Molecular prevalence and genetic characterization of Enterocytozoon bieneusi in cattle in a dairy farm in Türkiye.

Background: Microsporidia, which are unicellular and obligate intracellular eukaryotic pathogens, can infect many animal species and humans. Cattle are known to be an important source for the spread of Enterocytozoon bieneusi (E. bieneusi) to humans and animals. Therefore, this study aimed to investigate E. bieneusi in fecal samples collected from cattle and environmental samples within a dairy farm and to genotype E. bieneusi-positive samples. For this purpose, a Nested PCR targeting a region of the E. bieneusi ribosomal DNA internal transcribed spacer (ITS) was applied to the DNA samples extracted from fecal (n = 47) or environmental samples (n = 41). Later, sequencing data belonging to E. bieneusi-positive samples were analyzed by BLAST and phylogenetic analysis for genotyping.

Results: Nested PCR screening detected 15 E. bieneusi-positive samples and among them six (12.8%; 6/47) were detected in fecal samples while nine (21.9%; 9/41) were detected in environmental samples (including drinking water containers, mangers, feeding bottle, milk heating tank and towel). When cattle were categorized by their age, the molecular prevalence of E. bieneusi for cattle < 2 months old was detected as 19.2% (5/26). However, in cattle group > 2 months old, the molecular prevalence of E. bieneusi was 10% (1/10). Surprisingly, remaining cattle > 2 years old (n = 11) were found to be E. bieneusi-negative. BLAST and phylogenetic analyses revealed type IV as well as 11 new genotypes designated as NG1 to NG11.

Conclusion: These findings point out that cattle and farms are important sources for the transmission of E. bieneusi spores to humans or animals.