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1.
Wei Sheng Yan Jiu ; 48(4): 545-559, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31601334

RESUMO

OBJECTIVE: Real-time reverse transcription-polymerase chain reaction(real-time RT-PCR) assay based on Taqman and phylogenetic tree were developed for detecting hepatitis E virus in swine feces of pig farms from several provinces and city. METHODS: Designing prime and probe refering to HEV genotype sequences of Genbank, we developed a Taqman-based real-time RT-PCR assay and nested RT-PCR according to HEV conserved domain after optimizing reaction system, then detected the prevalence of HEV infection of pig farms. RESULTS: The sensitivity of the real-time RT-PCR assay established in this experiment was 19. 9 copies/µL, the amplification efficiency was 92. 9%-109. 1%, there was no cross reaction with Sapovirus, Norovirus and Hepatitis A. A total of 342 samples of swine feces were detected. There were two hundred and ten positive samples, and positive rate was 61. 4%. The positive rate of before-fattening was 56. 6%, and after-fattening was 66. 9%. The positive rate of before and after fattening samples had statistical difference(χ~2=24. 8, P<0. 05). The genotype identification system determined that the positive strains isolated in this study were HEV-4 type, and three subtypes of 4 b, 4 d and 4 h were detected. CONCLUSION: The pig farms of several provinces and city are contaminated by HEV extensively. The genotypes of the isolated strains are all HEV-4 type. The infection rate and infection subtype of pigs in different provinces and cities are different.


Assuntos
Fezes/virologia , Vírus da Hepatite E , Epidemiologia Molecular , Animais , Genótipo , Hepatite E , Filogenia , RNA Viral , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Reversa , Suínos , Doenças dos Suínos/virologia
2.
Arch Virol ; 164(12): 3059-3063, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549301

RESUMO

Swine are the only known hosts of swinepox virus (SWPV), the sole member of the genus Suipoxvirus, family Poxviridae. Rapid diagnosis is recommended for appropriate interventions because of the high morbidity associated with this virus. This study describes a real-time quantitative PCR (qPCR) assay for rapid detection and quantification of SWPV. The detection limit, repeatability, reproducibility, and specificity of this assay were determined. The efficiency was 96%, and the R2 value was 0.996. The detection limit was 1 fg or 10-0.5 TCID50/50 µL. Tests showed that the greatest source of error in the SWPV qPCR assay was variation between analysts rather than different qPCR kits or equipment. All nucleic acids from other viruses or samples collected from swine were negative in the specificity test. qPCR for SWPV is a new method with tested variables that allows main sources of error in laboratory diagnosis and viral quantification to be identified.


Assuntos
Infecções por Poxviridae/diagnóstico , Suipoxvirus/genética , Doenças dos Suínos/virologia , Animais , DNA Viral/genética , Limite de Detecção , Infecções por Poxviridae/veterinária , Reação em Cadeia da Polimerase em Tempo Real , Suipoxvirus/classificação , Suipoxvirus/isolamento & purificação , Suínos
3.
Arch Virol ; 164(12): 2943-2951, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549302

RESUMO

This study was performed to investigate the prevalence and genetic variation of hepatitis E virus (HEV) in Tibetan pigs and to determine its ability to infect mice. A total of 38 out of 229 (16.59%; 95% CI = 12.00%-22.10%) fecal samples from Tibetan pigs from the Qinghai-Tibetan Plateau in 2018 were positive for HEV RNA, which was detected by RT-nPCR. Significantly different detection rates were observed between samples from diarrheic and clinically healthy animals (OR = 9.56; 95% CI, 2.84-32.14; p < 0.001), suggesting a potential association between HEV infection and diarrhea in Tibetan pigs. Phylogenetic analysis showed that the HEV isolates were clustered into subtypes 4a (31 samples), 4b (1), 4d (2), and 4j (4). HEV-4a was the predominant subtype, indicating that it might be circulating in Tibetan pigs. Nine complete HEV genome sequences obtained from Tibetan pigs were found by phylogenetic analysis to be closely related to those of genotype 4 HEV isolates from humans. Two recombinant events were identified in both HEV-4a strains; a novel recombination breakpoint was first identified at the 3' end of the ORF2 region in the SWU/L9/2018 strain, and a common recombination region was found at the junction of the ORF1 and ORF2 regions in the SWU/31-12/2018 strain. Furthermore, HEV-4a could be detected in all BALB/c mice that were experimentally infected by gavage and contact exposure. The information presented here about the prevalence and genotype diversity of HEV from Tibetan pigs provides important insights into the epidemic features of HEV on the Qinghai-Tibetan Plateau.


