Molecular epidemiology and viremia of porcine astrovirus in pigs from Guangxi province of China

Universal primer multiplex PCR assay for detection and genotyping of porcine astroviruses

Porcine astroviruses (PAstV) are members of the family Astroviridae, Mamastravirus genus and have been identified to have five genotypes (PAstV1-5). These viruses are highly prevalent in pigs and can cause enteric disease as well as neurological or respiratory symptoms depending on their genotypes. At present, the epidemiological impacts of some PAstV genotypes on pigs are largely unknown and hence continuously monitoring of these PAstVs may be needed. The purpose of this research was to develop an improved and efficient detection tool for PAstVs and to evaluate the developed method using clinical samples. Initially, a set of five chimeric primers (CP), each comprising genotype specific primer pairs with an identical universal adapter at the 5' end, and a universal primer (UP) that is identical to universal adapter sequence, were designed. With these tools in place, a novel multiplex PCR system with universal primer was established for the simultaneous detection of the five types of PAstV. This method can specifically detect PAstV genotypes, with a limit of detection (LOD) of 5 copies/μL for each genotype irrespective of single or mixed target template. Using this new assay, 273 pig fecal samples were investigated for further assay evaluation. Among all samples, the positive rate was 70.0% with PAstV4 in 56.8% of the samples, PAstV2 in 38.8%, PAstV1 in 16.8%, and PAstV5 in 11.0%. More than one PAstV in a sample were detected in 39.2% of the samples. The consistency rate between the novel multiplex PCR and singleplex PCRs was 96.4-100%. Given its rapidity, specificity and sensitivity, the novel multiplex PCR is a useful approach for demonstrating single or mixed genotype infections of PAstV.

Multiplex gel-based PCR assay for the simultaneous detection of 5 genotypes of porcine astroviruses

Porcine astrovirus (PAstV) has been associated experimentally with diarrhea in piglets, but much more knowledge is needed about this virus. PAstV has high genetic variability, and 5 genotypes have been identified, namely PAstV1-5. To obtain information on the epidemiology of PAstV, we established a multiplex PAstV PCR assay to detect and differentiate the 5 PAstV genotypes simultaneously. The assay utilized specific primers for each genotype, producing fragments of 307, 353, 205, 253, and 467 bp, representing PAstV1-5, respectively. Our multiplex PCR assay amplified all 5 DNA fragments from single or mixed viral genomes without cross-reactions with other PAstV genotypes or other viruses in pigs. The limit of detection of the multiplex PCR assay was 5 × 102 copies/μL for PAstV1 and PAstV4, and 5 × 103 copies/μL for PAstV2, PAstV3, and PAstV5. We examined 76 pig fecal specimens with our multiplex PCR assay. PAstV was detected in 36 of 76 (47.4%) samples; ≥2 PAstVs were found in 20 of 76 (26.3%) samples. The multiplex PCR assay results were essentially the same as the results using a monoplex PAstV PCR assay, with a coincidence rate of >96%. Our multiplex PCR method provides a simple, sensitive, and specific detection tool for PAstV detection and epidemiologic surveys.

Metagenomic Analysis of RNA Fraction Reveals the Diversity of Swine Oral Virome on South African Backyard Swine Farms in the uMgungundlovu District of KwaZulu-Natal Province

Numerous RNA viruses have been reported in backyard swine populations in various countries. In the absence of active disease surveillance, a persistent knowledge gap exists on the diversity of RNA viruses in South African backyard swine populations. This is the first study investigating the diversity of oral RNA virome of the backyard swine in South Africa. We used three samples of backyard swine oral secretion (saliva) collected from three distantly located backyard swine farms (BSFs) in the uMgungundlovu District, KwaZulu-Natal, South Africa. Total viral RNA was extracted and used for the library preparation for deep sequencing using the Illumina HiSeq X instrument. The FASTQ files containing paired-end reads were analyzed using Genome Detective v 1.135. The assembled nucleotide sequences were analyzed using the PhyML phylogenetic tree. The genome sequence analysis identified a high diversity of swine enteric viruses in the saliva samples obtained from BSF2 and BSF3, while only a few viruses were identified in the saliva obtained from BSF1. The swine enteric viruses belonged to various animal virus families; however, two fungal viruses, four plant viruses, and five unclassified RNA viruses were also identified. Specifically, viruses of the family Astroviridae, according to the number of reads, were the most prevalent. Of note, the genome sequences of Rotavirus A (RVA) and Rotavirus C (RVC) at BSF2 and RVC and Hepatitis E virus (HEV) at BSF3 were also obtained. The occurrence of various swine enteric viruses in swine saliva suggests a high risk of diarrhoeic diseases in the backyard swine. Of note, zoonotic viruses in swine saliva, such as RVA, RVC, and HEV, indicate a risk of zoonotic spillover to the exposed human populations. We recommend the implementation of biosecurity to ensure sustainable backyard swine farming while safeguarding public health.

