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 different genotypes of M. granulomatis and M. viride based on sequencing of the internal transcribed spacer 1-5.8S rDNA (ITS-1-5.8S) and a fragment of the large subunit of the 28S rDNA (LSU). The aim of this study was to clarify the relationships between these genotypes and obtain a more accurate phylogenetic classification by sequencing two different loci of the RNA polymerase II second largest subunit (NRPB2), referred to as RPB1 and RPB2, and the translation elongation factor 1 alpha (EF1α). A total of 23 frozen isolates from 21 lizards, including the first isolates of M. granulomatis and M. viride from Parson’s chameleons (Calumma parsonii), were available for phylogenetic analysis. A total of 13 isolates belonged to the M. granulomatis complex and 10 isolates belonged to the 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. In consideration of the results of the present analyses, a phylogenetic reclassification is recommended. Three different genotypes of M. granulomatis can be distinguished, which can be phylogenetically addressed as subspecies. Six subspecies can be distinguished regarding M. viride.