3rd RESAMA Days

The EMBRC-France National Research Infrastructure aims to offer and facilitate access to the ecosystems and their marine resources of the 3 stations that make it up (Roscoff Biological Station SBR, Villefranche Sea Institute IMEV, and the Banyuls Oceanological Observatory OOB), as well as to a high-level technological environment.

EMBRC-France, through the establishment of a multi-site CRB, integrates zootechnical expertise, know-how for the provision of wild marine organisms (collections) or breeding.  The heads of aquariological services, Régis Lasbleiz (IMEV), Pascal Romans (OOB) and Gaëtan Schires (SBR) will detail the aquariological infrastructures of their site and the zootechnical innovations developed on the species of interest.

In the aquaculture sector, it is very classic and usual to implement rigorous mortality monitoring on fish farms. This monitoring is important to detect, understand and improve the difficulties encountered in the different phases of the animal life cycle.

This also adapts to the research animal facility and makes it possible to improve animal welfare and better comply with regulations on animal experimentation.

For 4 years now, the CRB has been changing its maintenance, production, breeding management and production management practices on xenopus laevis animals to qualitatively and quantitatively improve production efficiency, by mainly revising: breeding density, feeding, production management.

Consequently, the results are quantifiable: the loss rates between the tail bud/metamorphosed and metamorphosed/adult stages were divided by 2, and, morphologically, the animals regained an interesting BMI (gain in size 10% and weight 35%).

Monitoring mortalities in research animal facilities is an indicator that is certainly time-consuming but which, when well carried out, allows us to understand any zootechnical deviation and improve the overall health status of the structure. Aware of the constraints linked to this precise monitoring, RESAMA wanted to provide the community with a simple (PDF form), relevant (categorization of mortalities and euthanasias) tool, which also allows archiving and anonymous sharing on the RESAMA website.

In our Western countries, most human zoonoses have become rare. The health monitoring of animals and food, efficient animal and human health monitoring systems, the promotion of hygiene and the provision of care make it possible to maintain a balance which always requires constant vigilance and energy. Concerning aquariums, certain environmental mycobacteria (M. marinum, more rarely M. fortuitum, etc.) whose reservoir can be both fish and its environment can cause local, persistent skin infections following the inoculation of even minimal wounds. Rarely, the infection can reach the tendons or the underlying joint. In immunocompromised people, the infection can spread particularly to the lymph nodes or lungs. Prevention is based on a risk assessment and knowledge of the links in the chain of transmission of the pathogen: health monitoring of potential animal reservoirs, management of cleaning of aquariums, compliance with hygiene rules, individual protection (in particular waterproof gloves with cuffs, management of work clothes), information and consideration of the state of health of each person.

Symptoms of potential zoonoses in fish and amphibians in research animal facilities: After a brief reminder of the major zoonoses in research animal facilities, the results of mycobacteria detections within the framework of RESAMA were presented (by target species, by pathogen, by technique).

Among all the mycobacteria identified, it turns out that Mycobacterium fortuitum represents 15% of PCR-positive samples in fish, and 5% for M. marinum. Among Xenopus, M. marinum is present in 55% of positive samples. A photographic slideshow of main clinical signs in fish affected by mycobacteriosis was then presented.

To ensure health and well-being of animals but also of animal users/handlers, it is important to carry out health management of pet stores. This management is based on the search for pathogens (monitoring of animals) and the implementation of preventive and curative actions with a view to stopping or limiting the emergence of diseases (disinfection, quarantine, etc.). 3 levers of action are possible: the reservoir, the mode of transmission and the receptive host.

The choice of laboratory methods used within the framework of a surveillance network depends on several factors which concern in particular the characteristics of the pathogens sought (diversity, biological parameters, prevalence etc.), the intrinsic and extrinsic characteristics of the methods, the robustness of the methods and financial aspects. Through examples linked to bacteriological diagnosis in general and screening for infections by non-tuberculous mycobacteria or by Pseudoloma neurophilia, the presentation explains the different methods or combinations of methods used within the framework of the RESAMA network. Bacteriological analyzes thus consist of direct seeding on different media, selective or not for certain bacterial genera, then an antibiogram by diffusion. Screening for non-tuberculosis infections consists of the combination of a highly sensitive TaqMan PCR method targeting the hsp65 protein gene, followed by genotyping and sequencing if necessary. Screening for Pseudoloma neurophilia infections consists of literature-based TaqMan PCR and tailored nucleic acid extraction methods. These analyzes are carried out as part of the laboratory's quality approach. The results must be interpreted based on field data, as well as results obtained by other methods (notably histology).

Histological analyzes of samples (animals, tissues) as part of RESAMA analyses:

After exposing the constraints and techniques related to the preparation of samples for histological analysis, a photographic slideshow of the main infectious or non-infectious conditions encountered during RESAMA visits was then presented. Histology remains an essential tool for proper monitoring of the health of fish and amphibians and allows broad screening of different pathogens but also to quantify the intensity of the induced anatomopathological lesions.

The aim of the presentation is to present the existing devices at the IRSN of Cadarache (at the radionuclide ecotoxicology laboratory) with regard to fish breeding (zebrafish Danio rerio and carp Cyprinus carpio) as well as the experimental devices allowing the irradiation of fish.

The experimental installations on fish models at Ineris contribute to the prevention of environmental risks through the study of the mechanisms of action of endocrine disruptors and the implementation of biomonitoring tools for aquatic environments. The models studied are the zebrafish and the 3-spined stickleback with systems allowing the evaluation of the ecotoxicity of chemical substances, from the individual level to the population level in mesocosms.

Stability of water and environmental parameters (light, temperature, pH, water circulation, etc.) is essential to maintain zebrafish in healthy conditions and to achieve high egg production. Therefore, zebrafish pet stores should have an automatic alarm system that can inform users if any of these parameters is outside the acceptable thresholds. Commercial systems exist, but they are often very expensive and difficult to tailor to the needs of each installation. To solve this problem, we developed a custom alarm system based on a Raspberry Pi processor and an Arduino board that continuously measures light, temperature, humidity, water flow, water volume, pH, dissolved oxygen and water conductance. Any deviation from the pre-established thresholds generates an alarm by email sent to the pet store managers. The code is written in Python and is open source. The acquired data is saved in a PostgreSQL database. The recorded data is then visualized via a web page written in php using the jpgraph library. We provide all documentation and codes.

Presentation of the installations and operation of the aquatic animal facility of UMR7221 of the MNHN (“Evolution of endocrine regulations” laboratory). The aquatic animal facility, with a surface area of ​​230 m2, houses several species of amphibians (Xenopus laevis, Xenopus tropicalis, Ambystoma mexicanum) and a fish species (Danio rerio).

The ZEN zebrafish, presentation of a zebrafish animal facility for the ZEN (ZEbrafish Neurogenetics) research team led by Laure Bally-Cuif. The ZEN team uses this animal model to study the functioning of neural stem cells.