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Many emerging pathogens have recently been identified. Of these, 60% are zoonotic, meaning that they are capable of passing from animals to humans. Many are viruses, bacteria or fungi, but parasites follow the same rule. The ParaNEm group (Neglected and Emerging Parasites) is particularly interested in these emerging parasites, but also in neglected parasites (NP), which are not a priority and are the cause of many different pathologies in humans or in livestock. These NPs are zoonotic or enzootic, and can cause many losses on farms. An increasing number of cases of resistance to the antiparasitics administered are being observed, and new alternatives must be proposed as a matter of urgency. Neglected and emerging parasites mainly originate from wildlife or the environment, and it is essential to take a "One Health" approach to these parasites.

Objectives:

The study of neglected and emerging parasites requires the development of customised prophylactic tools.

The ParaNEm group has several objectives:

I- The discovery of new diagnostic targets for monitoring and anticipating emerging zoonotic parasites by setting up -omics studies (genomics, transcriptomics and proteomics) with various partners;

II- The discovery of new therapeutic targets to propose the use of new molecules that are effective against enzootic parasites that are resistant to many anti-parasitics. The strategy would then be to release the selection pressure on frequently used antiparasitics so that the parasites become sensitive again;

III- The development of innovative tools for monitoring parasites circulating in domestic and wild animals, in France (metropolitan and overseas), in European countries and worldwide, based on traditional molecular biology (PCR, qPCR, rt-PCR), MALDI-TOF technology and new sequencing technologies (Illumina, nanopore, etc.);

IV- Understand the relationship between these parasites and their hosts, as well as their pathogenicity, using parasite ecology, in vivo models and tissue and cell imaging (confocal imaging, flow cytometry, etc.).

Main results:

I- Development of a MALDI-TOF database for the identification of Trichinella spp. species from a protein extract of larvae. This technique is currently being transposed to other nematodes of interest (NEMATOF project).

Species identification of Trichinella originated from various host and different geographical location by MALDI-TOF. 2020, Karadjian et al., Exp Parasitol.

II- Implementation of a strategy for identifying larvae of nematodes other than Trichinella spp. from official regulatory controls on meat...

A two-step morphology-PCR strategy for the identification of nematode larvae recovered from muscles after artificial digestion at meat inspection. 2020, Karadjian et al., Parasitol Res.

... and development of a PCR-RFLP for the identification of larvae of the zoonotic nematode Toxocara spp.

Toxocara cati and Toxoplasma gondii in French Birds of Prey. 2022, Karadjian et al., J Wildl Dis.

Projets actuels:

• Project PARADISE:

PARADISE is an international consortium with optimal complementary expertise on the zoonotic parasites Cryptosporidium parvum and Giardia duodenalis. PARADISE aims to provide informative typing schemes and innovative detection strategies applicable to food matrices for both parasites. Coordination of task 4.1 (in WP4): G. karadjian (BIPAR JRU LSAn, PARANEM group), for the selection of aptamers specific to Cryptosporidium parvum and Giardia duodenalis.

• Project AptaTrich:

The AptaTrich project (Development of an aptamer-based test for trichinella detection) involves selecting Trichinella-specific aptamers capable of recognising circulating Trichinella proteins and then using these molecules for serodiagnosis (Aptamer-Based-ELISA, ELONA, etc.). Co-ordination: G. Karadjian (BIPAR JRU LSAn, PARANEM group)

• Project PARAVIR:

The PARAVIR project (detection of parasite viruses) is co-piloted by Grégory Karadjian (JRU BIPAR LSAn, PARANEM group) and Nolwenn Dheilly (JRU VIRO LSAn).

The aim of the project is to characterise the RNA viruses of parasites in order to find new diagnostic, vaccine and/or therapeutic targets.

The project plans to :

- To test and extend the scope of the methodology recently developed by Nolwenn Dheilly (VIRO JRU) and Yannick Blanchard (GVB Unit, LPPN) to enable the detection and genomic characterisation of new viruses;

- Discover and characterise new viruses in parasites of public health interest;

- Determine the phylogenetic position of these viruses relative to known viral diversity;

- Develop RT-PCR-type diagnostic tests to test for the presence of viruses in a larger number and greater diversity of samples.

•  Project NEMATOF:

The aim of the NEMATOF project (Identification of Nematodes by MALDI-TOF) is to transpose the method for identifying Trichinella spp. larvae to the larvae of difficult-to-identify plant nematodes and certain difficult-to-identify farm nematodes (Teladorsagia spp., Heterakis spp., etc.) and to expand the Trichinella database to include other nematodes. PARANEM is a partner in the project because it is a leader in the technique.

• Project PaPerFish:

The PaPerFish project (Parasites in fishery products: study of their distribution, zoonotic potential and consumer perception) aims to acquire data on potentially zoonotic parasites in fishery products by focusing on 2 aspects, firstly consumer perception of the risk associated with these parasites and secondly the study of the distribution and assessment of the zoonotic nature of little-known parasites. PARANEM is coordinating WP2 to study the zoonotic potential of the trematode Cryptocotyle lingua.

• Project NeuroTrich:

The NeuroTrich project (Study of the Trichinella neuronal system) is co-coordinated by Ladislav Simo (BIPAR JRU LSAn, NeuroTick group) and Grégory Karadjian (BIPAR JRU LSAn, PARANEM group). NeuroTrich should enrich our knowledge of the neural signalling pathways of T. spiralis and provide tools affecting the crucial components of the Trichinella neural system for the development of effective control strategies for T. spiralis. Once proof of concept has been achieved, the work could serve as a reference for all nematodes and provide an alternative target for strains resistant to current anthelmintics.

• Project AngioSurv:

The AngioSurv project (Monitoring the emergence of Angiostrongylus cantonensis in France) is looking at the contamination of french rats by the zoonotic nematode Angiostrongylus cantonensis and will carry out molecular characterisation of the parasite. The presence of this parasite would mean that it has been introduced into France and that its emergence is underway, with a non-negligible risk of human contamination.

Collaborations:

• National:

ANSES : VIRO JRU (Maisons-Alfort), PhEED Unit (Goustranville), SEEpiAS Unit (Nancy), B3PA Unit (Boulogne sur Mer), Unité de Nématologie (Rennes), VIPAC Unit (Plouzané), PBER Unit (Niort), Genomic plateform (Ploufragan) / GVB Unit (Ploufragan)

MNHN : MCAM JRU (Paris)

INRAE : ISP JRU (Nouzilly)

Wildlife conservation centers : Goupil Connexio (Ganges), Chêne vert (Allouville-Bellefosse), CHUV-FS (Maisons-Alfort)

• International:

Istituto Superiore di Sanità (ISS), Rome, Italiy

Robert Koch Institute (RKI), Berlin, Germany

Bundesinstitut für Risikobewertung (BfR), Berlin, Germany

School of Veterinary Medicine, University of Surrey, UK

Yerevan state university, Arménia

McGill University Health Centre, Montréal, Canada