Editor’s note: This article, Part 1 of 2, summarizes oral and poster presentations from the three-day event meeting of the One Health European Joint Program.

A European project helping to promote scientific progress on foodborne zoonoses has held its annual meeting virtually because of the coronavirus outbreak.

The second annual scientific meeting of the One Health European Joint Program (OHEJP) on foodborne zoonoses, antimicrobial resistance, and emerging threats was planned in Prague in the Czech Republic, this past week, but the COVID-19 pandemic meant the face-to-face part was cancelled.

As the 178 submitted abstracts already had been evaluated by the scientific committee, and the program was already drafted, organizers decided to host the event online with oral and poster presentations.

More than 750 participants registered for the meeting which had Stef Bronzwaer, European Food Safety Authority (EFSA) research coordinator, as a keynote speaker.

The OHEJP began in 2018 and runs through the end of 2022. It is coordinated by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) and involves 40 partners from 19 countries. Costing €90 million ($100 million), 50 percent is funded by the European Commission.

Oral presentations
Maaike van den Beld, from the National Institute for Public Health and the Environment (RIVM), spoke about improved food safety through whole genome sequencing (WGS) and data sharing.

In the Netherlands, WGS data from national lab surveillance of Listeria and Shiga toxin-producing E. coli (STEC) by RIVM is shared in a database with WGS data from food monitoring collected by Wageningen Food Safety Research as per the Dutch Food and Consumer Product Safety Authority (NVWA) demands.

In this database, 1,578 Listeria isolates were present, consisting of 217 clusters, of which 33 were of mixed origin. Overall, 95 clusters spanned more than two years. For STEC serotype O157, 190 of 205 isolates were of human origin. For serotype O26, 102 of 112 isolates were of human origin. Other STEC O-types comprise almost 1,000 isolates of which 59 percent are from humans.

Species dependent challenges exist to apply WGS and data sharing in national surveillance and source tracing. For Listeria, the time confinement for cluster detection and intervention strategies is complicated. For STEC, there is minimal overlap between human and food isolates. However, WGS surveillance and real-time data sharing enabled rapid source tracing and outbreak assessment and has led to better-targeted enforcement measures.

Claudia E. Coipan, of RIVM, used the example of an international Salmonella Enteritidis outbreak from Polish eggs to see if harmonization of molecular typing workflows was necessary.

Researchers compared the output of six different typing workflows used by European public health authorities in terms of cluster detection and concordance. They analyzed 180 isolates from confirmed and probable cases, representative of the genetic variation in the outbreak, and 22 unrelated Salmonella Enteritidis isolates. Analysis indicates the different workflows generated clusters with similar compositions.

Thomas Brauge, from ANSES, talked about the impact of two disinfectants on Listeria monocytogenes cells in biofilm on stainless steel.

Treatment with hydrogen peroxide or quaternary ammonium did not remove Listeria cells on the surfaces but changed cell viability state with the emergence of a majority of viable but non-cultivable cells (VBNC). These VBNC cells were transferred to the herring slices and returned in the viable cultivable state on agar media during commercial shelf life of the herring.

Julio Alvarez, from VISAVET, University Complutense in Madrid, spoke about how human Salmonella isolates are routinely whole genome sequenced in Minnesota to help outbreak investigation, which increases ability to link related cases but leads to a delay in serotype identification of clinical isolates, and makes establishing a relationship between cases in the first week after reporting challenging.

Researchers looked at temporal models to detect Salmonella outbreaks in the absence of serotype information. Information on patients reported to the Minnesota Department of Health in 2005 to 2018 was used. The best candidate models were able to identify more than 75 percent of known outbreaks within one week after the first cases were reported. Developed algorithms were able to identify known outbreaks over a four-year period and they also revealed possibly unsolved outbreaks.

María Ugarte-Ruiz, from the same university, covered detection and antimicrobial characterization of Salmonella in eggs from retail businesses in Madrid.

Isolation of Salmonella was carried out from eggs produced in Spain from 2003 to 2019 as part of a monitoring program. During this 19-year period, more than 200 isolates were recovered belonging mostly to serotypes Enteritidis, Infantis, Rissen, Anatum and Typhimurium. Overall, antimicrobial resistance levels were below 10 percent, except for ciprofloxacin, nalidixic acid, tetracycline and ampicillin, although amounts also vary depending on the serotype.

Idesbald Boone, from the Robert Koch Institute in Germany, found foods considered as being high risk of causing healthcare associated foodborne outbreaks being served to patients.

The survey, among 33 Italian and German healthcare facilities, explored data availability, accessibility and usefulness of patient food data in hospitals and nursing home residents. Variability was observed in the storage time of food menu data and their formats, from paper to electronic searchable databases. In Italy, outsourcing of catering was associated with a non-optimal awareness of the availability of food traceability data.

Poster presentations
Gerald Umhang, of ANSES, had a poster presenting the MEME project that started in January 2020 and has 20 partners from 15 European countries. The aim is to fill research gaps on detection and control of cystic (CE) and alveolar echinococcosis (AE). Producing epidemiological data on the presence of Echinococcus multilocularis and Echinococcus granulosus s.l. eggs in the food chain will focus on vegetables for human consumption.

As part of the project it is planned that targeted questionnaires will be developed for a sample of patients with CE in some hospitals and matched controls, to advance knowledge on food-related risk factors for human infection.

A poster from Karin Troell, of the Swedish National Veterinary Institute, described the PARADISE consortium. This project, from 2020 to 2022, will help develop methods to control foodborne parasites in the EU food chain as outbreak investigation and source attribution remain difficult.

Eleonora Ventola, from Istituto Superiore di Sanità, in Italy, had a poster looking at Yersinia enterocolitica in foods. Yersiniosis is the fourth most common foodborne zoonosis in the EU, according to the 2018 zoonoses report.

In 2019, a survey in Italy estimated contamination with pathogenic Yersinia enterocolitica in different foods, sampled at various stages of the production chain. A total of 437 samples, including pork, beef, wild boar and chicken meat, raw milk, shellfish, and fresh vegetables were analyzed.

Research found that pork products were the category most frequently contaminated by Yersinia enterocolitica. Presence of Yersinia was assessed using a Real Time-PCR targeted to the ail gene which is considered the marker of pathogenic Yersinia enterocolitica. Presence of this gene was detected in 11 samples, all from pork, beef and wild boar meat.

A study led by Jacek Sroka, of PIWET, estimated prevalence of Toxoplasma gondii infection in pigs and cattle slaughtered for human consumption in Poland. Sera of 3,111 pigs and 2,411 cattle from 16 regions were checked. Samples of the diaphragm and heart of seropositive animals were examined for Toxoplasma gondii DNA.

Seropositive results were found in 11.9 percent of pigs and 13 percent of cattle. Data analysis showed seropositivity increased with age of cattle and seropositive results were found more frequently in animals from small farms. Presence of Toxoplasma gondii antibodies in pigs and cattle and detection of parasite DNA in tissue may indicate a potential threat to consumer health.

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