Genetic Characterization and Zoonotic Analyses of Enterocytozoon bieneusi from Cats and Dogs in Shanghai in China.

Abstract

Background: Enterocytozoon bieneusi is reported to be a common microsporidian of humans and animals in various countries. However, limited information on E. bieneusi has been recorded in cats (Felis catus) and dogs (Canis familiaris) in China. Here, we undertook molecular epidemiological investigation of E. bieneusi in cats and dogs in Shanghai, China. Methods: A total of 359 genomic DNAs were extracted from individual fecal samples from cats (n = 59) and dogs (n = 300), and then were tested using a nested PCR-based sequencing approach employing internal transcribed spacer (ITS) of nuclear ribosomal DNA as the genetic marker. Results: Enterocytozoon bieneusi was detected in 34 of 359 (9.5%) (95% confidence interval [6.7 - 13.0%]) fecal samples from cats (32.2%; 19/59) and dogs (5.0%; 15/300), including 24 stray cats and dogs (22.6%; 24/106), as well as 10 household/raised cats and dogs (4.0%; 10/253). Correlation analyses revealed that E. bieneusi positive rates were significantly associated with stray cats and dogs (p < 0.05). The analysis of ITS sequence data revealed the presence of five known genotypes, CD7, CHN-HD2, D, PtEb IX, and Type IV, and two novel genotypes, D-like1 and PtEb IX-like1. Zoonotic genotype D was the predominant type with percentage of 61.8% (21/34). Phylogenetic analysis of ITS sequence data sets showed that genotypes D, D-like1, and Type IV were clustered within Group 1, showing zoonotic potential. The others were assigned into Group 10 with host specificity. Conclusions: These findings suggested that cats and dogs in Shanghai harbor zoonotic genotype D of E. bieneusi and may have a significant risk for zoonotic transmission. Further insight into the epidemiology of E. bieneusi in other animals, water, and the environment from other areas in China will be important to have an informed position on the public health significance of microsporidiosis caused by this microbe.