title: Circulation of four Anaplasma phagocytophilum ecotypes in Europe.
abstract: BACKGROUND
  Anaplasma phagocytophilum is the etiological agent of granulocytic anaplasmosis in humans and animals. Wild animals and ticks play key roles in the enzootic cycles of the pathogen. Potential ecotypes of A. phagocytophilum have been characterized genetically, but their host range, zoonotic potential and transmission dynamics has only incompletely been resolved.
  
  
  METHODS
  The presence of A. phagocytophilum DNA was determined in more than 6000 ixodid ticks collected from the vegetation and wildlife, in 289 tissue samples from wild and domestic animals, and 69 keds collected from deer, originating from various geographic locations in The Netherlands and Belgium. From the qPCR-positive lysates, a fragment of the groEL-gene was amplified and sequenced. Additional groEL sequences from ticks and animals from Europe were obtained from GenBank, and sequences from human cases were obtained through literature searches. Statistical analyses were performed to identify A. phagocytophilum ecotypes, to assess their host range and their zoonotic potential. The population dynamics of A. phagocytophilum ecotypes was investigated using population genetic analyses.
  
  
  RESULTS
  DNA of A. phagocytophilum was present in all stages of questing and feeding Ixodes ricinus, feeding I. hexagonus, I. frontalis, I. trianguliceps, and deer keds, but was absent in questing I. arboricola and Dermacentor reticulatus. DNA of A. phagocytophilum was present in feeding ticks and tissues from many vertebrates, including roe deer, mouflon, red foxes, wild boar, sheep and hedgehogs but was rarely found in rodents and birds and was absent in badgers and lizards. Four geographically dispersed A. phagocytophilum ecotypes were identified, that had significantly different host ranges. All sequences from human cases belonged to only one of these ecotypes. Based on population genetic parameters, the potentially zoonotic ecotype showed significant expansion.
  
  
  CONCLUSIONS
  Four ecotypes of A. phagocytophilum with differential enzootic cycles were identified. So far, all human cases clustered in only one of these ecotypes. The zoonotic ecotype has the broadest range of wildlife hosts. The expansion of the zoonotic A. phagocytophilum ecotype indicates a recent increase of the acarological risk of exposure of humans and animals.
authors.forename: Setareh
authors.initials: S
authors.lastname: Jahfari
authors.forename: E Claudia
authors.initials: EC
authors.lastname: Coipan
authors.forename: Manoj
authors.initials: M
authors.lastname: Fonville
authors.forename: Arieke Docters
authors.initials: AD
authors.lastname: van Leeuwen
authors.forename: Paul
authors.initials: P
authors.lastname: Hengeveld
authors.forename: Dieter
authors.initials: D
authors.lastname: Heylen
authors.forename: Paul
authors.initials: P
authors.lastname: Heyman
authors.forename: Cees
authors.initials: C
authors.lastname: van Maanen
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Butler
authors.forename: Gábor
authors.initials: G
authors.lastname: Földvári
authors.forename: Sándor
authors.initials: S
authors.lastname: Szekeres
authors.forename: Gilian
authors.initials: G
authors.lastname: van Duijvendijk
authors.forename: Wesley
authors.initials: W
authors.lastname: Tack
authors.forename: Jolianne M
authors.initials: JM
authors.lastname: Rijks
authors.forename: Joke
authors.initials: J
authors.lastname: van der Giessen
authors.forename: Willem
authors.initials: W
authors.lastname: Takken
authors.forename: Sipke E
authors.initials: SE
authors.lastname: van Wieren
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Takumi
authors.affiliation: Laboratory for Zoonoses and Environmental Microbiology, National Institute for Public Health and Environment (RIVM), Antonie van Leeuwenhoeklaan 9, P,O, Box 1, Bilthoven, The Netherlands. hein.sprong@rivm.nl.
authors.forename: Hein
authors.initials: H
authors.lastname: Sprong
mesh_terms: D041081:Anaplasma phagocytophilum / Q000145:classification* / Q000235:genetics; D000712:Anaplasmosis / Q000453:epidemiology / Q000469:parasitology*; D000818:Animals; D005060:Europe / Q000453:epidemiology; D005260:Female; D006239:Haplotypes; D006801:Humans; D026863:Ixodidae / Q000469:parasitology; D007814:Larva / Q000469:parasitology; D008297:Male; D009758:Nymph; D010802:Phylogeny