Genetic Diversity in Enterocytozoon bieneusi Isolates from Dogs and Cats in China: Host Specificity and Public Health Implications

Abstract

cTo explore the genetic diversity, host specificity, and zoonotic potential of Enterocytozoon bieneusi, feces from 348 stray and pet dogs and 96 pet cats from different locations in China were examined by internal transcribed spacer (ITS)-based PCR. E. bieneusi was detected in 15.5% of the dogs, including 20.5% of stray dogs and 11.7% of pet dogs, and in 11.5% of the pet cats. Higher infection rates were recorded in the >2-year and the 1-to 2-year age groups in dogs and cats, respectively. Altogether, 24 genotypes, including 11 known and 13 new, were detected in 65 infected animals. In 54 positive dogs, 18 genotypes, 9 known (PtEbIX, O, D, CM1, EbpA, Peru8, type IV, EbpC, and PigEBITS5) and 9 new (CD1 to CD9), were found. In contrast, 8 genotypes, 4 known (D, BEB6, I, and PtEbIX) and 4 new (CC1 to CC4), were identified in 11 infected cats. The dominant genotype in dogs was PtEbIX (26/54). Phylogenetic analysis revealed that 8 known genotypes (D, Peru8, type IV, CM1, EbpC, PigEBITS5, O, and EbpA) and 7 new genotypes (CD1 to CD4 and CC2 to CC4) were the members of zoonotic group 1, whereas genotypes CD7, CD8, and CD9 together with PtEbIX belonged to the dog-specific group, and genotypes CD6 and CC1 were placed in group 2 with BEB6 and I. Conversely, genotype CD5 clustered with CM4 without belonging to any previous groups. We conclude that zoonotic genotypes are common in dogs and cats, as are host-specific genotypes in dogs. M icrosporidia, obligate eukaryotic intracellular pathogens, are considered to be highly diverged and specialized parasites, formerly classified as protozoa (1) and recently included in the fungus kingdom without further subdivision (2). They infect a wide variety of vertebrate and invertebrate hosts (3). Among the human-infecting microsporidian species, Enterocytozoon bieneusi is the most frequently diagnosed in AIDS patients with chronic diarrhea, organ transplant recipients, children, the elderly, and patients with malignant diseases and diabetes (4, 5). In addition, E. bieneusi has been reported in various wild, domestic, and companion mammals and birds worldwide (4, 6). Thus, microsporidiosis by E. bieneusi is regarded as a zoonosis, although the range of animal hosts and their involvement in transmission are poorly understood.Recent molecular approaches based on sequence and phylogenetic analyses of the internal transcribed spacer (ITS) of ribosomal DNA (rDNA) enable us to assess the host specificity and public health significance of the organism (6, 7). There are now at least 204 reported ITS genotypes of E. bieneusi, and new genotypes have been identified in various animals, humans, and water bodies (6,(8)(9)(10). In phylogenetic analysis, these genotypes form some unique groups. Group 1 is found in humans and animals, while groups 2 to 8 are found mostly in specific hosts and wastewater (7,8,11).Recently, zoonotic E. bieneusi genotypes have been reported in AIDS patients, children, nonhuman primates, pigs, and urban wastewater in China (8,[10][11][12][13][14][15][16]. However, studies...

Stray cats are more frequently infected with zoonotic protists than pet cats

“…can cause severe generalised encephalitozoonosis or cataracts and uveitis in cats, these zoonotic agents are probably relatively rare, as evidenced by low seroprevalence (2%) in healthy cats (Buyukmihci et al 1977, Hsu et al 2011, Rebel-Bauder et al 2011). Whereas 13 genotypes of E. bieneusi have been reported in cats (Karim et al 2014), we detected only genotype D, which is one of the most frequently reported genotypes (Santín et al 2006, Xu et al 2016. In contrast to previous surveys (Dengjel et al 2001, Xu et al 2016), we did not find E. bieneusi in pet cats.…”

Enterocytozoon bieneusi Genotypes in Children in Northeast China and Assessment of Risk of Zoonotic Transmission

“…Despite repeated reports of E. bieneusi in humans and domestic and wild animals in China, the transmission routes of human microsporidiosis remain unclear (1,(8)(9)(10)(13)(14)(15). Contact with pigs was considered a risk factor for acquisition of E. bieneusi genotype EbpC in HIV ϩ farmers in Henan (8).…”

Zoonotic Enterocytozoon bieneusi in raw wastewater in Zhengzhou, China

“…It is worth noting that genotype D has been identified in humans as well as various animals, and is considered a zoonotic genotype (Yang et al 2015). The other zoonotic genotypes (PigEBITS5, EbpA, Peru8, Type IV) were also detected in animals in Zhengzhou (Karim et al 2014a, Qi et al 2015. Beside these, the remaining genotypes of positive samples (22/46) belonged to the potential zoonotic group (group 2).…”

“…According to previous reports from Zhengzhou (Karim et al 2014a, Qi et al 2015, E. bieneusi in wastewater mainly originated from animals faeces The ITS tree was rooted with GenBank sequence AY237213 WL15 (an E. bieneusi genotype from group 3). The subgroups in group 1 were named according to Thellier and Breton (2008) and Karim et al (2015).…”

“…Studies in dogs and cats showed that dogs are hosts for not only animal-adapted genotypes but also potential zoonotic genotypes, whereas cats are mainly infected by the zoonotic genotypes (Karim et al 2014a). A more comprehensive investigation of wildlife at a public zoo in Zhengzhou identified thirteen genotypes of E. bieneusi, including a few zoonotic genotypes .…”