Viral biogeography of the mammalian gut and parenchymal organs

The mammalian virome has been linked to health and disease but our understanding of how it is structured along the longitudinal axis of the mammalian gastrointestinal tract (GIT) and other organs is limited. Here, we report a metagenomic analysis of the prokaryotic and eukaryotic virome occupying luminal and mucosa-associated habitats along the GIT, as well as parenchymal organs (liver, lung and spleen), in two representative mammalian species, the domestic pig and rhesus macaque (six animals per species). Luminal samples from the large intestine of both mammals harboured the highest loads and diversity of bacteriophages (class Caudoviricetes, family Microviridae and others). Mucosal samples contained much lower viral loads but a higher proportion of eukaryotic viruses (families Astroviridae, Caliciviridae, Parvoviridae). Parenchymal organs contained bacteriophages of gut origin, in addition to some eukaryotic viruses. Overall, GIT virome composition was specific to anatomical region and host species. Upper GIT and mucosa-specific viruses were greatly under-represented in distal colon samples (a proxy for faeces). Nonetheless, certain viral and phage species were ubiquitous in all samples from the oral cavity to the distal colon. The dataset and its accompanying methodology may provide an important resource for future work investigating the biogeography of the mammalian gut virome.

Genomic Divergence Characterization and Quantitative Proteomics Exploration of Type 4 Porcine Astrovirus

Porcine astrovirus (PAstV) has been identified as an important diarrheic pathogen with a broad global distribution. The PAstV is a potential pathogen to human beings and plays a role in public health. Until now, the divergence characteristics and pathogenesis of the PAstV are still not well known. In this study, the PAstV-4 strain PAstV/CH/2022/CM1 was isolated from the diarrheal feces of a piglet in Shanghai, which was identified to be a recombination of PAstV4/JPN (LC201612) and PAstV4/CHN (JX060808). A time tree based on the ORF2 protein of the astrovirus demonstrated that type 2–5 PAstV (PAstV-2 to 5) diverged from type 1 PAstV (PAstV-1) at a point from 1992 to 2000. To better understand the molecular basis of the virus, we sought to explore the host cell response to the PAstV/CH/2022/CM1 infection using proteomics. The results demonstrate that viral infection elicits global protein changes, and that the mitochondria seems to be a primary and an important target in viral infection. Importantly, there was crosstalk between autophagy and apoptosis, in which ATG7 might be the key mediator. In addition, the NOD-like receptor X1 (NLRX1) in the mitochondria was activated and participated in several important antiviral signaling pathways after the PAstV/CH/2022/CM1 infection, which was closely related to mitophagy. The NLRX1 may be a crucial protein for antagonizing a viral infection through autophagy, but this has yet to be validated. In conclusion, the data in this study provides more information for understanding the virus genomic characterization and the potential antiviral targets in a PAstV infection.

Potential zoonotic swine enteric viruses: The risk ignored for public health

Swine could serve as a natural reservoir for a large variety of viruses, including potential zoonotic enteric viruses. The presence of viruses with high genetic similarity between porcine and human strains may result in the emergence of zoonotic or xenozoonotic infections. Furthermore, the globalization and intensification of swine industries exacerbate the transmission and evolution of zoonotic viruses among swine herds and individuals working in swine-related occupations. To effectively prevent the public health risks posed by zoonotic swine enteric viruses, designing, and implementing a comprehensive measure for early diagnosis, prevention, and mitigation, requires interdisciplinary a collaborative ''One Health" approach from veterinarians, environmental and public health professionals, and the swine industry. In this paper, we reviewed the current knowledge of selected potential zoonotic swine enteric viruses and explored swine intensive production and its associated public health risks.

