PHYLOGENETIC RECLASSIFICATION OF METARHIZIUM GRANULOMATIS AND METARHIZIUM VIRIDE SPECIES COMPLEX

Metarhizium (M.) granulomatis and M. viride have previously been described as pathogens causing hyalohyphomycosis in various species of captive chameleons and bearded dragons (Pogona vitticeps). Previous studies yielded five different genotypes of M. granulomatis and four different genotypes of M. viride based on sequencing of the internal transcribed spacer1-5,8s (ITS1-5,8S) and a fragment of the large subunit of the 28S rDNA (LSU). The aim of this study was to clarify relationships between these genotypes and to obtain a more accurate phylogenetic classification by sequencing of two different loci of the RNA polymerase II second largest subunit, being referred to as RPB1 and RPB2, and the translation elongation factor 1 alpha (TEF). A total of 23 frozen isolates from 21 lizards were available for phylogenetic analysis. 13 isolates belonged to M. granulomatis-complex and 10 isolates belonged to M. viride-complex. Following the amplification and sequencing of the protein-coding genes, the resulting nucleotide sequences were analyzed, trimmed and assembled. These were further analyzed with regard to differences in single nucleotide polymorphisms (SNPs) and amino acid structure. This was complemented by the construction of phylogenetic trees. The investigation revealed no correlations between the various genotypes and the affected animal species, the isolation site or the clinical/pathological findings. With respect to the present analyses, phylogenetic reclassification is required. Three different genotypes of M. granulomatis can be distinguished, which can be phylogenetically addressed as subspecies. Six subspecies can be distinguished regarding M. viride.