Increased rat-borne zoonotic disease hazard in greener urban areas

Molecular and Serological Survey of SARS-CoV-2 in Murid Rodents From Central Chile

The potential role of rodents as reservoirs for SARS-CoV-2 has gained global attention due to their proximity to humans and their involvement in zoonotic disease transmission. Rodents were sampled from urban, rural and natural areas across the Metropolitan Region of Chile between June 2023 and June 2024. Molecular testing (RT-qPCR) revealed no active infections among the 421 analysed individuals, while serological assays (ELISA) detected SARS-CoV-2 antibodies in 4 of 459 rodents (0.87%). All seropositive rodents were Rattus rattus captured in rural areas. These findings suggest localised exposure to SARS-CoV-2, possibly influenced by environmental or anthropogenic factors. The results align with global studies reporting sporadic rodent exposure to SARS-CoV-2, emphasising the importance of integrating molecular and serological approaches in zoonotic surveillance. Despite the low prevalence observed, the potential role of rodents in viral spillover and recombination events with other coronaviruses underscores the need for continued monitoring. These results contribute to understanding zoonotic dynamics and inform public health strategies in a One Health framework.

Genetic diversity of Bartonella spp. in rodents and fleas from Poland

Bartonella spp. are parasites of mammalian erythrocytes and endothelial cells, and are transmitted by blood-feeding arthropod ectoparasites, including fleas. This study aimed to: (i) identify the main flea species responsible for Bartonella transmission and the specific Bartonella species they carry, (ii) evaluate how host-related factors influence the prevalence of Bartonella, (iii) examine the genetic diversity of Bartonella from different flea species and mammalian hosts, including rodents and European moles, and (iv) determine the haplotypes of Bartonella derived from rodents. Blood samples were collected from seven rodent species and two European moles in Poland (n = 994), and fleas were collected from rodents (n = 833). Bartonella spp. were identified and genotyped through rpoB and gltA genes. Phylogenetic analysis revealed two dominant Bartonella spp. in rodents and fleas: B. grahamii and B. taylorii. Moreover, 17 haplotypes of B. taylorii and 9 of B. grahamii were identified. The sequences of Bartonella sp. from T. europaea clustered in a unique separate group, possibly indicating a novel species. The study confirmed fleas as vectors of Bartonella transmission in rodents and highlighted the significant genetic diversity of Bartonella spp. in both fleas and rodents.

National survey of the rat hepatitis E virus in rodents in Spain, 2022 to 2023

BackgroundRat hepatitis E virus (ratHEV) is an emerging virus causing acute and chronic hepatitis in humans. Rats are the main natural reservoir of this pathogen. Large-scale studies assessing ratHEV circulation in rodents in Spain are lacking.AimWe aimed to determine the prevalence of ratHEV in rats in Spain and evaluate potential transmission risk to humans.MethodsWe designed a cross-sectional nationwide study where black (Rattus rattus) and Norway (R. norvegicus) rats were collected and analysed between 2022 and 2023 for ratHEV infection using real-time (RT)-qPCR testing of liver tissue. Sequencing and analysis of ratHEV shedding in faeces were carried out in positive animals.ResultsRatHEV was detected in 125 of the 481 rats analysed, supposing a prevalence of 26.0% (95 CI%: 22.3-30.1). Positive rats were found in urban (25.6%), and farm (29.8%) settings. Black rats (31.3%) had 1.5 times higher odds of being infected by the virus than Norway rats (22.5%) (p = 0.049). Significantly higher prevalence of ratHEV was detected in rodents sampled from southern (31.9%) than northern (17.8%) Spain (p = 0.003). Viral RNA was detected in faeces from 45.5% of infected rats. Phylogenetic analysis evidenced a wide genetic diversity of ratHEV sequences, some showing high homology with ratHEV strains found in patients from Spain.ConclusionsCirculation of ratHEV appears to be heterogeneous and the virus appears to be endemic among rat populations in Spain, highlighting the possible risk of zoonotic transmission of this emerging virus in this country.

