Differential killer toxin sensitivity patterns of varieties of Cryptococcus neoformans.

Ten different killer sensitivity types are distinguished within Cryptococcus neoformans, namely four in var. neoformans and six in var. gattii. All strains of the var. gattii investigated were inhibited by killer toxins of C. laurentii CBS 139, whereas those of the var. neoformans were not. Killer sensitivity patterns are an easy-to-use method to differentiate between the two varieties of the clinically important yeast C. neoformans, and may be of help in epidemiological surveys.