Improved cultural selectivity of medically significant fungi by suppression of contaminating bacterial flora employing gallium (III) nitrate.

Incorporation of gallium (III) nitrate into unsupplemented Sabouraud Dextrose Agar to a final concentration of 512 mg/l (2 mM) suppressed bacterial growth, of the following genera Escherichia, Enterococcus, Klebsiella, Listeria, Pseudomonas and Staphylococcus, In contrast growth of Burkholderia cenocepacia, and yeast and filamentous fungi was not affected. Supplementation of selective mycological media with gallium (III) may aid in the selectivity of such media, particularly where clinical specimens are heavily contaminated with bacterial co-habitants and where antibiotic resistance in such bacterial flora may render antibiotic supplements ineffective.