and Its Impact onMultistrain Infections in Contrasting Epidemiological Contexts.

Abstract

Bovine anaplasmosis is a disease caused by, a tick-borne bacterial pathogen with global distribution, primarily determined by the range of its vector. In Argentina,is the main species associated withtransmission, even though this bacterium can also be mechanically transmitted. We studied complex infections (more than onevariant) in naturally infected bovines from two different epidemiological contexts: a region with the tick vector and a tick-free region. In the tick-free area, symptomatic infections were associated with a singlegenotype, while asymptomatic bovines from the same herd remained chronically infected with a low number of genotype variants. By contrast, in the region whereis present, the only symptomatic bovine showed highly diverse infections, with 19 distinctive genotypes. Additionally,genotypes were also detected in tick tissues. These findings, together with previous data, indicate thatharborspopulations that are maintained through tick generations by means of transovarial transmission. Furthermore, this tick species is responsible for maintainingdiversity in the bovine host over time through coinfection and superinfection events.