Size ◽  
Clinical Isolates ◽  
Medium Temperature ◽  
In Vitro Susceptibility ◽  
Broth Macrodilution

The effects of inoculum size, medium, temperature, and duration of growth on the in vitro susceptibility testing of Aspergillus fumigatus were investigated using broth micro- and macro-dilution techniques. The minimum inhibitory concentrations (MICs) of ketoconazole, miconazole, itraconazole, fluconazole, and amphotericin B were significantly influenced by the inoculum size, regardless of the techniques used. Two- to four-fold higher MIC values were obtained when the inoculum size was increased 100-fold. The use of peptone yeast extract glucose and RPMI 1640 media provided essentially identical MIC values at 30 and 35 °C after incubation for 48 h or longer. A comparison of broth micro- and macro-dilution techniques revealed that, under equivalent conditions, the latter with an inoculum size between 1 × 103and 1 × 104conidia (strain W73355)/mL consistently provided the lowest MICs of fluconazole (256 μg/mL), ketoconazole (8 μg/mL), miconazole (2 μg/mL), itraconazole (0.25 μg/mL), and amphotericin B (0.25 μg/mL). Using the broth macrodilution technique, we screened 24 clinical isolates of A. fumigatus obtained from the Detroit Medical Center in 1994. The MIC values of fluconazole, ketoconazole, miconazole, itraconazole and amphotericin B for all the isolates were 128–256, 8–16, 1–2, 0.25–0.5, and 0.25–1.0 μg/mL, respectively, indicating that none of the clinical isolates that we tested shows acquired resistance to the antifungals used.Key words: Aspergillus fumigatus, susceptibility test, antifungals, drug resistance, broth macrodilution.

scholarly journals Efficacy of LY303366 against Amphotericin B-Susceptible and -Resistant Aspergillus fumigatus in a Murine Model of Invasive Aspergillosis

1998 ◽  
Vol 42 (4) ◽  
pp. 873-878 ◽  
Author(s):  
Paul E. Verweij ◽  
Karen L. Oakley ◽  
Jacqui Morrissey ◽  
Graham Morrissey ◽  
David W. Denning
Keyword(s):  
Survival Rate ◽  
Invasive Aspergillosis ◽  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Murine Model ◽  
Survival Rates ◽  
In Vitro Susceptibility ◽  
Once Daily

ABSTRACT LY303366 is a novel antifungal echinocandin with excellent in vitro activity against Aspergillus spp. We compared four doses (1, 2.5, 10, and 25 mg/kg of body weight) of LY303366 with amphotericin B (0.5 to 5 mg/kg) in a temporarily neutropenic murine model of invasive aspergillosis against an amphotericin B-susceptible (AF210) and an amphotericin B-resistant (AF65) Aspergillus fumigatus isolate based on in vivo response. Mice were immunosuppressed with cyclophosphamide (200 mg/kg) and infected 3 days later. Treatment started 18 h after infection and lasted for 10 days. LY303366 was given once daily intravenously for 10 days, and amphotericin B (at 0.5, 2, and 5 mg/kg) was given once daily intraperitoneally for 10 days, or only on days 1, 2, 4, and 7 (at 5 mg/kg). Kidneys and lungs from survivors were cultured on day 11. Control mice in both experiments had 90 to 100% mortality. Amphotericin B at 0.5 mg/kg and LY303366 at 1 mg/kg yielded 10 to 20% survival rates for mice infected with either AF210 or AF65. Amphotericin B at 2 and 5 (both regimens) mg/kg yielded a 70 to 100% survival rate for mice infected with AF210 but a 10 to 30% survival rate for mice infected with AF65 (P = 0.01 to 0.04 compared with AF210). Against AF210 and AF65, LY303366 at 2.5, 10, and 25 mg/kg produced a survival rate of 70 to 80%, which was as effective as amphotericin B for AF210, but superior to amphotericin B for AF65 (P < 0.03 to 0.0006). For AF65, LY303366 at 10 and 25 mg/kg/day was superior to amphotericin B at 2 and 5 mg/kg/day in reducing tissue colony counts (P = 0.01 to 0.003), and for AF210, amphotericin B at 5 mg/kg/day and at 5 mg/kg in four doses was more effective than all four regimens of LY303366 in reducing renal culture counts (P = 0.01 to 0.0001). The present study shows, for the first time, that in vivo resistance of A. fumigatus to amphotericin B exists, although this could not be detected by in vitro susceptibility assays. Furthermore, LY303366 appears to be effective against amphotericin B-susceptible and -resistant A. fumigatus infection in this model and should be further evaluated clinically.

Sign in / Sign up

Export Citation Format

Share Document