Rickettsial infection in ticks infesting wild birds from two eco-regions of Argentina

BORGES COSTA F.; LABRUNA M. B.; FLORES F. S.; DIAZ L. A.; NAVA S.

REVISTA BRASILEIRA DE PARASITOLOGIA VETERINáRIA

BRAZILIAN COLL VETERINARY PARASITOLOGY

Año: 2016 vol. 25 p. 378 - 382

0103-846X

Several tick-borne Rickettsia species are recognized human pathogens in Argentina. Herein we evaluated rickettsial infection in ticks collected on passerine birds during 2011-2012 in two eco-regions of Argentina. Ticks were processed by molecular analysis through polymerase chain reaction (PCR) detection and DNA sequencing of fragments of two rickettsial genes, gltA and ompA. A total of 594 tick specimens (532 larvae and 62 nymphs), representing at least 4 species (Amblyomma tigrinum, Ixodes pararicinus, Heamaphysalis juxtakochi, Heamaphysalis leporispalustris), were evaluated. At least one A. tigrinum larva, collected on Coryphospingus cucullatus in Chaco Seco, was infected with Rickettsia parkeri, whereas at least 12 larvae and 1 nymph of I. pararicinus, collected from Troglodytes aedon, Turdus amaurochalinus, Turdus rufiventris, C. cucullatus and Zonotrichia capensis were infected with an undescribed Rickettsia agent, genetically related to several rickettsial endosymbionts of ticks of the Ixodes ricinus complex from other continents. R. parkeri, is a recognized human pathogen in several American countries including Argentina, where a recent study incriminated A. tigrinum as the potential vector of R. parkeri to humans. Birds could possibly play an important role in dispersing R. parkeri-infected A. tigrinum ticks. We report for the first time a rickettsial agent infecting I. pararicinus ticks.