Prevalence of Gastrointestinal Parasites in Zoo Animals and Phylogenetic Characterization of Toxascaris leonina (Linstow, 1902) and Baylisascaris transfuga (Rudolphi, 1819) in Jiangsu Province, Eastern China

Abstract

The burden of gastrointestinal parasites in zoo animals has serious implications for their welfare and the health of veterinarians and visitors. Zhuyuwan Zoo is located in the eastern suburb of Yangzhou city in eastern China, in which over 40 species of zoo animals are kept. In order to understand the infection status of GI parasites in Zhuyuwan Zoo, a total of 104 fresh fecal samples collected randomly from birds (n = 19), primates (n = 19), and non-primate mammals (n = 66) were analyzed using the saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Two Ascaris species were molecularly characterized. The results showed that the overall prevalence of parasitic infection was 42.3% (44/104). The parasitic infection rate in birds, primates, and non-primate mammals were 26.3% (5/19), 31.6% (6/19), and 50.0% (33/66), respectively. A total of 11 species of parasites were identified, namely, Trichostrongylidae, Capillaria sp., Trichuris spp., Strongyloides spp., Amidostomum sp., Toxascaris leonina, Baylisascaris transfuga, Parascaris equorum, Paramphistomum spp., Fasciola spp., and Eimeria spp. Paramphistomum spp. eggs were first detected from the captive Père David’s deer, and Fasciola spp. eggs were first reported from sika deer in zoo in China. A sequence analysis of ITS-2 and cox1 showed that the eggs isolated from the African lion (Panthera leo Linnaeus, 1758) were T. leonina, and the eggs from the brown bear (Ursus arctos Linnaeus, 1758) were B. transfuga. The public health threat posed by these potential zoonotic parasitic agents requires attention. These results lay a theoretical foundation for prevention and control of wild animal parasitic diseases at zoos in China.

Wild Animals in Captivity: An Analysis of Parasite Biodiversity and Transmission among Animals at Two Zoological Institutions with Different Typologies

“…Regarding the trichostrongylids, the only findings occurred in hoofed animals; NHP samples were always negative. The morphological and size similarity of the eggs found in hoofed animals makes it difficult, if not impossible, to differentiate the eggs of different genera, so identifications are usually conducted generically as “strongyle type” or “trichostrongylids” [ 32 , 103 , 104 , 105 ]; if anything, Nematodirus , due to its size, can be identified separately [ 61 , 104 ]. Depending on the helminth species and the intensity of the infection, animals may be asymptomatic or suffer from gastrointestinal symptoms (especially in trichostrongylid infections); Nematodirus can be highly pathogenic and cause death within a few days after the onset of symptoms [ 106 ].…”

“…The ascarid eggs found in carnivores belong to Baylisascaris . In the Brown bear, the species could correspond to Baylisascaris transfuga (Rudolphi 1819), which was identified in wild host species in Europe and Asia [ 105 , 107 ]. In the case of the striped skunk ( Mephitis mephitis ) samples, it could correspond to Baylisascaris columnaris Leidy 1856, which was detected in other European zoos [ 108 ].…”

“…We did not find Toxocara / Toxascaris infections despite their prevalence potentially being high in zoo animals [ 109 ]. In equids, Parascaris equorum can be recorded in zoo animals with a low prevalence, usually below 15% [ 32 , 33 , 105 , 110 ].…”