First detection and genomic characterization of porcine circovirus 3 in mosquitoes from pig farms in China.

The porcine circovirus type 3 (PCV3) becomes an important causative agent of swine disease since its discovery in 2016. PCV3 infection exhibits a wide range of clinical syndromes causing substantial economic losses in swine industry. Previous studies have reported the detection of numerous known viruses including circovirus in mosquitoes. However, the transmission of PCV3 in field-caught mosquitoes remains largely unknown. This study aims to detect PCV3 infection in mosquitoes and analyze its genomic characteristics. Here, we performed a PCR to detect the PCV3 in 269 mosquito samples collected from pig farms located in Heilongjiang, Jilin, and Yunnan provinces. The proportion of PCV3-positive mosquitoes was 32.0 % (86/269), ranging from 21.4%-42.5% at farm level, which may imply that mosquito serves as a route of transmission for PCV3. To determine the possible origin of PCV3 in mosquitoes, 80 pig serum samples were collected from the pig farms where mosquito sampling was also performed. The proportion of PCV3-positive farms ranged from 15.0%-30.0 % in which infection of positive pigs positively correlated with mosquitoes carrying the virus. Additionally, we sequenced the entire genome of 6 strains of PCV3 in mosquitoes and 2 strains of PCV3 in pigs. Sequence analysis indicated a 100 % nucleotide similarity between mosquito and pig viral isolates that were all collected from similar farms. Phylogenetic analysis showed that PCV3 could be divided into two clades, PCV3a and PCV3b, and the PCV3 strains isolated in mosquitoes were distributed on the two clades. Our results demonstrate that mosquitoes may serve as a potential transmission vector in the life-cycle of PCV3, revealing possible transmission routes of PCV3.

Molecular detection and genomic characterization of porcine circovirus 3 in pigs from Northeast China.

BACKGROUND: First identified in the United States in 2016, porcine circovirus type 3 (PCV3) is a newly emerging porcine circovirus exhibiting a wide range of clinical syndromes, which may be associated with the pathogenicity observed in pigs. RESULTS: The aim of this study was to identify and characterize the full genome sequence of PCV3 strains circulating in Northeast China. Herein, 105 lung samples isolated from sick pigs in Northeast China during 2018 were analyzed for PCV3. Using PCR, the total PCV3-positive rate was 33.3% (35/105), with rates of 17.8% (8/45), 66.7% (10/15), and 37.8% (17/45) in Heilongjiang, Jilin, and Liaoning province, respectively. Additionally, our findings showed that PCV3-positive samples had a high rate of co-infection with PCV2, PPV6, and PPV7. To study the evolution of the PCV3 in Northeast China, we sequenced the entire genome of 13 strains of PCV3. The results of phylogenetic analyses revealed that PCV3 could be divided into two clades, PCV3a and PCV3b. Interestingly, a G deletion at position 1072 was found in the 1999 nt genome of PCV3-CN2018LN-4 (MH277118). The G deletion terminated replicase protein translation and induced a truncated replicase protein. CONCLUSION: These results contribute to the understanding of PCV3 molecular epidemiology and evolution in Northeast China. A new strain of PCV3 with truncated replicase protein was identified.

Dynamic changes of pulmonary lesions on CT in patients with severe acute respiratory syndrome treated by non-invasivc positive pressure ventilation / 中华放射学杂志

Objective To study the dynamic changes of pulmonary lesions of severe acute respiratory syndrome(SARS)treated by non-invasive positive pressure ventilation(NIPPV)on CT. Methods Serial chest CT images in 18 patients with SARS were retrospectively analyzed before and after NIPPV(4—12 days),and a long-term follow-up(3—36 months)examination by CT was carried out.And 27 SARS cases without NIPPV were enrolled as the control group.Results(1)There were dynamic changes in 15 cases of 18 cases:partial multilobar consolidations of bilateral lungs changed into ground-glass opacities in 7 of 18 cases,a circular pulmonary emphysema around bronchial vascular strains of the lower lobes was seen in 5 of 18,subpleural pulmonary emphysema was seen in 8 of 18,pulmonary barotraumas were showed in 2 of 18.Residual of subpleural curvilinear shadow related to NIPPV was found in 2 cases on the follow-up scan.(2)Above changes on CT were not found in 27 cases without NIPPV.Conclusion There were changes of pulmonary lesions of SARS on CT related to NIPPV treatment,It is beneficial to assess the CT images in the NIPPV treatment of the related pneumonia in SARS.

Genetic Diversity of Xanthomonas oryzae pv.oryzae Strains from China,Japan and Philippines / 微生物学通报

The IS-PCR and Rep-PCR were used to analyze 19 strains of Xanthomonas oryzae pv.oryzae from China,Japan and Philippines.Four specific primers,especially,IS1113 and ERIC could distinguish the strains from different countries.Using UPGMA analysis,most strains were in group 2 and 3.No relationship were observed between UPGMA groups and pathotypes.