title: Coinfection with three Ehrlichia species in dogs from Thailand and Venezuela with emphasis on consideration of 16S ribosomal DNA secondary structure.
abstract: As part of a larger study to investigate tick-borne infections in dogs from Thailand and Venezuela, documentation of coinfection with three Ehrlichia species in two dogs, one from each country, became the focus of the present study. Although neither dog had clinical signs attributable to ehrlichiosis, both dogs were anemic and neutropenic and the Thai dog was thrombocytopenic. Genus- and species-specific PCR targeting the 16S rRNA genes indicated that both dogs were coinfected with Ehrlichia canis, E. platys, and E. equi. To our knowledge, these results provide the first molecular documentation for the presence of E. equi in dogs from these countries. Using universal bacterial PCR primers, one nearly full-length 16S rRNA gene could be amplified from each dog. The sequences were identical to each other and almost identical to that of E. platys (AF156784), providing the first E. platys 16S ribosomal DNA (rDNA) sequences reported from these two geographically divergent countries. To determine whether these sequence differences allow differentiation between these two strains and other published 16S rDNA E. platys sequences, we performed a phylogenetic analysis of the rRNA, incorporating the consideration of secondary structure.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606, USA.
authors.forename: J
authors.initials: J
authors.lastname: Suksawat
authors.forename: C
authors.initials: C
authors.lastname: Pitulle
authors.forename: C
authors.initials: C
authors.lastname: Arraga-Alvarado
authors.forename: K
authors.initials: K
authors.lastname: Madrigal
authors.forename: S I
authors.initials: SI
authors.lastname: Hancock
authors.forename: E B
authors.initials: EB
authors.lastname: Breitschwerdt
mesh_terms: D000818:Animals; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry* / Q000235:genetics; D004283:Dog Diseases / Q000382:microbiology*; D004285:Dogs; D004536:Ehrlichia / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D016873:Ehrlichiosis / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013785:Thailand; D014687:Venezuela
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S