The use of bacteriophages against Listeria as a ‘non-decontaminating’ processing aid

Ongoing EU legislative controversy over the use of bacteriophages is leading to unnecessary Listeria-deaths, argues biochemist Danielle van Dalen.

Photo credit: PA Images

According to the European Commission’s DG SANTE, the use of bacteriophages against Listeria is not allowed yet in European countries. The European Court of Justice, however, states that the Commission has not yet taken a decision regarding the use of bacteriophages. It merely concerns an ‘interpretation’, a term used by Director-General Anne Bucher in an official letter. National Inspection Services such as the Dutch NVWA are encouraged to treat the phage product Listex P100 as a decontaminant, whereas it should actually be used as a ‘non-decontaminating’ processing aid.

Use outside the EU

Due to the increasing risk of listeriosis, bacteriophages against the bacterium Listeria monocytogenes are used in eight countries, including the United States, Canada, Australia and Switzerland  The approved phage, ‘Listex P100’ is effective in food production. However, In Europe, the situation is still different. 

The phage prevents outgrowth

In the scientific article ‘Applicability of commercial phage-based products against Listeria monocytogenes for improvement of food safety in Spanish dry-cured ham and food contact surface’s), it is concluded that the phage Listex P100 is not so much effective in combating Listeria bacteria as it is in preventing their outgrowth. 


Completely harmless

According to the European Food Safety Authority (EFSA), Listex P100 is completely harmless, effective and does not contribute to antibacterial resistance (AMR). Ministers of Health of several EU Member States have therefore requested the Commission in writing to approve Listex P100. Even at a senior official level, it is not understood why, since 2007, the Commission has not been able to form an opinion on the way in which the use of Listex P100 in the production of food can be approved in the EU. 

Recognition of innovation?

The producer of Listex P100 is the Dutch company Micreos. Both the EU and the Dutch government awarded different prices to the ground-breaking work of this company. The EU claims to support both innovation and SMEs. However, DG SANTE’S policy, already under Italian fire for their lack of coordination on Coronavirus policy - did not seem to follow this. 

Fast switching because of Corona

That fast switching is possible is proven by the Coronavirus crisis. Commission President Ursula von der Leyen has now offered the German company Curevac extremely rapid authorisation and financial support (€80m) to develop an anti-COVID-19 vaccine. At her COVID-19 press conference on 17 March, von der Leyen said, "we all see that we are able to speed up any of the processes that are slow normally and take a lot of time and are very bureaucratic". 

"Even at a senior official level, it is not understood why, since 2007, the Commission has not been able to form an opinion on the way in which the use of Listex P100 in the production of food can be approved in the EU"

Listeria more deadly than Coronavirus

The Commission President did not mean that there is a difference between COVID-19 and Listeria victims. Listeria bacteria as such are more dangerous than COVID-19: a much higher percentage of Listeria victims die, experience miscarriages or persistent complaints such as paralysis. Of course the important difference is that a virus is an epidemic disease that occasionally pops up; Listeria bacteria are not transferable from person to person, but they are latently present.

A faster procedure for Listex P100 creates hope that the more than 1000 recent Listeria victims, especially in Spain, Germany and the Netherlands, don’t get any ‘successors’.  After years of incomprehensible bureaucratic delays, Listex P100 could be recognized as a 'non-decontaminating' processing aid within a short period of time by means of an accelerated procedure.

Additive or decontaminant?

Until 2007, Listex P100 was used both in the EU and in all other major markets as a regular processing aid in the production of ready-to-eat food of both plant and animal origin. However, DG SANTE wished to classify the use of Listex P100 as either a biocide, an additive, or a decontaminant. Under pressure from the Commission, Micreos then decided to go for 'decontaminant'. After the Commission went down this route, some Member States raised objections. Decontaminating products would mask the lack of hygiene in production facilities. 

