title: Genetic diversity and structure in Leishmania infantum populations from southeastern Europe revealed by microsatellite analysis.
abstract: BACKGROUND
  The dynamic re-emergence of visceral leishmaniasis (VL) in south Europe and the northward shift to Leishmania-free European countries are well-documented. However, the epidemiology of VL due to Leishmania infantum in southeastern (SE) Europe and the Balkans is inadequately examined. Herein, we aim to re-evaluate and compare the population structure of L. infantum in SE and southwestern (SW) Europe.
  
  
  METHODS
  Leishmania strains collected from humans and canines in Turkey, Cyprus, Bulgaria, Greece, Albania and Croatia, were characterized by the K26-PCR assay and multilocus enzyme electrophoresis (MLEE). Genetic diversity was assessed by multilocus microsatellite typing (MLMT) and MLM Types were analyzed by model- and distance- based algorithms to infer the population structure of 128 L. infantum strains.
  
  
  RESULTS
  L. infantum MON-1 was found predominant in SE Europe, whilst 16.8% of strains were MON-98. Distinct genetic populations revealed clear differentiation between SE and SW European strains. Interestingly, Cypriot canine isolates were genetically isolated and formed a monophyletic group, suggesting the constitution of a clonal MON-1 population circulating among dogs. In contrast, two highly heterogeneous populations enclosed all MON-1 and MON-98 strains from the other SE European countries. Structure sub-clustering, phylogenetic and Splitstree analysis also revealed two distinct Croatian subpopulations. A mosaic of evolutionary effects resulted in consecutive sub-structuring, which indicated substantial differentiation and gene flow among strains of both zymodemes.
  
  
  CONCLUSIONS
  This is the first population genetic study of L. infantum in SE Europe and the Balkans. Our findings demonstrate the differentiation between SE and SW European strains; revealing the partition of Croatian strains between these populations and the genetic isolation of Cypriot strains. This mirrors the geographic position of Croatia located in central Europe and the natural isolation of the island of Cyprus. We have analysed the largest number of MON-98 strains so far. Our results indicate extensive gene flow, recombination and no differentiation between MON-1 and MON-98 zymodemes. No correlation either to host specificity or place and year of strain isolation was identified. Our findings may be associated with intensive host migration and common eco-epidemiological characteristics in these countries and give valuable insight into the dynamics of VL.
authors.forename: Evi
authors.initials: E
authors.lastname: Gouzelou
authors.forename: Christos
authors.initials: C
authors.lastname: Haralambous
authors.forename: Maria
authors.initials: M
authors.lastname: Antoniou
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Christodoulou
authors.forename: Franjo
authors.initials: F
authors.lastname: Martinković
authors.forename: Tatjana
authors.initials: T
authors.lastname: Živičnjak
authors.forename: Despina
authors.initials: D
authors.lastname: Smirlis
authors.forename: Francine
authors.initials: F
authors.lastname: Pratlong
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Dedet
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Özbel
authors.forename: Seray Özensoy
authors.initials: SÖ
authors.lastname: Toz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Presber
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schönian
authors.affiliation: Laboratory of Molecular Parasitology, Hellenic Pasteur Institute, 127 Vasilissis Sofias Avenus, 11521, Athens, Greece. ksoteriadou@pasteur.gr.
authors.forename: Ketty
authors.initials: K
authors.lastname: Soteriadou
mesh_terms: D000818:Animals; D004285:Dogs; D005060:Europe; D014644:Genetic Variation; D006801:Humans; D018314:Leishmania infantum / Q000235:genetics*; D018895:Microsatellite Repeats; D010802:Phylogeny; D014421:Turkey