title: New species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus shows an ortholog of the E. canis major immunogenic glycoprotein gp36 with a new sequence of tandem repeats.
abstract: BACKGROUND
  Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses that inflict serious and fatal infections in companion animals and livestock. The aim of this paper was to phylogeneticaly characterise a new species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus from Minas Gerais, Brazil.
  
  
  METHODS
  The agent was isolated from the hemolymph of Rhipicephalus (B.) microplus engorged females that had been collected from naturally infested cattle in a farm in the state of Minas Gerais, Brazil. This agent was then established and cultured in IDE8 tick cells. The molecular and phylogenetic analysis was based on 16S rRNA, groEL, dsb, gltA and gp36 genes. We used the maximum likelihood method to construct the phylogenetic trees.
  
  
  RESULTS
  The phylogenetic trees based on 16S rRNA, groEL, dsb and gltA showed that the Ehrlichia spp isolated in this study falls in a clade separated from any previously reported Ehrlichia spp. The molecular analysis of the ortholog of gp36, the major immunoreactive glycoproteins in E. canis and ortholog of the E. chaffeensis gp47, showed a unique tandem repeat of 9 amino acids (VPAASGDAQ) when compared with those reported for E. canis, E. chaffeensis and the related mucin-like protein in E. ruminantium.
  
  
  CONCLUSIONS
  Based on the molecular and phylogenetic analysis of the 16S rRNA, groEL, dsb and gltA genes we concluded that this tick-derived microorganism isolated in Brazil is a new species, named E. mineirensis (UFMG-EV), with predicted novel antigenic properties in the gp36 ortholog glycoprotein. Further studies on this new Ehrlichia spp should address questions about its transmissibility by ticks and its pathogenicity for mammalian hosts.
authors.affiliation: Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
authors.forename: Alejandro Cabezas
authors.initials: AC
authors.lastname: Cruz
authors.forename: Erich
authors.initials: E
authors.lastname: Zweygarth
authors.forename: Mucio Flavio Barbosa
authors.initials: MF
authors.lastname: Ribeiro
authors.forename: Julia Angelica Gonçalves
authors.initials: JA
authors.lastname: da Silveira
authors.forename: Jose
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Libor
authors.initials: L
authors.lastname: Grubhoffer
authors.forename: James J
authors.initials: JJ
authors.lastname: Valdés
authors.forename: Lygia Maria Friche
authors.initials: LM
authors.lastname: Passos
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001179:Arthropod Vectors / Q000382:microbiology; D001431:Bacteriological Techniques; D004536:Ehrlichia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D006023:Glycoproteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D048494:Rhipicephalus / Q000382:microbiology*; D013045:Species Specificity; D015047:Zoonoses
chemical_list: D006023:Glycoproteins; D012336:RNA, Ribosomal, 16S