INVESTIGADORES
RUYBAL paula
congresos y reuniones científicas
Título:
Genetic Diversity of Anaplasma marginale in Argentina.
Autor/es:
PAULA RUYBAL; ROSALÍA MORETTA; ANDRES PEREZ; ROMINA PETRIGH; PATRICIA ZIMMER; ELDA ALCARAZ; IGNACIO ECHAIDE; SUSANA TORIONI DE ECHAIDE; KATHERINE M. KOCAN; JOSE DE LA FUENTE; MARISA FARBER
Lugar:
Buenos Aires, Argentina
Reunión:
Conferencia; VI International Conference on Ticks and Tick-borne Pathogens.; 2008
Institución organizadora:
INTA, CONICET y SECyT
Resumen:
Anaplasmosis is a worldwide major constrain in cattle production. This study reports the first characterization of Anaplasma marginale genetic diversity based on the genotype marker msp1a and its putative relationship with Riphicephalus (Boophilus) microplus infestation influence within Argentinean soil. For this purpose, we analyzed whole blood bovine samples from anaplasmosis outbreaks from B. microplus infested (9 samples) and eradicated/free (14 samples) regions. Sequence analysis revealed the existence of 15 different genotypes and 31 different repeat units. Twenty of these repeat units were already reported elsewhere, 8 of them being unique to Argentina. In addition, 6 new repeats are reported for the first time in this work. We also showed serine residue as a new variation at position 20 within the repeat unit, which has been suggested to be important in rickettsial adhesion to erythrocytes and tick cells. According to tick regions we defined three groups of repeat units associated to:-i) presence of ticks (20 repeats), ii) absence of ticks (6 repeats) and iii) randomly distributed (5 repeats). Moreover, we observed higher variability in Argentinean tick infested region compared to tick free/eradicated region. This observation, together with previous evidence suggesting that A. marginale msp1a repeat units could co-evolved with the tick vector, might represent an evidence of the role of tick-mediated transmission for the generation of genetic variability of this parasite. Furthermore, 2 and even 4 genotypes were found in two samples obtained from an enzootic area highly infested by ticks. Our findings are the first description of genetic variation of A. marginale in Argentine herds and suggest a higher variability according to tick influence.