Identification of a new orthonairovirus associated with human febrile illness in China.

The genus Orthonairovirus, which is part of the family Nairoviridae, includes the important tick-transmitted pathogens Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, as well as many other poorly characterized viruses found in ticks, birds and mammals1,2. In this study, we identified a new orthonairovirus, Songling virus (SGLV), from patients who reported being bitten by ticks in Heilongjiang Province in northeastern China. SGLV shared similar genomic and morphological features with orthonairoviruses and phylogenetically formed a unique clade in Tamdy orthonairovirus of the Nairoviridae family. The isolated SGLV induced cytopathic effects in human hepatoma cells in vitro. SGLV infection was confirmed in 42 hospitalized patients analyzed between 2017 and 2018, with the main clinical manifestations being headache, fever, depression, fatigue and dizziness. More than two-thirds (69%) of patients generated virus-specific antibody responses in the acute phase. Taken together, these results suggest that this newly discovered orthonairovirus is associated with human febrile illness in China.

[Stoichiometry of soil extracellular enzymes and its seasonal variation in natural forests with different altitudes in northern Greater Khingan Mountains, China]. / å¤§å ´å®‰å²­åŒ—éƒ¨ä¸åŒæµ·æ‹”å¤©ç„¶æž—åœŸå£¤èƒžå¤–é ¶åŒ–å­¦è®¡é‡ç‰¹å¾åŠå ¶å­£èŠ‚åŠ¨æ€.

In this study, we examined the characteristics and influence mechanism of soil extracellular enzyme activity (EEA) and enzymatic stoichiometry in different soils in forests at different altitudes (750-1420 m) in Aokelidui Mountains in the north of the Greater Khingan Mountains. The results showed that altitude, season and their interactions significantly affected the activities of ß-glucosidase (BG), ß-1,4-N-acetylglucosaminidase (NAG), L-leucine aminopeptidase (LAP), and acid phosphatase (AP). In May, BG and NAG activities gradually increased with increasing altitude, while AP activities increased first and then decreased with increasing altitude. In July, NAG activity increased with altitude, while AP activity increased first and then decreased. In September, NAG activity changed significantly in different altitudes, with the highest activity at 1420 m (124.22 nmol·h-1·g-1). With the increases of altitude, ln(BG): ln(NAG+LAP) showed a decreasing trend. Except for the altitude of 830 m, stoichiometric ratio in all altitudes was the highest in July. The ratio of logarithmic conversion of soil C, N, and P invertase activity was 1:1.25:0.82. Altitude and soil temperature were the main factors affecting soil extracellular enzyme activities. There was a significant positive correlation between soil temperature and BG, NAG, and AP. Enzymatic stoichiometry ln(BG):ln(NAG+LAP) and ln(NAG+LAP):ln(AP) showed significant positive and negative correlations with soil pH, and had a negative and positive relationship with DOC. The ratio of ln(BG):ln(AP) was greatly affected by soil bulk density.