# First detection of one of the tick-borne lymphadenopathy (TIBOLA) etiological agent in ticks from a highly frequented sub-urban forest near Paris, France

## TL;DR

Researchers found a tick-borne bacterium, Rickettsia conorii subsp. raoultii, in a suburban forest near Paris for the first time, highlighting the need for tick pathogen surveillance.

## Contribution

First detection of Rickettsia conorii subsp. raoultii, a TIBOLA-causing agent, in ticks from the Paris region using metatranscriptomic sequencing.

## Key findings

- Rickettsia conorii subsp. raoultii was detected in Dermacentor reticulatus ticks near Paris.
- Metatranscriptomic NGS identified both known and novel tick-borne pathogens.
- Ixodes ricinus ticks carried Anaplasma, Babesia, and Borrelia species as expected.

## Abstract

In the context of global changes including climate, environmental and socio-economic modifications, the surveillance of tick populations in term of species distribution and harboured pathogens is an absolute necessity. With this aim in view, ticks were collected in May 2022 in an highly frequented suburban forest located near Paris, France. The objective was to identify tick species and tick-borne pathogens that may warrant long-term monitoring, as well as to assess added value of metatranscriptomic Next Generation Sequencing (mNGS) for the detection of known and possibly new pathogens in ticks. Both Dermacentor reticulatus and Ixodes ricinus were collected. In addition to expected pathogens detected in I. ricinus (i.e., Anaplasma, Babesia, and Borrelia species), we report the detection of Rickettsia conorii subsp. raoultii, a zoonotic bacterium never identified in the region before and transmitted by a tick species on the rise: D. reticulatus.

Surveillance of tick populations is increasingly important in the present context of global changes to detect unexpected transmitted pathogens in new areas. In this preliminary survey, the collection of a small number of ticks (n = 40) allowed detection of classically identified pathogens in the forests surrounding Paris, France, but also for the first time a bacterium responsible for Tick-borne lymphadenopathy (TIBOLA).