A Novel Human Acute Encephalitis Caused by Pseudorabies Virus Variant Strain.

BACKGROUND: Pseudorabies virus (PRV) is a common pathogen in multiple animal species, particularly in pigs. However, PRV infection in humans is rare and, to the best of our knowledge, PRV has never been isolated from human cases before. METHODS: Four acute encephalitis cases in humans were confirmed as PRV infection based on clinical symptoms, laboratory diagnosis, and metagenomic next-generation sequencing (mNGS). Cerebrospinal fluid (CSF) samples were collected and applied for virus isolation. Etiological and genetic characteristics of this PRV human isolate were further determined. RESULTS: The patients manifested respiratory dysfunction and acute neurological symptoms. The mNGS revealed PRV-specific nucleotide sequences in patients' CSF samples (7-6198 reads and 0.2446%-80.58% coverage). The PRV envelope glycoprotein B antibody, glycoprotein E antibody, and neutralizing antibody were positively detected. For the first time, a PRV strain, designated hSD-1/2019, was isolated and identified from a CSF sample, and transmission electron microscopy revealed that hSD-1/2019 had typical morphology similar to that of swine PRV. Phylogenetic analysis illustrated that hSD-1/2019 was genetically closest to those PRV variant strains currently circulating in pigs in China, and this strain showed similar etiological characteristics to Chinese PRV variant strains, while different from Chinese classical strain. Moreover, hSD-1/2019 showed high pathogenicity and induced acute neurological symptoms in pigs. CONCLUSIONS: A PRV strain was isolated from an acute human encephalitis case. This isolate showed close phylogenetic relationships and similar etiological characteristics to Chinese PRV variant strains, implying the great risk of PRV transmission from pigs to humans.

Simultaneous Analysis of Two Phytohormones in Chili and Wheat Using HPLC Using Novel Calixarene as SPE Sorbent.

In this paper, a high-performance liquid chromatography with ultraviolet (HPLC-UV) detection method, using tetraazacalix[2]arene[2]triazine-modified silica gel (NCS) as solid-phase extraction (SPE) sorbent, was developed for extracting and purifying the two phytohormones (indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA)) in chili and wheat samples from different organs of chili and wheat. The limits of detection were about 0.02 and 0.04 µg/mL, and the limits of quantification were 0.04 and 0.20 µg/mL for IAA and IBA, respectively. The intraday and interday RSDs (n = 6) of peak areas and retention times were in the range of 0.76-1.20%. In addition, overall recoveries through the extraction and NCS-SPE purification ranged from 78.4% to 86.8% for IAA and IBA were obtained. Compared with the commercial SPE sorbents, NCS featured excellent selectivity to retain IAA and IBA in the sample matrices. In addition, the results more clearly indicated that high IAA and IBA content existed in roots and leaves of wheat and chili; in other organs of the plants, the concentration of the two phytohormones is lower. The results from theoretical computation were consistent with the retention behaviors of IAA and IBA on NCS. The proposed NCS-SPE-HPLC method is highly effective for trace analysis of the two phytohormones in plant samples.

Sensitive determination of four tetracycline antibiotics in pig plasma by field-amplified sample stacking open-tubular capillary electrochromatography with dimethylethanolamine aminated polychloromethyl styrene nano-latex coated capillary column.

This paper described the preparation and application of a new dimethylethanolamine aminated polychloromethyl styrene nano-latex (DMEAPL) coated capillary column (ccc-DMEAPL) in the determination of four tetracycline antibiotics (TCA) including tetracycline (TC), oxytetracycline (OTC), doxycycline (DC) and chlorotetracycline (CTC) in pig plasma. The ccc-DMEAPL column was characterized with steady EOF values of ca. 1.5-5.2×10(-5)cm(2)/Vs at pH 1.8-6.3. The optimized conditions for field-amplified sample stacking open-tubular capillary electrochromatography (FASS-OT-CEC) were as following: background electrolyte, 10mmol/L Na2HPO4+15mmol/L citric acid (pH 3.2); ccc-DMEAPL, 50µm i.d.×50cm (effective length 41.5cm), separation voltage, 18kV; column temperature, 25°C; UV detection wavelength, 270nm; water-plug injection: 30mbar×10s; sample electrokinetic injection, 10kV×20s. The four TCA were extracted with the solution of 10mmol/L Na2HPO4+15mmol/L citric acid+4g/L EDTA-2Na (pH 3.2). The FASS-OT-CEC method was validated in terms of linearity, sensitivity, selectivity, precision and accuracy. The LODs ranged from 3 to 7ng/mL, the recoveries for the four TCA were all more than 80%. The developed method was successfully applied for the determination of TCs in the actual pig plasma samples.

Development of HPLC and NACE methods for the simultaneous determination of benzoic and sorbic acids in sour snap beans containing oil.

The practical methods were developed for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA) in sour snap bean samples containing oil. BA and SA in the samples were extracted by ultrasonication with water, followed by cleanup procedures with precipitation for removing the potential proteins and with petroleum ether liquid-liquid extraction for removing the edible oil contained in the samples. The HPLC method was developed using Supelco C18 (250 mm x 4.6 mm id, 5 microm) as column, MeOH-20 mM NH(4)Ac (25:75 v/v) at 1.0 mL/min as the mobile phase and 230 nm as the detection wavelength. The optimal NACE method was established with a running buffer of 20.0 mM NH(4)Ac in 95% MeOH (pH* 10.6), and an applied voltage of -30 kV over a capillary of 50 microm id x 48.5 cm (40 cm to the detector window), which gave a baseline separation of BA and SA, and as well as of the blank matrix within ca. 10 min. Both HPLC and NACE methods gave the relatively lower limits of quantification at about 0.01-0.02 and 0.04-0.05 mg/kg, respectively, whereas the overall recoveries were larger than 85.0%. The proposed methods have been successfully applied to measure 15 real sour bean samples and the content profile of BA and SA in sour bean samples was obtained and evaluated.