Assuntos
Vírus da Hepatite E/classificação , Hepatite E/epidemiologia , Doenças dos Suínos/virologia , Animais , Evolução Molecular , Variação Genética , Hepatite E/veterinária , Vírus da Hepatite E/genética , Vírus da Hepatite E/patogenicidade , Camundongos , Filogenia , Prevalência , RNA Viral/genética , Suínos , Doenças dos Suínos/epidemiologia , Tibet
4.
BMC Infect Dis ; 19(1): 778, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488066

RESUMO

BACKGROUND: A diagnostic method to simultaneously detect and discriminate porcine circovirus type 1 (PCV1), porcine circovirus type 2 (PCV2) and porcine circovirus type 3 (PCV3) in clinical specimens is imperative for the differential diagnosis and monitoring and control of PCVs in the field. METHODS: Three primer pairs were designed and used to develop a multiplex PCR assay. And 286 samples from 8 farms in Hubei province were tested by the developed multiplex PCR assay to demonstrate the accuracy. RESULTS: Each of target genes of PCV1, PCV2 and PCV3 was amplified using the designed primers, while no other porcine viruses genes were detected. The limit of detection of the assay was 10 copies/µL of PCV1, PCV2 OR PCV3. The results of the tissue samples detection showed that PCV1, PCV2 and PCV3 are co-circulating in central China. The PCV1, PCV2 and PCV3 singular infection rate was 52.4% (150/286), 61.2% (175/286) and 45.1% (129/286), respectively, while the PCV1 and PCV2 co-infection rate was 11.2% (32/286), the PCV1 and PCV3 co-infection rate was 5.9% (17/286), the PCV2 and PCV3 co-infection rate was 23.4% (67/286), and the PCV1, PCV2 and PCV3 co-infection rate was 1.7% (5/286), respectively, which were 100% consistent with the sequencing method and real-time PCR methods. CONCLUSIONS: The multiplex PCR assay could be used as a differential diagnostic tool for monitoring and control of PCVs in the field. The results also indicate that the PCVs infection and their co-infection are severe in Hubei province, Central China.


Assuntos
Infecções por Circoviridae/diagnóstico , Circovirus/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/virologia , Animais , China , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/classificação , Circovirus/genética , Diagnóstico Diferencial , Genes Virais , Incidência , Tipagem Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/epidemiologia , Virologia/métodos
5.
Arch Virol ; 164(11): 2725-2733, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31468140

RESUMO

Porcine reproductive and respiratory syndrome (PRRS) is one of the most highly infectious diseases in the pig industry, resulting in enormous economic losses worldwide. In this study, a PRRS virus (PRRSV) strain was isolated from primary porcine alveolar macrophage cells in Xinjiang in northwest China. This new strain was sequenced and designated as XJzx1-2015, and its sequence was then compared to those of other representative PRRSV strains from around the world. Complete genomic characterisation showed that the full-length nucleotide sequence of XJzx1-2015 exhibited low-level similarity to NB/04 (91.6%), JXA1 (90.5%), CH-1a (90.2%), VR-2332 (86.9%), QYYZ (85.7%), and JL580 (82.2%), with the highest similarity to HK13 (91.7%) sequence identity. Nonstructural protein 2 (NSP2) and glycosylated protein (GP) 2 of XJzx1-2015 had deletions of five and two amino acids, respectively, corresponding to strain VR-2332 positions 475-479 and 173-174. Phylogenetic analysis based on complete genome sequences showed that XJzx1-2015 and four other strains from China formed a new subgenotype closely related to other sublineage 8.7 (JXA1-like) strains belonging to the North American genotype. However, phylogenetic analysis based on NSP2 and GP5 showed that XJzx1-2015 clustered with sublineage 8.7 (JXA1-like, CH-1a-like) and lineage 3 (QYYZ-like) strains, respectively. Recombination analysis indicated that XJzx1-2015 is an intersubgenotype recombinant of CH-1a-like and QYYZ-like strains. Overall, our findings demonstrate that XJzx1-2015 is a novel PRRSV strain with a significantly high frequency of mutation and a recombinant between lineage 3 and sublineage 8.7 identified in northwest China. These results provide important insights into PRRSV evolution.


