Potential Cross-species Transmission Research Articles

Isolation and characterization of a novel rodent hepevirus in long-tailed dwarf hamsters (Cricetulus longicaudatus) in China.

Hepeviruses have been identified in a broad range of animal hosts, including mammals, birds, and fish. In this study, rodents (n=91) from seven different species and ten pikas (Ochotona curzoniae) were collected in Qinghai Province, China. Using transcriptomic sequencing and confirmatory molecular testing, hepeviruses were detected in 27 of 45 (60 %) long-tailed dwarf hamsters (Cricetulus longicaudatus) and were undetected in other rodents and pika. The complete genome sequences from 14 representative strains were subsequently obtained, and phylogenetic analyses suggested that they represent a novel species within the genus Rocahepevirus, which we tentatively designated as Cl-2018QH. The virus was successfully isolated in human hepatoma (Huh-7) and murine fibroblast (17 Cl-1) cell lines, though both exhibited limited replication as assayed by detection of negative-sense RNA intermediates. A129 immunodeficient mice were inoculated with Cl-2018QH and the virus was consistently detected in multiple organs, despite relatively low viral loads. In summary, this study has described a novel rodent hepevirus, which enhances our knowledge of the genetic diversity of rodent hepeviruses and highlights its potential for cross-species transmission.

NS7a of SADS-CoV promotes viral infection via inducing apoptosis to suppress type III interferon production.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly discovered swine coronavirus with potential cross-species transmission risk. Although SADS-CoV-induced host cell apoptosis and innate immunity antagonization has been revealed, underlying signaling pathways remain obscure. Here, we demonstrated that infection of SADS-CoV induced apoptosis in vivo and in vitro, and that viral protein NS7a is mainly responsible for SADS-CoV-induced apoptosis in host cells. Furthermore, we found that NS7a interacted with apoptosis-inducing factor mitochondria associated 1 (AIFM1) to activate caspase-3 via caspase-6 in SADS-CoV-infected cells, and enhanced SADS-CoV replication. Importantly, NS7a suppressed poly(I:C)-induced expression of type III interferon (IFN-λ) via activating caspase-3 to cleave interferon regulatory factor 3 (IRF3), and caspase-3 inhibitor protects piglets against SADS-CoV infection in vivo. These findings reveal how SADS-CoV induced apoptosis to inhibit innate immunity and provide a valuable clue to the development of effective drugs for the clinical control of SADS-CoV infection.IMPORTANCEOver the last 20 years, multiple animal-originated coronaviruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV), and SARS-CoV-2, have caused millions of deaths, seriously jeopardized human health, and hindered social development, indicating that the study of animal-originated coronaviruses with potential for cross-species transmission is particularly important. Bat-originated swine acute diarrhea syndrome coronavirus (SADS-CoV), discovered in 2017, can not only cause fatal diarrhea in piglets, but also infect multiple human cells, with a potential risk of cross-species transmission, but its pathogenesis is unclear. In this study, we demonstrated that NS7a of SADS-CoV suppresses IFN-λ production via apoptosis-inducing factor mitochondria associated 1 (AIFM1)-caspase-6-caspase-3-interferon regulatory factor 3 (IRF3) pathway, and caspase-3 inhibitor (Z-DEVD-FMK) can effectively inhibit SADS-CoV replication and protect infected piglets. Our findings in this study contribute to a better understanding of SADS-CoV-host interactions as a part of the coronaviruses pathogenesis and using apoptosis-inhibitor as a drug as potential therapeutic approaches for prevention and control of SADS-CoV infection.

