Pigmentibacter ruber gen. nov., sp. nov., a novel bacterium of the family Silvanigrellaceae isolated from human blood.

A Gram-negative, aerobic, non-motile, pleomorphic, red-pigmented bacterium, designated HNSRY-1T, was isolated from the blood sample of a near drowning patient in Republic of China. Strain HNSRY-1T grew at 15-37 °C (optimum, 35 °C), with pH 6.0-8.0 (optimum, pH 7.0) and 0-1.5% (W/V) NaCl (optimum, 1%). The predominant fatty acids (> 5%) in HNSRY-1T cells are iso-C15:0, C17:0, C17:1 ω8c, C16:0, and C16:1 ω6c/C16:1 ω7c. The major respiratory quinone is MK-8. The polar lipids are phosphatidylglycerol, phosphatidylethanolamine, three unidentified lipids and four unidentified aminolipids. The 16S rRNA gene sequence-based phylogenetic analysis indicated that strain HNSRY-1T belonged to the family Silvanigrellaceae, forming a distinct phylogenetic line distantly related (< 96.4% sequence similarity) to known species of the family. The ANI values of strain HNSRY-1T compared to the closely related species were below the determined genus division threshold limit (92-94% ANI), and AAI values were lower than the determined genus division threshold limit (80% AAI). Whole genome sequencing revealed a genome size of 3.63 Mb with a DNA G + C content at 29.6%. The half-lethal dose of strain HNSRY-1T on KM mice is about 1.12 × 108 CFU/ml. Virulence gene analysis showed that the pathogenicity of HNSRY-1T may be related to tufA, htpB, katA, wbtL, wbtM, pseB, clpP, cheY, cheV3, acpXL, pilB, fliN, ggt, flgG, fliP, nueB, pseA, bioB and flil. Based on these findings from the polyphasic taxonomy studies, a novel genus and species of the family Silvanigrellaceae. Pigmentibacter ruber gen. nov., sp. nov. is proposed, with type strain HNSRY-1T (= KCTC 72920T = CGMCC 1.18525T).

Identification of the first case of SFTSV infection in the Hunan Province of China and epidemiological surveillance in the locality.

This study reports the etiological identification, clinical diagnosis, and the results of the local epidemiological surveillance of the first case of severe fever with thrombocytopenia syndrome virus (SFTSV) infection in 2014 in Hunan Province, China. The infected patient was isolated and closely monitored. The virus is a member of the Bunyaviridae sandfly family and is characterized by real-time PCR, electron microscopy, immunofluorescence, and whole-genome sequencing. We also detected IgG and IgM antibodies against SFTSV among the local human population and domestic animals in a serological surveillance. Prevalence of SFTSV-specific antibodies was monitored in the local population for two years after the identification of the first SFTS case. Approximately 5% (4/77) of the people who had direct contact with the patient were seropositive, which is significantly higher than the seropositivity of the general local population [1.57% (44/2800), P < 0.05]. Furthermore, the percentage of the general population who were seropositive was higher in 2015 than in 2014 (χ2 = 7.481, P = 0.006). The epidemiological investigation found that the SFTSV is epidemic in goats, cattle, and chickens in Hunan Province. The risk of infection of domestic animals can be minimized by feeding in pens rather than allowing foraging.