Molecular Detection and Genetic Characterization of Potential Zoonotic Swine Enteric Viruses in Northern China

Despite significant economic and public health implications, swine enteric viruses that do not manifest clinical symptoms are often overlooked, and data on their epidemiology and pathogenesis are still scarce. Here, an epidemiological study was carried out by using reverse transcription-polymerase chain reaction (RT-PCR) and sequence analysis in order to better understand the distribution and genetic diversity of porcine astrovirus (PAstV), porcine encephalomyocarditis virus (EMCV), porcine kobuvirus (PKV), and porcine sapovirus (PSaV) in healthy pigs reared under specific pathogen-free (SPF) or conventional farms. PKV was the most prevalent virus (51.1%, 247/483), followed by PAstV (35.4%, 171/483), then PSaV (18.4%, 89/483), and EMCV (8.7%, 42/483). Overall, at least one viral agent was detected in 300 out of 483 samples. Out of the 300 samples, 54.0% (162/300), 13.0% (39/300), or 1.0% (3/300) were found coinfected by two, three, or four viruses, respectively. To our knowledge, this is the first report of EMCV detection from porcine fecal samples in China. Phylogenetic analysis revealed genetically diverse strains of PAstV, PKV, and PSaV circulating in conventional and SPF farms. Detection of swine enteric viruses with a high coinfection rate in healthy pigs highlights the importance of continuous viral surveillance to minimize future economic and public health risks.

Epidemiology of Astrovirus, Norovirus and Sapovirus in Greek pig farms indicates high prevalence of Mamastrovirus suggesting the potential need for systematic surveillance

Backround

Astrovirus, Norovirus and Sapovirus exhibit a wide distribution in swine pig herds worldwide. However, the association of porcine Astrovirus (PAstV), porcine Norovirus (PoNoV) and porcine Sapovirus (PoSaV) with disease in pigs remains uncertain. In this study, we investigated the prevalence of PAstV, PoNoV and PoSaV in Greek pig farms using both conventional RT-PCR and SYBR-Green Real-time RT-PCR in an effort to compare the sensitivity of the two methods. We examined 1400 stool samples of asymptomatic pigs originating from 28 swine farms throughout Greece in pools of five.

Results

PAstV was detected in all 28 swine farms examined, with an overall prevalence of 267/280 positive pools (95.4%). Porcine Caliciviruses prevalence was found at 36 and 57 out of the 280 examined samples, by the conventional and SYBR-Green Real time RT-PCR, respectively. Sequencing and phylogenetic analysis of the positive samples revealed that the detected PAstV sequences are clustered within PAstV1, 3 and 4 lineages, with PAstV3 being the predominant haplotype (91.2%). Interestingly, sequencing of the Calicivirus positive samples demonstrated the presence of non-target viruses, i.e. Sapovirus, Kobuvirus and Sapelovirus sequences and one sequence highly similar to bat Astrovirus, while no Norovirus sequence was detected.

Conclusions

The high prevalence of PAstV in Greek pig farms poses a necessity for further investigation of the pathogenicity of this virus and its inclusion in surveillance programs in case that it proves to be important. To our knowledge, this is the first epidemiological study of these viruses in pig farms in Greece.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-021-00245-8.

Epidemiological investigation and genetic characterization of porcine astrovirus genotypes 2 and 5 in Yunnan province, China

Astroviruses (AstVs) are among the most important viruses causing diarrhea in human infants and many animals, posing a threat to public health safety and a burden on the economy. Five porcine AstV (PAstV) genotypes have been identified in various countries, including China. However, the epidemiology of PAstV in Yunnan province, China, remains unknown. In this study, 489 fecal samples from pigs in all 16 prefectures/cities of Yunnan were collected between April and August of 2020 for epidemiological investigation. The total infection rate of PAstV-2 or PAstV-5 was 39.9%, with suckling piglets having the highest infection rate (62.3%). The ORF2 genes of seven PAstV-2 and 10 PAstV-5 isolates were sequenced and phylogenetically analyzed. In addition to coinfections with PAstV-2 and PAstV-5, coinfections of PAstV with other diarrhea-inducing viruses (e.g., porcine bocavirus) were also discovered. A comparison of ORF2-encoded capsid protein sequences revealed that there were multiple insertions and deletions in the seven Yunnan PAstV-2 sequences, while point mutations, but no deletions or insertions, were found in the 10 Yunnan PAstV-5 sequences, which were very similar to the reference sequences. This is the first epidemiological investigation and genetic characterization of PAstV-2 and PAstV-5 in Yunnan province, China, demonstrating the current PAstV infection situation in Yunnan.