Genetic characterizations of Cryptosporidium spp. from children with or without diarrhea in Wenzhou, China: high probability of zoonotic transmission

BackgroundCryptosporidium is a highly pathogenic parasite responsible for diarrhea in children worldwide. Here, the epidemiological status and genetic characteristics of Cryptosporidium in children with or without diarrhea were investigated with tracking of potential sources in Wenzhou City, China.MethodsA total of 1032 children were recruited, 684 of whom had diarrhea and 348 without, from Yuying Children’s Hospital in Wenzhou, China. Samples of stool were collected from each participant, followed by extraction of DNA, genotyping, and molecular identification of Cryptosporidium species and subtypes.ResultsTwenty-two of the 1032 (2.1%) children were infected with Cryptosporidium spp. with 2.5% (17/684) and 1.4% (5/348) in diarrhoeic and asymptomatic children, respectively. Four Cryptosporidium species were identified, including C. parvum (68.2%; 15/22), C. felis (13.6%; 3/22), C. viatorum (9.1%; 2/22), and C. baileyi (9.1%; 2/22). Two C. parvum subtypes named IIdA19G1 (n = 14) and IInA10 (n = 1), and one each of C. felis (XIXa) and C. viatorum (XVaA3g) subtype was found as well.ConclusionsThis is the first research that identified Cryptosporidium in children of Wenzhou, China, using PCR. Identification of zoonotic C. parvum, C. felis, C. viatorum, and their subtypes indicate potential cross-species transmission of Cryptosporidium between children and animals. Additionally, the presence of C. baileyi in children suggests that this species has a wider host range than previously believed and that it possesses the capacity to infect humans.

Fungal metabolite 6-pentyl-α-pyrone reduces canine coronavirus infection

Canine coronavirus (CCoV) can produce a self-limited enteric disease in dogs but, because of notable biological plasticity of coronaviruses (CoVs), numerous mutations as well as recombination events happen leading to the emergence of variants often more dangerous for both animals and humans.Indeed, the emergence of new canine-feline recombinant alphacoronaviruses, recently isolated from humans, highlight the cross-species transmission potential of CoVs.Consequently, new effective antiviral agents are required to treat CoV infections. Among the candidates for the development of drugs against CoVs infection, fungal secondary metabolites (SMs) represent an important source to investigate. Herein, antiviral ability of 6-pentyl-α-pyrone (6 PP), a SM obtained by Trichoderma atroviride, was assessed against CCoV. During in vitro infection, nontoxic concentration of 6 PP significantly increased cell viability, reduced morphological signs of cell death, and inhibited viral replication of CCoV. In addition, we found a noticeable lessening in the expression of aryl hydrocarbon receptor (AhR), a strategic modulator of CoVs infection.Overall, due to the variety of their chemical and biological properties, fungal SMs can decrease the replication of CoVs, thus identifying a suitable in vitro model to screen for potential drugs against CoVs, using a reference strain of CCoV (S/378), non-pathogenic for humans.

Cross-Species Transmission Potential of H4 Avian Influenza Viruses in China: Epidemiological and Evolutionary Study.

H4 avian influenza viruses (AIVs) have been widely detected in live poultry markets in China. However, the potential public health impact of H4 AIVs remains largely uncertain. Here, we fully analyzed the distribution and phylogenetic relationship of H4 AIVs in China. We obtained 31 isolates of H4 viruses in China during 2009-2022 through surveillance in poultry-associated environments, such as live poultry markets and poultry farms. Genomic sequence analysis together with publicly available data revealed that frequent reassortment and introduction of H4 AIV from wild birds to poultry may have occurred. We identified 62 genotypes among 127 whole genome sequences of H4 viruses in China, indicating that H4 AIVs had great genetic diversity in China. We also investigated molecular markers and found that drug resistance mutations frequently occurred in the M2 protein and a few mutations related to receptor binding and the host signature in H4 AIVs. Our study demonstrates the cross-species transmission potential of H4 AIVs in China and provides some reference significance for its risk assessment.

Equine brucellosis in Iran: serological, bacteriological and molecular analysis.

