Comparative genomic analysis between newly sequenced Brucella suis Vaccine Strain S2 and the Virulent Brucella suis Strain 1330.

BACKGROUND: Brucellosis is a bacterial disease caused by Brucella infection. In the late fifties, Brucella suis vaccine strain S2 with reduced virulence was obtained by serial transfer of a virulent B. suis biovar 1 strain in China. It has been widely used for vaccination in China since 1971. Until now, the mechanisms underlie virulence attenuation of S2 are still unknown. RESULTS: In this paper, the whole genome sequencing of S2 was carried out by Illumina Hiseq2000 sequencing method. We further performed the comparative genomic analysis to find out the differences between S2 and the virulent Brucella suis strain 1330. We found premature stops in outer membrane autotransporter omaA and eryD genes. Single mutations were found in phosphatidylcholine synthase, phosphorglucosamine mutase, pyruvate kinase and FliF, which have been reported to be related to the virulence of Brucella or other bacteria. Of the other different proteins between S2 and 1330, such as Omp2b, periplasmic sugar-binding protein, and oligopeptide ABC transporter, no definitive implications related to bacterial virulence were found, which await further investigation. CONCLUSIONS: The data presented here provided the rational basis for designing Brucella vaccines that could be used in other strains.

[Determination of elements of hypericum perforatum L. in Xinjiang by microwave digestion-ICP-AES].

Sample digestion by microwave is of some merits: simple, rapid, saving agents, nonpollution and being easy digested. HNO3-HClO4 (5:1) was used as a microwave digestion agent. A direct method is reported for the determination of Fe, Ca, Mg, Zn, Mn, Cu, Na, K, Ba, Al, Pb and Cr in Hypericum perforatum L. in Xinjiang by inductively coupled plasma atomic emission spectrometry(ICP-AES). The selection of digestion conditions of the technique is described. The recoveries for these elements were 93.2%-103.0%, and the relative standard deviation (RSD) of the twelve samples were 0.4%-2.9%. According to standard sample GBW07602 bush twigs and leaves, the authors checked the method for accuracy and precision. The results were found to be basically consistent with the reference values. It was proved that the method features satisfactory precision and accuracy. The method was applied to the determination of plant materials with good agreement.

[Determination of twelve elements in ephedrine extraction by microwave digestion-AAS].

The sample digested by microwave are of some merits: simple, rapid, saving agents, nonpollution and being easily digested. Microwave-digested sample with HNO3-H2O2 and AAS method were established for the determination of Fe, Ca, Mg, Zn, Mn, Cu, Na, K, Ni, Cd, Pb and Cr in ephedrine extraction. In this paper, the selection of digestion conditions, including pressure, power, acids and time of digestion was evaluated. According to standard sample GBW08501 Tea-leaves, we checked the method accuracy and precision. The accuracy values are in the range of 91.1%-105%. The RSDs of flame atomic spectrometry and graphite furnace atomic spectrometry are in the range of 0.2%-2.3% and less than 7%, respectively. The results are very consistent with the the reference values. It proved that the method has satisfactory precision and accuracy. The proposed method is simple, rapid, of nonpollution and safe. It was has been applied to the determination of trace elements in ephedrine extraction and provided useful data for production in factory.