Procedure stopped in 2017

After a short 'public consultation' in Midsummer 2017 - intended to provoke a negative opinion? - DG SANTE decided not to follow the unexpectedly favourable outcome (seven in favour, two against) for Listex P100; it simply announced that the 'decontamination procedure' had been stopped for lack of support among Member States. Micreos was shown the regulatory door without further communication. Thus, in this way innovation and employment are disappearing from Europe and the chance of Listeria outbreaks increases again.

Processing aid

NVWA spokesperson Paula de Jonge is right: Listex P100 can best be used as a processing aid. That was also the initial opinion of the Dutch government. In fact, even the highest European judge shares this verdict - he calls Listex P100 a 'non-decontaminating processing aid'. In his 'Order' of 26 September 2019, the judge states very sharply that the European Commission has in fact never published any judgment other than that the 'decontamination procedure' was stopped. 

The judge therefore understands the Commission as much as we all do: namely that Listex P100 is not a decontaminant. Food Control and the judge seem to agree: it is a ‘non-decontaminating processing aid’ that prevents contamination with Listeria bacteria above permitted limits.

"Who are the victims of such a risky, slow and disorderly EU policy? In a direct sense: thousands of Europeans who are victims of listeriosis – the deadliest bacterial food contaminant"

Ban on Listex P100?

In a non-public letter to all EU Chief Veterinary Officers in November 2019, the Commission sought to turn this non-existent policy into a ban on the use of Listex P100 in the EU. In doing so, DG SANTE simultaneously took two different positions: one towards the European Court of Justice boiling down to that the Commission had only given an 'interpretation' regarding Listex P100 – and another towards the Member States via a camouflaged 'instruction' to remove Listex P100 from the market. Bureaucracy versus public interest.

In its 'Order', the European Court of Justice saw this coming: "Accordingly, if the applicant [Micreos] disagrees with the legal position expressed, prima facie, in the contested acts by the Commission, it is free to seek legal remedies against acts adopted by national authorities, such as the Belgian and Estonian authorities to which the applicant refers, allowing the national courts to make an order for reference to the Court of Justice pursuant to Article 267 TFEU". 

Court case against the Belgian State

Coincidentally, it is Belgium - which at ministerial level questioned in writing the correctness of DG SANTE's Listex P100 policy – that published a ban on the use of Listex P100, apparently requested by the Commission (a Belgian official). In close consultation with the Belgian authorities, Micreos subsequently decided to initiate a court case against the Belgian State. It is expected that this will lead to a Belgian judicial decision to refer the case to the European Court of Justice. 


Who are the victims of such a risky, slow and disorderly EU policy? In a direct sense: thousands of Europeans who are victims of listeriosis – as mentioned the deadliest bacterial food contaminant. Immediately after the previous Commissioner for Health Vytenis Andriukaitis stated that Listex P100 was not necessary to prevent listeriosis outbreaks, there were more than 1000 victims in mid-2019 in Spain, Germany and the Netherlands, leading to dozens of deaths, miscarriages and life-long health problems. 

Indirectly: a brake on innovation, employment and stimulation of the economy through SMEs, which still create more than 80 percent of employment in Europe. In a post-COVID 19 period of economic recovery, the delay by officials must stop because it is costing human lives and jobs. Or do we want Micreos to leave The Netherlands? After more than 10 years of indecision, it is time for politicians to correct their official errors.

Not all small and innovative companies have the courage and perseverance of Micreos. This modest Dutch company therefore deserves all Dutch support so that it can help prevent even more Listeria victims.


On Thursday 30 April, the Parliament Magazine and PA International will run a Webinar with members of the European Parliament and relevant stakeholders entitled ‘Disease Outbreaks and the EU’s Precationary Measures: The Listeriosis victims’ perspective’.  This would be a good time for the Dutch government to remind DG SANTE of the statement of Commission President von der Leyen - and to make Listex P100 fully available to European food producers.

This article was originally published in Dutch on the website of VMT on 16 April 2020: 


Tech & Research Health
Share this page