Detection of DNA Viruses in Free-Ranging Rat Populations in Hungary

To address a gap in our understanding of viral infections in epidemiologically important rat species, we aimed to detect DNA viruses from the tissues of free-ranging rat populations in Hungary. DNA viruses were identified from the parenchymal organs of 230 Rattus norvegicus and Rattus rattus, using family-specific pan-PCR assays followed by sequencing of the PCR products. Adeno-, herpes-, circo-, and polyomaviruses were detected, while irido-, pox-, and dependoparvoviruses were not. Adenovirus DNA was present in 6.5% of the samples, herpesvirus and polyomavirus DNA in 12.2%, and circovirus DNA in 1.7%. All detected herpesviruses belonged to the β and γ subfamilies, with a majority being β herpesviruses. Some adenovirus and herpesvirus sequences were novel, while only the known Rattus norvegicus polyomavirus 1 was detected for polyomaviruses. The rare circovirus-positive samples revealed the presence of both rodent and bird circoviruses, indicating the ability of circoviruses to cross species barriers. Our findings show that rats host a variety of DNA viruses, many of which were previously uncharacterized, highlighting the need for further diagnostic studies.

First detection of Hepatitis E virus (Rocahepevirus ratti) in French urban wastewater: Potential implications for human contamination

Hepatitis E virus (HEV) is considered as an emerging zoonotic pathogen circulating in a wide range of animals. In recent decades, the genus Paslahepevirus frequently isolated in pigs were the most involved in human clinical practice. In addition, the genus Rocahepevirus have been isolated in rodents, and transmission to humans is increasingly reported worldwide, although gaps remain regarding the exposure factors. In this study, the presence of HEV was investigated in urban wastewater, swine slaughterhouse wastewater and river waters, in a geographical area where its circulation had previously been reported. In addition to the expected detection of Paslahepevirus in almost all waters samples collected, Rocahepevirus strains were detected with the same frequencies in urban and river waters, at concentrations up to 40-fold higher. No Rocahepeviruses were detected in swine slaughterhouse wastewater. This is the first study demonstrating the presence of Rocahepevirus in French wastewater. Although no evidence of transmission was reported among patients followed for a suspected HEV infection in the same area between April 2019 and October 2023 (i.e. 135/3078 serological tests positive for anti-HEV IgM detection; 46/822 blood samples positive for Paslahepevirus genome detection but none for Rocahepevirus), the circulation of Rocahepevirus in waters in such concentrations raises the question of the possible zoonotic transmission to human. Indeed, the waterborne transmission of HEV is now well documented in industrialized countries, and the exploration of the growing number of human infections in Europe involving Rocahepevirus has not until now made it possible to clarify the transmission routes.

Distribution dynamics and urbanization-related factors of Hantaan and Seoul virus infections in China between 2001 and 2020: A machine learning modelling analysis

Objectives

The epidemical and clinical features of distinct hantavirus infections exhibit heterogeneity. However, the evolving epidemics and distinct determines of the two hantavirus infections remain uncertain.

Methods

Data on hemorrhagic fever with renal syndrome (HFRS) cases and genotyping were collected from multiple sources to explore the distribution dynamics of different endemic categories. Four modelling algorithms were used to examine the relationship between infected hantavirus genotypes in HFRS patients, as well as assess the impacts of urbanization-related factors on HFRS incidence.

Results

The number of cities dominated by Hantaan (HTNV) and Seoul (SEOV) viruses was projected to decrease between two phases, while the mixed endemic cities increased. Patients with SEOV infection predominantly presented gastrointestinal symptoms. The modeling analysis revealed that built-up land and real GDP demonstrated the highest contribution to HTNV and SEOV infections, respectively. The impact of nightlight index and park green land was more pronounced in HTNV-dominant cities, while cropland, impervious surface, and floor space of commercialized buildings sold contributed more to HFRS incidence in SEOV-dominant cities.

Conclusions

Our findings fill a gap for the three endemic categories of HFRS, which may guide the development of targeted prevention and control measures under the conditions of urbanization development.

Rat-Bite Fever due to the genus Streptobacillus

Rat-bite fever (RBF) is a zoonotic infection and systemic febrile illness transmitted to humans by Rattus spp. contacts following a scratch, bite, or touching excrement, such as urine, feces, and oral secretions. Infection with members of the genus Streptobacillus is the most common cause of this infectious disease. In this review article, we updated the knowledge on the RBF caused by the genus Streptobacillus based on the isolation and identification methods, virulence factors, clinical signs, differential diagnoses, antibiogram, treatment, geographical distribution, and epidemiology. Moreover, the present paper's comprehensive analysis of over 200 infection cases attributed to this genus, spanning from 1915 to 2023, sheds light on its epidemiology and provides valuable insights for the future.

