Search

Isozyme variation among 54 isolates of Microsporum canis, 18 Microsporum cookei isolates and two Diheterospora isolates were studied using starch gel electrophoresis. Of eight enzymes examined, four were polymorphic (EST, G6P, MDH and PEP), having from two to four electrophoretic forms. Within each species, consistent and reproducible isozyme patterns of the eight enzyme systems were obtained. Phenotypic diversity (H) in M. canis was higher than in M. cookei (H = 0.459 and H = 0.408 respectively), but phenotypic differentiation of M. canis isolates from different geographical regions (Auckland, Wellington and Palmerston North, New Zealand) was low, with a proportion of total diversity (Gst) of 0.151 found among the localities. The results suggest that the isolates of M. canis from different geographical regions are closely related, supporting the theory of a common lineage.

Fifty-four isolates of Microsporum canis (Arthroderma otae) from humans, cats and dogs obtained from Auckland, Palmerston North and Wellington, New Zealand and 18 M. cookei and two Diheterospori spp. from soils were examined for variation using eight isozyme loci. M. canis isolates were from infected and non-infected cases. Isozyme analysis separated the three species which were further subdivided into electrophoretic types (ETs). Clustering analysis using normalized percentage disagreement (PTC) average linkage method revealed two clusters for M. cookei with two subclusters in cluster 2. M. canis had three main divisions (clusters 3, 4 and 5) and Diheterospora formed a separate division. The presence of isolates from different sources in the same clusters and lack of statistical significance as measured by confidence intervals suggests the existence of isolates with common lineage.