Wildlife Is a Potential Source of Human Infections of Enterocytozoon bieneusi and Giardia duodenalis in Southeastern China

Abstract

Wildlife is known to be a source of high-impact pathogens affecting people. However, the distribution, genetic diversity, and zoonotic potential of Cryptosporidium, Enterocytozoon bieneusi, and Giardia duodenalis in wildlife are poorly understood. Here, we conducted the first molecular epidemiological investigation of these three pathogens in wildlife in Zhejiang and Shanghai, China. Genomic DNAs were derived from 182 individual fecal samples from wildlife and then subjected to a nested polymerase chain reaction–based sequencing approach for detection and characterization. Altogether, 3 (1.6%), 21 (11.5%), and 48 (26.4%) specimens tested positive for Cryptosporidium species, E. bieneusi, and G. duodenalis, respectively. Sequence analyses revealed five known (BEB6, D, MJ13, SC02, and type IV) and two novel (designated SH_ch1 and SH_deer1) genotypes of E. bieneusi. Phylogenetically, novel E. bieneusi genotype SH_deer1 fell into group 6, and the other genotypes were assigned to group 1 with zoonotic potential. Three novel Cryptosporidium genotypes (Cryptosporidium avian genotype V-like and C. galli-like 1 and 2) were identified, C. galli-like 1 and 2 formed a clade that was distinct from Cryptosporidium species. The genetic distinctiveness of these two novel genotypes suggests that they represent a new species of Cryptosporidium. Zoonotic assemblage A (n = 36) and host-adapted assemblages C (n = 1) and E (n = 7) of G. duodenalis were characterized. The overall results suggest that wildlife act as host reservoirs carrying zoonotic E. bieneusi and G. duodenalis, potentially enabling transmission from wildlife to humans and other animals.

Prevalence and genetic diversity of Giardia duodenalis in pet dogs from Zhengzhou, central China and the association between gut microbiota and fecal characteristics during infection

“…The simple life cycle consists of trophozoites that cause symptoms and infective cysts that accompany host fecal shedding [ 2 ]. Susceptible hosts ingest cysts through contaminated food or water, or via the fecal-oral route, and then the fresh cysts are discharged from the host with the feces and can infect other susceptible hosts through contaminating food or water, or via the fecal-oral route [ 3 ].…”

“…Eight G. duodenalis assemblages have been named and classified to date. Infections in humans and other mammals are associated with assemblages A and B, and dogs and other canines often report being infected with assemblages C and D [ 3 ]. Sporadic reports of assemblages C, D, E and F in humans have also impacted the concept that assemblages C—H is widely considered to be host specific to a certain extent [ [4] , [5] , [6] , [7] ].…”

Prevalence and Genetic Characterization of Giardia duodenalis and Blastocystis spp. in Black Goats in Shanxi Province, North China: From a Public Health Perspective

“…Of them, G. duodenalis (synonmy G. intestinalis and G. lamblia ) is the only species of Giardia that infects humans [ 6 , 7 , 8 , 9 ]. In early investigations, previously reported G. duodenalis were divided into eight assemblages/genotypes (A–H), in which A and B belonged to the zoonotic group [ 10 , 11 ], and C–H were considered as host-specific assemblages: C and D for canines, E for artiodactyls, F for felines, G for rodents, and H for marine mammals [ 12 ]. In the last decade, assemblages C, D, E, and F were also detected or isolated from human stool specimens; however, the zoonotic role of these assemblages in humans was still unknown [ 13 , 14 ].…”

Stray cats and dogs carrying zoonoticEnterocytozoon bieneusigenotype D in China: a public health concern

“…zoo animals [17] and humans [18], in Australia and China. The prevalence and risk factors such as host species, age, sex, location, temperature and season were analysed and E. bieneusi genotypes were identified.…”