Occurrence and significance of Cryptococcus neoformans in vegetables and fruits.

ABSTRACT

Cryptococcus neoformans was isolated from three of 437 (0.6%) samples of a wide variety of vegetables collected from a number of markets in Delhi. The vegetables yielding C. neoformans were tomato, Lycopersicon esculentum (1/70), 'vegetable sponge', Luffa cylindrica (1/56) and brinjal, Solanum melongena (1/55). Only solitary samples of these three vegetables were found to be positive. In vitro studies at 25 degrees C revealed that a reference C. neoformans isolate readily colonized, as did Candida albicans and Candida viswanathii (controls), sterilized slices of almost all the test vegetables and fruits (cut or uncut surface) which included tomato, 'vegetable sponge', brinjal, potato, carrot, radish, apple, guava, pineapple, pear, papaya, banana and mango. Sterilized juices of the same vegetables and fruits also supported adequate growth of the reference C. neoformans isolate as well as of C. albicans and C. viswanathii. However, the growth of C. neoformans on the afore-mentioned vegetables and fruits was rapidly masked by miscellaneous molds and bacteria if the test samples had not been sterilized prior to inoculation. Cryptococcus neoformans was not found in any of the 275 fruit samples investigated from the same markets. The results indicate that vegetables and fruits are unsuitable as natural habitats for C. neoformans although it may be sporadically isolated from these sources.