Assuntos
Genoma Viral/genética , Síndrome Respiratória e Reprodutiva Suína/epidemiologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Doenças dos Suínos/epidemiologia , Sequência de Aminoácidos , Animais , China/epidemiologia , Macrófagos Alveolares/virologia , Filogenia , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , RNA Viral/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Suínos , Doenças dos Suínos/virologia
6.
J Vet Sci ; 20(4): e32, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364317

RESUMO

The recent emergence and re-emergence of porcine epidemic diarrhea virus (PEDV) underscore the urgent need for the development of novel, safe, and effective vaccines against the prevailing strain. In this study, we generated a cold-adapted live attenuated vaccine candidate (Aram-P29-CA) by short-term passage of a virulent PEDV isolate at successively lower temperatures in Vero cells. Whole genome sequencing identified 12 amino acid changes in the cold-adapted strain with no insertions and deletions throughout the genome. Animal inoculation experiments confirmed the attenuated phenotype of Aram-P29-CA virus in the natural host. Pregnant sows were orally administered P29-CA live vaccines two doses at 2-week intervals prior to parturition, and the newborn piglets were challenged with the parental virus. The oral homologous prime-boost vaccination of P29-CA significantly improved the survival rate of the piglets and notably mitigated the severity of diarrhea and PEDV fecal shedding after the challenge. Furthermore, strong antibody responses to PEDV were detected in the sera and colostrum of immunized sows and in the sera of their offspring. These results demonstrated that the cold-adapted attenuated virus can be used as a live vaccine in maternal vaccination strategies to provide durable lactogenic immunity and confer passive protection to litters against PEDV.


Assuntos
Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinas Virais/farmacologia , Animais , Animais Recém-Nascidos , Cercopithecus aethiops , Temperatura Baixa , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Feminino , Genótipo , Vírus da Diarreia Epidêmica Suína/genética , Gravidez , Distribuição Aleatória , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas Atenuadas/farmacologia , Células Vero
7.
J Vet Sci ; 20(4): e35, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364320

RESUMO

The major immunogenic protein capsid (Cap) of porcine circovirus type 2 (PCV2) is critical to induce neutralizing antibodies and protective immune response against PCV2 infection. This study was conducted to investigate the immune response of recombinant adenovirus expressing PCV2b Cap and C-terminal domain of Yersinia pseudotuberculosis invasin (Cap-InvC) fusion protein in pigs. The recombinant adenovirus rAd-Cap-InvC, rAd-Cap and rAd were generated and used to immunize pigs. The phosphate-buffered saline was used as negative control. The specific antibodies levels in rAd-Cap-InvC and ZJ/C-strain vaccine groups were higher than that of rAd-Cap group (p < 0.05), and the neutralization antibody titer in rAd-Cap-InvC group was significantly higher than those of other groups during 21-42 days post-immunization (DPI). Moreover, lymphocyte proliferative level, interferon-γ and interleukin-13 levels in rAd-Cap-InvC group were increased compared to rAd-Cap group (p < 0.05). After virulent challenge, viruses were not detected from the blood samples in rAd-Cap-InvC and ZJ/C-strain vaccine groups after 49 DPI. And the respiratory symptom, rectal temperature, lung lesion and lymph node lesion were minimal and similar in the ZJ/C-strain and rAd-Cap-InVC groups. In conclusion, our results demonstrated that rAd-Cap-InvC was more efficiently to stimulate the production of antibody and protect pigs from PCV2 infection. We inferred that InvC is a good candidate gene for further development and application of PCV2 genetic engineering vaccine.


Assuntos
Vacinas contra Adenovirus/administração & dosagem , Proteínas do Capsídeo/imunologia , Infecções por Circoviridae/veterinária , Circovirus/imunologia , Imunização/veterinária , Doenças dos Suínos/prevenção & controle , Adesinas Bacterianas/genética , Adesinas Bacterianas/imunologia , Animais , Infecções por Circoviridae/prevenção & controle , Infecções por Circoviridae/virologia , Feminino , Proteínas Recombinantes/imunologia , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas Sintéticas/administração & dosagem , Yersinia pseudotuberculosis/genética
8.
J Vet Sci ; 20(4): e42, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364326

