RESUMEN
The aim of this study is to identify and characterize virus isolates (which are named for Bacgiang Agriculture and Forestry University [BAFU]) from diseased Cherry Valley duck and mule duck flocks and investigate the damage caused by a novel parvovirus-related virus (DuPV) to tissues and organs, including the brain, cerebellum, kidney, liver, lung, spleen, and spinal cord. The results of phylogenetic analysis show that DuPV-BAFU evolved from a goose lineage and duck parvoviruses rather than from Muscovy duck parvoviruses. In the genetic lineages, DuPVs were identified from the DuPV samples analyzed, and DuPV-BAFU was found to be closely clustered with two known goose origin parvoviruses (GPVa2006 and GPV1995) and a duck GPVs. Finally, structural modeling revealed that DuPV-BAFU and the closely related viruses GPVa2006 and GPV1995 possessed identical clusters of receptor-interacting amino acid residues in the VP3 protein, a major determinant of viral receptor binding and host specificity. Significantly, these three viruses differed from DuPVs, Muscovy duck parvoviruses, and other goose parvoviruses at these positions. These results also demonstrated that DuPV-BAFU represents a new variant of goose-origin parvovirus that currently circulates in ducklings and causes beak atrophy and dwarfism syndrome, as noted in the previous reports in Europe, Taiwan, and China. This new finding highlights the need for future surveillance of DuPV-BAFU in waterfowl in order to gain a better understanding of both the evolution and the biology of this emerging parvovirus in waterfowl.
Identificación molecular y patogenicidad de un nuevo parvovirus de ganso de origen en pato aislado del síndrome de atrofia del pico y enanismo de las aves acuáticas en el norte de Vietnam. El objetivo de este estudio es identificar y caracterizar aislados de virus detectados en la Universidad de Agricultura y Silvicultura de Bacgiang (BAFU) de parvadas de patos enfermos Cherry Valley e híbridos y también investigar el daño causado por un nuevo virus relacionado con parvovirus del pato (DuPV) en tejidos y órganos, incluidos el cerebro, el cerebelo, los riñones, el hígado, los pulmones, el bazo y la médula espinal. Los resultados del análisis filogenético mostraron que el virus DuPV-BAFU evolucionó a partir de un linaje de parvovirus de patos y gansos en lugar del parvovirus de patos reales. En los linajes genéticos, se identificaron virus DuPV a partir de las muestras de DuPV analizadas, y se encontró que el DuPV-BAFU estaba estrechamente agrupado con dos parvovirus conocidos de origen de ganso (GPVa2006 y GPV1995) y con parvovirus de pato. Finalmente, el modelado estructural reveló que el virus DuPV-BAFU y los virus estrechamente relacionados GPVa2006 y GPV1995 poseían grupos idénticos de residuos de aminoácidos que interactúan con el receptor en la proteína VP3, que es un determinante importante de la unión al receptor viral y la especificidad del huésped. Significativamente, estos tres virus diferían de los DuPV, los parvovirus del pato real y de otros parvovirus del ganso en estas posiciones. Estos resultados también demostraron que el virus DuPV-BAFU representa una nueva variante del parvovirus de origen ganso que actualmente circula en patitos y causa atrofia del pico y síndrome de enanismo, como se señaló en reportes anteriores en Europa, Taiwán y China. Este nuevo hallazgo destaca la necesidad de una vigilancia futura para el virus DuPV-BAFU en las aves acuáticas para comprender mejor tanto la evolución como la biología de este parvovirus emergente en las aves acuáticas.
