Fungal dermatitis, glossitis and disseminated visceral mycosis caused by different Metarhizium granulomatis genotypes in veiled chameleons (Chamaeleo calyptratus) and first isolation in healthy lizards

• Published in: Veterinary microbiology 2017-08, Vol.207, p.74-82
• Main Authors: Schmidt, Volker, Klasen, Linus, Schneider, Juliane, Hübel, Jens, Pees, Michael
• Format: Article
• Language: English
• Subjects: Animals; Antifungal agents; Antifungal Agents - pharmacology; Chamaeleo calyptratus; Clavicipitaceae; Dermatitis; Dermatomycoses - microbiology; Dermatomycoses - veterinary; Drug Resistance, Fungal; Fungal infections; Fungi; Furcifer pardalis; Genotype & phenotype; Genotypes; Glossitis; Glossitis - microbiology; Glossitis - veterinary; Hemorrhage; Lizards; Lizards - microbiology; Medical treatment; Metarhizium; Metarhizium - classification; Metarhizium - genetics; Metarhizium - isolation & purification; Metarhizium granulomatis; Metarhizium viride; Mycosis; Nystatin; Pets; Pharyngitis; Phylogeny; Pogona vitticeps; Reptiles; Reptiles & amphibians; Ribosomal DNA; Studies; Systemic mycosis; Terbinafine; Viscera - microbiology; Viscera - pathology
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/j.vetmic.2017.06.005

•Analysis of ribosomal DNA yielded five different genotypes of Metarhizium (M.) granulomatis.•Isolation of M. granulomatis from clinical unaffected veiled chameleons, panther chameleons and inland bearded dragon.•Comparing of survival time depending on associated pathology, route of infection and genotypes.•Advanced antifungal susceptibility testing of M. granulomatis and formulation of treatment options.•Analysis of GenBank entries labelled as M. granulomatis and describing options for molecular biological differentiation. Metarhizium (M.) granulomatis (formerly Chamaeleomyces granulomatis) invariably causes fatal fungal glossitis and systemic mycosis in veiled chameleons (Chamaeleo calyptratus). Isolation of M. granulomatis in other lizards thus far has not been described. The aim of this study therefore was to obtain information on the presence of M. granulomatis in reptiles kept as pets, and to examine whether there was an association between specific genotypes and clinical/pathological outcomes. Besides 18S ribosomal (r) DNA (SSU) and internal transcribed spacer1-5.8S (ITS1-5.8S) rDNA, a fragment of the large subunit of the 28S rDNA (LSU), including the domains 1 (D1) and D2, were sequenced for identification of the fungus and phylogenetic analysis. Metarhizium granulomatis was isolated from 23 veiled chameleons, two panther chameleons (Furcifer pardalis) and one central bearded dragon (Pogona vitticeps). Only the veiled chameleons revealed corresponding pathological findings in the form of glossal hemorrhage, granulomatous glossitis, pharyngitis, dermatitis and/or visceral mycosis. The infection site correlated to survival times of infected veiled chameleons. Combined long-term treatment with terbinafine and nystatin based on susceptibility testing may be helpful for prevention of disease and visceral spreading of the fungus, but elimination of the fungal pathogen or successful treatment of diseased veiled chameleons have not been achieved yet. Sequencing of the ribosomal genes yielded five different genotypes, with genotype A being strongly correlated with dermatitis, and remaining genotypes with pharyngitis and glossitis. However, disseminated visceral mycosis developed irrespective of the genotypes.