title: Molecular analysis of Baylisascaris columnaris revealed mitochondrial and nuclear polymorphisms.
abstract: BACKGROUND
  Baylisascaris species are intestinal nematodes of skunks, raccoons, badgers, and bears belonging to the genus Ascarididae. Oral uptake of embryonated Baylisascaris sp. eggs by a wide variety of mammals and birds can lead to visceral, ocular and neurological larva migrans. B. procyonis, the raccoon roundworm, is known to cause severe illness in intermediate hosts and in humans, whereas the skunk roundworm B. columnaris is probably less pathogenic. Skunks and raccoons are kept as pets in Europe, sometimes together with cats and dogs, living in close contact with humans. B. procyonis and B. columnaris are difficult to differentiate based on morphological criteria and molecular and phylogenetic information concerning B. columnaris is missing. This is the first study on the genetic characterisation of B. columnaris, based on mitochondrial and nuclear molecular markers.
  
  
  METHODS
  B. columnaris worms were isolated from pet skunks, and used for molecular analysis. PCR primers targeted at mitochondrial cytochrome c oxidase 1 and 2 (CO1 and CO2), ribosomal ITS1-5.8S-ITS2 and ribosomal 28S genes were used. DNA sequences from B. columnaris, B. procyonis and B. transfuga from bears were analysed by cluster analysis.
  
  
  RESULTS
  Four different multi-locus genotypes were found in B. columnaris, based on 14 single nucleotide polymorphisms (SNPs) and two insertions / deletions in CO1, CO2, ITS1-5.8S-ITS2 and 28S.
  
  
  CONCLUSIONS
  The genetic characteristics of B. columnaris show close resemblance to those of B. procyonis, but in contrast to B. procyonis, show several polymorphisms in both mitochondrial and nuclear markers. These polymorphisms could be used as a tool to differentiate B. columnaris from B. procyonis in molecular diagnostic assays, and to identify B. columnaris by PCR, in addition to or replacing morphometric analysis. This might lead to more insight into the zoonotic relevance of B. columnaris in humans.
authors.affiliation: National Institute for Public Health and Environment, RIVM, Center for Zoonoses and Environmental Microbiology, cZ&O, Antonie van Leeuwenhoeklaan 9, PO Box 1, Bilthoven 3720 BA, The Netherlands. frits.franssen@rivm.nl
authors.forename: Frits
authors.initials: F
authors.lastname: Franssen
authors.forename: Kayin
authors.initials: K
authors.lastname: Xie
authors.forename: Hein
authors.initials: H
authors.lastname: Sprong
authors.forename: Joke
authors.initials: J
authors.lastname: van der Giessen
mesh_terms: D000818:Animals; D017191:Ascaridida Infections / Q000469:parasitology* / Q000662:veterinary; D001199:Ascaridoidea / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D012889:Mephitidae / Q000469:parasitology; D008969:Molecular Sequence Data; D057805:Pets / Q000469:parasitology; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018509:DNA, Helminth; D004272:DNA, Mitochondrial; D021903:DNA, Ribosomal Spacer; D012339:RNA, Ribosomal, 28S; D012340:RNA, Ribosomal, 5.8S; D003576:Electron Transport Complex IV