Equine brucellosis significantly impacts the health and functionality of horses, leading to complications such as bursitis infection, septic tenosynovitis, septic arthritis, and non-specific lameness resulting from joint infections. In the present study, we used the Rose Bengal plate agglutination test (RBPT), serum agglutination test (SAT), and the 2-mercaptoethanol (2-ME) assays to find equine brucellosis. From June 2018 to September 2022, 876 blood samples were randomly taken from apparently healthy racing horses in certain parts of Iran, such as Kerman, Isfahan, Tehran, Qom, and Kurdistan. DNA extraction was carried out directly on all 63 serum samples identified as seropositive through RBPT. An additional 30 seronegative serum samples were also randomly chosen for study. Bacterial culture was also done on milk, blood, and vaginal swabs taken from seropositive horses.The bacteria that were found in the samples were then put through Bruce-ladder PCR. Our results indicated that 63 (7.1%), 21 (2.3%), and 2 (0.2%) of horses were seropositive using RBPT, SAT, and 2-ME, respectively. Also, none of the 30 DNA-extracted serum samples from seronegative horses tested positive for Brucella DNA, while 44.5% (28/63) of the DNA samples from seropositive horses yielded positive results for Brucella DNA. Out of the seropositive samples, 26 had DNA from Brucella abortus and 2 had DNA from Brucella melitensis. Also, B. melitensis biovar 1 was found in two milk samples from mares in the provinces of Kerman and Isfahan. It was identified using classical biotyping, and molecular assays. It was seen that some of healthy racing horses in some parts of Iran had antibodies against Brucella. The bacteriology and PCR methodologies provide a more comprehensive and reliable means of identifying Brucella spp. infections in horse, especially when the RBPT test came back positive. This underscores the imperative for employing molecular, bacterial, and serological methods in the diagnosis and monitoring of this zoonotic infection. Additionally, this finding suggests that Brucella is being transmitted to equine hosts as a result of its presence in ruminants. The mechanism of transmission may involve interactions between infected ruminants and susceptible equines. This discovery is significant as it underscores the potential cross-species transmission of Brucella and highlights the importance of understanding and managing the spread of the pathogen in both ruminant and equine populations.

Evolution of the SARS-CoV-2 Omicron Variants: Genetic Impact on Viral Fitness.

Over the last three years, the pandemic of COVID-19 has had a significant impact on people's lives and the global economy. The incessant emergence of variant strains has compounded the challenges associated with the management of COVID-19. As the predominant variant from late 2021 to the present, Omicron and its sublineages, through continuous evolution, have demonstrated iterative viral fitness. The comprehensive elucidation of the biological implications that catalyzed this evolution remains incomplete. In accordance with extant research evidence, we provide a comprehensive review of subvariants of Omicron, delineating alterations in immune evasion, cellular infectivity, and the cross-species transmission potential. This review seeks to clarify the underpinnings of biology within the evolution of SARS-CoV-2, thereby providing a foundation for strategic considerations in the post-pandemic era of COVID-19.

Prevalence of Astroviruses in Different Animal Species in Poland.

Astroviruses (AstVs) are small RNA viruses characterized by a high mutation rate, the ability to recombine, and interspecies transmission, which allows them to infect a multitude of hosts including humans, companion animals, and farmed animals as well as wildlife. AstVs are stable in the environment, and their transmission is usually through the fecal-oral route or via contaminated water and food. Although direct zoonotic transmission was not confirmed, interspecies transmission events have occurred or have been indicated to occur in the past between wild and domestic animals and humans. They cause large economic losses, mainly in the poultry sector, due to gastroenteritis and mortality. In young children, they are the second most common cause of diarrhea. This study involved 166 intestine samples and pools of spleen, lymph node, and kidney samples collected from 352 wild animals, 52 pigs, and 31 companion animals. Astroviruses were detected in the intestine samples and were separately detected in pools of tissue samples prepared for individual animals using a heminested RT-PCR protocol. Amplicons were subjected to Sanger sequencing, and a phylogenetic analysis of 320 nt RNA-dependent RNA polymerase (RdRp) fragments referring to known nt sequences of astroviruses was performed. Astroviral RNA was detected in the intestine samples and/or tissue pools of red foxes (nine positive intestines and six positive tissue pools), rats (two positive intestines and three positive tissue pools), a cat (one AstV detected in an intestine sample), pigs (eight positive tissue pools), and wild boars (two positive pools of spleens, kidneys, and lymph nodes). No astroviral RNA was detected in wild mustelids, dogs, or other small wild animals including rodents. A phylogenetic analysis revealed that the astroviruses detected during this study were mostly host-specific, such as porcine, canine, and rat astroviruses that were highly homologous to the sequences of reference strains. In one of two wild boars, an AstV distinct to porcine species was found with the highest nt identity to Avastroviruses, i.e., turkey astroviruses, which suggests potential cross-species transmission of the virus, as previously described. Here, we present the first detection of astroviruses in the population of wild animals, companion animals, and pigs in Poland, confirming that astroviruses are frequent pathogens circulating in animals in the field. Our study also suggests potential cross-species transmission of Avaastrovirus to wild boars; however, further molecular characterization is needed.

