title: Absence of Wolbachia endobacteria in the human parasitic nematode Dracunculus medinensis and two related Dracunculus species infecting wildlife.
abstract: BACKGROUND
  Wolbachia endosymbionts are a proven target for control of human disease caused by filarial nematodes. However, little is known about the occurrence of Wolbachia in taxa closely related to the superfamily Filarioidea. Our study addressed the status of Wolbachia presence in members of the superfamily Dracunculoidea by screening the human parasite Dracunculus medinensis and related species from wildlife for Wolbachia.
  
  
  RESULTS
  D. medinensis, D. lutrae and D. insignis specimens were all negative for Wolbachia colonization by PCR screening for the Wolbachia ftsZ, 16S rRNA and Wolbachia surface protein (wsp) sequences. The quality and purity of the DNA preparations was confirmed by amplification of nematode 18S rRNA and cytochrome c oxidase subunit I sequences. Furthermore, Wolbachia endobacteria were not detected by whole mount fluorescence staining, or by immunohistochemistry using a Wolbachia-specific antiserum. In contrast, positive control Brugia malayi worms were shown to harbour Wolbachia by PCR, fluorescence staining and immunohistochemistry.
  
  
  CONCLUSIONS
  Three examined species of Dracunculus showed no evidence of Wolbachia endobacteria. This supports that members of the superfamily Dracunculoidea are free of Wolbachia. Within the order Spirurida, these endosymbionts appear restricted to the Filarioidea.
authors.affiliation: Parasitology Division, New England Biolabs, 240 County Road, Ipswich, MA 01938, USA. foster@neb.com.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Foster
authors.forename: Frédéric
authors.initials: F
authors.lastname: Landmann
authors.forename: Louise
authors.initials: L
authors.lastname: Ford
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Johnston
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Elsasser
authors.forename: Albrecht I
authors.initials: AI
authors.lastname: Schulte-Hostedde
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Taylor
authors.forename: Barton E
authors.initials: BE
authors.lastname: Slatko
mesh_terms: D000818:Animals; D000835:Animals, Wild; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004320:Dracunculiasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D004321:Dracunculus Nematode / Q000382:microbiology*; D005260:Female; D005869:Ghana / Q000453:epidemiology; D006801:Humans; D008907:Mink / Q000469:parasitology; D009864:Ontario / Q000453:epidemiology; D010041:Otters / Q000469:parasitology; D013045:Species Specificity; D020577:Wolbachia / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial