Sixty bovine spongiform encephalopathy (BSE) cases of Classical or unknown type (BARB‐60 cases) were born after the date of entry into force of the EU total feed ban on 1 January 2001. The European ...Commission has requested EFSA to provide a scientific opinion on the most likely origin(s) of these BARB‐60 cases; whether feeding with material contaminated with the BSE agent can be excluded as the origin of any of these cases and, if so, whether there is enough scientific evidence to conclude that such cases had a spontaneous origin. The source of infection cannot be ascertained at the individual level for any BSE case, including these BARB‐60 cases, so uncertainty remains high about the origin of disease in each of these animals, but when compared with other biologically plausible sources of infection (maternal, environmental, genetic, iatrogenic), feed‐borne exposure is the most likely. This exposure was apparently excluded for only one of these BARB‐60 cases. However, there is considerable uncertainty associated with the data collected through the field investigation of these cases, due to a time span of several years between the potential exposure of the animal and the confirmation of disease, recall difficulty, and the general paucity of documented objective evidence available in the farms at the time of the investigation. Thus, feeding with material contaminated with the BSE agent cannot be excluded as the origin of any of the BARB‐60 cases, nor is it possible to definitively attribute feed as the cause of any of the BARB‐60 cases. A case of disease is classified as spontaneous by a process of elimination, excluding all other definable possibilities; with regard to the BARB‐60 cases, it is not possible to conclude that any of them had a spontaneous origin.
A risk-based microbiological criterion is described, that is based on the relative risk associated to the analytical result of a number of samples taken from a food lot. The acceptable limit is a ...specific level of risk and not a specific number of microorganisms, as in other microbiological criteria. The approach requires the availability of a quantitative microbiological risk assessment model to get risk estimates for food products from sampled food lots. By relating these food lot risk estimates to the mean risk estimate associated to a representative baseline data set, a relative risk estimate can be obtained. This relative risk estimate then can be compared with a critical value, defined by the criterion. This microbiological criterion based on a relative risk limit is particularly useful when quantitative enumeration data are available and when the prevalence of the microorganism of concern is relatively high. The use of the approach is therefore illustrated with an example of Campylobacter in broiler meat. It shows that this microbiological criterion can be applied in practice. An advantage of the method is that the acceptable limit is directly defined in terms of risk, without the need to define other food safety standards.
•A microbiological criterion can be based on a critical relative risk.•The criterion requires a quantitative risk assessment model and a baseline data set.•The method is particularly applicable for highly prevalent pathogens.
After more than 20 years of work with discussing the setting of microbiological criteria for
Listeria monocytogenes in foods, Codex Alimentarius on Food Hygiene has finalised a proposal that was ...recently adopted by the Codex Alimentarius Commission. The effort of developing procedures for making the microbiological criteria risk-based to the greatest extent possible has challenged scientists and managers during this long time period. Yet, the establishment of microbiological criteria for
L. monocytogenes is still being discussed and several approaches are possible. Setting of microbiological criteria continues to be a risk management decision – even when using mathematical modelling to enhance the scientific level of a risk-based approach.
EFSA received an application from the Dutch Competent Authority, under Article 20 of Regulation (EC) No 1069/2009 and Regulation (EU) No 142/2011, for the evaluation of an alternative method for ...treatment of Category 3 animal by‐products (ABP). It consists of the hydrolysis of the material to short‐carbon chains, resulting in medium‐chain fatty acids that may contain up to 1% hydrolysed protein, for use in animal feed. A physical process, with ultrafiltration followed by nanofiltration to remove hazards, is also used. Process efficacy has been evaluated based on the ability of the membrane barriers to retain potential biological hazards present. Small viruses passing the ultrafiltration membrane will be retained at the nanofiltration step, which represents a Critical Control Point (CCP) in the process. This step requires the Applicant to validate and provide certification for the specific use of the nanofiltration membranes used. Continuous monitoring and membrane integrity tests should be included as control measures in the HACCP plan. The ultrafiltration and nanofiltration techniques are able to remove particles of the size of virus, bacteria and parasites from liquids. If used under controlled and appropriate conditions, the processing methods proposed should reduce the risk in the end product to a degree which is at least equivalent to that achieved with the processing standards laid down in the Regulation for Category 3 material. The possible presence of small bacterial toxins produced during the fermentation steps cannot be avoided by the nanofiltration step and this hazard should be controlled by a CCP elsewhere in the process. The limitations specified in the current legislation and any future modifications in relation to the end use of the product also apply to this alternative process, and no hydrolysed protein of ruminant origin (except ruminant hides and skins) can be included in feed for farmed animals or for aquaculture.