Chlorogenic acid inhibits porcine deltacoronavirus release by targeting apoptosis

Porcine deltacoronavirus (PDCoV), belonging to family Coronaviridae, genus Deltacoronavirus, can cause acute diarrhea in piglets, and also possesses cross-species transmission potential, leading to severe economic losses and threatening public health. However, no approved drug against PDCoV infection is available. Here, we investigated the antiviral effect of chlorogenic acid (CGA), the main active component of Lonicerae Japonicae Flos, against PDCoV infection. The results showed that CGA inhibited the replication of PDCoV significantly both in LLC-PK1 and ST cells, with a selectivity index greater than 80. CGA decreased the synthesis of PDCoV viral RNA and protein, and viral titers in a dose-dependent manner. The results of the time-of-addition assay indicated that CGA mainly affected the early stage of virus replication and viral release. Moreover, CGA significantly reduced apoptosis caused by PDCoV infection, and the application of apoptosis agonist and inhibitor revealed that apoptosis could promote progeny virus release. Further study demonstrated that CGA can inhibit virus release by directly targeting apoptosis caused by PDCoV infection. In conclusion, CGA is an effective agent against PDCoV, which provides a foundation for drug development for the treatment of PDCoV and other coronavirus infections.

Circular replication-associated protein-encoding single-stranded DNA virus with risk of spillover is widely prevalent in domestic animals in China

Circular replication-associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses are highly diverse and have a broad range of hosts. In this study, we report the detection of Bo-Circo-like virus AH20-1 in the feces of diarrheal cattle. The virus has a circular genome of 3,912 nucleotides, three major putative open reading frames, and encodes a Rep gene of 310 amino acids. We found that the virus is closely related to the Bo-Circo-like virus CH strain, which belongs to the novel Kirkoviridae family. Furthermore, we conducted a nationwide surveillance program and found that the virus is prevalent in China (23.6%, 205/868), with the BCLa subtype being the predominant strain. Our findings suggest that the virus can infect sheep, highlighting the potential for cross-species transmission. Our pressure analysis indicates that the CRESS-DNA Kirkoviridae family has broad host adaptation, and that selection pressure played an important role in the evolution of its Rep genes. Our study underscores the need for continued epidemiological surveillance of this virus due to its widespread prevalence in our ruminant population and potential for cross-species transmission.

VarEPS-Influ:an risk evaluation system of occurred and virtual variations of influenza virus genomes.

Influenza viruses undergo frequent genomic mutations, leading to potential cross-species transmission, phenotypic changes, and challenges in diagnostic reagents and vaccines. Accurately evaluating and predicting the risk of such variations remain significant challenges. To address this, we developed the VarEPS-Influ database, an influenza virus variations risk evaluation system (VarEPS-Influ). This database employs a 'multi-dimensional evaluation of mutations' strategy, utilizing various tools to assess the physical and chemical properties, primary, secondary, and tertiary structures, receptor affinity, antibody binding capacity, antigen epitopes, and other aspects of the variation's impact. Additionally, we consider space-time distribution, host species distribution, pedigree analysis, and frequency of mutations to provide a comprehensive risk evaluation of mutations and viruses. The VarEPS-Influ database evaluates both observed variations and virtual variations (variations that have not yet occurred), thereby addressing the time-lag issue in risk predictions. Our current one-stop evaluation system for influenza virus genomic variation integrates 1065290 sequences from 224927 Influenza A, Band C isolates retrieved from public resources. Researchers can freely access the data at https://nmdc.cn/influvar/.