RESUMO

Foot-and-mouth disease (FMD) is an acute epidemic that spreads rapidly among cattle and pigs. In 2014, in Korea, despite enforced vaccination, the type O Southeast Asia (SEA) topotype viruses (Mya-98 lineage) infected mainly cattle and pigs simultaneously, thereby causing enormous damage. If a vaccine that is completely protective against this FMD virus is developed and used, it can become a very important preventive measure in Asia, which is where this type of virus mainly circulates. The SEA topotype has been steadily evolving and transforming into new variations since it became epidemic in Asia. Therefore, it became necessary to develop a new vaccine that could provide protection against the FMD virus strain that was responsible for the 2014-2015 outbreak in Korea. This study aimed to develop a vaccine that would provide complete protection against the SEA topotype FMD virus to control sporadic FMD outbreaks, which occur despite the enforcement of vaccination, and to completely prevent virus shedding, thereby preventing the virus from spreading. The vaccine candidate virus developed in this study showed low pathogenicity and can be distinguished from the wild-type FMD virus strain. The developed vaccine was able to protect mice from SEA and Middle East-South Asia topotype virus strains and induced high titers of antibodies against both virus strains in pigs, thereby confirming the sufficiency of its protective function. In particular, the results of the SEA topotype virus challenge test in pigs revealed that perfect immunity was created in the vaccinated pigs, without virus shedding and viremia.


Assuntos
Vírus da Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Doenças dos Suínos/prevenção & controle , Vacinas Virais/farmacologia , Animais , Febre Aftosa/imunologia , Febre Aftosa/virologia , República da Coreia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/virologia
9.
Vet Microbiol ; 235: 86-92, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31282383

RESUMO

Although PCV2 infections generally cause mild disease in pigs, concurrent co-infections with other pathogens can damage the immune system and cause more severe diseases, collectively termed porcine circovirus associated diseases (PCVAD). Involvement of porcine parvovirus (PPV, a common cause of reproductive failure in naïve dams) in PCVAD caused by PCV2, has been reported. As this co-infection can be difficult to eliminate, there is a critical need to develop an effective vaccine to protect against PPV or synergistic effects of PCV2 and PPV under field conditions. In this study, we designed chimeric PCV2 virus-like particles (cVLPs) displaying a B-cell epitope derived from PPV1 structural protein around the surface of the 2-fold axes of PCV2 VLPs, based on 3D-structure analysis of the PCV2 capsid. The cVLPs were successfully prepared, verified by transmission electron microscopy and chromatography, with robust antibody titers against PCV2 and PPV1 produced in mice and guinea pigs. In addition, in guinea pigs challenged with 106 TCID50 PCV2, cVLPs conferred more effective immune protection (based on viral load) than a commercial PCV2 vaccine. Finally, antibody responses and immune protection against PPV were also evaluated. In guinea pigs vaccinated with cVLPs, although PPV antibodies detected by a hemagglutination inhibition (HI) assay appeared later after vaccination in the PCV2 cVLPs group than in the commercial PPV vaccine group, there were fewer PPV genomic DNA copies in the PCV2 cVLPs group than in a PBS group. In conclusion, guinea pigs vaccinated with cVLPs developed effective protective immunity against PCV2 challenge, with some protective immunity against PPV. This study provided valuable research data to pursue molecular design of chimeric epitopes PCV2 VLPs.


Assuntos
Infecções por Circoviridae/veterinária , Coinfecção/veterinária , Epitopos de Linfócito B/imunologia , Imunidade Humoral , Infecções por Parvoviridae/veterinária , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Linfócitos B/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Circovirus/imunologia , Coinfecção/virologia , Feminino , Cobaias , Camundongos , Infecções por Parvoviridae/imunologia , Infecções por Parvoviridae/prevenção & controle , Parvovirus Suíno/imunologia , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Vacinas Atenuadas/imunologia , Vacinas de Partículas Semelhantes a Vírus/imunologia
10.
Emerg Microbes Infect ; 8(1): 1017-1026, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31287780

RESUMO

Host switch events of influenza A viruses (IAVs) continuously pose a zoonotic threat to humans. In 2013, swine-origin H1N1 IAVs emerged in dogs soon after they were detected in swine in the Guangxi province of China. This host switch was followed by multiple reassortment events between these H1N1 and previously circulating H3N2 canine IAVs (IAVs-C) in dogs. To evaluate the phenotype of these newly identified viruses, we characterized three swine-origin H1N1 IAVs-C and one reassortant H1N1 IAV-C. We found that H1N1 IAVs-C predominantly bound to human-type receptors, efficiently transmitted via direct contact in guinea pigs and replicated in human lung cells. Moreover, the swine-origin H1N1 IAVs-C were lethal in mice and were transmissible by respiratory droplets in guinea pigs. Importantly, sporadic human infections with these viruses have been detected, and preexisting immunity in humans might not be sufficient to prevent infections with these new viruses. Our results show the potential of H1N1 IAVs-C to infect and transmit in humans, suggesting that these viruses should be closely monitored in the future.


