Identification and Genotyping of Enterocytozoon bieneusi in China

Abstract

In this study, the prevalence of Enterocytozoon bieneusi in China was investigated. Twelve genotypes of E. bieneusi were identified, of which 10 were novel genotypes. Further, 41.6% of the genotypes were found in both humans and animals. This is the first report of E. bieneusi in China.Microsporidia are a diverse group of obligate intracellular pathogens consisting of approximately 1,300 formally described species in 160 genera that infect a wide range of invertebrate and vertebrate hosts, including humans (8,16). Enterocytozoon bieneusi, the most frequently diagnosed microsporidial species in humans, was first reported in an AIDS patient in 1985 (4). Over the last 2 decades, E. bieneusi has been detected in humans, other mammals, and birds in more than 30 countries (1,6,10,12). However, the prevalence of this parasite in China has been unclear.Currently, sequencing of the internal transcribed spacer (ITS) region of the rRNA gene is regarded as the standard method for species identification and genotyping of E. bieneusi isolates (17). More than 90 genotypes or variants of E. bieneusi that infect humans and animals have been identified (16). Recent molecular epidemiological studies indicated that some genotypes are host specific (17). Further, 8 genotypes (WL15, D, Peru6, EbpC, Peru10, Peru16, WL11, and Type IV) have been found in both humans and animals, indicating the potential for zoonotic transmission and the importance for surveillance of the epidemiology of E. bieneusi (17).We investigated the prevalence of E. bieneusi infection in humans and animals in China. A total of 220 fecal samples were collected. Among them, 40 fecal samples were from diarrheal children in the First Hospital of Jilin University in Changchun City, northeast China, 61 were from pigs in a livestock production facility, 26 were from dogs in a pet market, and 93 were from cows. Both human and animal samples were collected in the same area around Changchun City; however, the human samples were not from the same farm as the animal samples. The collection of human and animal stool samples was approved by the Ethics Committee of the Institute of Zoonosis, Jilin University. DNA was extracted from each fecal sample with a modified protocol as described previously (7).A nested PCR with primers based on the specific ITS sequences of E. bieneusi was applied for pathogen identification as previously reported (2, 5). E. bieneusi ITS sequences were determined, and a multiple alignment was performed using the ClustalX program. To assess the extent of genetic diversity and evolutionary relationships among the previously known genotypes of Enterocytozoon spp. and the novel genotypes, a neighbor-joining tree based on the evolutionary distances calculated by the Kimura two-parameter model (15) was constructed using the MEGA 4.0 program (19).E. bieneusi-specific sequences were amplified from 56 of the 220 fecal samples (9 from humans, 2 from dogs, 35 from cows, and 10 from pigs) ( Table 1). The 56 sequences were classified into 12 genotypes, which include...

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

“…Two recent studies in central China reported the occurrence of E. bieneusi in 5.7% (39/683) of adult AIDS patients, 4.2% (29/683) of HIV-negative adult participants, 10.8% (8/74) of hospitalized case children with an average age of 20.7 months, and 3.2% (16/499) of control children with an average age of 42.6 months (8, 9). The pathogen was also detected in 22.5% (9/40) of in-hospital children with diarrhea (age unknown) in Changchun (10). The present study ascertained infection with the organism in diarrheic (25%, 1/4) and nondiarrheic (22.2%, 8/36) in-hospital children mostly aged Ͻ12 months and 5.6% (10/178) of healthy primary school children aged 6 to 12 years.…”

“…Genotypic typing and phylogenetic analysis facilitated classification of the almost 200 genotypes identified thus far into genetic group 1 with zoonotic potential and several other host-adapted genetic clusters (4)(5)(6)(7). Infections with E. bieneusi in humans have been repeatedly reported worldwide, although epidemiologic data to indicate the prevalence and risk of human microsporidiosis in China are limited (8)(9)(10). The frequent and close contact of humans with livestock in China is of potential zoonotic concern (6,7).…”

“…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).…”

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

“…However, studies in companion animals, such as dogs and cats, which are considered highrisk hosts for the zoonotic transmission of such diseases, remain scarce. One study by Zhang and colleagues reported two new genotypes of E. bieneusi in dogs in China (17). Likewise, studies in dogs and cats have been few in other parts of the world.…”

Zoonotic Enterocytozoon bieneusi in raw wastewater in Zhengzhou, China

“…To date, BEB6 has been usually derived from animals (especially sheep and cattle) (Ye et al 2015, Zhao et al 2015, but also identified in human and nonhuman primates in Henan Province (Wang et al 2013, Karim et al 2014b. Genotypes I and J reported in captive wildlife in Zhengzhou had also been detected in humans in Jilin, China (Zhang et al 2011). The novel genotypes (HNWW1 to HNWW5) showed only difference 1-3 bases from known zoonotic or potential zoonotic genotypes.…”