Identification of novel B-cell epitopes on the capsid protein of type 1 porcine astrovirus, using monoclonal antibodies

Porcine astrovirus (PAstV) is prevalent in pigs worldwide and could cause clinical symptoms such as diarrhea and encephalitis. The capsid protein (Cap) of PAstV plays a determinant role for virus immunological characteristics. In this study, the major antigenic regions of PAstV1 Cap were expressed through prokaryotic expression systems and immunized to BALB/c mice. Finally, two anti-Cap monoclonal antibodies (named mAb F4-4 and D3F10) were screened by indirect immune-fluorescence assay (IFA). A series of truncated GST-fused or artificially synthesized peptides were used to detect their reactivity with the mAbs and PAstV positive serum. Two novel B cell epitopes (120-GNNTFG-125, 485-RISDPTWFSA-494) were identified by using these two mAbs. Moreover, sequence alignment result showed that epitope 120-GNNTFG-125 was highly conserved in type 1 PAstV capsid protein. Cross-reactivity analysis further confirmed the genotype-specificity of mAb F4-4. The results of this study demonstrated to be the first description of monoclonal antibody preparation and B-cell epitope mapping on PAstV capsid protein, which may provide new information on the biological significance of PAstV capsid protein and lay a foundation for the development of PAstV immunological tests and genotype diagnostic methods.

Experimental porcine astrovirus type 3-associated polioencephalomyelitis in swine

Porcine astrovirus type 3 (PoAstV3) is an emerging virus in the family Astroviridae that has been recently associated with polioencephalomyelitis/encephalitis. Herein, we describe the experimental oral and intravenous inoculation of an infectious central nervous system (CNS) tissue homogenate containing PoAstV3 to cesarean-derived, colostrum-deprived pigs, and the subsequent development of clinical signs, histologic lesions, specific humoral immune response, and detection of viral particles by electron microscopy (EM) and viral RNA by RT-qPCR (reverse transcriptase quantitative polymerase chain reaction) and in situ hybridization (ISH). IgG against a portion of the PoAstV3 ORF2 capsid was first detected at 7 days post-inoculation (DPI) in 2 of 4 inoculated animals and in all inoculated animals by 14 DPI. At 21 and 28 DPI, 2 of 4 inoculated animals developed ataxia, tetraparesis, and/or lateral recumbency. All inoculated animals had histologic lesions in the CNS including perivascular lymphoplasmacytic cuffs, multifocal areas of gliosis with neuronal necrosis, satellitosis, and radiculoneuritis, and PoAstV3 RNA as detected by RT-qPCR within multiple anatomic regions of the CNS. Consistent viral structures were within the soma of a spinal cord neuron in the single pig examined by EM. Of note, PoAstV3 was not only detected by ISH in neurons of the cerebrum and spinal cord but also neurons of the dorsal root ganglion and nerve roots consistent with viral dissemination via axonal transport. This is the first study reproducing CNS disease with a porcine astrovirus strain consistent with natural infection, suggesting that pigs may serve as an animal model to study the pathogenesis of neurotropic astroviruses.

Metagenomic characterization of swine slurry in a North American swine farm operation

Modern day large-scale, high-density farming environments are inherently susceptible to viral outbreaks, inadvertently creating conditions that favor increased pathogen transmission and potential zoonotic spread. Metagenomic sequencing has proven to be a useful tool for characterizing the microbial burden in both people, livestock, and environmental samples. International efforts have been successful at characterizing pathogens in commercial farming environments, especially swine farms, however it is unclear whether the full extent of microbial agents have been adequately captured or is representative of farms elsewhere. To augment international efforts we performed metagenomic next-generation sequencing on nine swine slurry and three environmental samples from a United States of America (U.S.A.) farm operation, characterized the microbial composition of slurry, and identified novel viruses. We assembled a remarkable total of 1792 viral genomes, of which 554 were novel/divergent. We assembled 1637 Picobirnavirus genome segments, of which 538 are novel. In addition, we discovered 10 new viruses belonging to a novel taxon: porcine Statoviruses; which have only been previously reported in human, macaques, mouse, and cows. We assembled 3 divergent Posaviruses and 3 swine Picornaviruses. In addition to viruses described, we found other eukaryotic genera such as Entamoeba and Blastocystis, and bacterial genera such as Listeria, Treponema, Peptoclostridium and Bordetella in the slurry. Of these, two species Entamoeba histolytica and Listeria monocytogenes known to cause human disease were detected. Further, antimicrobial resistance genes such as tetracycline and MLS (macrolide, lincosamide, streptogramin) were also identified. Metagenomic surveillance in swine fecal slurry has great potential for novel and antimicrobial resistant pathogen detection.

