Sunday, March 16, 2008

Sunday March 16, 2008
Propofol lipidic infusion promotes resistance to antifungals !


See this interesting study explaining why sometime antifungals do not work ! and why there are discrepancies between in vitro and in vivo susceptibility to antifungals.


During study, Candida and Aspergillus were studied regarding the ability to grow and its susceptibility profile to antifungals in the presence of propofol infusion and its lipidic vehicle.

The intensity of fluorescence after staining with FUN1, in the presence and absence of propofol infusion, was determined by flow cytometry. Radioactivity assays were also performed in order to quantify the input of [3H]- itraconazole into the fungal cell in the presence of propofol. Assays were repeated after addition of sodium azide, in order to block efflux pumps.

Results

  • Propofol infusion promoted budding of Candida and the germination of Aspergillus, latter forming a lipid layer around the hypha.
  • An increase of minimal fungicidal concentrations regarding both Candida and Aspergillus strains was found for all antifungals when incubated simultaneously with propofol infusion.
  • A decrease of the intensity of fluorescence of Candida cells was systematically observed, as well as a significant reduced intracellular uptake of [3H] itraconazole in cells treated with propofol infusion, even after the blockade of efflux pumps.

Conclusion

Propofol infusion, due to its lipidic vehicle, increased the fungal germination and promoted resistance to antifungals. This effect seems to be related to the reduced access and/or permeabilization to fungal cells by antifungals
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Reference: click to get article / abstract

Propofol lipidic infusion promotes resistance to antifungals by reducing drug input into the fungal cell - BMC Microbiol. 2008; 8: 9. - pdf non-pdf version is available here

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