Effects of vasoactive amines and albumin upon yeast susceptibility to antifungals
Abstract number: 1733_1457
Costa-de-Oliveira S., Silva Dias A., Pina-Vaz C., Gonçalves Rodrigues A.
Critically-ill patients are often administered a variety of therapeutical drugs namely vasoactive amines and albumin. Following a prospective study about fungaemia conducted at our University hospital, several risk factors for invasive fungal disease and unfavourable outcome were detected. A significant correlation was found between fungaemia and those prescriptions. Previous studies showed the promotion of germination of A. fumigatus and the increase of antifungal resistance following incubation with albumin (Rodrigues et al, 2005).
Objective: To evaluate the effect of albumine and vasoactive amines like adrenaline, noradrenaline, dopamine and dobutamine upon the susceptibility of Candida to several antifungals.
Methods: 15 clinical strains (3 C. glabrata, 4 C. parapsilosis, 5 C. albicans and 3 C. tropicalis) plus 3 control strains belonging to American Type Culture Collection (ATCC) were studied. Susceptibility tests, according by the microdilution protocol M27-A2 from CLSI, were performed to amphotericin B, fluconazole, voriconazole and posaconazole; minimal inhibitory concentrations (MIC) were determined. MIC values were re-determined in the presence of 2% and 4% of albumin (Octapharma, Viena, Austria), 10, 25 and 100 mg/mL of adrenaline (Braun), 2.5, 5 and 100 mg/mL of noradrenaline (Braun) and 10, 50 and 200 mg/mL of both dobutamine (Sigma, Germany) and dopamine (Sigma).
Results: All strains showed initial low MIC values to the antifungals tested. In the presence of 2% and 4% of albumin, MIC of all antifungal drugs increased from 2 to 10 dilutions. The MIC values of azoles increased from 2 to 4 dilutions in the presence of adrenaline and noroadrenaline. These effects were more consistent observed with the non-albicans strains tested.
Conclusion: Vasoactive and inotropic amines have the potential to promote antifungal resistance when administered to patients simultaneously receiving antifungal therapy, especially in non-albicans species. Such fact may help to explain the increasing incidence of invasive fungal disease caused by such species among critical care patients.
Rodrigues et al, Med Mycol 43: 7117 2005.
|Session name:||European Society of Clinical Microbiology and Infectious Diseases|
|Location:||ICC, Munich, Germany|
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