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Title: Ancylostoma ailuropodae sp. n. (Nematoda: Ancylostomatidae), a new hookworm parasite isolated from wild giant pandas in Southwest China

item XIE, YUE - Sichuan Agricultural University
item Hoberg, Eric
item Urban, Joseph
item YANGA, GUANGYOU - Sichuan Agricultural University

Submitted to: Parasites & Vectors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2017
Publication Date: 2/5/2017
Citation: Xie, Y., Hoberg, E.P., Urban Jr, J.F., Yanga, G. 2017. Ancylostoma ailuropodae sp. n. (Nematoda: Ancylostomatidae), a new hookworm parasite isolated from wild giant pandas in Southwest China. Parasites & Vectors. 10:227-296. doi: 10.1186/s13071-017-2209-2212.

Interpretive Summary: Hookworms are one of the most common soil-transmitted worm (helminth) infections that infect more than 740 million people worldwide causing serious iron deficiency anemia and protein malnutrition, mainly in tropical and subtropical areas. Furthermore, hookworm infections in domestic and wild animals can cause significant veterinary and public health problems. The giant panda (Ailuropoda melanoleuca), one of the most endangered and rarest species in China, is regarded as one of the most preeminent species for wildlife preservation worldwide. Some of these wild giant pandas have become closely associated with humans as they are housed for breeding and conservation and biological investigations. Although ecological, genetic, and etiological studies have shown that the panda faces extinction due to habitat loss, poor reproduction and low resistance to infectious diseases, recent surveys strongly indicate that parasitic infections represent the leading health threat to giant pandas in China. The recent collection of parasites from a giant panda that died in the Fengtongzai Natural Reserve in Sichuan Province in China resulted in the recovery of fresh Ancylostoma specimens and provided an opportunity to fill some gaps in knowledge. We have used DNA sequence and morphological analysis, applying clear species criteria established in a phylogenetic to recognize and describe a previously unknown hookworm species from the giant Panda. A putative sister-species relationship with the “anthropozoonotic” A. ceylanicum suggests a possible zoonotic risk of transmission and infection to humans. This information is important to wild-life biologists and parasitologists, and those charged with management of the giant panda, as well as a cautionary tale to the general public to understand the disease potential of interaction with wild-life and domesticated animal species.

Technical Abstract: Hookworms belonging to the genus Ancylostoma cause ancylostomiasis, a disease of considerable concern in humans and domestic and wild animals. Molecular and epidemiological data support evidence for the zoonotic potential among species of Ancylostoma where transmission to humans is facilitated by rapid urbanization and increased human-wildlife interactions. Here, we describe a previously unrecognized species of hookworm in the genus Ancylostoma in the wild giant panda, building on microscopic examinations and genetic analysis by sequencing the nuclear internal transcribed spacer (ITS) 1-5.8 S-ITS2 and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes. Ancylostoma ailuropodae sp. n. is proposed for these hookworms. Morphologically the hookworm specimens differ from other congeneric species primarily based on the structure of the buccal capsule in males and females, characterized by 2 pairs of ventral and 2 pairs of sub-ventral teeth; males differ in the structure and shape of the copulatory bursa, where the dorsal ray possesses 2 digitations. Pair-wise nuclear and mitochondrial DNA comparisons, genetic distance analysis, and phylogenetic data strongly indicate that A. ailuropodae from giant pandas is a separate species which shared a most recent common ancestor with A. ceylanicum in the genus Ancylostoma (family Ancylostomatidae). Ancylostoma ailuropodae is the 3rd hookworm described from the Ursidae and the 15th species assigned to the genus Ancylostoma. A sister-species association with A. ceylanicum and phylogenetic distinctiveness from the monophyletic Uncinaria among ursids and other carnivorans indicate a history of host colonization in diversification among these hookworms. Further, a history for host colonization within this assemblage and the relationship for A. ailuropodae demonstrate the potential of this species as a zoonotic parasite and as a possible threat to human health. The cumulative morphological, molecular and phylogenetic data presented for A. ailuropodae provides a better understanding of the taxonomy, diagnostics and evolutionary biology of the hookworms.