First detection and genotyping of Encephalitozoon cuniculi in a new host species, gyrfalcon (Falco rusticolus).

Recently, the pathogenic species of microsporidia of the genus Encephalitozoon have been detected increasingly, also in representatives of the Aves class. Our study presents laboratory proof of Encephalitozoon cuniculi (E. cuniculi) genotype II in a new host, gyrfalcon (Falco rusticolus), with suspect microsporidiosis. E. cuniculi is an obligate intracellular microsporidian parasite that infects a wide range of mammalian hosts, including humans. Characterization of the internal transcribed spacer of the rRNA gene has identified three genotypes of E. cuniculi based on the number of 5'-GTTT-3' repeats present: a genotype I from rabbits and mice, containing three repeats; a genotype II from mice and dogs, containing two repeats; and a genotype III from dogs and fox, containing four repeats. Samples of faeces from 30 gyrfalcons were examined for the presence of microsporidia spores, using microscopical, molecular methods and sequencing. Microscopic analysis showed presence of brightly fluorescing oval shapes of size 1.5 × 3 μm, characteristic of the strain Microsporidia in five samples. The PCR method, using species non-specific (530F/580R) and species-specific (ECUNR/ECUNF) primers, proved the presence of E. cuniculi spores in two samples. After sequencing were confirmed, E. cuniculi genotype II which implies new host species for this parasite.