PHENOTYPIC AND GENOTYPIC ANALYSIS OF VARIABILITY IN ASPERGILLUS-FUMIGATUS

Sixty-one isolates and collection strains of Aspergillus fumigatus wer e compared for their phenotypic (morphological features and isoenzyme profiles) and genotypic (restriction enzyme-generated mitochondrial DN A and ribosomal DNA profiles and random amplified polymorphic DNA patt erns) features, The examined strains exhibited highly variable colony morphologies and growth rates at different temperatures, but their mic romorphologies and conidial diameters were characteristic of the speci es. Of the isoenzymes studied, the beta-arylesterase and phosphatase p atterns were the most divergent, and the 61 strains could be classifie d into seven groups. The glucose 6-phosphate dehydrogenase and catalas e isoenzyme patterns displayed only a limited variability, while the p rofiles of superoxide dismutase, lactate dehydrogenase, and glutamate dehydrogenase, were highly conserved, The HaeIII-generated mitochondri al DNA patterns and SmaI-digested repetitive DNA and ribosomal DNA hyb ridization patterns of almost all strains were also invariable, The le vel of variation was much higher when random amplified polymorphic DNA analysis was applied, Although the patterns of the strains were very similar with most of the primers, the application of some primers made if possible to cluster the A, fumigatus isolates into several groups. The results indicate that the random amplified polymorphic DNA techni que could be used more efficiently than isoenzyme analysis for typing A, fumigatus isolates, A good correlation was found between the dendro grams obtained from the isoenzyme and random amplified polymorphic DNA data, but the isoenzyme and amplified DNA patterns did not correlate with the pathogenicity, pigment production, or geographical origin of the strains, One ''A. fumigatus'' strain (strain FRR 1266) exhibited u nique isoenzyme, mitochondrial DNA, ribosomal DNA, and random amplifie d polymorphic DNA patterns; it is proposed that this strain represents a new species of the section Fumigati.