Transmission of HCoV-OC43 to pet hamsters

Coronaviruses (CoVs) are a significant group of pathogens that pose a serious threat to both human and animal health, with some being zoonotic and displaying frequent cross-species transmission. Human CoV-OC43 (HCoV-OC43) is one of the four common human CoVs that can cause seasonal mild to moderate respiratory diseases in humans. In this study, we identified HCoV-OC43 for the first time in two asymptomatic pet hamsters, which share a high similarity with the human-derived HCoV-OC43 strain, suggesting potential cross-species transmission of HCoV-OC43 to pet hamsters. The finding emphasizes the need to strengthen pathogen monitoring of livestock and pets in close contact with humans to provide early warning of public safety.

Prediction of mammalian virus cross-species transmission based on host proteins.

Most emerging viruses are spilled over from mammals. Understanding the mechanism of virus cross-species transmission and identifying zoonotic viruses before their emergence are critical for the prevention and control of newly emerging viruses. This study systematically investigated the host proteins associated with the cross-species transmission of mammalian viruses based on 1,271 pairs of virus-mammal interactions including 382 viruses from 33 viral families and 73 mammal species from 11 orders. Numerous host proteins were found to contribute to the cross-species transmission of mammalian viruses. Host proteins potentially contributing to virus cross-species transmission are specific to viral families, and few overlaps of such host proteins are observed in different viral families. Based on these host proteins, the random-forest (RF) models were built to predict the cross-species transmission potential of mammalian viruses. Moderate performance was obtained when using all viruses together. However, when modeling by viral family, the performance of the RF models varied much among viral families. In 13 viral families such as Flaviviridae, Retroviridae, and Poxviridae, the AUC of the RF model was greater than 0.8. Finally, the contribution of virus receptors to cross-species transmission was evaluated, and the virus receptor was found to have a minor effect in predicting the cross-species transmission of mammalian viruses. The study deepens our understanding of the mechanism of virus cross-species transmission and provides a framework for predicting the cross-species transmission of mammalian viruses. IMPORTANCE Emerging viruses pose serious threats to humans. Understanding the mechanism of virus cross-species transmission and identifying zoonotic viruses before their emergence are critical for the prevention and control of emerging viruses. This study systematically identified host factors associated with cross-species transmission of mammalian viruses and further built machine-learning models for predicting cross-species transmission of the viruses based on host factors including virus receptors. The study not only deepens our understanding of the mechanism of virus cross-species transmission but also provides a framework for predicting the cross-species transmission of mammalian viruses based on host factors.

Host range, transmissibility and antigenicity of a pangolin coronavirus.

The pathogenic and cross-species transmission potential of SARS-CoV-2-related coronaviruses (CoVs) remain poorly characterized. Here we recovered a wild-type pangolin (Pg) CoV GD strain including derivatives encoding reporter genes using reverse genetics. In primary human cells, PgCoV replicated efficiently but with reduced fitness and showed less efficient transmission via airborne route compared with SARS-CoV-2 in hamsters. PgCoV was potently inhibited by US Food and Drug Administration approved drugs, and neutralized by COVID-19 patient sera and SARS-CoV-2 therapeutic antibodies in vitro. A pan-Sarbecovirus antibody and SARS-CoV-2 S2P recombinant protein vaccine protected BALB/c mice from PgCoV infection. In K18-hACE2 mice, PgCoV infection caused severe clinical disease, but mice were protected by a SARS-CoV-2 human antibody. Efficient PgCoV replication in primary human cells and hACE2 mice, coupled with a capacity for airborne spread, highlights an emergence potential. However, low competitive fitness, pre-immune humans and the benefit of COVID-19 countermeasures should impede its ability to spread globally in human populations.

Phylogeographic Aspects of Bat Lyssaviruses in Europe: A Review.

During the last few decades, bat lyssaviruses have become the topic of intensive molecular and epidemiological investigations. Since ancient times, rhabdoviruses have caused fatal encephalitis in humans which has led to research into effective strategies for their eradication. Modelling of potential future cross-species virus transmissions forms a substantial component of the recent infection biology of rabies. In this article, we summarise the available data on the phylogeography of both bats and lyssaviruses in Europe and the adjacent reg ions, especially in the contact zone between the Palearctic and Ethiopian realms. Within these zones, three bat families are present with high potential for cross-species transmission and the spread of lyssaviruses in Phylogroup II to Europe (part of the western Palearctic). The lack of effective therapies for rabies viruses in Phylogroup II and the most divergent lyssaviruses generates impetus for additional phylogenetic and virological research within this geographical region.

