Molecular Detection and Genotyping of Enterocytozoon bieneusi in Beef Cattle in Shanxi Province, North China

Simple Summary Enterocytozoon bieneusi is an important zoonotic intestinal protozoan that can infect humans and many types of animals. Currently, the prevalence and genotyping of E. bieneusi in beef cattle in China's Shanxi province is still unknown. Thus, nested PCR was applied in the present study to investigate the prevalence and genotypes of E. bieneusi by examining 401 fecal samples collected from beef cattle in two representative counties of Shanxi province. The results showed that the overall prevalence of E. bieneusi in beef cattle in Shanxi province is 22.44% (90/401). Six known genotypes (I, BEB4, J, BEB6, BEB8 and PigSpEb2) and two novel genotypes (designated CSC1 and CSC2) were identified, and genotype I was the predominant genotype in these two counties. Phylogenetic tree analysis indicated that five known genotypes and two novel genotypes were clustered into Group 2, whereas the genotype PigSpEb2 belongs to zoonotic Group 1. To our knowledge, the present study is the first to demonstrate the presence of E. bieneusi in beef cattle in Shanxi province, enriching the data on prevalence and genotypes of E. bieneusi in beef cattle and providing baseline data for executing intervention measures to control it in the study regions. Enterocytozoon bieneusi is an intracellular pathogen that can parasitize humans and a variety of animals. The infection of E. bieneusi in most hosts is asymptomatic, but in immunocompromised individuals, it can lead to serious complications such as acute diarrhea, dehydration, and even death. However, no data on the prevalence and genotyping of E. bieneusi in beef cattle in Shanxi province are currently available. In this study, a total of 401 fecal samples were collected from beef cattle in farms from two representative counties-Qi county and Jishan county-in Shanxi province, north China. Nested PCR was applied to determine the prevalence and genotypes of E. bieneusi by amplifying and sequencing the internal transcribed spacer (ITS) regions of the rRNA gene. A total of 90 out of 401 samples were detected as E. bieneusi-positive, with 22.44% overall prevalence of E. bieneusi in beef cattle in Shanxi province. The highest prevalence of E. bieneusi was detected in calves (28.67%, 41/143) and male beef cattle (28.13%, 54/192). Statistical analysis revealed that the prevalence of E. bieneusi was significantly associated with gender and age factors (p < 0.05), but without any statistical difference among regions. Moreover, six known E. bieneusi genotypes (BEB4, BEB6, BEB8, J, I, and PigSpEb2) and two novel genotypes (designated CSC1 and CSC2) were identified by analysis of ITS sequences, and genotype I was the predominant genotype in these two counties. Phylogenetic analysis showed that five known genotypes and two novel genotypes were clustered into Group 2, but PigSpEb2 belonged to Group 1. To our knowledge, the present study demonstrated the presence and identified genotypes of E. bieneusi in beef cattle in Shanxi province for the first time, extending the data on prevalence and genotypes of E. bieneusi in beef cattle and providing baseline data for executing intervention measures to control it in the study regions.