Molecular characterization and zoonotic potential of Entamoeba spp., Enterocytozoon bieneusi and Blastocystis from captive wild animals in northwest China

Abstract

Background: Parasites Entamoeba spp., Enterocytozoon bieneusi and Blastocystis are prevalent pathogens causing gastrointestinal illnesses in animals and humans. Consequently, researches on their occurrence, distribution and hosts are crucial for the well-being of both animals and humans. Due to the confined spaces and frequent interaction between animals and humans, animal sanctuaries have emerged as potential reservoirs for these parasites. In this study, the wildlife sanctuary near the Huang Gorge of the Qinling Mountains in northwest China is chosen as an ideal site for parasite distribution research, considering its expansive stocking area and high biodiversity.

Results: We collected 191 fecal specimens from 37 distinct wildlife species and extracted genomic DNA. We identified these three parasites by amplifying specific gene regions and analyzed their characteristics and evolutionary relationships. All the parasites exhibited a high overall infection rate, reaching 90.05%. Among them, seven Entamoeba species were identified, accounting for a prevalence of 54.97%, with the highest infection observed in Entamoeba bovis. In total, 11 Enterocytozoon bieneusi genotypes were discovered, representing a prevalence of 35.08%, including three genotypes of human-pathogenic Group 1 and two novel genotypes (SXWZ and SXLG). Additionally, 13 Blastocystis subtypes were detected, showing a prevalence of 74.87% and encompassing eight zoonotic subtypes. All of the above suggests significant possibilities of parasite transmission between animals and humans.

Conclusions: This study investigated the occurrence and prevalence of three intestinal parasites, enhancing our understanding of their genetic diversity and host ranges in northwest China. Furthermore, the distribution of these parasites implies significant potential of zoonotic transmission, underscoring the imperative for ongoing surveillance and implementation of control measures. These efforts are essential to mitigate the risk of zoonotic disease outbreaks originating from wildlife sanctuary.

Keywords: Blastocystis; Entamoeba spp.; Enterocytozoon bieneusi; Phylogeny; Prevalence; Wildlife; Zoonotic potential.

Fig. 1

Phylogenetic trees derived from SSU rDNA data focusing on Entamoeba spp. identified in this study and reference strains. The numbers near nodes show the bootstrap values of NJ and ML analyses out of 1,000 replicates, respectively. The newly characterized sequences in this study are highlighted in bold brown. The scale bar corresponds to 10 substitutions per 100 nucleotide positions. The pie chart displays the Entamoeba species detected in this study

Fig. 2

Phylogenetic trees derived from ITS data focusing on Enterocytozoon bieneusi identified in this study and reference genotypes. The numbers near nodes show the bootstrap values of NJ and ML analyses out of 1,000 replicates, respectively. The newly characterized sequences in this study are highlighted in brown, blue and red (novel genotypes). The scale bar corresponds to 10 substitutions per 100 nucleotide positions. The pie chart displays the Enterocytozoon bieneusi genotypes detected in this study

Fig. 3

Phylogenetic trees derived from SSU rDNA data focusing on Blastocystis identified in this study and reference subtypes. The numbers near nodes show the bootstrap values of NJ and ML analyses out of 1,000 replicates, respectively. The newly characterized sequences in this study are highlighted in turquoise. The scale bar corresponds to 10 substitutions per 100 nucleotide positions. The pie chart displays the Blastocystis subtypes detected in this study

Fig. 4

Location of the sampling site in this study. A, map to show the collecting sites in China. The map of China [drawing review number: GS (2019)1652] cited from the MAP WORD (www.tianditu.gov.cn). B, map to show the collecting sites in Shaanxi province, China