Genotyping and Age-Related Distribution of Enterocytozoon bieneusi in Preweaned Calves in Türkiye

Enterocytozoon bieneusi is recognized as the most common microsporidian parasite, exhibiting a broad host spectrum that includes a wide range of animal species, as well as humans. However, no comprehensive data are available on the prevalence, age-related distribution, or genotype diversity of E. bieneusi in preweaned calves in Türkiye. Therefore, this study aimed to provide comprehensive data and expand current knowledge on E. bieneusi in preweaned calves from different age groups.

We screened a total of 240 fecal samples collected from preweaned calves using nested PCR to determine the occurrence and age-related distribution of E. bieneusi. Genotyping of the detected isolates and evaluation of their zoonotic potential were subsequently performed based on ITS sequence analysis.

Enterocytozoon bieneusi was identified in 38 out of 240 fecal specimens, corresponding to an overall prevalence of 15.8%. Sequence analyses revealed the presence of two known genotypes, BEB8 and J. While genotype J was identified as the predominant genotype circulating among calves in the study area, genotype BEB8 was detected for the first time in a mammalian host in Türkiye. Phylogenetic analysis further revealed that both genotypes clustered within Group 2, which includes ruminant-adapted genotypes.

This is the first comprehensive report on the occurrence, age-related distribution, and genotyping of E. bieneusi in preweaned calves in Türkiye, highlighting the potential role of calves as reservoirs or carriers of this pathogen.