Attitudes of clients of Dutch pest controllers towards integrated pest management (IPM) and preventive measures in relation to rodent nuisance

BACKGROUND

Rodent management with lethal methods (e.g., rodenticides) comes with downsides for rodent welfare, the environment and non-target species. To reduce chemical use and prevent rodent nuisance, pest controllers in the Netherlands must work according to the principles of integrated pest management (IPM). A condition for the success of IPM is that there is sufficient engagement of all parties involved, including clients of pest controllers. The aim of this study was to gain insight into the attitudes of clients regarding rodent control, IPM and the application of preventive measures. Insight into their attitudes may contribute to a better implementation of IPM and with that to a more sustainable rodent management based on more effective prevention. An online survey among 248 clients of Dutch pest controllers from both the agricultural and other sectors was carried out.

RESULTS

Respondents from the agricultural sector had a relatively negative attitude towards IPM, the new IPM regulations in the Netherlands and had little confidence in prevention. In other sectors, respondents were more positive about IPM and had more confidence in prevention. The respondents from the latter subgroup had a similar attitude compared to Dutch pest controllers who participated in a previous survey.

CONCLUSION

The findings of the study provide information for the further development and practical implementation of IPM and preventive measures and with that a more sustainable and animal friendly rodent management. They can also be helpful for a better communication and cooperation between pest controllers and their clients. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Potentially zoonotic pathogens and parasites in opportunistically sourced urban brown rats (Rattus norvegicus) in and around Helsinki, Finland, 2018 to 2023

BackgroundBrown rats (Rattus norvegicus) are synanthropic rodents with worldwide distribution, which are known to harbour many zoonotic pathogens and parasites. No systematic zoonotic surveys targeting multiple pathogens and parasites have previously been conducted in urban rats in Finland.AimIn Helsinki, Finland, we explored the presence and prevalence in brown rats of certain pathogens and parasites (including helminths, viruses and bacteria) across potentially zoonotic taxa.MethodsWe opportunistically received rat carcasses from pest management operators and citizens from 2018 to 2023. We searched for heart- or lungworms, performed rat diaphragm digestion to check for Trichinella and morphologically identified intestinal helminths. We assessed virus exposure by immunofluorescence assay or PCR, and detected bacteria by PCR (Leptospira) or culture (Campylobacter).ResultsAmong the rats investigated for helminths, no heart- or lungworms or Trichinella species were detected and the most common finding was the cestode Hymenolepis nana (in 9.7% of individuals sampled, 28/288). For some of the surveyed virus taxa, several rats were seropositive (orthopoxviruses, 5.2%, 11/211; arenaviruses, 2.8%, 6/211; hantaviruses 5.2%, 11/211) or tested positive by PCR (rat hepatitis E virus, 1.8%, 4/216). Campylobacter jejuni (6.6%, 17/259) and Leptospira interrogans (1.2%, 2/163) bacteria were also present in the rat population examined.ConclusionsPrevalences of potentially zoonotic pathogens and parasites in brown rats in Helsinki appeared low. This may explain low or non-existent diagnosis levels of rat-borne pathogen and parasite infections reported in people there. Nevertheless, further assessment of under-diagnosis, which cannot be excluded, would enhance understanding the risks of zoonoses.

Do Babesia microti Hosts Share a Blood Group System Gene Ortholog, Which Could Generate an Erythrocyte Antigen That Is Essential for Parasite Invasion?

The United States of America (US) has the highest annual number of human babesiosis cases caused by Babesia microti (Bm). Babesia, like malaria-causing Plasmodium, are protozoan parasites that live within red blood cells (RBCs). Both infectious diseases can be associated with hemolysis and organ damage, which can be fatal. Since babesiosis was made a nationally notifiable condition by the Centers for Disease Control and Prevention (CDC) in January 2011, human cases have increased, and drug-resistant strains have been identified. Both the Bm ligand(s) and RBC receptor(s) needed for invasion are unknown, partly because of the difficulty of developing a continuous in vitro culture system. Invasion pathways are relevant for therapies (e.g., RBC exchange) and vaccines. We hypothesize that there is at least one RBC surface antigen that is essential for Bm invasion and that all Bm hosts express this. Because most RBC surface antigens that impact Plasmodium invasion are in human blood group (hBG) systems, which are generated by 51 genes, they were the focus of this study. More than 600 animals with at least one hBG system gene ortholog were identified using the National Center for Biotechnology Information (NCBI) command-line tools. Google Scholar searches were performed to determine which of these animals are susceptible to Bm infection. The literature review revealed 28 Bm non-human hosts (NHH). For 5/51 (9.8%) hBG system genes (e.g., RhD), no NHH had orthologs. This means that RhD is unlikely to be an essential receptor for invasion. For 24/51 (47.1%) hBG system genes, NHH had 4-27 orthologs. For the ABO gene, 15/28 NHH had an ortholog, meaning that this gene is also unlikely to generate an RBC antigen, which is essential for Bm invasion. Our prior research showed that persons with blood type A, B, AB, O, RhD+, and RhD- can all be infected with Bm, supporting our current study's predictions. For 22/51 (43.1%) hBG system genes, orthologs were found in all 28 NHH. Nineteen (37.3%) of these genes encode RBC surface proteins, meaning they are good candidates for generating a receptor needed for Bm invasion. In vitro cultures of Bm, experimental Bm infection of transgenic mice (e.g., a CD44 KO strain), and analyses of Bm patients can reveal further clues as to which RBC antigens may be essential for invasion.

