Otterly diverse - A high diversity of Dracunculus species (Spirurida: Dracunculoidea) in North American river otters (Lontra canadensis)

Michael J Yabsley; Kayla B Garrett; Alec T Thompson; Erin K Box; Madeline R Giner; Ellen Haynes; Heather Barron; Renata M Schneider; Sarah M Coker; James C Beasley; Ernest J Borchert; Renn Tumlison; Allison Surf; Casey G Dukes; Colleen Olfenbuttel; Justin D Brown; Liandrie Swanepoel; Christopher A Cleveland

doi:10.1016/j.ijppaw.2024.100922

Otterly diverse - A high diversity of Dracunculus species (Spirurida: Dracunculoidea) in North American river otters (Lontra canadensis)

Int J Parasitol Parasites Wildl. 2024 Mar 11:23:100922. doi: 10.1016/j.ijppaw.2024.100922. eCollection 2024 Apr.

Authors

Michael J Yabsley^{1

2

3}, Kayla B Garrett^{1

2}, Alec T Thompson^{1

3}, Erin K Box¹, Madeline R Giner¹, Ellen Haynes¹, Heather Barron⁴, Renata M Schneider⁵, Sarah M Coker¹, James C Beasley^{2

6}, Ernest J Borchert^{2

6}, Renn Tumlison⁷, Allison Surf⁷, Casey G Dukes^{1

8}, Colleen Olfenbuttel⁸, Justin D Brown⁹, Liandrie Swanepoel¹, Christopher A Cleveland^{1

3}

Affiliations

¹ Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA.
² Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA.
³ Center for Ecology of Infectious Diseases, Athens, GA, 30602, USA.
⁴ Clinic for the Rehabilitation of Wildlife, Sanibel, FL, 33957, USA.
⁵ South Florida Wildlife Center, Fort Lauderdale, FL, USA.
⁶ Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.
⁷ Applied Science and Technology, Henderson State University, Arkadelphia, AR, 71999, USA.
⁸ North Carolina Wildlife Resources Commission, NCSU Centennial Campus, 1751 Varsity Drive, Raleigh, NC, 27606, USA.
⁹ Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, 16802, USA.

Abstract

The genus Dracunculus contains numerous species of subcutaneous parasites of mammals and reptiles. In North America, there are at least three mammal-infecting species of Dracunculus. Reports of Dracunculus infections have been reported from river otters (Lontra canadensis) since the early 1900s; however, little is known about the species infecting otters or their ecology. Most reports of Dracunculus do not have a definitive species identified because females, the most common sex found due to their larger size and location in the extremities of the host, lack distinguishing morphological characteristics, and few studies have used molecular methods to confirm identifications. Thus, outside of Ontario, Canada, where both D. insignis and D. lutrae have been confirmed in otters, the species of Dracunculus in river otters is unknown. In the current study, molecular characterization of nematodes from river otters revealed a high diversity of Dracunculus species. In addition to confirming D. insignis infections, two new clades were detected. One clade was a novel species in any host and the other was a clade previously detected in Virginia opossums (Didelphis virginiana) from the USA and a domestic dog from Spain. No infections with D. lutrae were detected and neither new lineage was genetically similar to D. jaguape, which was recently described from a neotropical otter (Lontra longicaudis) from Argentina. These data also indicate that Dracunculus spp. infections in otters are widespread throughout Eastern North America. Currently the life cycles for most of the Dracunculus spp. infecting otters are unknown. Studies on the diversity, life cycle, and natural history of Dracunculidae parasites in wildlife are important because the related parasite, D. medinensis (human Guinea worm) is the subject of an international eradication campaign and there are increasing reports of these parasites in new geographic locations and new hosts, including new species in humans and domestic dogs.

Keywords: Guinea worm; Mustelid; North America; Subcutaneous parasite; Wildlife.