In the absence of culture methods for noroviruses, detection in foods relies on molecular techniques such as Reverse Transcription-Polymerase Chain Reaction (RT-PCR) on extracted viral RNA followed ...by PCR product confirmation by hybridisation and/or sequencing. However, in order to obtain a successful detection it is of great importance to remove the tissue inhibitors during the viral RNA extraction. To select the most efficient extraction procedure of oysters we have compared four protocols. A pool of digestive gland material from oyster samples was divided into 1.5 g portions and spiked with 10-fold dilutions of human faecal samples containing norovirus genogroup II. The samples were tested on three different occasions using four different sample treatment protocols. The protocols were assessed with regard to their ability to recover viral RNA and detect norovirus in spiked oysters and for their in-house reproducibility. One method using viral elution by a Mixer Mill Cell Disrupter resulted in a 10-fold better recovery than the other three protocols when an RT-seminested PCR (G2SKR/COG2F and G2SKR/G2SKF) detection approach was applied. Although less distinctive this was also the case when NoV was detected by a single round RT-PCR approach using the primers JV13i and JV12y. The second most efficient method was a method using chloroform extraction and polyethylene precipitation.
The European Commission asked EFSA for a scientific opinion on chronic wasting disease in two parts. Part one, on surveillance, animal health risk‐based measures and public health risks, was ...published in January 2017. This opinion (part two) addresses the remaining Terms of Reference, namely, ‘are the conclusions and recommendations in the EFSA opinion of June 2004 on diagnostic methods for chronic wasting disease still valid? If not, an update should be provided’, and ‘update the conclusions of the 2010 EFSA opinion on the results of the European Union survey on chronic wasting disease in cervids, as regards its occurrence in the cervid population in the European Union’. Data on the performance of authorised rapid tests in North America are not comprehensive, and are more limited than those available for the tests approved for statutory transmissible spongiform encephalopathies surveillance applications in cattle and sheep. There are no data directly comparing available rapid test performances in cervids. The experience in Norway shows that the Bio‐Rad TeSeE™ SAP test, immunohistochemistry and western blotting have detected reindeer, moose and red deer cases. It was shown that testing both brainstem and lymphoid tissue from each animal increases the surveillance sensitivity. Shortcomings in the previous EU survey limited the reliability of inferences that could be made about the potential disease occurrence in Europe. Subsequently, testing activity in Europe was low, until the detection of the disease in Norway, triggering substantial testing efforts in that country. Available data neither support nor refute the conclusion that chronic wasting disease does not occur widely in the EU and do not preclude the possibility that the disease was present in Europe before the survey was conducted. It appears plausible that chronic wasting disease could have become established in Norway more than a decade ago.
In 2006, the Danish government decided to take new measures to control Salmonella and Campylobacter in Danish and imported retail meat. The legal basis for these new measures was article 14 in the EU ...food law, which states that food shall not be placed on the market if it is unsafe, among others, for reasons of contamination. This provision allows each member state to make a specific risk assessment of food batches, and decide whether a batch poses an unacceptable risk to the consumer or not. Here we present the basis for the risk assessment model on Campylobacter used in this new approach and the results of more than 3000 batches of broiler meat tested since 2007. The risk was assessed for batches with one or more samples positive for Campylobacter (>100 cfu/g). Reductions in the number of positive batches from 2007 to 2010 were observed for both domestic (from 17% to 7%, p = 0.01) and imported broiler meat (from 39% to 18%, p < 0.0001). During 2007–2010, only relatively few batches were deemed unsafe due to the presence of Campylobacter. The proportion of batches of domestic and imported broiler meat deemed unsafe varied from 0.3% to 1.0% for Danish broiler meat and from 0.2% to 7.7% for imported broiler meat. Still this initiative has been successful in significantly reducing the occurrence of Campylobacter in fresh meat available on the Danish retail market.
To our knowledge, this is the first example of a risk based control system that enables quantitative day to day risk assessment of food batches.
