title: A novel Ehrlichia genotype strain distinguished by the TRP36 gene naturally infects cattle in Brazil and causes clinical manifestations associated with ehrlichiosis.
abstract: A novel Ehrlichia genotype most closely related to E. canis was reported in North American cattle in 2010, and a similar agent was subsequently identified in the hemolymph of Brazilian Rhipicephalus (Boophilus) microplus ticks and isolated in 2012. The purpose of this study was to determine whether this or other novel ehrlichial agents naturally infect Brazilian cattle. Using PCR targeting the genus-conserved dsb gene, DNA from this novel ehrlichial agent in Brazilian cattle was detected. Attempts to isolate the organism in vitro were performed using DH82 cells, but morulae and ehrlichial DNA could only be detected for approximately one month. In order to further molecularly characterize the organism, PCR was performed using primers specific for multiple E. canis genes (dsb, rrs, and trp36). Sequence obtained from the conserved rrs and dsb genes demonstrated that the organism was 99-100% identical to the novel Ehrlichia genotypes previously reported in North American cattle (rrs gene) and Brazilian ticks (rrs and dsb genes). However, analysis of the trp36 gene revealed substantial strain diversity between these Ehrlichia genotypes strains, including divergent tandem repeat sequences. In order to obtain preliminary information on the potential pathogenicity of this ehrlichial agent and clinical course of infection, a calf was experimentally infected. The calf showed clinical signs of ehrlichiosis, including fever, depression, lethargy, thrombocytopenia, and morulae were observed in peripheral blood monocytes. This study reports a previously unrecognized disease-causing Ehrlichia sp. in Brazilian cattle that is consistent with the genotype previously described in North America cattle and ticks from Brazil. Hence, it is likely that this is the organism previously identified as Ehrlichia bovis in Brazil in 1982. Furthermore, we have concluded that strains of these Ehrlichia genotypes can be molecularly distinguished by the trp36 gene, which has been widely utilized to define E. canis strain diversity.
authors.affiliation: Department of Pathology, Center of Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA; Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil. Electronic address: danmoura@ufmt.br.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Aguiar
authors.affiliation: Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil.
authors.forename: Thayza F
authors.initials: TF
authors.lastname: Ziliani
authors.affiliation: Department of Pathology, Center of Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil.
authors.forename: Andreia L T
authors.initials: AL
authors.lastname: Melo
authors.affiliation: Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil.
authors.forename: Isis A
authors.initials: IA
authors.lastname: Braga
authors.affiliation: Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil.
authors.forename: Rute
authors.initials: R
authors.lastname: Witter
authors.affiliation: Laboratório de Parasitologia Veterinária e Doenças Parasitárias, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Leodil C
authors.initials: LC
authors.lastname: Freitas
authors.affiliation: Clinica Médica de Grandes Animais, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: André L H
authors.initials: AL
authors.lastname: Rondelli
authors.affiliation: Clinica Médica de Grandes Animais, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Michele A
authors.initials: MA
authors.lastname: Luis
authors.affiliation: Laboratório de Patologia Clínica Veterinária, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Eveline C B
authors.initials: EC
authors.lastname: Sorte
authors.affiliation: Laboratório de Virologia e Rickettsioses, Hospital Veterinário da Universidade Federal de Mato Grosso (HOVET-UFMT), Cuiabá, MT, Brazil.
authors.forename: Felipe W
authors.initials: FW
authors.lastname: Jaune
authors.affiliation: Laboratório de Medicina Veterinária Preventiva II, Universidade do Oeste Paulista, Presidente Prudente, SP, Brazil.
authors.forename: Vamilton A
authors.initials: VA
authors.lastname: Santarém
authors.affiliation: Colegiado do curso de Medicina Veterinária, Universidade Federal do Vale do São Francisco, Petrolina, PE, Brazil.
authors.forename: Mauricio C
authors.initials: MC
authors.lastname: Horta
authors.affiliation: Laboratório de Patologia Veterinária, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Carolina A
authors.initials: CA
authors.lastname: Pescador
authors.affiliation: Laboratório de Patologia Veterinária, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Edson M
authors.initials: EM
authors.lastname: Colodel
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Herbert S
authors.initials: HS
authors.lastname: Soares
authors.affiliation: Laboratório de Parasitologia Veterinária e Doenças Parasitárias, HOVET-UFMT, Cuiabá, MT, Brazil.
authors.forename: Richard C
authors.initials: RC
authors.lastname: Pacheco
authors.affiliation: Estação Ecológica de Taiamã, Instituto Chico Mendes de Conservação da biodiversidade (ICMBio), Cáceres, MT, Brazil.
authors.forename: Selma S M
authors.initials: SS
authors.lastname: Onuma
authors.affiliation: Departamento de Medicina Veterinária Preventiva e Saúde Animal, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo B
authors.initials: MB
authors.lastname: Labruna
authors.affiliation: Department of Pathology, Center of Biodefense and Emerging Infectious Diseases, Sealy Center for Vaccine Development and Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: Jere W
authors.initials: JW
authors.lastname: McBride
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D004536:Ehrlichia / Q000235:genetics*; D016873:Ehrlichiosis / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005838:Genotype
chemical_list: D001426:Bacterial Proteins
keywords: A. bovis; Bovine; Brazil; E. bovis; E. canis; dsb