Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free:

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site:, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Google Analytics

Targeted advertising cookies


The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at or by post at:

24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal Oniris

Home page

Precise and early quantification of spoilage due to Brochothrix thermosphacta

PMAxx Brochothrix
Development of a molecular method targeting only viable cells

Food spoilage results in a degradation of sensory qualities (smell, taste, texture) which results mainly from the metabolism of so-called spoilage bacteria and which generates considerable food losses for food industry manufacturers. Brochothrix thermosphacta is a bacterium that causes spoilage in many seafood and meat products. This bacterium is a model for the scientists at SECALIM who seek to understand the capacities of this bacterium to settle durably in the industrial environment in particular by its capacity to form biofilms. As part of this study, the aim was to develop a precise and rapid molecular method known as PMA-qPCR, which allows only the viable Brochothrix cells present in cold-smoked salmon to be quantified and responsible for its spoilage. The tools allowing the specific and sensitive detection as well as the quantification of this bacterium in food products are very useful, since the culture method commonly used to quantify viable cells of B. thermosphacta requires several days of incubation and may underestimate cells that would not be immediately cultivable. SECALIM researchers have designed a new set of PCR (Polymerase Chain reaction) primers allowing the amplification and quantification of the rpoC gene present in a single copy in the genome of the bacteria. The efficiency and specificity of this quantitative PCR were compared with those obtained for two other sets of primers already published, targeting the rpoC and rpoB genes. In combination with labeling of bacterial DNA using PMA or PMAxx viability dyes, qPCR has been shown to be specific and effective, regardless of the dye and primer set used, for the selective quantification of DNA from viable cells in pure culture and in cold-smoked salmon samples, thus allowing efficient discrimination between viable and dead cells. PMA / PMAxx-qPCR could represent a relevant tool for smoked salmon producers to rapidly detect and quantify B. thermosphacta in their products early enough before the spoilage is noticeable by the consumer and thus limit food losses. Finally, this method could be adapted to other matrices such as meat products also very sensitive to spoilage due to B. thermosphacta.

Publication: Bouju-Albert, A., Saltaji, S., Dousset, X., Prévost, H., & Jaffrès, E. (2021). Quantification of viable Brochothrix thermosphacta in cold-smoked salmon using PMA/PMAxx-qPCR. Frontiers in Microbiology, 12 (1907).

Parteners and funding: This study was carried out by UMR INRAE Oniris SECALIM and funded as part of the regional ALTEROBIO project funded by the Pays de la Loire Region.