# Rickettsia tillamookensis-like strain in brown dog ticks in Brazil

## TL;DR

A new strain of Rickettsia, similar to Rickettsia tillamookensis, was found in ticks from Brazil, raising questions about its potential impact on human health.

## Contribution

The discovery of a Rickettsia tillamookensis-like strain in Brazilian ticks adds to the understanding of rickettsial diversity and potential zoonotic risks.

## Key findings

- Rickettsia tillamookensis-like strain was detected in brown dog ticks from northeastern Brazil.
- A dog with infected ticks showed antibodies to Rickettsia rickettsii, indicating possible exposure to related rickettsiae.

## Abstract

Brown dog ticks (Rhipicephalus linnaei) collected from dogs in northeastern Brazil in 2015 tested positive for a rickettsial organism phylogenetically related to Rickettsia tillamookensis (referred to as R. tillamookensis-like). One of the dogs with R. tillamookensis-like-positive ticks tested positive for IgG antibodies to Rickettsia rickettsii antigens, suggesting a potential reaction to spotted fever group rickettsiae. Future research should assess whether the rickettsia detected herein is R. tillamookensis or a closely related species, its distribution, potential vectors, and possible pathogenicity to humans.