Coincidental detection of genomes of porcine parvoviruses and porcine circovirus type 2 infecting pigs in Japan.

The infection status of 15 viruses in 120 pigs aged about 6 months was investigated based on tonsil specimens collected from a slaughterhouse. Only 5 species of porcine parvoviruses and porcine circovirus type 2 (PCV2) were detected at high frequencies; 67% for porcine parvovirus (PPV) (PPV-Kr or -NADL2 as the new abbreviation), 58% for PPV2 (CnP-PARV4), 39% for PPV3 (P-PARV4), 33% for PPV4 (PPV4), 55% for PBo-likeV (PBoV7) and 80% for PCV2. A phylogenetic analysis of PPV3 suggested that Japanese PPV3s showed a slight variation, and possibly, there were farms harboring homogeneous or heterogeneous PPV3s. Statistical analyses indicated that the detection of PCV2 was significantly coincidental with each detection of PPV, PPV2 and PPV3, and PPV and PPV4 were also coincidentally detected. The concurrent infection with PCV2 and porcine parvoviruses in the subclinically infected pigs may resemble the infection status of pigs with the clinical manifestations of porcine circovirus associated disease which occurs in 3-5 months old pigs and is thought to be primarily caused by the PCV2 infection.

Prevalence and genomic characterization of porcine parvoviruses detected in Chiangmai area of Thailand in 2011.

Porcine parvovirus (PPV) causes reproductive failure in sows and has spread worldwide. Several new types of porcine parvoviruses have recently been identified in pig herds. The prevalence of five porcine parvoviruses in the Chiangmai area of Thailand was studied. The prevalence in 80 pigs was 53% for PPV (PPV-Kr or -NADL2 being the new abbreviations), 83% for PPV2 (CnP-PARV4), 73% for PPV3 (P-PARV4), 44% for PPV4 (PPV4), and 18% for PBo-likeV (PBoV7). Over 60% of the pigs carried more than three of the five porcine parvoviruses and occurrence together of the two pairs of viral genes, PPV1/PPV3 and PPV2/PBo-likeV were observed. Phylogenetic analyses for PPV2 and PPV3 indicated the existence of only two major clades of PPV2 and one major clade of PPV3.

Coexistence of multiple strains of porcine parvovirus 2 in pig farms.

The porcine parvovirus 2 (PPV2) genome was first identified in 2001 in Myanmar. Recently, the PPV2 genome has been found in several other countries. In this study, the prevalence of PPV2 in Japanese domestic pigs was investigated and found to be 58% (69/120) in healthy domestic pigs and 100% (69/69) in sick domestic pigs. Sequencing and phylogenetic analysis of the PCR products of the VP1 gene and an almost full length PPV2 clone indicated that diverged PPV2 strains exist in Japan. Clearly distinct strains of PPV2 were detected in 7 of the 10 pig farms.

Analysis of the VP6 gene of human and porcine group A rotavirus strains with unusual subgroup specificities.

Full-length VP6 amino acid sequences of human and porcine rotaviruses with subgroup (SG) (I + II) and SG non-(I + II) were analyzed in comparison with those of SG I and SG II. In human rotaviruses, the strains in the same SG shared a very high degree of amino acid identity, ranging from 97.4% to 99.4% for SG I, 95.9% to 100% for SG II, and 99.4% to 100% for SG non-(I + II), while viruses in different SGs shared somewhat lower sequence identity at 90.4-93.1%. Conserved amino acids that distinguished the strains of SG I from SG II were observed at 21 positions. The viruses with SG non-(I + II) shared sequence identity with SG II as high as 97.2-99.7%, suggesting that they belonged to genogroup II. Similarly, porcine rotaviruses in the same SG shared 96.4-99.7% for SG I, 98.2-100% for SG II, 97.4-100% for SG (I + II), and 96.2-99.7% for SG non-(I + II), while strains in different SGs shared sequence identity ranging from 91.9% to 94.4%. Interestingly, the strains with SG (I + II) and SG non-(I + II) shared a high degree of sequence identity with SG I, at 96.4-100% and 94.7-99.7% respectively, suggesting that they are related to porcine SG I strains. The conserved amino acids which distinguished SG I from SG II were observed at 13 positions. The strains with SG I, SG (I + II), and SG non-(I + II) showed identical amino acid residues at these positions. Phylogenetic analysis strongly supported the findings of the sequence analysis.

Multiple combinations of P[13]-like genotype with G3, G4, and G5 in porcine rotaviruses.

Epidemiological surveillance of porcine rotavirus (PoRV) strains was carried out in Chiang Mai Province, Thailand, from 2002 to 2003, and eight rotavirus isolates could not be completely typed by PCR. Of these, six were G3 and one was G4 and displayed a P-nontypeable genotype, while another isolate was both G and P nontypeable. Analysis of a partial VP4 gene of all eight P-nontypeable strains revealed a high degree of amino acid sequence identities (94.7% to 100%), suggesting that they belonged to the same P genotype. Comparison of the amino acid sequences of two representative strains (namely, strains CMP178 and CMP213) with those of 27 other known P genotypes revealed a high degree of amino acid sequence identity with those of P[13] porcine rotavirus reference strains HP113 and HP140, which were recently isolated in India. However, amino acid sequence comparison with non-P[13] rotavirus strains revealed relatively low identities, ranging from 58.2% to 84.8% for full-length VP4 sequences and 35.1% to 80.6% for VP8* sequences. Phylogenetic analysis revealed that CMP178 and CMP213 clustered together in a monophyletic branch with P[13]-like genotypes HP113 and HP140 which was clearly separated from the other lineages of P[13] or P[22] strains. Altogether, these findings indicate that PoRV strains CMP178 and CMP213 should be considered the P[13]-like VP4 genotype, a rare genotype that has been identified only in pigs. This study provides additional evidence of increasing genetic diversity among group A rotaviruses in nature.

WITHDRAWN: Molecular Characterization of VP4 and VP7 Genes of Nontypeable Strains Identifies a Novel P[28] Genotype in Porcine Rotaviruses.

This article has been retracted.