Livestock as possible reservoir of Escherichia albertii in Switzerland

INTRODUCTION

Escherichia albertii is an emerging zoonotic foodborne pathogen. Its prevalence, distribution, and reservoirs are not yet clearly defined. In this study, we evaluated the occurrence and genomic characteristics of E. albertii in livestock from Switzerland. A total of 515 caecal samples from sheep, cattle, calves, and fattening swine were collected between May 2022 and August 2022 at abattoir level. Using an E. albertii-specific PCR targeting the Eacdt-gene, 23,7 % (51/215) of swine from 24 different farms were positive. One (1 %) out of 100 calves showed a positive PCR result, while all samples from sheep and cattle were PCR negative. Eight E. albertii isolates could be recovered from swine samples and were analysed using whole-genome sequencing. All eight isolates belonged to ST2087 or a ST4619 group subclade, as did most genomes of the 11 available global swine isolates from public databases. These two clusters shared the presence of a virulence plasmid harboring the sitABCD and iuc genes. In summary, we demonstrate that fattening swine constitute an E. albertii reservoir in Switzerland and describe specific swine-associated lineages.

Evaluation of the prevalence of stomach ulcers in slaughtered pigs in a Swiss -abattoir

INTRODUCTION

The development of gastric ulcers in pigs has various reasons. In Switzerland, the last survey on the prevalence of gastric ulcers and possible risk factors was performed in 2005. We aimed to reassess gastric ulcers prevalence today, in 2021. A total of 1005 stomachs from fattening pigs from 136 batches and around 87 herds were evaluated at a Swiss abattoir. The Pars oesophagea of the stomach was scored from 0=healthy to 10=severe ulceration and strictures. Scores were compared between pigs produced under the labels «Integrierte Produktion Schweiz» (IPS, n=242 stomachs, 18 farms) and «Qualitätsmanagement-Schweizerfleisch» (QM, n=649, 58 farms) and others (n=114). The results showed a prevalence of 27,2 % mild mucosal changes (Scores 1-3), 14,9 % moderate mucosal changes (Scores 4-6) and 19,1 % severe mucosal changes (Scores 7-10). Only 38,8 % of the stomachs were rated 0 and thus considered healthy. Compared to the results from 2005, there is no difference concerning the lowest scores (0-2) and the highest scores (9-10). However, there was a shift from the medium scores (3-4) to higher scores (5-8). Stomach scores turned out to be herd specific. There were differences (p < 0,01) between labels, indicating that IPS pigs had less affected stomachs. Stomachs that were empty at slaughter showed higher scores (p < 0,001). The mean carcass weight of the pigs in the slaughter groups was negatively correlated (p < 0,05) to their median stomach score. Confiscations were not related to stomach scores. The results suggest that pig stomach health has not improved since 2005. The differences between labels seem to have resulted from different regulations prescribing a minimum particle size of enrichment material in IPS. The reasons for gastric ulcer development, including those on the individual herd within label, still have to be further clarified in order to allow targeted countermeasures. Given apparent farm-specificity, scoring of a limited number of stomachs per herd during the slaughter process could facilitate the establishment of a feedback scheme.

Stay alert: probability of African Swine Fever introduction from Eastern Asia is almost as high as from Eastern Europe

INTRODUCTION

African Swine Fever (ASF) is a severe viral disease infecting all suid species. Since the first outbreak in Georgia in 2007, it has slowly spread towards Western Europe and reached the European Union when first cases were detected in Poland and the Baltic States in 2014. ASF was first reported in China in 2018 and since then, it has spread to 14 countries within two years. This study aimed to estimate the introduction probability of ASF from Eastern Asia in a qualitative risk assessment, and to compare it to the probability from Eastern Europe, which was assessed in an earlier risk assessment. A high probability of introduction was estimated for the import of meat and meat products, which was found to be the most likely route of introduction. Less important routes were introduction by human contamination (low probability) or import of feed or blood products (very low probability). Import of domestic pigs or free-ranging wild boar, contaminated means of transport, or infected semen, embryo or ticks were all estimated to be negligible. For Eastern Europe, import of meat and meat products was also estimated to pose a high risk and was therefore the most likely route of introduction. Higher probabilities were estimated for import of live pigs, contaminated feed or means of transport and human contamination. Overall, the probability of introduction from Eastern Asia is only slightly lower than from Eastern Europe. As it is important to detect the first case as quickly as possible, it is important not to fall victim to habituation effects, but to remain vigilant.