► A risk based control system is presented. ► A quantitative case-by-case risk assessment model is developed. ► Case-by-case risk estimates of Campylobacter positive meat batches are presented. ► This initiative has reduced the Campylobacter occurrence in broiler meat.
This study examined the ability of (i) pure nisin, (ii) nisin-producing Lactococcus lactis strain CHCC5826, and (iii) the non-nisin-producing L. lactis strain CHCH2862 to affect the composition of ...the intestinal microbiota of human flora-associated rats. The presence of both the nisin-producing and the non-nisin-producing L. lactis strains significantly increased the number of Bifidobacterium cells in fecal samples during the first 8 days but decreased the number of enterococci/streptococci in duodenum, ileum, cecum, and colon samples as detected by selective cultivation. No significant changes in the rat fecal microbiota were observed after dosage with nisin. Pearson cluster analysis of denaturing gradient gel electrophoresis profiles of the 16S rRNA genes present in the fecal microbial population revealed that the microbiota of animals dosed with either of the two L. lactis strains were different from that of control animals dosed with saline. However, profiles of the microbiota from animals dosed with nisin did not differ from the controls. The concentrations of nisin estimated by competitive enzyme-linked immunosorbent assay (ELISA) were approximately 10-fold higher in the small intestine and 200-fold higher in feces than the corresponding concentrations estimated by a biological assay. This indicates that nisin was degraded or inactivated in the gastrointestinal tract, since fragments of this bacteriocin are detected by ELISA while an intact molecule is needed to retain biological activity.
Abstract Background Current detection and genotyping methods of genogroup (G) I and II noroviruses (NoVs) consist of a 2-step approach including detection of viral RNA by TaqMan realtime RT-PCR ...(RT-qPCR) followed by conventional RT-PCR and sequencing of partial regions of ORF1 or ORF2. Objective To develop novel long-template one-step TaqMan assays (L-RT-qPCR) for the rapid detection and direct genotyping of GI and GII NoVs and to evaluate the sensitivity and specificity of the assays. Study design GI and GII-specific broadly reactive L-RT-qPCR assays were developed by combining existing NoV primers and probes targeting the open reading frame (ORF)1–ORF2 junction as well as region C at the 5′–ORF2. The assays were validated using GI and GII RNA transcripts and a coded panel of 75 stool samples containing NoV strains representing 9 GI genotypes and 12 GII genotypes, as well as sapoviruses, astroviruses, polioviruses, and rotaviruses. L-RT-qPCR products were typed by sequencing. Results The novel GI and GII L-RT-qPCR assays detected and typed all but one of the NoV positive panel samples. As few as 5–500 RNA copies could be accurately typed by sequencing of amplicons. Conclusions We developed novel one-step TaqMan RT-qPCR assays for the sensitive detection and direct genotyping of GI and GII NoVs from clinical and environmental matrices.
Breeding programmes to promote resistance to classical scrapie, similar to those for sheep in existing transmissible spongiform encephalopathies (TSE) regulations, have not been established in goats. ...The European Commission requested a scientific opinion from EFSA on the current knowledge of genetic resistance to TSE in goats. An evaluation tool, which considers both the weight of evidence and strength of resistance to classical scrapie of alleles in the goat PRNP gene, was developed and applied to nine selected alleles of interest. Using the tool, the quality and certainty of the field and experimental data are considered robust enough to conclude that the K222, D146 and S146 alleles both confer genetic resistance against classical scrapie strains known to occur naturally in the EU goat population, with which they have been challenged both experimentally and under field conditions. The weight of evidence for K222 is greater than that currently available for the D146 and S146 alleles and for the ARR allele in sheep in 2001. Breeding for resistance can be an effective tool for controlling classical scrapie in goats and it could be an option available to member states, both at herd and population levels. There is insufficient evidence to assess the impact of K222, D146 and S146 alleles on susceptibility to atypical scrapie and bovine spongiform encephalopathy (BSE), or on health and production traits. These alleles are heterogeneously distributed across the EU Member States and goat breeds, but often at low frequencies (< 10%). Given these low frequencies, high selection pressure may have an adverse effect on genetic diversity so any breeding for resistance programmes should be developed at Member States, rather than EU level and their impact monitored, with particular attention to the potential for any negative impact in rare or small population breeds.
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