RESUMEN
To determine whether the novel porcine parvovirus type 4 (PPV4) recently reported in America is prevalent in China, a set of specific primers was designed and used for molecular survey of PPV4 among the clinical samples collected from various provinces of China between 2006 and 2010. The results showed that PPV4 is present in Chinese swine herds at a rate of 2.09% (12/573) among the clinical samples examined and 0.76% (1/132) among the samples taken from healthy animals. We also noted that PPV4 was not detected in samples taken prior to 2009. Analysis of the coding sequences showed that the Chinese and American PPV4 genome sequences are closely related with greater than 99% nucleotide sequence identity. Similar to a previous study, viral genomes in head-to-tail configuration of various lengths of the non-coding region were detected. Our findings confirmed that PPV4 is a unique recently discovered virus in pigs. Phylogenetically, PPV4 is most closely related to bovine parvovirus 2 (BPV2, which is not a Bocavirus and is not assigned to any Parvovirinae genus) and shares limited ORF1 (33.6%) and ORF2 (24.5%) amino acid identity. With respect to genome structure and organization, PPV4 encodes an ORF3 in the middle of the viral genome that resembles the Bocavirus genus. However, the PPV4 ORF3 encoded protein shares minimal amino acid identity with the ORF3 encoded proteins of the Bocavirus genus.
Asunto(s)
Infecciones por Parvoviridae/veterinaria , Parvovirus Porcino/clasificación , Parvovirus Porcino/aislamiento & purificación , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/virología , Animales , China/epidemiología , Análisis por Conglomerados , Cartilla de ADN/genética , ADN Viral/química , ADN Viral/genética , Datos de Secuencia Molecular , Infecciones por Parvoviridae/epidemiología , Infecciones por Parvoviridae/virología , Parvovirus Porcino/genética , Filogenia , Prevalencia , Análisis de Secuencia de ADN , Homología de Secuencia , PorcinosRESUMEN
Nested RT-PCR was used to investigate bovine viral diarrhea virus in 511 specimens collected from Chinese pigs exhibiting clinical symptoms between 2007 and 2010. Of these, 137 samples were BVDV-positive and the BVDV prevalence rate was 23.1% (9/39) in 2007, 27.7% (44/159) in 2008, 33.6% (34/101) in 2009, and 23.6% (50/212) in 2010. Twenty of 137 BVDV-positive samples were used for further genetic analysis of the 5'-UTR. Phylogenetic analysis revealed that they were BVDV-1 and subtyped into BVDV-1a, BVDV-1b, BVDV-1m, BVDV-1o and an unknown subgenotype. This study showed that BVDVs were highly prevalent in Chinese pig herds and appropriate measures should be taken to control BVDV prevalence in pig herds.