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

• Published in: Parasites & vectors Vol. 5; no. 1; p. 291
• Main Authors: Cruz, Alejandro Cabezas, Zweygarth, Erich, Ribeiro, Mucio Flavio Barbosa, da Silveira, Julia Angelica Gonçalves, de la Fuente, Jose, Grubhoffer, Libor, Valdés, James J, Passos, Lygia Maria Friche
• Format: Journal Article
• Language: English
• Published: England Springer-Verlag 11.12.2012; BioMed Central Ltd; BioMed Central; BMC
• Subjects: Amino Acid Sequence; amino acids; Analysis; Animals; Arachnids; Arthropod Vectors - microbiology; Bacteriological Techniques; Boophilus microplus; Cattle; Colleges & universities; Deoxyribonucleic acid; Discovery and exploration; Distribution; DNA; Ehrlichia; Ehrlichia - classification; Ehrlichia - genetics; Ehrlichia - isolation & purification; Ehrlichia spp; etiological agents; Farms; females; Gene Expression Regulation, Bacterial - physiology; genes; Genetic aspects; Glycoproteins; Glycoproteins - genetics; Glycoproteins - isolation & purification; Glycoproteins - metabolism; Gp36 major immunogenic protein; Health aspects; Health sciences; Hemolymph; hosts; Humans; Immune response; Immunogenicity; Infection; Ixodidae; Life Sciences; Livestock; Microbiology; Microorganisms; Molecular Sequence Data; New species; Nucleotide sequence; Parasites; Pathogenicity; pets; Phylogenetic analysis; Phylogenetics; Phylogeny; Rhipicephalus; Rhipicephalus (Boophilus) microplus; Rhipicephalus - microbiology; ribosomal RNA; RNA; RNA, Ribosomal, 16S - genetics; rRNA 16S; Species Specificity; tandem repeat sequences; Tick-borne diseases; ticks; Vectors; Zoonoses; Brazil; China; Phylogenetic analysis; Rhipicephalus (Boophilus) microplus; Gp36 major immunogenic protein; Ehrlichia spp
• ISSN: 1756-3305; 1756-3305
• DOI: 10.1186/1756-3305-5-291

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.