title: Genetic diversity of Anaplasma marginale in Argentina.
abstract: Bovine anaplasmosis caused by Anaplasma marginale is a worldwide major constraint to cattle production. The A. marginale major surface protein 1 alpha (msp1alpha) gene contains a variable number of tandem repeats in the amino terminal region and has been used for the characterization of pathogen genetic diversity. This study reports the first characterization of A. marginale genetic diversity in Argentina based on msp1alpha genotypes and its putative relationship with Rhipicephalus (Boophilus) microplus infestations. Herein, we analyzed whole blood bovine samples from anaplasmosis outbreaks in R. microplus infested (9 samples) and eradicated/free (14 samples) regions. Sequence analysis revealed the existence of 15 different msp1alpha genotypes with 31 different repeat units. Six new repeat sequences were discovered in this study and 13/31 (42%) repeats were unique to Argentinean strains. The analysis of msp1alpha repeat sequences according to R. microplus infestations resulted in three repeat groups: (i) found in tick-infested regions (20 repeats), (ii) found in tick free regions (6 repeats) and (iii) randomly distributed (5 repeats). Moreover, A. marginale msp1alpha genetic diversity was higher in tick-infested regions than in tick free areas. These results, together with previous evidence suggesting that A. marginale msp1alpha repeat units co-evolved with the tick vector, might represent an evidence of the role of tick-mediated transmission for the generation of pathogen genetic diversity.
authors.affiliation: Instituto de Biotecnología, Centro de Investigaciones de Ciencias Veterinarias y Agronómicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Los Reseros y Las Cabañas, CP 1686, Hurlingam, Buenos Aires, Argentina. pruybal@cnia.inta.gov.ar
authors.forename: Paula
authors.initials: P
authors.lastname: Ruybal
authors.forename: Rosalia
authors.initials: R
authors.lastname: Moretta
authors.forename: Andres
authors.initials: A
authors.lastname: Perez
authors.forename: Romina
authors.initials: R
authors.lastname: Petrigh
authors.forename: Patricia
authors.initials: P
authors.lastname: Zimmer
authors.forename: Elda
authors.initials: E
authors.lastname: Alcaraz
authors.forename: Ignacio
authors.initials: I
authors.lastname: Echaide
authors.forename: Susana
authors.initials: S
authors.lastname: Torioni de Echaide
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Kocan
authors.forename: Jose
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Marisa
authors.initials: M
authors.lastname: Farber
mesh_terms: D000595:Amino Acid Sequence; D042322:Anaplasma marginale / Q000235:genetics*; D000818:Animals; D001118:Argentina; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype
chemical_list: D001425:Bacterial Outer Membrane Proteins; C449089:major surface protein 1a, Anaplasma