Scientific Opinion on the safety and efficacy of micro-organism DSM 11798 when used as a technological feed additive for pigs

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Article
EFSA Journal 2013;11(5):3203 [18 pp.].
doi
10.2903/j.efsa.2013.3203
EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP)
Panel Members
Gabriele Aquilina, Alex Bach, Vasileios Bampidis, Maria De Lourdes Bastos, Lucio Guido Costa, Gerhard Flachowsky, Mikolaj Antoni Gralak, Christer Hogstrand, Lubomir Leng, Secundino López-Puente, Giovanna Martelli, Baltasar Mayo, Fernando Ramos, Derek Renshaw, Guido Rychen, Maria Saarela, Kristen Sejrsen, Patrick Van Beelen, Robert John Wallace and Johannes Westendorf.
Acknowledgement

The Panel wishes to thank the members of the Working Group on Mycotoxin detoxifying agents, including Georges Bories, Andrew Chesson and Jürgen Gropp, for the preparatory work on this scientific opinion.

Type
Opinion of the Scientific Committee/Scientific Panel
On Request From
European Commission
Question Number
EFSA-Q-2012-00719
Adopted
16 April 2013
Published
6 May 2013
Affiliation
European Food Safety Authority (EFSA), Parma, Italy
Note
Article (281.82 KB)281.82 KB
Abstract

The additive, based on a single bacterial strain (DSM 11798), is intended for use in feeds for pig to reduce the epoxide group of contaminating trichothecene mycotoxins to a less toxic metabolite. To establish an identity for the strain a phylogenetic analysis was made based on the genomic sequence of the strain and 24 genome sequences available for the family Coriobacteriaceae. The three approaches used consistently suggested an assignment to a new taxonomic unit within the family Coriobacteriaceae. The Panel accepts that a new species and/or genus may have to be established. In the interim the deposition of the bacterium in a European culture collection is sufficient to ensure that any authorisation would apply only to the additive under application. Based on the results of a tolerance study the additive is considered safe for piglets and pigs for fattening at the maximum dose proposed. The live organism is not expected to present a hazard for consumers and the negative findings in a series of genotoxicity and oral toxicity tests indicates that toxic metabolites are not produced. Since the additive is expected to act only by the biotransformation of trichothecene mycotoxins to less toxic forms, no hazards for consumers would arise from the use of the additive in animal production. The additive was non-irritant to eyes and skin and was not a skin sensitiser, but the potential for respiratory sensitization cannot be excluded. As the strain has a very limited capability to survive in aerobic conditions, its use in animal production is unlikely to introduce an environmental concern. The evidence presented in ex vivo and in vivo studies with deoxynivalenol confirms that the capacity to transform trichothecenes can be realised in pigs when the additive is incorporated into diets at a minimum dose of 1.7 x 108 CFU/kg complete feed.

Summary

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety for the target animals, consumers, users and the environment and the efficacy of a bacterial product when used as a technological additive to reduce the concentration of contaminating trichothecene mycotoxins in feed.

In 2005, the FEEDAP Panel published an opinion on the strain of bacterium which is the subject of this application but which was then assigned to a species of Eubacterium. As there was no data on the prevalence of the strain in the digestive tract of farm animals or humans, and thus no estimate of natural exposure, and as the tolerance studies did not provide sufficient reassurance, the Panel was unable to conclude on the safety of the strain for the target species. The applicant has now resubmitted an application for the use of this additive as a technological additive (functional group m, substances for reduction of the contamination of feed by mycotoxins) for use with pigs.

In order to establish an identity for the strain under application (DSM 11798) a phylogenetic analysis was made based on the assembled and annotated genomic sequence of the strain and 24 genome sequences available for the family Coriobacteriaceae. The genome set was used to create phylogenies at three levels: (i) based on the 16S rRNA gene sequence, (ii) based on a set of 58 concatenated core bacterial proteins sequences, and (iii) based on the average nucleotide identity of the whole genome sequences. All three approaches consistently place the strain in a subgroup of Coriobacteriaceae. These data suggest the assignment of the strain to a new taxonomic unit within the family Coriobacteriaceae. The Panel accepts that the taxonomic position of the active agent is unclear and may warrant establishing a new species and/or genus. In the interim the deposition of the bacterium in a European culture collection is sufficient to ensure that any authorisation would apply only to the additive under application.

No resistance to antibiotics of human and veterinary clinical significance and no homologies with known virulence factors could be detected in the strain.

Based on the results of a tolerance study in which piglets were exposed to a 100-fold overdose of the additive, additive is considered safe for piglets at the maximum dose proposed. This conclusion can be extended to pigs for fattening.

The live organism is not expected to present a hazard for consumers and the negative findings in a series of genotoxicity and oral toxicity tests gives reassurance that toxic metabolites are not produced. As current legislation includes a guidance level for DON which already ensures animal and consumer safety and since the additive is expected to act only by the biotransformation of trichothecene mycotoxins to less toxic forms, no hazards for consumers would arise from the use of the additive in animal production at the recommended dose range.

The additive was non-irritant to eyes and skin and was not a skin sensitiser. Although the additive is formulated to minimise exposure by inhalation some exposure of the respiratory tract remains possible and the potential for respiratory sensitization cannot be excluded.

The active agent would appear to naturally occur in the digestive tract but, as a potentially new genus, no data on its prevalence is available. However, as the strain has a very limited capability to survive in aerobic conditions, its use in animal production is unlikely to introduce an environmental concern.

The active agent has the capacity to reduce the epoxide group of trichothecenes to produce less toxic metabolites. The evidence presented in ex vivo and in vivo studies with deoxynivalenol confirms that this capacity can be realised in piglets when the additive is incorporated into diets at a minimum dose of 1.7 x 108 CFU/kg complete feed. The FEEDAP Panel concludes that the additive at a minimum dose of 1.7 x 108 CFU/kg complete feed has the capacity to biotransform trichothecenes from contaminated feed for all pigs.

 

Keywords
Bacterial transformation, trichothecene mycotoxins, deoxynivalenol, safety, efficacy, piglets, pigs for fattening
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Number of Pages
18