Genotyping of Enterocytozoon bieneusi isolates detected in stray cats of Izmir, Turkiye

The phylum Microsporidia includes obligate intracellular parasites that can infect humans and various animals. To date, 17 different species within the phylum have been reported to infect humans. Among them, Enterocytozoon bieneusi (E. bieneusi) is one of the most frequently detected species in humans. Identification of E. bieneusi as well as its genotypes in humans and animals is important to reveal their role in transmission to each other. Cats are blamed as the source of E. bieneusi transmission to humans. In this study, we aimed to genotype 170 E. bieneusi positive samples isolated from stool of stray cats living in Izmir province of Turkiye. According to the results, 47 samples were amplified by nested PCR protocol targeting ITS region and successfully sequenced. The phylogenetic analysis showed the presence of zoonotic genotype D and type IV in stray cats, which are also frequently detected in humans. Among the E. bieneusi genotypes detected, the prevalence of type IV (93.6%; 44/47) was very high compared to genotype D. Overall, the identification of zoonotic genotypes of E. bieneusi supports that stray cats can play an important role in the transmission of E. bieneusi to humans in Izmir.