Emergence and Comparative Genome Analysis of Salmonella Ohio Strains from Brown Rats, Poultry, and Swine in Hungary

Rats are particularly important from an epidemiological point of view, because they are regarded as reservoirs for diverse zoonotic pathogens including enteric bacteria. This study is the first to report the emergence of Salmonella serovar Ohio in brown rats (Rattus norvegicus) and food-producing animals in Hungary. We first reveal the genomic diversity of the strains and their phylogenomic relationships in the context of the international collection of S. Ohio genomes. This pathogen was detected in 4.3% (4/92) of rats, captured from multiple sites in Hungary. A whole-genome-based genotype comparison of S. Ohio, Infantis, Enteritidis, and Typhimurium strains showed that 76.4% (117/153) of the virulence and antimicrobial resistance genes were conserved among these serovars, and none of the genes were specific to S. Ohio. All S. Ohio strains lacked virulence and resistance plasmids. The cgMLST phylogenomic comparison highlighted a close genetic relationship between rat and poultry strains of S. Ohio from Hungary. These strains clustered together with the international S. Ohio genomes from aquatic environments. Overall, this study contributes to our understanding of the epidemiology of Salmonella spp. in brown rats and highlights the importance of monitoring to minimize the public health risk of rodent populations. However, further research is needed to understand the route of infection and evolution of this serovar.

T(r)icky Environments: Higher Prevalence of Tick-Borne Zoonotic Pathogens in Rodents from Natural Areas Compared with Urban Areas

Background: Urban areas are unique ecosystems with stark differences in species abundance and composition compared with natural ecosystems. These differences can affect pathogen transmission dynamics, thereby altering zoonotic pathogen prevalence and diversity. In this study, we screened small mammals from natural and urban areas in the Netherlands for up to 19 zoonotic pathogens, including viruses, bacteria, and protozoan parasites. Materials and Methods: In total, 578 small mammals were captured, including wood mice (Apodemus sylvaticus), bank voles (Myodes glareolus), yellow-necked mice (Apodemus flavicollis), house mice (Mus musculus), common voles (Microtus arvalis), and greater white-toothed shrews (Crocidura russula). We detected a wide variety of zoonotic pathogens in small mammals from both urban and natural areas. For a subset of these pathogens, in wood mice and bank voles, we then tested whether pathogen prevalence and diversity were associated with habitat type (i.e., natural versus urban), degree of greenness, and various host characteristics. Results: The prevalence of tick-borne zoonotic pathogens (Borrelia spp. and Neoehrlichia mikurensis) was significantly higher in wood mice from natural areas. In contrast, the prevalence of Bartonella spp. was higher in wood mice from urban areas, but this difference was not statistically significant. Pathogen diversity was higher in bank voles from natural habitats and increased with body weight for both rodent species, although this relationship depended on sex for bank voles. In addition, we detected methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase/AmpC-producing Escherichia coli, and lymphocytic choriomeningitis virus for the first time in rodents in the Netherlands. Discussion: The differences between natural and urban areas are likely related to differences in the abundance and diversity of arthropod vectors and vertebrate community composition. With increasing environmental encroachment and changes in urban land use (e.g., urban greening), it is important to better understand transmission dynamics of zoonotic pathogens in urban environments to reduce potential disease risks for public health.

