To characterize the prevalence of viruses associated with grapevine leafroll disease in China, 249 grapevine (Vitis spp.) samples (86 popular cultivars and a rootstock) from 19 provinces and regions were collected and tested for Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, GLRaV-4, and GLRaV-4 strain 5 by SYBR Green real-time reverse-transcription polymerase chain reaction (RT-PCR), and RT-PCR and sequencing. GLRaV-3 was found in 100% of the samples while GLRaV-1, GLRaV-2, and GLRaV-4 were detected in 24.9% (62/249), 15.3% (38/249), and 0.80% (2/249) of the samples, respectively. Single infections with GLRaV-3 were found in 66.3% (165/249) of the samples, and the remaining samples were mixed infections of GLRaV-3 with one or two other GLRaVs, those with GLRaV-1 being the most common (18.5%, 46/249). The genetic variability of Chinese GLRaV-3 isolates was characterized based on the coat protein (CP) gene. In total, 153 full-length CP gene sequences (94 sequences newly generated) of Chinese GLRaV-3 isolates from different grapevine-growing regions showed 89.3 to 100.0% and 92.7 to 100.0% identity at the nucleotide and amino acid levels, respectively. The average nucleotide diversity for the population of Chinese GLRaV-3 isolates was estimated at 0.037 (standard error = 0.0032). GLRaV-3 isolates from China segregated into five distinct phylogenetic groups and two novel recombination events were found in the viral population. This is the first and most extensive report of the prevalent species of GLRaV in China, which also provides an assessment of genetic variability of GLRaV-3 Chinese isolates.

The pathogenesis of minimal change nephrotic syndrome (MCNS) remains unclear. Respiratory tract viruses could contribute to MCNS, and respiratory syncytial virus (RSV) is the most common one. In this study, we planned to investigate the effects of RSV on the proteinuria and glomerular structure of rats and to explore the role of RSV in the pathogenesis of MCNS. Rats were inoculated with 6 x 10(2), 10(4), and 10(6) PFU (plaque-forming units) RSV and killed on days 4, 8, 14, 28, and 60 postinoculation (RSV(4), RSV(8), RSV(14), RSV(28), and RSV(60)). The proteinuria and serum parameters were measured; renal histology was observed by light microscopy and electron microscopy; immune complex deposits were detected by immunofluorescence microscopy; and RSV RNA and RSV titer were determined by in situ hybridization and plaque assay, respectively. After inoculation, the proteinuria increased, especially in 6 x 10(6) PFU RSV(14),(28). The serum albumin of 6 x 10(6) PFU RSV(14),(28) and different-titer RSV(60) decreased. Slight hypercellularity in minority glomeruli and swelling in partial tubular epithelial cells were observed in RSV(4),(8), whereas a relief of the above changes and no abnormalities were detected in RSV(14) and RSV(28),(60), respectively, under a light microscope. Extensive foot process effacement was observed in 6 x 10(6) PFU RSV(14),(28),(60) under an electron microscope. No immune complex deposits were detected in the renal tissues. RSV RNA signal and RSV titer of renal tissues, depending on the dose of inoculum, reached their climax on day 8 postinoculation. Our study reports for the first time that RSV can lead to nephropathy in rats on days 14-60 postinoculation, especially in 6 x 10(6) PFU RSV-inoculated rats, which may be a new exploration of the pathogenesis of MCNS.