Detection and Genetic Diversity of a Novel Water Buffalo Astrovirus Species Found in the Guangxi Province of China

Astroviruses (AstVs) are major causative agents of gastroenteritis and have been detected worldwide. Little is known about the prevalence of neurotropic AstVs in Chinese water buffaloes, but a novel species which is associated with encephalitis and meningitis has recently been found. In this study, based on nested RT-PCR, rapid amplification of the 3′-cDNA end (3′-RACE) and next-generation sequencing (NGS), we examined the infection of AstVs in water buffaloes in the Guangxi Province of China. The results showed that the AstV infection was found in 40% (6/15) of the farms examined, and the prevalence of AstV in their feces was 11% (33/297). In addition, two near-full-length and two complete open reading frame 2 (ORF2) genes of AstVs from fecal sources were sequenced. Phylogenetic analysis of the ORF2 sequences indicated three lineages of BufAstVs, BufAstV lineage 1 was close related to the BoAstV, lineage 2 was related to the BufAstVs, and lineage 3 was classified as novel AstVs, which had a close relationship with the neurotropic/neurovirulent AstVs strains found in bovine, ovine, and musks. Moreover, genomic a recombination between the BufAstV and BoAstV strains was identified. This is a novel study reporting the genetic diversity of BufAstV infection in China especially found the similar neurotropic strains from fecal sources of water buffaloes, and it also provides details of the epidemiology, genetic recombination, and interspecies transmission of BoAstV and BufAstV in water buffaloes from the Guangxi Province of China.

Establishment of a Multiplex RT-PCR Method for the Detection of Five Known Genotypes of Porcine Astroviruses

Porcine astroviruses (PAstVs) are prevalent in pigs worldwide, and five genotypes have been reported to circulate in China. However, little is known about the coinfection status of PAstVs. For differential and simultaneous diagnoses of these five genotypes of PAstVs, a multiplex RT-PCR method was established on the basis of the ORF2 gene of type 1 PAstV, and the ORF1ab genes of type two to five PAstVs. This quintuple PCR system was developed through optimization of multiplex PCR and detection sensitivity and specificity. The results showed that this multiplex RT-PCR method could specifically detect all the five PAstV genotypes without cross-reaction to any other major viruses circulating in Chinese pig farms. The detection limit of this method was as low as 10 pg of standard plasmids of each PAstV genotype. In addition, a total of 275 fecal samples collected from different districts of Guangxi, China, between April 2019 and November 2020, were tested by this newly established multiplex RT-PCR. Moreover, the sensitivity and specificity of monoplex and multiplex RT-PCR methods were compared by detecting the same set of clinical positive samples. The results revealed that PAstV1 (31/275), PAstV2 (49/275), PAstV3 (36/275), PAstV4 (41/275), and PAstV5 (22/275) were all detected, and dual (PAstV1+PAstV2, PAstV1+PAstV3, PAstV2+PAstV3, PAstV2+PAstV4, PAstV3+PAstV4, and PAstV4+PAstV5) or triple genotypes (PAstV1+PAstV2+PAstV3 and PAstV2+PAstV3+PAstV4) of coinfections were also unveiled in this study. The detection result of multiplex PCR was consistent with that of monoplex PCR. Compared with monoplex PCR, this multiplex PCR method showed obvious advantages such as time and cost efficiency and high sensitivity and specificity. This multiplex RT-PCR method offered a valuable tool for the rapid and accurate detection of PAstV genotypes circulating in pig herds and will facilitate the surveillance of PAstV coinfection status.