Communicating and disseminating One Health: successes of the One Health European Joint Programme

The application of a One Health approach recognizes that human health, animal health, plant health and ecosystem health are intrinsically connected. Tackling complex challenges associated with foodborne zoonoses, antimicrobial resistance, and emerging threats is imperative. Therefore, the One Health European Joint Programme was established within the European Union research programme Horizon 2020. The One Health European Joint Programme activities were based on the development and harmonization of a One Health science-based framework in the European Union (EU) and involved public health, animal health and food safety institutes from almost all EU Member States, the UK and Norway, thus strengthening the cooperation between public, medical and veterinary organizations in Europe. Activities including 24 joint research projects, 6 joint integrative projects and 17 PhD projects, and a multicountry simulation exercise facilitated harmonization of laboratory methods and surveillance, and improved tools for risk assessment. The provision of sustainable solutions is integral to a One Health approach. To ensure the legacy of the work of the One Health European Joint Programme, focus was on strategic communication and dissemination of the outputs and engagement of stakeholders at the national, European and international levels.

Antimicrobial resistance and phylogenetic relatedness of extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in peridomestic rats (Rattus norvegicus and Rattus tanezumi) linked to city areas and animal farms in Hong Kong

Extended-spectrum β-lactamase-producing Escherichia (E.) coli (ESBL-EC) in the clinical setting have emerged as a major threat to public and animal health. Wildlife, including Rattus spp. may serve as reservoirs and spreaders of ESBL-EC in the environment. Peridomestic rats are well adapted to living in proximity to humans and animals in a variety of urban and agricultural environments and may serve as sentinels to identify variations of ESBL-EC within their different habitats. In this study, a set of 221 rats (Rattus norvegicus, R. tanezumi, R. andamanensis, and Niviventer huang) consisting of 104 rats from city areas, 44 from chicken farms, 52 from pig farms, and 21 from stables of horse-riding schools were screened for ESBL-EC. Overall, a total of 134 ESBL-EC were isolated from the caecal samples of 130 (59%) rats. The predominant blaESBL genes were blaCTX-M-14, blaCTX-M-15, blaCTX-M-55, and blaCTX-M-65. Phylogenetic analysis revealed a total of 62 sequence types (STs) and 17 SNP clusters. E. coli ST10 and ST155 were common to ESBL-EC from city areas and chicken farms, and ST44 were found among ESBL-EC from city areas and pig farms. Extra-intestinal pathogenic E. coli (ExPEC) ST69, ST131 and ST1193 were found exclusively among rats from city areas, and avian pathogenic E. coli (APEC) ST177 was restricted to ESBL-EC originating from chicken farms. Phylogenetic analysis showed that the populations of rodent ESBL-EC from city areas, chicken farms and pig farms were genetically different, suggesting a certain degree of partitioning between the human and animal locations. This study contributes to current understanding of ESBL-EC occurring in rats in ecologically diverse locations.

Evolution and genetic characterization of Seoul virus in wild rats Rattus norvegicus from an urban park in Lyon, France 2020-2022

BACKGROUND

Seoul virus (SEOV) is an orthohantavirus primarily carried by rats. In humans, it may cause hemorrhagic fever with renal syndrome (HFRS). Its incidence is likely underestimated and given the expansion of urban areas, a better knowledge of SEOV circulation in rat populations is called for. Beyond the need to improve human case detection, we need to deepen our comprehension of the ecological, epidemiological, and evolutionary processes involved in the transmission of SEOV.

METHODOLOGY / PRINCIPAL FINDINGS

We performed a comprehensive serological and molecular characterization of SEOV in Rattus norvegicus in a popular urban park within a large city (Lyon, France) to provide essential information to design surveillance strategies regarding SEOV. We sampled rats within the urban park of 'La Tête d'Or' in Lyon city from 2020 to 2022. We combined rat population genetics, immunofluorescence assays, SEOV high-throughput sequencing (S, M, and L segments), and phylogenetic analyses. We found low structuring of wild rat populations within Lyon city. Only one sampling site within the park (building created in 2021) showed high genetic differentiation and deserves further attention. We confirmed the circulation of SEOV in rats from the park with high seroprevalence (17.2%) and high genetic similarity with the strain previously described in 2011 in Lyon city.

CONCLUSION/SIGNIFICANCE

This study confirms the continuous circulation of SEOV in a popular urban park where the risk for SEOV transmission to humans is present. Implementing a surveillance of this virus could provide an efficient early warning system and help prepare risk-based interventions. As we reveal high gene flow between rat populations from the park and the rest of the city, we advocate for SEOV surveillance to be conducted at the scale of the entire city.

