title: Low genetic diversity associated with low prevalence of Anaplasma marginale in water buffaloes in Marajó Island, Brazil.
abstract: The rickettsia Anaplasma marginale is the etiologic agent of bovine anaplasmosis, an important tick-borne disease affecting cattle in tropical and subtropical regions of the world. In endemic regions, the genetic diversity of this pathogen is usually related to the high prevalence of the disease in cattle. The major surface protein 1 alpha (MSP1a) has been used as a marker to characterize the genetic diversity and for geographical identification of A. marginale strains. The present study reports the characterization of A. marginale MSP1a diversity in water buffaloes. Blood samples were collected from 200 water buffaloes on Marajó Island, Brazil where the largest buffalo herd is located in the Western hemisphere. Fifteen buffaloes (7.5%) were positive for A. marginale msp1α by PCR. Four different strains of A. marginale with MSP1a tandem repeat structures (4-63-27), (162-63-27), (78-24-24-25-31) and (τ-10-10-15) were found, being (4-63-27) the most common. MSP1a tandem repeats composition in buffalos and phylogenetic analysis using msp1α gene showed that the A. marginale strains identified in buffaloes are closely related to A. marginale strains from cattle. The results demonstrated low genetic diversity of A. marginale associated with low bacterial prevalence in buffaloes and suggested that buffaloes may be reservoirs of this pathogen for cattle living in the same area. The results also suggested that mechanical transmission and not biological transmission by ticks might be playing the major role for pathogen circulation among water buffaloes in Marajó Island, Brazil.
authors.affiliation: Departamento de Patologia Veterinária, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil.
authors.forename: Jenevaldo B
authors.initials: JB
authors.lastname: Silva
authors.affiliation: Departamento de Clínica Veterinária, Universidade Federal do Pará, Castanhal, Pará, Brazil.
authors.forename: Adivaldo H
authors.initials: AH
authors.lastname: Fonseca
authors.affiliation: Departamento de Parasitologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil.
authors.forename: José D
authors.initials: JD
authors.lastname: Barbosa
authors.affiliation: SaBio Instituto de Investigación en Recursos Cinegéticos IREC, CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; Center for Infection and Immunity of Lille (CIIL), INSERM U1019 - CNRS UMR 8204, Université Lille Nord de France, Institut Pasteur de Lille, Lille, France.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cabezas-Cruz
authors.affiliation: SaBio Instituto de Investigación en Recursos Cinegéticos IREC, CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA. Electronic address: Jose_delafuente@yahoo.com.
authors.forename: José
authors.initials: J
authors.lastname: de la Fuente
mesh_terms: D000595:Amino Acid Sequence; D042322:Anaplasma marginale / Q000235:genetics* / Q000302:isolation & purification; D000712:Anaplasmosis / Q000453:epidemiology*; D000818:Animals; D001096:Arachnid Vectors / Q000382:microbiology*; D001483:Base Sequence; D001938:Brazil; D002020:Buffaloes; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D016415:Sequence Alignment / Q000662:veterinary; D017422:Sequence Analysis, DNA / Q000662:veterinary; D017282:Tick-Borne Diseases / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D013987:Ticks / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial
keywords: Anaplasma marginale; Anaplasmosis; Buffalo; Genetics; MSP1a