Identification of potential SLA-I-specific T-cell epitopes within the structural proteins of porcine deltacoronavirus

Porcine deltacoronavirus (PDCoV) is an emerging swine enteropathogenic coronavirus that mainly threatens newborn piglets and poses a potential broad cross-species transmission risk. The antigenic epitopes of PDCoV are currently unidentified, and no information about T cell epitopes is available. Here, T-cell epitopes of PDCoV structural proteins were predicted using computational methods. 17 epitope peptides were synthesized and then screened using ELIspot, intracellular cytokine staining (ICS), and RT-qPCR detection of IFN-γ mRNA to evaluate their ability to elicit interferon-gamma (IFN-γ) responses in peripheral blood mononuclear cells (PBMCs) from PDCoV-challenged pigs. Five peptides (M1, M2, M3, N6, and S4) elicited high levels of IFN-γ and were investigated further as potential T-cell epitope candidates. All five peptides were cytotoxic T lymphocyte (CTL) epitopes, and two peptides (M3, N6) were recognized simultaneously by CD8 + and CD4 + T cells. A multi-epitope peptide combining the five epitopes (designated “5T”) was synthesized and its immune response and protection efficacy was evaluated in a piglet model. ELISpot assay results indicated that 5T induces robust epitope-specific cellular immune responses. Four epitopes (M1, M2, N6, S4) elicited IFN-γ responses in 5T-vaccinated piglets. No obvious protection efficacy was detected in piglets vaccinated with 5T alone. Our results provide valuable information concerning PDCoV-related antigenic epitopes and will be useful in the design of epitope-based vaccines.

Multiple clonal transmissions of clinically relevant extended-spectrum beta-lactamase–producing Escherichia coli among livestock, dogs, and wildlife in Chile

Extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli) are a main cause of human deaths associated with antimicrobial resistance (AMR). Despite hundreds of reports of the faecal carriage of ESBL-E. coli in domestic and wild animals, the dynamics of its circulation remains poorly understood. We used whole genome sequencing of 19 ESBL-E. coli previously isolated in the same local setting from dogs, livestock, and a wild rodent in Central Chile to assess potential cross-species transmission of ESBL-E. coli. Isolates harboured a large number of AMR (n=95) and virulence (n=45) genes, plasmids replicons (n=24) and E. coli Sequence Types including top extraintestinal pathogenic E. coli ST410, ST58, ST88, and ST617. Almost identical clones (<50 SNPs difference, same antibiotic and heavy metal resistance genes, virulence genes, and plasmids) were found in faeces of dogs, cattle or sheep from the same farm, and in a dog and a wild rodent living in proximity. To our knowledge, this is the first report of multiple clonal cross-species transmission of ESBL-E. coli in domestic and potentially wild animals of Latin America. Our results suggest that relatively rare spread of AMR across animal species can still occur by both clonal and plasmid dissemination. Our study highlights the need for establishing preventive measures to limit the circulation of these bacteria among animals in agricultural settings, particularly given the highly pathogenic profile of several E. coli strains detected in these animals.

A Novel Simian Adenovirus Associating with Human Adeno-virus Species G Isolated from Long-Tailed Macaque Feces.