Isolation and Characterization of Porcine Astrovirus 5 from a Classical Swine Fever Virus-Infected Specimen

Many new astroviruses have been identified in humans and other animals in recent years, but only a few have been successfully isolated for extensive biological study. Here, we report an unusual isolation of a porcine astrovirus 5 (PAstV5) strain from a clinical classical swine fever virus (CSFV)-infected tissue sample. Incubation of porcine PK-15 cells with an extract of the CSFV-positive tissue resulted in unexpected cytopathic effects (CPEs), and high-throughput viromic sequencing identified PAstV5 and porcine circovirus type 2 (PCV2) as well as CSFV in the culture. After clearance of CSFV and PCV2, a pure PAstV5 strain, named PAstV5-AH29-2014, was obtained. Analysis revealed virus of typical astroviral morphology with a genome of 6,448 nucleotides, sharing 84.3 to 88.9% nucleotide identity with previously published PAstV5 strains. A mechanistic study showed that CSFV coinfection was likely an important factor for successful isolation by significantly enhancing PAstV5 replication in PK-15 cells via suppression of a type I interferon response. Altogether, PAstV5-AH29-2014, as the first isolated PAstV5 strain, will provide critical material for the investigation of the biological and pathogenic properties of this virus as well as for future development of relevant biological and diagnostic reagents.IMPORTANCE Porcine astroviruses are mainly associated with gastroenteritis and neurological diseases in pigs, and five genotypes have been identified (PAstV1-5). However, the clinical manifestations of genotypes other than PAstV1 have not yet been determined because of the failure of in vitro virus isolation. Here, we report a surprising isolation of a PAstV5 strain from a clinical classical swine fever virus (CSFV)-infected tissue sample, which can stably passage in PK-15 cells, and coinfection with CSFV significantly enhanced the replication of PAstV5, possibly through suppression of beta interferon production. Thus, the first isolated PAstV5 strain will be useful for investigating the biological and pathogenic properties of this virus, and the findings obtained in this study provide new insights into defining the interaction mechanism between CSFV and PAstV5.

Coinfection and Genetic Characterization of Porcine Astrovirus in Diarrheic Piglets in China From 2015 to 2018

Porcine astrovirus (PAstV) is broadly distributed globally and exists as at least five distinct genotypes. PAstV, which was recently identified as an important pathogen of diarrhea in piglets, is widely distributed in China. However, few studies have investigated the coinfection and genetic characterization of PAstV in diarrheic piglets in China. In this study, 89 PAstV-positive samples were identified in 543 diarrhea samples in China from 2015 to 2018, of which 75.28% (67/89) were coinfected with three to five different porcine pathogens, while none were positive for PAstV only. Among the 543 diarrhea samples, statistical analysis showed that PAstV-induced diarrhea was potentially associated with coinfection of PEV (p < 0.01) and GARV (p < 0.01). Phylogenetic analysis showed that the 27 identified PAstV strains belong to three different genotypes and that PAstV-2 (81.48%, 22/27) was predominant in diarrheic piglets in China, followed by PAstV-4 (11.11%, 3/27) and PAasV-5 (7.41%, 2/27). Sequence analysis revealed that the 27 RdRp genes identified in this study had nucleotide homologies of 53.8-99.5%. In addition, the RdRp gene of PAstV-4 strain JL/MHK/2018/0115 harbored a unique insert of three nucleotides (GAA) as compared with other known PAstV-4 strains. Furthermore, the genotypes of PAstV varied among different geographical locations, although PAstV-2 was the most widely distributed in China. These data demonstrate that PAstV coinfection with other porcine pathogens was common and there was genetic diversity of PAstV in diarrheic piglets in China.

Genetic characterization and phylogenetic analysis of feline astrovirus from Anhui province in eastern China

This study aimed to explore the phylogenetic and molecular characteristics of feline astrovirus. A total of 33 fecal samples of domestic cats with or without diarrhea were collected from the Anhui province, and two positive samples were detected. The complete genome and ORF2 of the two strains were sequenced and phylogenetically analyzed. AH-1-2020 and AH-2-2020 displayed 83.4% homology, and their homologies with other reference strains were 75.3%-83.4% and 83.4%-95.0%, respectively. Phylogenetic tree analysis revealed that all strains could be classified into three different clusters; therefore, the mean amino acid genetic distances (p-dist) among the three clusters were estimated. The results suggested that the two strains and other FeAstV strains were grouped into three genotypes, with AH-1-2020 belonging to a novel genotype. High similarity was observed (65.9%-66.5% nucleotide identity and 63.8%-64.8% amino acid identity) in ORF2 between porcine astrovirus type 1 and AH-1-2020. Furthermore, inter-specific recombination between porcine astrovirus type 1 and FeAstV was observed. We, therefore, inferred that inter-specific transmission may exist between pigs and cats; however, further studies are required to verify this. This is the first report on the genetic characterization and phylogenetic analysis of FeAstVs in the Anhui province and would further the current understanding of the genetic diversity and epidemiology of FeAstVs.