Assuntos
Doenças do Cão/virologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/virologia , Animais , China , Doenças do Cão/mortalidade , Cães , Feminino , Cobaias , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Influenza Humana/mortalidade , Influenza Humana/virologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/mortalidade , Infecções por Orthomyxoviridae/virologia , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/isolamento & purificação , Vírus Reordenados/patogenicidade , Suínos , Doenças dos Suínos/mortalidade , Virulência
11.
Emerg Microbes Infect ; 8(1): 989-999, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31267843

RESUMO

It has recently been proposed that the Eurasian avian-like H1N1 (EA H1N1) swine influenza virus (SIV) is one of the most likely zoonotic viruses to cause the next influenza pandemic. Two main genotypes EA H1N1 viruses have been recognized to be infected humans in China. Our study finds that one of the genotypes JS1-like viruses are avirulent in mice. However, the other are HuN-like viruses and are virulent in mice. The molecular mechanism underlying this difference shows that the NP gene determines the virulence of the EA H1N1 viruses in mice. In addition, a single substitution, Q357K, in the NP protein of the EA H1N1 viruses alters the virulence phenotype. This substitution is a typical human signature marker, which is prevalent in human viruses but rarely detected in avian influenza viruses. The NP-Q357K substitution is readily to be occurred when avian influenza viruses circulate in pigs, and may facilitate their infection of humans and allow viruses also carrying NP-357K to circulate in humans. Our study demonstrates that the substitution Q357K in the NP protein plays a key role in the virulence phenotype of EA H1N1 SIVs, and provides important information for evaluating the pandemic risk of field influenza strains.


Assuntos
Vírus da Influenza A Subtipo H1N1/patogenicidade , Influenza Humana/virologia , Mutação de Sentido Incorreto , Infecções por Orthomyxoviridae/veterinária , Proteínas de Ligação a RNA/genética , Doenças dos Suínos/virologia , Proteínas do Core Viral/genética , Animais , China , Feminino , Genótipo , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Orthomyxoviridae/virologia , Filogenia , Proteínas de Ligação a RNA/metabolismo , Suínos , Proteínas do Core Viral/metabolismo , Virulência , Replicação Viral
12.
Arch Virol ; 164(10): 2519-2523, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31270607

RESUMO

A newly identified atypical porcine pestivirus (APPV) associated with congenital tremors in newborn piglets has been shown to have a worldwide geographic distribution. In view of the function of Erns in pestivirus infection and replication, the viral load and histological distribution of APPV in different tissues of naturally infected piglets were analyzed by quantitative RT-PCR and immunohistochemical detection using Erns as the target. The results showed that the viral copy number was higher in the cerebellum, submandibular lymph nodes, and thymus than in other tissues, indicating that these are important target organs of APPV. The histological distribution of APPV was mainly in the matrix and nerve fiber in nervous tissues, endothelial cells in lymphoid tissues, and epithelial cells in other tissues, suggesting that these cells were target cells of APPV. The results will provide basic data for elucidating the pathogenesis and deepening the understanding of this newly discovered pathogen.


Assuntos
Estruturas Animais/virologia , Animais Recém-Nascidos , Infecções por Pestivirus/veterinária , Pestivirus/isolamento & purificação , Doenças dos Suínos/virologia , Suínos , Carga Viral , Animais , Imuno-Histoquímica , Infecções por Pestivirus/virologia , Reação em Cadeia da Polimerase em Tempo Real
13.
Arch Virol ; 164(10): 2435-2449, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31273470

