Enterocytozoon bieneusi

Huang, Xiaolong, Zhou, Ziyao, Liu, Haifeng, Deng, Lei, Bi, Bo, Chai, Yijun, Zhong, Zhijun, Hu, Yanchun, Fu, Hualin & Peng, Guangneng, 2019, New genotypes and molecular characterization of Enterocytozoon bieneusi in captive black bears in China, International Journal for Parasitology: Parasites and Wildlife 10, pp. 1-5 : 2-3

3.1. Prevalence of E. bieneusi in Asiatic black bears

In total, 57 of the 305 fecal specimens from Asiatic black bears (18.7%) were found to be positive for E. bieneusi via ITS-PCR amplification ( Table 1). All three tested farms showed evidence of E. bieneusi infection, and the infection rate of E. bieneusi in the different farms ranged from 4.5% to 47.8%. The highest infection rate of E. bieneusi was observed in farm 3 (47.8%, 44/92), followed by farm 2 (7.2%, 9/125) and farm 1 (4.5%, 4/88). The differences in infection rate among the three farms were statistically significant (P <0.01) ( Table 1). No statistically significant differences were noted with respect to the ages (P = 0.47) or gender (P = 0.69) of the bears ( Table 2).

3.2. Genetic characterization and genotype distribution of E. bieneusi in Asiatic black bears

Five genotypes were identified by sequence analysis of the ITS gene in 57 E. bieneusi -positive specimens, including three known genotypes (SC02, MJ2, MJ5) and two novel genotypes. The two novel genotypes were named SCBB1 and SCBB2. Genotype SC02, which was identified in the largest number of E. bieneusi -positive specimens (66.7%, 38/57), was present in all three farms, followed by genotype MJ5 (22.8%, 13/ 57), which was detected in farm 2 and farm 3 and genotype MJ2 (7%, 4/57), which was detected in farm 1 and farm 3.

One Single Nucleotide Polymorphisms (SNP) within the 243-bp region of the ITS gene sequence of E. bieneusi was found in each of the two novel genotypes compared to the known genotypes. Genotype SCBB1 had one SNP (insertion: G) relative to genotype CHB1 (KU852466). Genotype SCBB2 had another SNP (substitution: G/C) relative to genotype MJ5 (MF522186).