Asunto(s)
Enanismo , Infecciones por Parvoviridae , Parvovirus , Enfermedades de las Aves de Corral , Aminoácidos , Animales , Atrofia/veterinaria , Pico/patología , Patos , Enanismo/patología , Enanismo/veterinaria , Infecciones por Parvoviridae/veterinaria , Parvovirinae , Parvovirus/genética , Filogenia , Vietnam , VirulenciaRESUMEN
There have been only a few antigen genes of Eimeria brunetti reported up to now. In this study, the gene encoding the microneme protein 2 (EbMIC2) was isolated from oocysts of E. brunetti by RT-PCR and the immunogenicity of recombinant EbMIC2 was observed. The EbMIC2 was cloned into vector pMD19-T for sequencing. The sequence was compared with the published EbMIC2 gene from GenBank revealed homology of the nucleotide sequence and amino acids sequence were 99.43 and 98.63%, respectively. The correct recombinant pMD-EbMIC2 plasmid was inserted into the pET-28a (+) expressing vector and transformed into competent Escherichia coli BL21 cells for expression. The expressed product was analyzed using SDS-PAGE and Western-blot. The results indicated that the recombinant EbMIC2 protein was recognized strongly by serum from naturally infected chicken with E. brunetti. Rat rcEbMIC2 antisera bound to bands of about 36 kDa in the somatic extract of E. brunetti sporozoites. The recombinant plasmid pVAX1-EbMIC2 was constructed and then the efficacies of recombinant plasmid and recombinant protein were evaluated. The results of IgG antibody level and cytokines concentration suggested that recombinant EbMIC2 could increase the IgG antibody level and induce the expressions of cytokines. Animal challenge experiments demonstrated that the recombinant EbMIC2 protein and recombinant plasmid pVAX1-EbMIC2 could significantly increase the average body weight gains, decrease the mean lesion scores and the oocyst outputs of the immunized chickens and presented high anti-coccidial index. All results suggested that EbMIC2 could become an effective candidate for the development of new vaccine against E. brunetti infection.
Asunto(s)
Pollos/parasitología , Coccidiosis/veterinaria , Brotes de Enfermedades/veterinaria , Eimeria/aislamiento & purificación , Enfermedades de las Aves de Corral/parasitología , Proteínas Protozoarias/aislamiento & purificación , Animales , Antígenos de Protozoos/genética , Antígenos de Protozoos/inmunología , China/epidemiología , Clonación Molecular , Coccidiosis/epidemiología , Coccidiosis/parasitología , ADN Complementario/química , ADN Complementario/metabolismo , Eimeria/inmunología , Regulación de la Expresión Génica , Sueros Inmunes/inmunología , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/prevención & control , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Vacunas Antiprotozoos/normas , ARN Protozoario/aislamiento & purificación , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Transcripción Reversa , Alineación de Secuencia/veterinaria , Vacunación/veterinaria , Vacunas Sintéticas/normasRESUMEN
This study aimed to determine the changes of cytokines, specific serum IgG and several parameters in chickens vaccinated with DNA vaccine encoding Eimeria brunetti apical membrane antigen-1 (EbAMA1) antigen. Two-week-old chickens were divided into five groups (four groups for experiment) randomly. Experimental groups of chickens were immunized with DNA vaccine while control group of chickens were injected with pVAX1 plasmid alone or TE buffer solution. All immunizations were boosted 2 weeks later. The EbAMA1 specific IgG antibody responses were measured at weeks 1-6 post-second immunizations and several parameters were also identified. The result showed that the antibody titers in chickens vaccinated with DNA vaccines were significantly different from those of the control groups 1 week after the second immunization and reached the maximum values 3 weeks post-second immunization. IFN-γ concentration was increased the highest level against EbAMA1 of all chickens vaccinated with vaccines up to 56-fold, follow by the specific IgG antibody levels were increased 10-17-fold compared with those of TE solution and plasmid (pVAX1) control chickens 1-6 weeks post-second immunization. In case of the levels of IL-10 and IL-17 was increased in experimental chickens with 4-5-fold. Even though it was statistically significant, TGF-ß and IL-4 levels were higher in vaccinated than unvaccinated chickens. The results suggested that DNA vaccines encoding E. brunetti apical membrane antigen-1 (EbAMA1) could increase serum specific IgG antibody and cytokines concentration and could give protection against E. brunetti infection.