RESUMO

A total of 472 samples from domestic pigs collected in China from 2015 to 2018 were tested for the presence of porcine circovirus types 2 and 3 (PCV2 and PCV3, respectively) by conventional polymerase chain reaction analysis. The prevalence of PCV2, PCV3, and PCV2/3 co-infection was 50.0%, 13.3%, and 6.78%, respectively. The complete genomic sequences of 66 PCV2 isolates and four PCV3 isolates were determined. Based phylogenetic analysis, the PCV2 isolates were assigned to three genotypes, PCV2a, PCV2b, and PCV2d, representing 13.6% (9/66), 25.8% (17/66), and 60.6% (40/66) of the total, respectively. All four PCV3 isolates shared a high degree of similarity in their complete nucleotide sequences (98.8-99.8% identity) and ORF2 amino acid sequences (98.6-99.5% identity). These results indicate that all three PCV2 genotypes (PCV2a, PCV2b, and PCV2d) are present on pig farms and that PCV2d has become the predominant genotype. The predicted amino acid sequences of the four PCV3 isolates indicated that PCV3-CN-JL53/PCV3-CN-LN56, PCV3-CN-HLJ3, and PCV3-CN-0710, belonged to the genotypes PCV3a, PCV3b, and PCV3a-IM, respectively. In view of the great harm that PCV2 causes to the pig industry, the epidemic trend of PCV3 should continue to be closely monitored. This study provides information about the prevalence, genetic diversity, and molecular epidemiology of PCV2 and PCV3 in China from 2015 to 2018.


Assuntos
Infecções por Circoviridae/veterinária , Circovirus/classificação , Circovirus/isolamento & purificação , Variação Genética , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/virologia , Animais , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Circovirus/genética , Fazendas , Genótipo , Epidemiologia Molecular , Reação em Cadeia da Polimerase , Prevalência , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Sus scrofa , Suínos
14.
Arch Virol ; 164(10): 2621-2625, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31350613

RESUMO

Porcine epidemic diarrhea virus (PEDV) is a deadly epizootic swine coronavirus that is of importance to the world pork industry. Since the re-emergence of the virulent genotype 2b (G2b) in 2014, Jeju Island in South Korea has faced periodic outbreaks, leading to the occurrence of endemics in provincial herds. In this study, we examined the complete genome sequences and molecular characteristics of novel G2b PEDV variants with a two-amino-acid deletion in the neutralizing epitope of the spike (S) gene, which were concurrently identified on a re-infected farm and its neighboring farm on Jeju Island. Whole-genome sequencing of the Jeju S-DEL isolates KNU-1829 and KNU-1830 revealed the presence of a continuous 9-nucleotide deletion within the nonstructural protein coding region. Their genomes were 28,023 nucleotides in length, 15 nucleotides shorter than those of the classical G2b PEDV strains. The two S-DEL isolates had 96.4-99.2% and 98.3-99.7% identity at the S-gene and full-genome level, respectively, to other global G2b PEDV strains. Genetic and antigenic analyses indicated that the S-DEL isolates are most closely related to the primary strain identified from the initial exposure at the same farm, but the virus appears to undergo continuous evolution, possibly leading to antigenic drift under recurrent or endemic pressure. This study provides important information about the antigenic diversity of PEDV circulating in the endemic areas, which arises from continuous non-lethal mutations to ensure viral fitness in the host environment.


Assuntos
Infecções por Coronavirus/veterinária , Surtos de Doenças , Genoma Viral , Vírus da Diarreia Epidêmica Suína/genética , Deleção de Sequência , Glicoproteína da Espícula de Coronavírus/genética , Doenças dos Suínos/virologia , Animais , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Fazendas , Ordem dos Genes , Ilhas/epidemiologia , Filogenia , Vírus da Diarreia Epidêmica Suína/classificação , Vírus da Diarreia Epidêmica Suína/isolamento & purificação , RNA Viral/genética , República da Coreia/epidemiologia , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Suínos , Doenças dos Suínos/epidemiologia , Proteínas não Estruturais Virais/genética
15.
Environ Pollut ; 253: 358-364, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325880

RESUMO

Spread of pathogens in pig farms not only causes transfection of diseases to other pigs or even farmers working in the farms, but also induces pollution to the living atmospheric environment of the residents around the farm. Therefore, it is necessary to establish a rapid and simple monitoring method. In this study, full genome sequences of common viruses were analyzed in pig farms, in combination with the design of primers, optimization of the reaction parameters, so as to establish a multiplex RT-PCR assay for the identification of classical swine fever virus (CSFV), Japanese encephalitis virus (JEV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus Type 2 (PCV-2), porcine pseudorabies virus (PRV) and porcine parvovirus virus (PPV), which are common in pig farms. This method has a minimal detectable concentration of 10-3 ng/µL, which is highly specific. Furthermore, multiplex RT-PCR was applied to examine air samples from 4 pig farms located in different cities of China. The results were in line with those obtained by single PCR. Therefore, this study can be expected to provide essential technique support for the early warning mechanism as well as disease prevention and control system against the major viruses.


