Since late 2010, porcine epidemic diarrhea virus (PEDV) has rapidly disseminated all over the China and caused considerable morbidity and high mortality (up to 100%) in neonatal piglets. 79.66% (141 of 177) pig farms in 29 provinces (excluding Tibet and Hainan, China) and 72.27% (417 of 577) samples were positive for PEDV confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The full-length S genes of representative field strains were sequenced. 33 field strains share 93.5%–99.9% homologies with each other at the nucleotide sequence level and 92.3%–99.8% homologies with each other at the amino acids sequence level. Most field strains have nucleotide deletion and insertion regions, and show lower homologies (93.5%–94.2%) with Chinese classical strain CH/S, however higher homologies (97.1%–99.3%) with recent strain CHGD-1. The phylogenetic analysis showed there are classical strains and variants prevailing in pig herd in China. PEDV has a high detection rate in pig herds in China. Sequence analysis indicated the S genes of recent field strains have heterogeneity and the variants are predominant.

Peanut stripe virus (PStV) is one of the most common viruses infecting peanut that causes great economic losses every year. The 3ʹ-terminal 1082 bp of 74 PStV isolates collected from 12 districts of Shandong province, China were sequenced. Their coat protein (CP) genes were 864 bp in length and shared identities of 98.0%~100% and 98.3% ~100% at nt and aa levels. The identities between the CP genes of these isolates and other 36 isolates from the GenBank were 93.5%~100% and 92.0%~100% at nt and aa levels, respectively. PStV isolates can be clustered into two phylogenetic groups. The isolates from United States, mainland China, and Indonesia formed group I and those from Viet Nam, Thailand, and Taiwan formed group II. The PStV isolates in group I can be further classified to two subgroups. The gene flow of PStV populations within a country was frequent, but that between countries was infrequent.

BackgroundPKV is a new emerging pathogen detected in diarrhea pigs. At present, no more detection methods were reported except RT-PCR method. this study was to develop a fast diagnostic method based on the LAMP reaction for rapid detection of PKV nucleic acid in fecal samples.FindingsTwo pairs of primers were designed to amplify the conservative 3D gene of PKV genome. The PKV RT-LAMP method possessed well specificity and had 100 times higher sensitivity than common reverse transcription PCR (RT-PCR), which could detect up to 10 RNA copies of the target gene.ConclusionsThe results showed that the optimal reaction condition for RT-LAMP was achieved at 64°C for 50 min. Furthermore, the RT-LAMP procedure does not demand special equipment and is time-saving.

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