Metagenomics has demonstrated its capability in outbreak investigations and pathogen surveillance and discovery. With high-throughput and effective bioinformatics, many disease-causing agents, as well as novel viruses of humans and animals, have been identified using metagenomic analysis. In this study, a VIDISCA metagenomics workflow was used to identify potential unknown viruses in 33 fecal samples from asymptomatic long-tailed macaques (Macaca fascicularis) in Ratchaburi Province, Thailand. Putatively novel astroviruses, enteroviruses, and adenoviruses were detected and confirmed by PCR analysis of long-tailed macaque fecal samples collected from areas in four provinces, Ratchaburi, Kanchanaburi, Lopburi, and Prachuap Khiri Khan, where humans and monkeys live in proximity (total n = 187). Astroviruses, enteroviruses, and adenoviruses were present in 3.2%, 7.5%, and 4.8% of macaque fecal samples, respectively. One adenovirus, named AdV-RBR-6-3, was successfully isolated in human cell culture. Whole-genome analysis suggested that it is a new member of the species Human adenovirus G, closely related to Rhesus adenovirus 53, with evidence of genetic recombination and variation in the hexon, fiber, and CR1 genes. Sero-surveillance showed neutralizing antibodies against AdV-RBR-6-3 in 2.9% and 11.2% of monkeys and humans, respectively, suggesting cross-species infection of monkeys and humans. Overall, we reported the use of metagenomics to screen for possible new viruses, as well as the isolation and molecular and serological characterization of the new adenovirus with cross-species transmission potential. The findings emphasize that zoonotic surveillance is important and should be continued, especially in areas where humans and animals interact, to predict and prevent the threat of emerging zoonotic pathogens.

Virus diversity, wildlife-domestic animal circulation and potential zoonotic viruses of small mammals, pangolins and zoo animals

Wildlife is reservoir of emerging viruses. Here we identified 27 families of mammalian viruses from 1981 wild animals and 194 zoo animals collected from south China between 2015 and 2022, isolated and characterized the pathogenicity of eight viruses. Bats harbor high diversity of coronaviruses, picornaviruses and astroviruses, and a potentially novel genus of Bornaviridae. In addition to the reported SARSr-CoV-2 and HKU4-CoV-like viruses, picornavirus and respiroviruses also likely circulate between bats and pangolins. Pikas harbor a new clade of Embecovirus and a new genus of arenaviruses. Further, the potential cross-species transmission of RNA viruses (paramyxovirus and astrovirus) and DNA viruses (pseudorabies virus, porcine circovirus 2, porcine circovirus 3 and parvovirus) between wildlife and domestic animals was identified, complicating wildlife protection and the prevention and control of these diseases in domestic animals. This study provides a nuanced view of the frequency of host-jumping events, as well as assessments of zoonotic risk.

Occurrence and limited zoonotic potential of Cryptosporidium spp., Giardia duodenalis, and Balantioides coli infections in free-ranging and farmed wild ungulates in Spain

Little information is currently available on the occurrence and molecular diversity of the enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Balantioides coli in wild ungulates and the role of these host species as potential sources of environmental contamination and consequent human infections. The presence of these three pathogens was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were retrospectively collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from the five Spanish bioregions. Overall infection rates were 3.0% (42/1382; 95% CI: 2.1–3.9%) for Cryptosporidium spp., 5.4% (74/1382; 95% CI: 4.2–6.5%) for G. duodenalis, and 0.7% (9/1382; 95% CI: 0.3–1.2%) for B. coli. Cryptosporidium infection was detected in roe deer (7.5%), wild boar (7.0%) and red deer (1.5%), and G. duodenalis in southern chamois (12.9%), mouflon (10.0%), Iberian wild goat (9.0%), roe deer (7.5%), wild boar (5.6%), fallow deer (5.2%) and red deer (3.8%). Balantioides coli was only detected in wild boar (2.5%, 9/359). Sequence analyses revealed the presence of six distinct Cryptosporidium species: C. ryanae in red deer, roe deer, and wild boar; C. parvum in red deer and wild boar; C. ubiquitum in roe deer; C. scrofarum in wild boar; C. canis in roe deer; and C. suis in red deer. Zoonotic assemblages A and B were detected in wild boar and red deer, respectively. Ungulate-adapted assemblage E was identified in mouflon, red deer, and southern chamois. Attempts to genotype samples positive for B. coli failed. Sporadic infections by canine- or swine-adapted species may be indicative of potential cross-species transmission, although spurious infections cannot be ruled out. Molecular evidence gathered is consistent with parasite mild infections and limited environmental contamination with (oo)cysts. Free-ranging wild ungulate species would not presumably play a significant role as source of human infections by these pathogens. Wild ruminants do not seem to be susceptible hosts for B. coli.