Assuntos
Microbiologia do Ar , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Vírus , Animais , China , Circovirus , Primers do DNA , Fazendas , Reação em Cadeia da Polimerase Multiplex , Vírus da Síndrome Respiratória e Reprodutiva Suína , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Suínos , Doenças dos Suínos/virologia
16.
Lett Appl Microbiol ; 69(4): 258-263, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278766

RESUMO

Porcine epidemic diarrhoea virus (PEDV) causes severe diarrhoea in neonatal suckling piglets with a high mortality. Maternal vaccines that can induce lactogenic immunity to protect suckling piglets via colostrums and milk are pivotal for the prevention and control of PEDV infection in neonatal suckling piglets. In this study, a group of pregnant sows were first orally immunized with coated PEDV-loaded microspheres and boosted with killed PEDV vaccines (heterologous prime-boost). It has been detected that the levels of PEDV-specific antibodies (IgG and IgA) in their sera and milks were higher than other negative groups (P < 0·001 or P < 0·05). Furthermore, it has been proved by the neutralization assay that the induced antibodies could significantly inhibit virus infection as compared to other negative groups (P < 0·01 or P < 0·05). Importantly, after PEDV challenge, more than 90% of the suckling piglets delivered by the sows in the heterologous prime-boost group were completely protected. Overall, the results show that 'heterologous prime-boost' form is an efficient and effective way to provide protection for suckling piglets against PEDV through lactogenic immunity. SIGNIFICANCE AND IMPACT OF THE STUDY: As a widespread swine pathogen, PEDV affects the swine industry enormously. It causes enteritis in swine of all ages and is often fatal in neonatal piglets. Our data show that pregnant sows were immunized with 'coated PEDV-loaded microspheres + killed PEDV vaccines' (heterologous prime-boost immunization) could protect more than 90% suckling piglets delivered by the sows against the virus. These findings provide a new model of developing safe and effective immunizations for newborn animals against established and emerging enteric infections.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Vírus da Diarreia Epidêmica Suína/imunologia , Doenças dos Suínos/prevenção & controle , Animais , Infecções por Coronavirus/virologia , Diarreia/prevenção & controle , Diarreia/veterinária , Diarreia/virologia , Feminino , Leite , Gravidez , Suínos , Doenças dos Suínos/virologia , Vacinação
17.
Arch Virol ; 164(9): 2351-2354, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31222429

RESUMO

Porcine bocavirus (PBoV), which belongs the genus Bocaparvovirus, has been identified throughout the world. However, serological methods for detecting anti-PBoV antibodies are presently limited. In the present study, an indirect enzyme-linked immunosorbent assay (PBoV-rNP1 ELISA) based on a recombinant form of nucleoprotein 1 (NP1) of PBoV was established for investigating the seroprevalence of PBoV in 2025 serum specimens collected in north-central China from 2016 to 2018, and 42.3% of the samples tested positive for anti-PBoV IgG antibodies, indicating that the seroprevalence of PBoV is high in pig populations in China.


Assuntos
Anticorpos Antivirais/sangue , Bocavirus/isolamento & purificação , Nucleoproteínas/imunologia , Infecções por Parvoviridae/veterinária , Doenças dos Suínos/virologia , Animais , Anticorpos Antivirais/imunologia , Bocavirus/classificação , Bocavirus/genética , China/epidemiologia , Ensaio de Imunoadsorção Enzimática , Nucleoproteínas/genética , Infecções por Parvoviridae/sangue , Infecções por Parvoviridae/epidemiologia , Infecções por Parvoviridae/virologia , Filogenia , Estudos Soroepidemiológicos , Suínos , Doenças dos Suínos/sangue , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia
18.
Vet Microbiol ; 234: 1-7, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31213264

RESUMO

Hepatitis E virus is a zoonotic pathogen for which pigs have been identified as the main reservoir in industrialised countries. HEV infection dynamics in pig herds and pigs are influenced by several factors, including herd practices and possibly co-infection with immunomodulating viruses. This study therefore investigates the impact of porcine circovirus type 2 (PCV2) on HEV infection and transmission through experimental HEV/PCV2 co-infection of specific-pathogen-free pigs. No statistical difference between HEV-only and HEV/PCV2-infected animals was found for either the infectious period or the quantity of HEV shed in faeces. The HEV latency period was shorter for HEV/PCV2 co-infected pigs than for HEV-only infected pigs (11.6 versus 12.3 days). Its direct transmission rate was three times higher in cases of HEV/PCV2 co-infection than in cases of HEV-only infection (0.12 versus 0.04). On the other hand, the HEV transmission rate through environmental accumulation was lower in cases of HEV/PCV2 co-infection (4.3·10-6 versus 1.5·10-5 g/RNA copies/day for HEV-only infected pigs). The time prior to HEV seroconversion was 1.9 times longer in HEV/PCV2 co-infected pigs (49.4 versus 25.6 days for HEV-only infected pigs). In conclusion, our study shows that PCV2 affects HEV infection and transmission in pigs under experimental conditions.


