POLYMERASE CHAIN REACTION-MEDIATED GENOTYPING OF HORTAEA-WERNECKII, CAUSATIVE AGENT OF TINEA-NIGRA

The black yeast Hortaea werneckii is known to be a causative agent of human tinea nigra but is also found in the environment. Strains from d issimilar sources were studied by polymerase chain reaction fingerprin ting of nuclear DNA, using primers annealing to repetitive and random sequences. The seven groups found correspond to those known from restr iction fragment length polymorphism (RFLP) studies of the mitochondria l DNA of the same strains. Two main groups contained strains from huma n as well as from nonhuman sources. The human strains did not cluster, but were randomly distributed over several populations. It was conclu ded that these strains are not pathogenic. The factor common to both n iches is a relatively high salt concentration.