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Phylogenetic and epidemiological characteristics of H9N2 avian influenza viruses in Shandong Province, China from 2019 to 2021

ZHAO Yi-ran, ZHAO Yu-zhong, LIU Si-dang, XIAO Yi-hong, LI Ning, LIU Kui-hao, MENG Fan-liang, ZHAO Jun, LIU Meng-da, LI Bao-quan
2023, 22 (3): 881-896.   DOI: 10.1016/j.jia.2022.08.114
Abstract240)      PDF in ScienceDirect      

H9N2 avian influenza virus (AIV) has widely circulated in poultry worldwide and sporadic infections in humans and mammals.  During our surveillance of chicken from 2019 to 2021 in Shandong Province, China, we isolated 11 H9N2 AIVs.  Phylogenetic analyses showed that the eight gene segments of the 11 isolates were closely related to several sublineages of Eurasian lineage: BJ/94-like clades (HA and NA genes), G1-like clades (PB2 and M genes), and SH/F/98-like clades (PB1, PA, NP and NS genes).  The isolates showed mutation sites that preferentially bind to human-like receptors (HA) and mammalian fitness sites (PB2, PB1 and PA), as well as mutations in antigen and drug resistance sites.  Moreover, studies with mice revealed four isolates with varying levels of pathogenicity.  The average antibody titer of the H9N2 AIVs was 8.60 log2.  Based on our results, the epidemiological surveillance of H9N2 AIVs should be strengthened.

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Identification of an H1N1 subtype of swine influenza virus and serological analysis
SUN Fa-chao, TAN Min, ZHANG Yuan-chao, WANG Yu-chao, CAO Sheng-liang, DING Guo-fei, CONG Fang-yuan, GUO Li-hong, LIU Si-dang, XIAO Yi-hong
2019, 18 (7): 1436-1442.   DOI: 10.1016/S2095-3119(19)62579-7
Abstract229)      PDF in ScienceDirect      
To investigate the epizootic of swine influenza virus (SIV), 60 nasal swabs were collected from a clinical cases of pig farm in Tai’an City, Shandong Province of China in April 2017.  SIV was isolated by inoculating into 10-day-old Special Pathogen Free embryonated eggs and the whole genome was sequenced.  An H1N1 subtype SIV was isolated and designated as A/swine/Shandong/TA04/2017(H1N1).  Phylogenetic analysis showed that apart from the polymerase A (PA) fragment belonging to the 2009 pandemic H1N1 branch, seven genome segments belonged to avian-like H1N1 influenza virus lineage.  The cleavage site sequence of the hemagglutinin (HA) protein was PSIQSR↓G, which is a typical molecular biological characteristic.  Five potential N-glycosylation sites (N14, N26, N277, N484 and N543) were found in the HA gene.  To further investigate the epidemiology of SIV in this farm, the 995 serum samples were assessed with EAH1N1 2009 pandemic H1N1 and H3N2 antigens.  The results showed that the total positive rate was 65.43%.  The positive rates of single virus infection detected by EAH1N1, 2009pdmH1N1 and H3N2 for serum HI (Hemagglutination inhibition) were 48.35, 30.85 and 7.47%, respectively.  The results showed that SIV in Shandong Province has been reassorted in some segments and the SIV-positive rate was high on the SIV outbreak farm.  These data provide evidence of an epizootic of SIV.
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Spatial variability of soil total nitrogen, phosphorus and potassium in Renshou County of Sichuan Basin, China
GAO Xue-song, XIAO Yi, DENG Liang-ji, LI Qi-quan, WANG Chang-quan, LI Bing, DENG Ou-ping, ZENG Min
2019, 18 (2): 279-289.   DOI: 10.1016/S2095-3119(18)62069-6
Abstract356)      PDF (3400KB)(734)      
Understanding soil nutrient distributions and the factors affecting them are crucial for fertilizer management and environmental protection in vulnerable ecological regions.  Based on 555 soil samples collected in 2012 in Renshou County, located in the purple soil hilly area of Sichuan Basin, China,  the spatial variability of soil total nitrogen (TN), total phosphorus (TP) and total potassium (TK) was studied with geostatistical analysis and the relative roles of the affecting factors were quantified using regression analysis.  The means of TN, TP and TK contents were 1.12, 0.82 and 9.64 g kg–1, respectively.  The coefficients of variation ranged from 30.56 to 38.75% and the nugget/sill ratios ranged from 0.45 to 0.61, indicating that the three soil nutrients had moderate variability and spatial dependence.  Two distribution patterns were observed.  TP and TK were associated with patterns of obvious spatial distribution trends while the spatial distribution of TN was characterized by higher variability.  Soil group, land use type and topographic factors explained 26.5, 35.6 and 8.4% of TN variability, respectively, with land use being the dominant factor.  Parent material, soil group, land use type and topographic factors explained 17.5, 10.7, 12.0 and 5.0% of TP variability, respectively, and both parent material and land use type played important roles.  Only parent material and soil type contributed to TK variability and could explain 25.1 and 13.7% of TK variability, respectively.  More attention should focus on adopting reasonable land use types for the purposes of fertilizer management and consider the different roles of the affecting factors at the landscape scale in this purple soil hilly area. 
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