Assuntos
Infecções por Circoviridae/veterinária , Coinfecção/veterinária , Hepatite E/veterinária , Doenças dos Suínos/transmissão , Animais , Circovirus/fisiologia , Coinfecção/virologia , Fezes/virologia , Hepatite E/transmissão , Vírus da Hepatite E , Distribuição Aleatória , Organismos Livres de Patógenos Específicos , Suínos , Doenças dos Suínos/virologia , Latência Viral , Eliminação de Partículas Virais
19.
J Appl Microbiol ; 127(3): 658-669, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31183947

RESUMO

AIMS: Purification of porcine circovirus type 2 (PCV2) using Gram-positive enhancer matrix (GEM) surface display technology and immunogenicity evaluation of the purified antigen. METHODS AND RESULTS: A recombinant bifunctional protein containing a protein anchor domain and a 'virus anchor' domain was designed as a protein linker (PL) between PCV2 and GEM particles. By incubating with PL and GEM particles sequentially, PCV2 could be purified and enriched through a simple centrifugation process with GEM surface display technology. Our data showed that one unit (2·5 × 109 particles) of GEM particles with 80 µg PL could purify 100 ml of PCV2-containing culture supernatant (viral titre: 106·5 TCID50 per ml-1 ) with a recovery rate up to 99·6%. The impurity removal efficiency of this method, calculated according to decreased total protein content during purification, was approximately 98%. Furthermore, in vivo experimentation showed that piglets immunized with purified PCV2 could elicit strong immune responses to prevent against PCV2 infection. CONCLUSION: Porcine circovirus type 2 could be efficiently purified and enriched with GEM display technology via a crucial PL, and the purified PCV2 could elicit effective immune responses against PCV2 infection. SIGNIFICANCE AND IMPACT OF THE STUDY: The GEM-based purification method established here is cost-efficient and high-throughput, and may represent a promising large-scale purification method for PCV2 vaccine production.


Assuntos
Circovirus/imunologia , Vacinas Virais/imunologia , Vacinas Virais/isolamento & purificação , Animais , Técnicas de Visualização da Superfície Celular , Infecções por Circoviridae/prevenção & controle , Proteínas Recombinantes , Suínos , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia
20.
J Vet Med Sci ; 81(8): 1074-1079, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31155550

RESUMO

The incidence of diseases caused by nontuberculous mycobacteria (NTM) is increasing annually worldwide, including Japan. Mycobacterium avium subsp. hoiminissuis (MAH) is one of the most common NTM species responsible for chronic lung diseases in animals and humans. In the current study, mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing was employed to characterize the genetic diversity of swine MAH isolates from Kyushu, Japan. In total, 309 isolates were obtained from the lymph nodes of 107 pigs not displaying any clinical signs of disease, of which 307 were identified as MAH, comprising 173 strains. Based on eight established MIRU-VNTR loci, the MAH strains represented 50 genotypes constituting three lineages, and 29 had not been described in the Mac French National Institute for Agricultural Research Nouzilly MIRU-VNTR (Mac-INMV) database. MAH was the dominant M. avium complex (MAC) in pigs from Kyushu, and there was high genetic diversity among genotype profiles of MAH from Kyushu. We identified three predominant genotype profiles in the tested area sharing high relatedness with genotype profiles of strains isolated in European countries. MAH was the most common NTM in pigs from Kyushu and exhibited high diversity, with new strain-derived genotypes.


Assuntos
Pneumopatias/veterinária , Infecções por Mycobacterium/veterinária , Mycobacterium avium/classificação , Doenças dos Suínos/virologia , Animais , Variação Genética , Genótipo , Japão , Pneumopatias/virologia , Linfonodos/virologia , Repetições Minissatélites , Tipagem Molecular , Infecções por Mycobacterium/virologia , Mycobacterium avium/genética , Mycobacterium avium/isolamento & purificação , Suínos
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