Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011.</p><p><b>METHODS</b>Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates.</p><p><b>RESULTS</b>A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously.</p><p><b>CONCLUSION</b>Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.</p>

Related substances study in ibuprofen raw materials and its preparations / 中国药学杂志

OBJECTIVE: To establish the determination method of the related substances in ibuprofen raw materials, tablets and capsules. METHODS: High performance liquid chromatography (HPLC) was used for the determination of 2-(4-isobutyl phenyl) propanoic acid, 4-isobutyl benzoic acid, sodium methyl hydroxybenzoate(provided by national institutes for food and drug control), 4′-isobutyl acetophenone (known impurities of JP), the relative substance A, J, N (known impurities of EP), and the unknown impurities. A Kromasil C18 column (4.6 mm × 250 mm, 5 μm) was used as the analytical column, acetonitrile-water (pH adjusted to 3.0 by phosphoric acid) (45:55) were used as the mobile phase, the flowing rate was 1.0 mL · min-1, the detection wavelength was set at 254 nm, and the column temperature was 35°C. RESULTS: The relative substances detected in ibuprofen raw materials and its preparations were mainly 4-isobutyl benzoic acid and 4′-isobutyl acetophenone. The contents of unknown impurities were also high in the preparations of some manufacturers. CONCLUSION: The method can be used for the analysis of the related substances in ibuprofen raw materials and its preparations.