First identification and molecular subtyping of Blastocystis sp. in zoo animals in southwestern China

Abstract

Background Blastocystis sp. is an anaerobic protozoan that parasitizes many animal hosts and the human gastrointestinal tract, and its pathogenicity is controversial. Captive wildlife may be potential reservoirs for human infection with Blastocystis sp. The present study was performed to investigate the prevalence and subtype distribution of Blastocystis sp. in zoo animals in Sichuan Province, southwestern China. Methods A total of 420 fresh fecal samples were collected from 54 captive wildlife species in four zoos in southwestern China between June 2017 and September 2019. The prevalence and subtype (ST) genetic characteristics of Blastocystis sp. were determined by PCR amplification of the barcode region of the SSU rRNA gene and phylogenetic analysis. Results Overall, 15.7% (66/420) of the animal samples and 20.7% (14/54) of the species tested were shown to be infected with Blastocystis sp. The highest prevalence of Blastocystis sp. was found in Panzhihua Zoo (24.3%), which was significantly higher than that in Chengdu Zoo (6.9%), and Xichang Zoo (2.9%) (P < 0.05). There are also significant differences in the prevalence of Blastocystis sp. among different species (P < 0.05), and the highest of Blastocystis sp. prevalence was observed in white-cheeked gibbon, black great squirrel, and red giant flying squirrel (100%). Subtype analysis of Blastocystis sp. revealed nine subtypes, including six zoonotic STs (ST1-5, and ST8) and three animal-specific STs (ST10, ST14, and ST17), with ST17 as the predominant subtype (26/66) in Blastocystis sp.-positive isolates. Conclusions To our knowledge, this is the first report on the prevalence and subtype distribution of Blastocystis sp. among captive wildlife in zoos in southwestern China. This study highlights that these animals may serve as reservoirs for human Blastocystis sp. infections.

The Coexistence of Blastocystis spp. in Humans, Animals and Environmental Sources from 2010–2021 in Asia

“…Blastocystis spp. are anaerobic unicellular eukaryotes that are widespread among humans and animals around the world [1][2][3]. They reside in the gastrointestinal tract wherein their role in gut health and disease is unresolved [4].…”

Genetic characterization of Blastocystis from wild animals in Sichuan Wolong National Natural Reserve, southwestern of China-Zoonotic potential

“…Epidemiological studies have been conducted in domestic animals including pig, cattle, dairy cattle, sheep and goat but only few reported on captive wildlife has been documented in China [2]. The prevalence of Blastocystis in wild animals examined in this study was 10.0% (30/300), which was lower than that of captive wild animals from zoo animals in Western Australian (42%, 32/76) [3] [14] and in captive mammalian wildlife in Bangladesh National Zoo (15.5%,31/200) [24]. While in this study the Blastocystis prevalence in wild animals was higher than that in zoo animals in three cities in China (6.0%, 27/450) [29].…”

“…In China, Blastocystis has been found in humans, domestic and captive wildlife animals (e.g., belonging to the orders Carnivora, Artiodactyla, Perissodactyla, Rodentia, and Primates) [2,[12][13][14][15][16], highlighting that these animals may be potential hosts for human infection with this pathogen. However, only limited studies have been conducted on Blastocystis isolated from wild animals in China, and its role as reservoirs of infection for humans and other animals is remain unknown.…”

Genetic characterization and zoonotic potential of Blastocystis from wild animals in Sichuan Wolong National Natural Reserve, Southwest China

“…Epidemiological studies have been conducted in domestic animals, including pigs, cattle, sheep, and goats, but only a few reports on captive wildlife have been documented in China [ 13 ]. The prevalence of Blastocystis in the wild animals examined in this study was 10.0% (30/300); this is lower than that previously found in zoo animals in Western Australia (42%, 32/76) [ 25 ], wild animals on Qinling Mountains, China (40.2%, 200/497) [ 42 ], zoo animals in Japan (39.0%, 46/118) [ 2 ], wild animals in Brazil (34.4%, 115/334) [ 35 ], zoo animals in the United Kingdom (34.2%, 79/231), various captive animals in France (32.2%, 99/307) [ 12 ], captive wildlife in four zoos of southwestern China (15.7%, 66/420) [ 15 ], and captive mammalian wildlife in Bangladesh National Zoo (15.5%, 31/200) [ 29 ]. However, the prevalence is higher than that observed in animals from three city zoos in China (6.0%, 27/450) [ 23 ].…”

“…In China, Blastocystis has been found in humans and both domestic and captive wildlife animals belonging to the orders Carnivora, Artiodactyla, Perissodactyla, Rodentia, and primates [ 10 , 13 – 15 , 37 , 43 ], highlighting these animals as potential hosts for human infection with Blastocystis . However, limited studies have been conducted in which Blastocystis has been isolated from wild animals in China, and their role as a reservoir of infection for humans and other animals remains unknown.…”