Prevalence, genetic diversity and eco-epidemiology of pathogenic Leptospira species in small mammal communities in urban parks Lyon city, France

Rodents are recognized as the main reservoirs of Leptospira spp. Rats, in particular, serve as hosts for the widely predominant Leptospira interrogans serovar Icterohaemorrhagiae, found worldwide. Several studies have shown the importance of other reservoirs, such as mice or hedgehogs, which harbor other leptospires' serovars. Nevertheless, our knowledge of circulating Leptospira spp. in reservoirs other than rats remains limited. In this context, we proposed an eco-health approach to assess the health hazard associated with leptospires in urban green spaces, where contacts between human/small mammals and domestic animals are likely. We studied the prevalence, the diversity of circulating strains, and epidemiology of pathogenic Leptospira species in small terrestrial mammal communities (rodents and shrews), between 2020-2022, in two parks in Lyon metropolis, France. Our study showed a significant carriage of Leptospira spp. in small terrestrial mammals in these parks and unveiled a global prevalence rate of 11.4%. Significant variations of prevalence were observed among the small mammal species (from 0 to 26.1%), with Rattus norvegicus exhibiting the highest infection levels (26.1%). We also observed strong spatio-temporal variations in Leptospira spp. circulation in its reservoirs. Prevalence seems to be higher in the peri-urban park and in autumn in 2021 and 2022. This is potentially due to differences in landscape, abiotic conditions and small mammal communities' composition. Our study suggests an important public health relevance of rats and in a lesser extent of other rodents (Apodemus spp., Clethrionomys glareolus and Mus musculus) as reservoirs of L. interrogans, with rodent species carrying specific serogroups/serovars. We also emphasize the potential hazard associated between the shrew Crocidura russula and L. kirschneri. Altogether, these results improve our knowledge about the prevalence of leptospirosis in an urban environment, which is an essential prerequisite for the implementation of prevention of associated risks.

Cross-Reactivity of Human, Wild Boar, and Farm Animal Sera from Pre- and Post-Pandemic Periods with Alpha- and Βeta-Coronaviruses (CoV), including SARS-CoV-2

Panels of pre- and post-pandemic farm animals, wild boar and human sera, including human sera able to neutralize SARS-CoV-2 in vitro, were tested in serological tests to determine their cross-reactivity with β- and α-CoV originating from farm animals. Sera were tested in neutralization assays with high ascending concentrations (up to 1 × 104 TCID50 units/well) of β-CoV Bovine coronavirus (BCV), SARS-CoV-2, and porcine α-CoV-transmissible gastroenteritis virus (TGEV). In addition, sera were tested for immunostaining of cells infected with β-CoV porcine hemagglutinating encephalomyelitis (PHEV). Testing revealed a significantly higher percentage of BCV neutralization (78%) for sera of humans that had experienced a SARS-CoV-2 infection (SARS-CoV-2 convalescent sera) than was observed for human pre-pandemic sera (37%). Also, 46% of these human SARS-CoV-2 convalescent sera neutralized the highest concentration of BCV (5 × 103 TCID50/well) tested, whereas only 9.6% of the pre-pandemic sera did. Largely similar percentages were observed for staining of PHEV-infected cells by these panels of human sera. Furthermore, post-pandemic sera collected from wild boars living near a densely populated area in The Netherlands also showed a higher percentage (43%) and stronger BCV neutralization than was observed for pre-pandemic sera from this area (21%) and for pre- (28%) and post-pandemic (20%) sera collected from wild boars living in a nature reserve park with limited access for the public. High percentages of BCV neutralization were observed for pre- and post-pandemic sera of cows (100%), pigs (up to 45%), sheep (36%) and rabbits (60%). However, this cross-neutralization was restricted to sera collected from specific herds or farms. TGEV was neutralized only by sera of pigs (68%) and a few wild boar sera (4.6%). None of the BCV and PHEV cross-reacting human pre-pandemic, wild boar and farm animal sera effectively neutralized SARS-CoV-2 in vitro. Preexisting antibodies in human sera effectively neutralized the animal β-CoV BCV in vitro. This cross-neutralization was boosted after humans had experienced a SARS-CoV-2 infection, indicating that SARS-CoV-2 activated a "memory" antibody response against structurally related epitopes expressed on the surface of a broad range of heterologous CoV, including β-CoV isolated from farm animals. Further research is needed to elucidate if a symptomless infection or environmental exposure to SARS-CoV-2 or another β-CoV also triggers such a "memory" antibody response in wild boars and other free-living animals.